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  #1   Report Post  
Jebus
 
Posts: n/a
Default Old speaker boxes

Hello. I currently have 2 old (about 30 years old), but very nice (made out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic, there's
a piece of fabric covering the hole (almost like a small grill). Over time
from all the use of the speakers, this cloth has become stretched and causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it with
another part? would adding more of these holes produce better sound?
Thanks.


  #2   Report Post  
Nelson
 
Posts: n/a
Default Old speaker boxes


"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.


Just a guess from the description, but these sound like bass reflex
enclosures,
and probably are tuned. I would NOT add more holes, unless you want to lose
much of the bass. If the fabric is "slapping" on any part of its support on
bass
note. you could glue it down, stretch it tighter, replace it, or just lose
it, depending
on how important its appearance is to you.
FWIW
Nelson



  #3   Report Post  
Nelson
 
Posts: n/a
Default Old speaker boxes


"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.


Just a guess from the description, but these sound like bass reflex
enclosures,
and probably are tuned. I would NOT add more holes, unless you want to lose
much of the bass. If the fabric is "slapping" on any part of its support on
bass
note. you could glue it down, stretch it tighter, replace it, or just lose
it, depending
on how important its appearance is to you.
FWIW
Nelson



  #4   Report Post  
Nelson
 
Posts: n/a
Default Old speaker boxes


"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.


Just a guess from the description, but these sound like bass reflex
enclosures,
and probably are tuned. I would NOT add more holes, unless you want to lose
much of the bass. If the fabric is "slapping" on any part of its support on
bass
note. you could glue it down, stretch it tighter, replace it, or just lose
it, depending
on how important its appearance is to you.
FWIW
Nelson



  #5   Report Post  
Jebus
 
Posts: n/a
Default Old speaker boxes

Well appearnce won't matter cuz there's a soft covering that is velcroed
over the speakers (classic speaker grill, lol). I was figuring the just
removing it would be best since I would have to completly open the case to
glue it back on or replace it. But as long as i can be sure that removing
it is ok then that's what I think would be easiest. Thanks.

"Nelson" wrote in message
...

"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they

have
the cone in the back for air to come out. Well these tanks have

something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.


Just a guess from the description, but these sound like bass reflex
enclosures,
and probably are tuned. I would NOT add more holes, unless you want to

lose
much of the bass. If the fabric is "slapping" on any part of its support

on
bass
note. you could glue it down, stretch it tighter, replace it, or just lose
it, depending
on how important its appearance is to you.
FWIW
Nelson







  #6   Report Post  
Jebus
 
Posts: n/a
Default Old speaker boxes

Well appearnce won't matter cuz there's a soft covering that is velcroed
over the speakers (classic speaker grill, lol). I was figuring the just
removing it would be best since I would have to completly open the case to
glue it back on or replace it. But as long as i can be sure that removing
it is ok then that's what I think would be easiest. Thanks.

"Nelson" wrote in message
...

"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they

have
the cone in the back for air to come out. Well these tanks have

something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.


Just a guess from the description, but these sound like bass reflex
enclosures,
and probably are tuned. I would NOT add more holes, unless you want to

lose
much of the bass. If the fabric is "slapping" on any part of its support

on
bass
note. you could glue it down, stretch it tighter, replace it, or just lose
it, depending
on how important its appearance is to you.
FWIW
Nelson





  #7   Report Post  
Jebus
 
Posts: n/a
Default Old speaker boxes

Well appearnce won't matter cuz there's a soft covering that is velcroed
over the speakers (classic speaker grill, lol). I was figuring the just
removing it would be best since I would have to completly open the case to
glue it back on or replace it. But as long as i can be sure that removing
it is ok then that's what I think would be easiest. Thanks.

"Nelson" wrote in message
...

"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they

have
the cone in the back for air to come out. Well these tanks have

something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.


Just a guess from the description, but these sound like bass reflex
enclosures,
and probably are tuned. I would NOT add more holes, unless you want to

lose
much of the bass. If the fabric is "slapping" on any part of its support

on
bass
note. you could glue it down, stretch it tighter, replace it, or just lose
it, depending
on how important its appearance is to you.
FWIW
Nelson





  #8   Report Post  
Jeff Wiseman
 
Posts: n/a
Default Old speaker boxes

Sounds like it was there to prevent 3-year-olds from rolling
marbles into the port opening :-)

Once they are in there, just try removing them!

You could probably remove them with no problem as long as there
are no 3-4 year olds in the house :-)



Jebus wrote:

Well appearnce won't matter cuz there's a soft covering that is velcroed
over the speakers (classic speaker grill, lol). I was figuring the just
removing it would be best since I would have to completly open the case to
glue it back on or replace it. But as long as i can be sure that removing
it is ok then that's what I think would be easiest. Thanks.

"Nelson" wrote in message
...

"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they

have
the cone in the back for air to come out. Well these tanks have

something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.


Just a guess from the description, but these sound like bass reflex
enclosures,
and probably are tuned. I would NOT add more holes, unless you want to

lose
much of the bass. If the fabric is "slapping" on any part of its support

on
bass
note. you could glue it down, stretch it tighter, replace it, or just lose
it, depending
on how important its appearance is to you.
FWIW
Nelson



  #9   Report Post  
Jeff Wiseman
 
Posts: n/a
Default Old speaker boxes

Sounds like it was there to prevent 3-year-olds from rolling
marbles into the port opening :-)

Once they are in there, just try removing them!

You could probably remove them with no problem as long as there
are no 3-4 year olds in the house :-)



Jebus wrote:

Well appearnce won't matter cuz there's a soft covering that is velcroed
over the speakers (classic speaker grill, lol). I was figuring the just
removing it would be best since I would have to completly open the case to
glue it back on or replace it. But as long as i can be sure that removing
it is ok then that's what I think would be easiest. Thanks.

"Nelson" wrote in message
...

"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they

have
the cone in the back for air to come out. Well these tanks have

something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.


Just a guess from the description, but these sound like bass reflex
enclosures,
and probably are tuned. I would NOT add more holes, unless you want to

lose
much of the bass. If the fabric is "slapping" on any part of its support

on
bass
note. you could glue it down, stretch it tighter, replace it, or just lose
it, depending
on how important its appearance is to you.
FWIW
Nelson



  #10   Report Post  
Jeff Wiseman
 
Posts: n/a
Default Old speaker boxes

Sounds like it was there to prevent 3-year-olds from rolling
marbles into the port opening :-)

Once they are in there, just try removing them!

You could probably remove them with no problem as long as there
are no 3-4 year olds in the house :-)



Jebus wrote:

Well appearnce won't matter cuz there's a soft covering that is velcroed
over the speakers (classic speaker grill, lol). I was figuring the just
removing it would be best since I would have to completly open the case to
glue it back on or replace it. But as long as i can be sure that removing
it is ok then that's what I think would be easiest. Thanks.

"Nelson" wrote in message
...

"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they

have
the cone in the back for air to come out. Well these tanks have

something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.


Just a guess from the description, but these sound like bass reflex
enclosures,
and probably are tuned. I would NOT add more holes, unless you want to

lose
much of the bass. If the fabric is "slapping" on any part of its support

on
bass
note. you could glue it down, stretch it tighter, replace it, or just lose
it, depending
on how important its appearance is to you.
FWIW
Nelson





  #11   Report Post  
Michael Savage
 
Posts: n/a
Default Old speaker boxes

Why not use a couple of PC fan guards over the ports to keep any stay parts
or loose Hamsters :-) from getting in........................




"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.




  #12   Report Post  
Michael Savage
 
Posts: n/a
Default Old speaker boxes

Why not use a couple of PC fan guards over the ports to keep any stay parts
or loose Hamsters :-) from getting in........................




"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.




  #13   Report Post  
Michael Savage
 
Posts: n/a
Default Old speaker boxes

Why not use a couple of PC fan guards over the ports to keep any stay parts
or loose Hamsters :-) from getting in........................




"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.




  #14   Report Post  
Bruce Tyler
 
Posts: n/a
Default Old speaker boxes

On Tue, 16 Dec 2003 01:48:27 GMT, "Jebus"
wrote:

Hello. I currently have 2 old (about 30 years old), but very nice (made out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic, there's
a piece of fabric covering the hole (almost like a small grill). Over time
from all the use of the speakers, this cloth has become stretched and causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it with
another part? would adding more of these holes produce better sound?
Thanks.


I would say, by all means cut it away, especially if it is causing a
vibration with bass rumble as this is very annoying. It may be
possible to fit/add a modern fitting to enhance your bass reflex as 30
years ago, not many speakers really had inverted port fittings like
many bass boxes nowadays do.. They simply had holes as ports which
still helped but because of better speaker travel in modern bass
cones, it is better to have inverted ports to suck out the best of the
bass echo... I suppose there is an art to getting the best post size
per the box size but the fact that your boxes already have a port,
this would be a guide to the needed size...

I had a similar experience just a month ago to a few days ago. Here's
how...

About 12 or 13 years ago I built a pair of speaker boxes. They
measured 550mm(H) x 410mm(W) x 300mm(D),, thats about 22"x 16.5"x
12".. They were built from a very dense 1" custom board (not the best
wood but nice and solid and I mean "solid" and very heavy for their
size) and I put into each of them a 10" bass and a midrange/tweeter
approx 3" dia and lined the insides with an a polyester fibre cloth
about 2" thich,, similar to what they use in sleeping bags and quilts.
They worked really well as all-rounder speakers..

4 Months ago, right..!!! I hear a funny "furry" gushing sound out of
one of these speakers. I looked closely to see that the foam surrounds
on the bass cones has literally rotted to the point where I touched
them only to see them crumble away before my eyes. The
midrange/tweeters suffered the same fate as well - rotten.. I decided
to retire these speakers althogether, putting them out in the garage
for the time being. I bought a pair of P/A type speakers with 12" bass
units in them and replaced the 12" drivers with a better pair. Wow,,
what a difference. I was thrilled to bits with the outcome...

Well about a month ago I decided to re-use the boxes out in the
garrage. I made a template up and cut out bigger holes, so as to fit
12" bass units from the 10" units that were in them before they got
the rot.. I bought two more 12" units like in the above modified P/A
speakers above. These 12" bass units were so good on their own, that I
decided to use them as sub type woofers in the old boxes. They worked
exceptionally well,, but,, they had a gaping great big 3" hole in each
cabinet where the tweeters sat. Although they acted as a reflex port,
they looked an eye-sore so I visited the local electronics store and
found some plastic ports of "identical" size. What a stroke of luck.
They fitted straight in - no gluing or screwing required,, simply
pushed them in nice and tight... These ports are about 4" deep,
slightly tapered and somewhat enhanced the bass echo even further.
Before, you could feel a definite pout of air from the naked hole as
the bass cones moved back and forth. The reflected bass was good but a
little "boomie". Now, with the plastic ports, there is little air gust
but a lot of deep, rich sound coming from the port... I guess I struck
it reasonably correct, by luck...

As for your boxes,, I suggest that "if" you can,, try to do something
similar. If your boxes are good (and it sounds as if they are),, try
not to destroy the essential design and character of them but old
and/or tatty bits of fabric will do little to help so it may be a
pre-requisite to get rid of the cloth and forge ahead...
  #15   Report Post  
Bruce Tyler
 
Posts: n/a
Default Old speaker boxes

On Tue, 16 Dec 2003 01:48:27 GMT, "Jebus"
wrote:

Hello. I currently have 2 old (about 30 years old), but very nice (made out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic, there's
a piece of fabric covering the hole (almost like a small grill). Over time
from all the use of the speakers, this cloth has become stretched and causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it with
another part? would adding more of these holes produce better sound?
Thanks.


I would say, by all means cut it away, especially if it is causing a
vibration with bass rumble as this is very annoying. It may be
possible to fit/add a modern fitting to enhance your bass reflex as 30
years ago, not many speakers really had inverted port fittings like
many bass boxes nowadays do.. They simply had holes as ports which
still helped but because of better speaker travel in modern bass
cones, it is better to have inverted ports to suck out the best of the
bass echo... I suppose there is an art to getting the best post size
per the box size but the fact that your boxes already have a port,
this would be a guide to the needed size...

I had a similar experience just a month ago to a few days ago. Here's
how...

About 12 or 13 years ago I built a pair of speaker boxes. They
measured 550mm(H) x 410mm(W) x 300mm(D),, thats about 22"x 16.5"x
12".. They were built from a very dense 1" custom board (not the best
wood but nice and solid and I mean "solid" and very heavy for their
size) and I put into each of them a 10" bass and a midrange/tweeter
approx 3" dia and lined the insides with an a polyester fibre cloth
about 2" thich,, similar to what they use in sleeping bags and quilts.
They worked really well as all-rounder speakers..

4 Months ago, right..!!! I hear a funny "furry" gushing sound out of
one of these speakers. I looked closely to see that the foam surrounds
on the bass cones has literally rotted to the point where I touched
them only to see them crumble away before my eyes. The
midrange/tweeters suffered the same fate as well - rotten.. I decided
to retire these speakers althogether, putting them out in the garage
for the time being. I bought a pair of P/A type speakers with 12" bass
units in them and replaced the 12" drivers with a better pair. Wow,,
what a difference. I was thrilled to bits with the outcome...

Well about a month ago I decided to re-use the boxes out in the
garrage. I made a template up and cut out bigger holes, so as to fit
12" bass units from the 10" units that were in them before they got
the rot.. I bought two more 12" units like in the above modified P/A
speakers above. These 12" bass units were so good on their own, that I
decided to use them as sub type woofers in the old boxes. They worked
exceptionally well,, but,, they had a gaping great big 3" hole in each
cabinet where the tweeters sat. Although they acted as a reflex port,
they looked an eye-sore so I visited the local electronics store and
found some plastic ports of "identical" size. What a stroke of luck.
They fitted straight in - no gluing or screwing required,, simply
pushed them in nice and tight... These ports are about 4" deep,
slightly tapered and somewhat enhanced the bass echo even further.
Before, you could feel a definite pout of air from the naked hole as
the bass cones moved back and forth. The reflected bass was good but a
little "boomie". Now, with the plastic ports, there is little air gust
but a lot of deep, rich sound coming from the port... I guess I struck
it reasonably correct, by luck...

As for your boxes,, I suggest that "if" you can,, try to do something
similar. If your boxes are good (and it sounds as if they are),, try
not to destroy the essential design and character of them but old
and/or tatty bits of fabric will do little to help so it may be a
pre-requisite to get rid of the cloth and forge ahead...


  #16   Report Post  
Bruce Tyler
 
Posts: n/a
Default Old speaker boxes

On Tue, 16 Dec 2003 01:48:27 GMT, "Jebus"
wrote:

Hello. I currently have 2 old (about 30 years old), but very nice (made out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic, there's
a piece of fabric covering the hole (almost like a small grill). Over time
from all the use of the speakers, this cloth has become stretched and causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it with
another part? would adding more of these holes produce better sound?
Thanks.


I would say, by all means cut it away, especially if it is causing a
vibration with bass rumble as this is very annoying. It may be
possible to fit/add a modern fitting to enhance your bass reflex as 30
years ago, not many speakers really had inverted port fittings like
many bass boxes nowadays do.. They simply had holes as ports which
still helped but because of better speaker travel in modern bass
cones, it is better to have inverted ports to suck out the best of the
bass echo... I suppose there is an art to getting the best post size
per the box size but the fact that your boxes already have a port,
this would be a guide to the needed size...

I had a similar experience just a month ago to a few days ago. Here's
how...

About 12 or 13 years ago I built a pair of speaker boxes. They
measured 550mm(H) x 410mm(W) x 300mm(D),, thats about 22"x 16.5"x
12".. They were built from a very dense 1" custom board (not the best
wood but nice and solid and I mean "solid" and very heavy for their
size) and I put into each of them a 10" bass and a midrange/tweeter
approx 3" dia and lined the insides with an a polyester fibre cloth
about 2" thich,, similar to what they use in sleeping bags and quilts.
They worked really well as all-rounder speakers..

4 Months ago, right..!!! I hear a funny "furry" gushing sound out of
one of these speakers. I looked closely to see that the foam surrounds
on the bass cones has literally rotted to the point where I touched
them only to see them crumble away before my eyes. The
midrange/tweeters suffered the same fate as well - rotten.. I decided
to retire these speakers althogether, putting them out in the garage
for the time being. I bought a pair of P/A type speakers with 12" bass
units in them and replaced the 12" drivers with a better pair. Wow,,
what a difference. I was thrilled to bits with the outcome...

Well about a month ago I decided to re-use the boxes out in the
garrage. I made a template up and cut out bigger holes, so as to fit
12" bass units from the 10" units that were in them before they got
the rot.. I bought two more 12" units like in the above modified P/A
speakers above. These 12" bass units were so good on their own, that I
decided to use them as sub type woofers in the old boxes. They worked
exceptionally well,, but,, they had a gaping great big 3" hole in each
cabinet where the tweeters sat. Although they acted as a reflex port,
they looked an eye-sore so I visited the local electronics store and
found some plastic ports of "identical" size. What a stroke of luck.
They fitted straight in - no gluing or screwing required,, simply
pushed them in nice and tight... These ports are about 4" deep,
slightly tapered and somewhat enhanced the bass echo even further.
Before, you could feel a definite pout of air from the naked hole as
the bass cones moved back and forth. The reflected bass was good but a
little "boomie". Now, with the plastic ports, there is little air gust
but a lot of deep, rich sound coming from the port... I guess I struck
it reasonably correct, by luck...

As for your boxes,, I suggest that "if" you can,, try to do something
similar. If your boxes are good (and it sounds as if they are),, try
not to destroy the essential design and character of them but old
and/or tatty bits of fabric will do little to help so it may be a
pre-requisite to get rid of the cloth and forge ahead...
  #17   Report Post  
Svante
 
Posts: n/a
Default Old speaker boxes

Jeff Wiseman wrote in message ...
Sounds like it was there to prevent 3-year-olds from rolling
marbles into the port opening :-)

Once they are in there, just try removing them!


:-) :-)

Pardon me I, just cannot resist telling you about my grandfather who
had a glass bottle made for vodka. It had a flat top with the
bottleneck rising from that. For some reason the top was not perfectly
flat, but had sunk down a bit at the neck, which made it completely
impossible to pour the last drop out of the bottle.
I don't think he used that bottle very much... :-)
  #18   Report Post  
Svante
 
Posts: n/a
Default Old speaker boxes

Jeff Wiseman wrote in message ...
Sounds like it was there to prevent 3-year-olds from rolling
marbles into the port opening :-)

Once they are in there, just try removing them!


:-) :-)

Pardon me I, just cannot resist telling you about my grandfather who
had a glass bottle made for vodka. It had a flat top with the
bottleneck rising from that. For some reason the top was not perfectly
flat, but had sunk down a bit at the neck, which made it completely
impossible to pour the last drop out of the bottle.
I don't think he used that bottle very much... :-)
  #19   Report Post  
Svante
 
Posts: n/a
Default Old speaker boxes

Jeff Wiseman wrote in message ...
Sounds like it was there to prevent 3-year-olds from rolling
marbles into the port opening :-)

Once they are in there, just try removing them!


:-) :-)

Pardon me I, just cannot resist telling you about my grandfather who
had a glass bottle made for vodka. It had a flat top with the
bottleneck rising from that. For some reason the top was not perfectly
flat, but had sunk down a bit at the neck, which made it completely
impossible to pour the last drop out of the bottle.
I don't think he used that bottle very much... :-)
  #20   Report Post  
Mikey
 
Posts: n/a
Default Old speaker boxes

You should consult a speaker building book.


"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.






  #21   Report Post  
Mikey
 
Posts: n/a
Default Old speaker boxes

You should consult a speaker building book.


"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.




  #22   Report Post  
Mikey
 
Posts: n/a
Default Old speaker boxes

You should consult a speaker building book.


"Jebus" wrote in message
...
Hello. I currently have 2 old (about 30 years old), but very nice (made

out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic,

there's
a piece of fabric covering the hole (almost like a small grill). Over

time
from all the use of the speakers, this cloth has become stretched and

causes
unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it

with
another part? would adding more of these holes produce better sound?
Thanks.




  #23   Report Post  
Sanders
 
Posts: n/a
Default Old speaker boxes


Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.

John
Bruce Tyler wrote:

On Tue, 16 Dec 2003 01:48:27 GMT, "Jebus"
wrote:


Hello. I currently have 2 old (about 30 years old), but very nice (made out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic, there's
a piece of fabric covering the hole (almost like a small grill). Over time


from all the use of the speakers, this cloth has become stretched and causes


unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it with
another part? would adding more of these holes produce better sound?
Thanks.



I would say, by all means cut it away, especially if it is causing a
vibration with bass rumble as this is very annoying. It may be
possible to fit/add a modern fitting to enhance your bass reflex as 30
years ago, not many speakers really had inverted port fittings like
many bass boxes nowadays do.. They simply had holes as ports which
still helped but because of better speaker travel in modern bass
cones, it is better to have inverted ports to suck out the best of the
bass echo... I suppose there is an art to getting the best post size
per the box size but the fact that your boxes already have a port,
this would be a guide to the needed size...

I had a similar experience just a month ago to a few days ago. Here's
how...

About 12 or 13 years ago I built a pair of speaker boxes. They
measured 550mm(H) x 410mm(W) x 300mm(D),, thats about 22"x 16.5"x
12".. They were built from a very dense 1" custom board (not the best
wood but nice and solid and I mean "solid" and very heavy for their
size) and I put into each of them a 10" bass and a midrange/tweeter
approx 3" dia and lined the insides with an a polyester fibre cloth
about 2" thich,, similar to what they use in sleeping bags and quilts.
They worked really well as all-rounder speakers..

4 Months ago, right..!!! I hear a funny "furry" gushing sound out of
one of these speakers. I looked closely to see that the foam surrounds
on the bass cones has literally rotted to the point where I touched
them only to see them crumble away before my eyes. The
midrange/tweeters suffered the same fate as well - rotten.. I decided
to retire these speakers althogether, putting them out in the garage
for the time being. I bought a pair of P/A type speakers with 12" bass
units in them and replaced the 12" drivers with a better pair. Wow,,
what a difference. I was thrilled to bits with the outcome...

Well about a month ago I decided to re-use the boxes out in the
garrage. I made a template up and cut out bigger holes, so as to fit
12" bass units from the 10" units that were in them before they got
the rot.. I bought two more 12" units like in the above modified P/A
speakers above. These 12" bass units were so good on their own, that I
decided to use them as sub type woofers in the old boxes. They worked
exceptionally well,, but,, they had a gaping great big 3" hole in each
cabinet where the tweeters sat. Although they acted as a reflex port,
they looked an eye-sore so I visited the local electronics store and
found some plastic ports of "identical" size. What a stroke of luck.
They fitted straight in - no gluing or screwing required,, simply
pushed them in nice and tight... These ports are about 4" deep,
slightly tapered and somewhat enhanced the bass echo even further.
Before, you could feel a definite pout of air from the naked hole as
the bass cones moved back and forth. The reflected bass was good but a
little "boomie". Now, with the plastic ports, there is little air gust
but a lot of deep, rich sound coming from the port... I guess I struck
it reasonably correct, by luck...

As for your boxes,, I suggest that "if" you can,, try to do something
similar. If your boxes are good (and it sounds as if they are),, try
not to destroy the essential design and character of them but old
and/or tatty bits of fabric will do little to help so it may be a
pre-requisite to get rid of the cloth and forge ahead...


  #24   Report Post  
Sanders
 
Posts: n/a
Default Old speaker boxes


Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.

John
Bruce Tyler wrote:

On Tue, 16 Dec 2003 01:48:27 GMT, "Jebus"
wrote:


Hello. I currently have 2 old (about 30 years old), but very nice (made out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic, there's
a piece of fabric covering the hole (almost like a small grill). Over time


from all the use of the speakers, this cloth has become stretched and causes


unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it with
another part? would adding more of these holes produce better sound?
Thanks.



I would say, by all means cut it away, especially if it is causing a
vibration with bass rumble as this is very annoying. It may be
possible to fit/add a modern fitting to enhance your bass reflex as 30
years ago, not many speakers really had inverted port fittings like
many bass boxes nowadays do.. They simply had holes as ports which
still helped but because of better speaker travel in modern bass
cones, it is better to have inverted ports to suck out the best of the
bass echo... I suppose there is an art to getting the best post size
per the box size but the fact that your boxes already have a port,
this would be a guide to the needed size...

I had a similar experience just a month ago to a few days ago. Here's
how...

About 12 or 13 years ago I built a pair of speaker boxes. They
measured 550mm(H) x 410mm(W) x 300mm(D),, thats about 22"x 16.5"x
12".. They were built from a very dense 1" custom board (not the best
wood but nice and solid and I mean "solid" and very heavy for their
size) and I put into each of them a 10" bass and a midrange/tweeter
approx 3" dia and lined the insides with an a polyester fibre cloth
about 2" thich,, similar to what they use in sleeping bags and quilts.
They worked really well as all-rounder speakers..

4 Months ago, right..!!! I hear a funny "furry" gushing sound out of
one of these speakers. I looked closely to see that the foam surrounds
on the bass cones has literally rotted to the point where I touched
them only to see them crumble away before my eyes. The
midrange/tweeters suffered the same fate as well - rotten.. I decided
to retire these speakers althogether, putting them out in the garage
for the time being. I bought a pair of P/A type speakers with 12" bass
units in them and replaced the 12" drivers with a better pair. Wow,,
what a difference. I was thrilled to bits with the outcome...

Well about a month ago I decided to re-use the boxes out in the
garrage. I made a template up and cut out bigger holes, so as to fit
12" bass units from the 10" units that were in them before they got
the rot.. I bought two more 12" units like in the above modified P/A
speakers above. These 12" bass units were so good on their own, that I
decided to use them as sub type woofers in the old boxes. They worked
exceptionally well,, but,, they had a gaping great big 3" hole in each
cabinet where the tweeters sat. Although they acted as a reflex port,
they looked an eye-sore so I visited the local electronics store and
found some plastic ports of "identical" size. What a stroke of luck.
They fitted straight in - no gluing or screwing required,, simply
pushed them in nice and tight... These ports are about 4" deep,
slightly tapered and somewhat enhanced the bass echo even further.
Before, you could feel a definite pout of air from the naked hole as
the bass cones moved back and forth. The reflected bass was good but a
little "boomie". Now, with the plastic ports, there is little air gust
but a lot of deep, rich sound coming from the port... I guess I struck
it reasonably correct, by luck...

As for your boxes,, I suggest that "if" you can,, try to do something
similar. If your boxes are good (and it sounds as if they are),, try
not to destroy the essential design and character of them but old
and/or tatty bits of fabric will do little to help so it may be a
pre-requisite to get rid of the cloth and forge ahead...


  #25   Report Post  
Sanders
 
Posts: n/a
Default Old speaker boxes


Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.

John
Bruce Tyler wrote:

On Tue, 16 Dec 2003 01:48:27 GMT, "Jebus"
wrote:


Hello. I currently have 2 old (about 30 years old), but very nice (made out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic, there's
a piece of fabric covering the hole (almost like a small grill). Over time


from all the use of the speakers, this cloth has become stretched and causes


unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it with
another part? would adding more of these holes produce better sound?
Thanks.



I would say, by all means cut it away, especially if it is causing a
vibration with bass rumble as this is very annoying. It may be
possible to fit/add a modern fitting to enhance your bass reflex as 30
years ago, not many speakers really had inverted port fittings like
many bass boxes nowadays do.. They simply had holes as ports which
still helped but because of better speaker travel in modern bass
cones, it is better to have inverted ports to suck out the best of the
bass echo... I suppose there is an art to getting the best post size
per the box size but the fact that your boxes already have a port,
this would be a guide to the needed size...

I had a similar experience just a month ago to a few days ago. Here's
how...

About 12 or 13 years ago I built a pair of speaker boxes. They
measured 550mm(H) x 410mm(W) x 300mm(D),, thats about 22"x 16.5"x
12".. They were built from a very dense 1" custom board (not the best
wood but nice and solid and I mean "solid" and very heavy for their
size) and I put into each of them a 10" bass and a midrange/tweeter
approx 3" dia and lined the insides with an a polyester fibre cloth
about 2" thich,, similar to what they use in sleeping bags and quilts.
They worked really well as all-rounder speakers..

4 Months ago, right..!!! I hear a funny "furry" gushing sound out of
one of these speakers. I looked closely to see that the foam surrounds
on the bass cones has literally rotted to the point where I touched
them only to see them crumble away before my eyes. The
midrange/tweeters suffered the same fate as well - rotten.. I decided
to retire these speakers althogether, putting them out in the garage
for the time being. I bought a pair of P/A type speakers with 12" bass
units in them and replaced the 12" drivers with a better pair. Wow,,
what a difference. I was thrilled to bits with the outcome...

Well about a month ago I decided to re-use the boxes out in the
garrage. I made a template up and cut out bigger holes, so as to fit
12" bass units from the 10" units that were in them before they got
the rot.. I bought two more 12" units like in the above modified P/A
speakers above. These 12" bass units were so good on their own, that I
decided to use them as sub type woofers in the old boxes. They worked
exceptionally well,, but,, they had a gaping great big 3" hole in each
cabinet where the tweeters sat. Although they acted as a reflex port,
they looked an eye-sore so I visited the local electronics store and
found some plastic ports of "identical" size. What a stroke of luck.
They fitted straight in - no gluing or screwing required,, simply
pushed them in nice and tight... These ports are about 4" deep,
slightly tapered and somewhat enhanced the bass echo even further.
Before, you could feel a definite pout of air from the naked hole as
the bass cones moved back and forth. The reflected bass was good but a
little "boomie". Now, with the plastic ports, there is little air gust
but a lot of deep, rich sound coming from the port... I guess I struck
it reasonably correct, by luck...

As for your boxes,, I suggest that "if" you can,, try to do something
similar. If your boxes are good (and it sounds as if they are),, try
not to destroy the essential design and character of them but old
and/or tatty bits of fabric will do little to help so it may be a
pre-requisite to get rid of the cloth and forge ahead...




  #26   Report Post  
Sanders
 
Posts: n/a
Default Old speaker boxes


Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.

John
Bruce Tyler wrote:

On Tue, 16 Dec 2003 01:48:27 GMT, "Jebus"
wrote:


Hello. I currently have 2 old (about 30 years old), but very nice (made out
of 2 in. thick wood). However, as many woofers are made today, they have
the cone in the back for air to come out. Well these tanks have something
like that, but in the front. However, isteand of anything plastic, there's
a piece of fabric covering the hole (almost like a small grill). Over time


from all the use of the speakers, this cloth has become stretched and causes


unwanted vibrations/sound in the bass parts especially. Is it safe to
remove this or should i replace the cloth? or should i just replace it with
another part? would adding more of these holes produce better sound?
Thanks.



I would say, by all means cut it away, especially if it is causing a
vibration with bass rumble as this is very annoying. It may be
possible to fit/add a modern fitting to enhance your bass reflex as 30
years ago, not many speakers really had inverted port fittings like
many bass boxes nowadays do.. They simply had holes as ports which
still helped but because of better speaker travel in modern bass
cones, it is better to have inverted ports to suck out the best of the
bass echo... I suppose there is an art to getting the best post size
per the box size but the fact that your boxes already have a port,
this would be a guide to the needed size...

I had a similar experience just a month ago to a few days ago. Here's
how...

About 12 or 13 years ago I built a pair of speaker boxes. They
measured 550mm(H) x 410mm(W) x 300mm(D),, thats about 22"x 16.5"x
12".. They were built from a very dense 1" custom board (not the best
wood but nice and solid and I mean "solid" and very heavy for their
size) and I put into each of them a 10" bass and a midrange/tweeter
approx 3" dia and lined the insides with an a polyester fibre cloth
about 2" thich,, similar to what they use in sleeping bags and quilts.
They worked really well as all-rounder speakers..

4 Months ago, right..!!! I hear a funny "furry" gushing sound out of
one of these speakers. I looked closely to see that the foam surrounds
on the bass cones has literally rotted to the point where I touched
them only to see them crumble away before my eyes. The
midrange/tweeters suffered the same fate as well - rotten.. I decided
to retire these speakers althogether, putting them out in the garage
for the time being. I bought a pair of P/A type speakers with 12" bass
units in them and replaced the 12" drivers with a better pair. Wow,,
what a difference. I was thrilled to bits with the outcome...

Well about a month ago I decided to re-use the boxes out in the
garrage. I made a template up and cut out bigger holes, so as to fit
12" bass units from the 10" units that were in them before they got
the rot.. I bought two more 12" units like in the above modified P/A
speakers above. These 12" bass units were so good on their own, that I
decided to use them as sub type woofers in the old boxes. They worked
exceptionally well,, but,, they had a gaping great big 3" hole in each
cabinet where the tweeters sat. Although they acted as a reflex port,
they looked an eye-sore so I visited the local electronics store and
found some plastic ports of "identical" size. What a stroke of luck.
They fitted straight in - no gluing or screwing required,, simply
pushed them in nice and tight... These ports are about 4" deep,
slightly tapered and somewhat enhanced the bass echo even further.
Before, you could feel a definite pout of air from the naked hole as
the bass cones moved back and forth. The reflected bass was good but a
little "boomie". Now, with the plastic ports, there is little air gust
but a lot of deep, rich sound coming from the port... I guess I struck
it reasonably correct, by luck...

As for your boxes,, I suggest that "if" you can,, try to do something
similar. If your boxes are good (and it sounds as if they are),, try
not to destroy the essential design and character of them but old
and/or tatty bits of fabric will do little to help so it may be a
pre-requisite to get rid of the cloth and forge ahead...


  #27   Report Post  
Dick Pierce
 
Posts: n/a
Default Old speaker boxes

Sanders wrote in message ...
Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.


Sorry, but this is a load of nonsense on several points:

1. MOST foam surrounds have a lower mechanical compliance or,
equivalently, higher mechanical stiffness than typical "rubber"
(actually one alloy of polybutdene or another) surrounds.

2. In most resaonble high compliance woofers that one would find
in a vented enclosure, the surround is NOT responsible for
most of the mechanical stiffness anyway, it's the centering
spider.

3. Your analysis that "the speaker must get back to '0' as fast
as possible", while it might seem intuitively correct, is wrong.
Once you are above the mechanical resonance of the loudspeaker,
the driver is MASS controlled, NOT stiffness controlled, as you
assert. As such, it is NOT the ability to return to a given
position, but the need for acceleration. Now, as we hopefully
remember:

F = ma

Where F is force applied by the voice coil, m is mass of the cone
and a is it's acceleration. Notice the complete absence of a
stiffness term: the suspension does not playb a dominant role at
all over most of the operating bandwidth of the speaker.

And it does NOT need to accelerate "as fast as possible," but
only at the rate determined by the incoming signal.

At resonance, the speaker is predomintly resistance (either
mechanical or, for the most part electrical) controlled and ONLY
below resonance is it stiffness controlled and only then does the
suspension's stiffness play a role. And, at that point, it is only
the magnitude of the stiffness that counts.

4. If your assertion were correct, all drivers with high compliance,
low stiffness surrounds would have worse transient response than
stiffer drivers. Yet drivers with high compliance/low stiffness
surrounds, as a general rule, tend to go deeper in the bass, for
the simple fact that their mechanical resonances are lower. With
a lower mechanical resonance, the badnwidth of the system is wider,
and wider band systems, all else being equal, have better transient
response, as defined by the fundamental relation:

dT * dF = 1/2

where dT is the uncertainty in time and dF is the uncertainty in
frequency (e.g. bandwidth). What this fundamentally means is that
wider bandwidth systems (large dF) have better transient capabilities
than narrow band systems (small dT).

5. Optimally tuned reflex systems do NOT require suspensions with high
stiffness, as you claim, they require suspensions of the correct
stiffness, which is dependent upon the entire system design. One
can (and many people successfully have) designed reflex systems
using high-compliance drivers. In, for example, the classical lossless
B4 maximally flat alignment, one of the requirements is that the
driver compliance be about the same as the driver compliance. That
means that if you are designing a system with a large cabinet volume,
as a means of positioning your self high on the efficiency side of
the efficiency/bandwidth/volume relation, you MUST have a high-
compliance driver. Otherwise the driver resonance will be too high,
tuning will be significantly compromised and the system will, in fact
have fairly dismal transient response, contrary to your assertion.

6. Improvements in transient response of reflex systems can be had
by moving in the realm of QB3 alignments, which can only be had
with low-Q, low resonance drivers, which is, despite your assertion,
contrary to the notion of stiff suspensions. All other things being
equal, the stiffer the suspe4nsion, the higher the total Q and the
higher the driver resonance.

7. Please explain what the difference is between a "ported speaker"
and a "bass reflex speaker." (subtle hint: there isn't any)
  #28   Report Post  
Dick Pierce
 
Posts: n/a
Default Old speaker boxes

Sanders wrote in message ...
Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.


Sorry, but this is a load of nonsense on several points:

1. MOST foam surrounds have a lower mechanical compliance or,
equivalently, higher mechanical stiffness than typical "rubber"
(actually one alloy of polybutdene or another) surrounds.

2. In most resaonble high compliance woofers that one would find
in a vented enclosure, the surround is NOT responsible for
most of the mechanical stiffness anyway, it's the centering
spider.

3. Your analysis that "the speaker must get back to '0' as fast
as possible", while it might seem intuitively correct, is wrong.
Once you are above the mechanical resonance of the loudspeaker,
the driver is MASS controlled, NOT stiffness controlled, as you
assert. As such, it is NOT the ability to return to a given
position, but the need for acceleration. Now, as we hopefully
remember:

F = ma

Where F is force applied by the voice coil, m is mass of the cone
and a is it's acceleration. Notice the complete absence of a
stiffness term: the suspension does not playb a dominant role at
all over most of the operating bandwidth of the speaker.

And it does NOT need to accelerate "as fast as possible," but
only at the rate determined by the incoming signal.

At resonance, the speaker is predomintly resistance (either
mechanical or, for the most part electrical) controlled and ONLY
below resonance is it stiffness controlled and only then does the
suspension's stiffness play a role. And, at that point, it is only
the magnitude of the stiffness that counts.

4. If your assertion were correct, all drivers with high compliance,
low stiffness surrounds would have worse transient response than
stiffer drivers. Yet drivers with high compliance/low stiffness
surrounds, as a general rule, tend to go deeper in the bass, for
the simple fact that their mechanical resonances are lower. With
a lower mechanical resonance, the badnwidth of the system is wider,
and wider band systems, all else being equal, have better transient
response, as defined by the fundamental relation:

dT * dF = 1/2

where dT is the uncertainty in time and dF is the uncertainty in
frequency (e.g. bandwidth). What this fundamentally means is that
wider bandwidth systems (large dF) have better transient capabilities
than narrow band systems (small dT).

5. Optimally tuned reflex systems do NOT require suspensions with high
stiffness, as you claim, they require suspensions of the correct
stiffness, which is dependent upon the entire system design. One
can (and many people successfully have) designed reflex systems
using high-compliance drivers. In, for example, the classical lossless
B4 maximally flat alignment, one of the requirements is that the
driver compliance be about the same as the driver compliance. That
means that if you are designing a system with a large cabinet volume,
as a means of positioning your self high on the efficiency side of
the efficiency/bandwidth/volume relation, you MUST have a high-
compliance driver. Otherwise the driver resonance will be too high,
tuning will be significantly compromised and the system will, in fact
have fairly dismal transient response, contrary to your assertion.

6. Improvements in transient response of reflex systems can be had
by moving in the realm of QB3 alignments, which can only be had
with low-Q, low resonance drivers, which is, despite your assertion,
contrary to the notion of stiff suspensions. All other things being
equal, the stiffer the suspe4nsion, the higher the total Q and the
higher the driver resonance.

7. Please explain what the difference is between a "ported speaker"
and a "bass reflex speaker." (subtle hint: there isn't any)
  #29   Report Post  
Dick Pierce
 
Posts: n/a
Default Old speaker boxes

Sanders wrote in message ...
Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.


Sorry, but this is a load of nonsense on several points:

1. MOST foam surrounds have a lower mechanical compliance or,
equivalently, higher mechanical stiffness than typical "rubber"
(actually one alloy of polybutdene or another) surrounds.

2. In most resaonble high compliance woofers that one would find
in a vented enclosure, the surround is NOT responsible for
most of the mechanical stiffness anyway, it's the centering
spider.

3. Your analysis that "the speaker must get back to '0' as fast
as possible", while it might seem intuitively correct, is wrong.
Once you are above the mechanical resonance of the loudspeaker,
the driver is MASS controlled, NOT stiffness controlled, as you
assert. As such, it is NOT the ability to return to a given
position, but the need for acceleration. Now, as we hopefully
remember:

F = ma

Where F is force applied by the voice coil, m is mass of the cone
and a is it's acceleration. Notice the complete absence of a
stiffness term: the suspension does not playb a dominant role at
all over most of the operating bandwidth of the speaker.

And it does NOT need to accelerate "as fast as possible," but
only at the rate determined by the incoming signal.

At resonance, the speaker is predomintly resistance (either
mechanical or, for the most part electrical) controlled and ONLY
below resonance is it stiffness controlled and only then does the
suspension's stiffness play a role. And, at that point, it is only
the magnitude of the stiffness that counts.

4. If your assertion were correct, all drivers with high compliance,
low stiffness surrounds would have worse transient response than
stiffer drivers. Yet drivers with high compliance/low stiffness
surrounds, as a general rule, tend to go deeper in the bass, for
the simple fact that their mechanical resonances are lower. With
a lower mechanical resonance, the badnwidth of the system is wider,
and wider band systems, all else being equal, have better transient
response, as defined by the fundamental relation:

dT * dF = 1/2

where dT is the uncertainty in time and dF is the uncertainty in
frequency (e.g. bandwidth). What this fundamentally means is that
wider bandwidth systems (large dF) have better transient capabilities
than narrow band systems (small dT).

5. Optimally tuned reflex systems do NOT require suspensions with high
stiffness, as you claim, they require suspensions of the correct
stiffness, which is dependent upon the entire system design. One
can (and many people successfully have) designed reflex systems
using high-compliance drivers. In, for example, the classical lossless
B4 maximally flat alignment, one of the requirements is that the
driver compliance be about the same as the driver compliance. That
means that if you are designing a system with a large cabinet volume,
as a means of positioning your self high on the efficiency side of
the efficiency/bandwidth/volume relation, you MUST have a high-
compliance driver. Otherwise the driver resonance will be too high,
tuning will be significantly compromised and the system will, in fact
have fairly dismal transient response, contrary to your assertion.

6. Improvements in transient response of reflex systems can be had
by moving in the realm of QB3 alignments, which can only be had
with low-Q, low resonance drivers, which is, despite your assertion,
contrary to the notion of stiff suspensions. All other things being
equal, the stiffer the suspe4nsion, the higher the total Q and the
higher the driver resonance.

7. Please explain what the difference is between a "ported speaker"
and a "bass reflex speaker." (subtle hint: there isn't any)
  #30   Report Post  
Dick Pierce
 
Posts: n/a
Default Old speaker boxes

Sanders wrote in message ...
Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.


Sorry, but this is a load of nonsense on several points:

1. MOST foam surrounds have a lower mechanical compliance or,
equivalently, higher mechanical stiffness than typical "rubber"
(actually one alloy of polybutdene or another) surrounds.

2. In most resaonble high compliance woofers that one would find
in a vented enclosure, the surround is NOT responsible for
most of the mechanical stiffness anyway, it's the centering
spider.

3. Your analysis that "the speaker must get back to '0' as fast
as possible", while it might seem intuitively correct, is wrong.
Once you are above the mechanical resonance of the loudspeaker,
the driver is MASS controlled, NOT stiffness controlled, as you
assert. As such, it is NOT the ability to return to a given
position, but the need for acceleration. Now, as we hopefully
remember:

F = ma

Where F is force applied by the voice coil, m is mass of the cone
and a is it's acceleration. Notice the complete absence of a
stiffness term: the suspension does not playb a dominant role at
all over most of the operating bandwidth of the speaker.

And it does NOT need to accelerate "as fast as possible," but
only at the rate determined by the incoming signal.

At resonance, the speaker is predomintly resistance (either
mechanical or, for the most part electrical) controlled and ONLY
below resonance is it stiffness controlled and only then does the
suspension's stiffness play a role. And, at that point, it is only
the magnitude of the stiffness that counts.

4. If your assertion were correct, all drivers with high compliance,
low stiffness surrounds would have worse transient response than
stiffer drivers. Yet drivers with high compliance/low stiffness
surrounds, as a general rule, tend to go deeper in the bass, for
the simple fact that their mechanical resonances are lower. With
a lower mechanical resonance, the badnwidth of the system is wider,
and wider band systems, all else being equal, have better transient
response, as defined by the fundamental relation:

dT * dF = 1/2

where dT is the uncertainty in time and dF is the uncertainty in
frequency (e.g. bandwidth). What this fundamentally means is that
wider bandwidth systems (large dF) have better transient capabilities
than narrow band systems (small dT).

5. Optimally tuned reflex systems do NOT require suspensions with high
stiffness, as you claim, they require suspensions of the correct
stiffness, which is dependent upon the entire system design. One
can (and many people successfully have) designed reflex systems
using high-compliance drivers. In, for example, the classical lossless
B4 maximally flat alignment, one of the requirements is that the
driver compliance be about the same as the driver compliance. That
means that if you are designing a system with a large cabinet volume,
as a means of positioning your self high on the efficiency side of
the efficiency/bandwidth/volume relation, you MUST have a high-
compliance driver. Otherwise the driver resonance will be too high,
tuning will be significantly compromised and the system will, in fact
have fairly dismal transient response, contrary to your assertion.

6. Improvements in transient response of reflex systems can be had
by moving in the realm of QB3 alignments, which can only be had
with low-Q, low resonance drivers, which is, despite your assertion,
contrary to the notion of stiff suspensions. All other things being
equal, the stiffer the suspe4nsion, the higher the total Q and the
higher the driver resonance.

7. Please explain what the difference is between a "ported speaker"
and a "bass reflex speaker." (subtle hint: there isn't any)


  #31   Report Post  
John Byrns
 
Posts: n/a
Default Old speaker boxes


WOW! This antique technological backwater has been honored with a post
from Dick Pierce. I haven't seen a post by Dick for years in any of the
groups I frequent, but for my money Dick is easily the most knowledgeable
speaker guy I have encountered. I was troubled by the obvious
inaccuracies of "Sanders" post, but I don't know enough about speakers to
post meaningfully on the subject, thanks to Dick for giving us the
straight scoop.


Regards,

John Byrns


In article ,
(Dick Pierce) wrote:

Sanders wrote in message

...
Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.


Sorry, but this is a load of nonsense on several points:

1. MOST foam surrounds have a lower mechanical compliance or,
equivalently, higher mechanical stiffness than typical "rubber"
(actually one alloy of polybutdene or another) surrounds.

2. In most resaonble high compliance woofers that one would find
in a vented enclosure, the surround is NOT responsible for
most of the mechanical stiffness anyway, it's the centering
spider.

3. Your analysis that "the speaker must get back to '0' as fast
as possible", while it might seem intuitively correct, is wrong.
Once you are above the mechanical resonance of the loudspeaker,
the driver is MASS controlled, NOT stiffness controlled, as you
assert. As such, it is NOT the ability to return to a given
position, but the need for acceleration. Now, as we hopefully
remember:

F = ma

Where F is force applied by the voice coil, m is mass of the cone
and a is it's acceleration. Notice the complete absence of a
stiffness term: the suspension does not playb a dominant role at
all over most of the operating bandwidth of the speaker.

And it does NOT need to accelerate "as fast as possible," but
only at the rate determined by the incoming signal.

At resonance, the speaker is predomintly resistance (either
mechanical or, for the most part electrical) controlled and ONLY
below resonance is it stiffness controlled and only then does the
suspension's stiffness play a role. And, at that point, it is only
the magnitude of the stiffness that counts.

4. If your assertion were correct, all drivers with high compliance,
low stiffness surrounds would have worse transient response than
stiffer drivers. Yet drivers with high compliance/low stiffness
surrounds, as a general rule, tend to go deeper in the bass, for
the simple fact that their mechanical resonances are lower. With
a lower mechanical resonance, the badnwidth of the system is wider,
and wider band systems, all else being equal, have better transient
response, as defined by the fundamental relation:

dT * dF = 1/2

where dT is the uncertainty in time and dF is the uncertainty in
frequency (e.g. bandwidth). What this fundamentally means is that
wider bandwidth systems (large dF) have better transient capabilities
than narrow band systems (small dT).

5. Optimally tuned reflex systems do NOT require suspensions with high
stiffness, as you claim, they require suspensions of the correct
stiffness, which is dependent upon the entire system design. One
can (and many people successfully have) designed reflex systems
using high-compliance drivers. In, for example, the classical lossless
B4 maximally flat alignment, one of the requirements is that the
driver compliance be about the same as the driver compliance. That
means that if you are designing a system with a large cabinet volume,
as a means of positioning your self high on the efficiency side of
the efficiency/bandwidth/volume relation, you MUST have a high-
compliance driver. Otherwise the driver resonance will be too high,
tuning will be significantly compromised and the system will, in fact
have fairly dismal transient response, contrary to your assertion.

6. Improvements in transient response of reflex systems can be had
by moving in the realm of QB3 alignments, which can only be had
with low-Q, low resonance drivers, which is, despite your assertion,
contrary to the notion of stiff suspensions. All other things being
equal, the stiffer the suspe4nsion, the higher the total Q and the
higher the driver resonance.

7. Please explain what the difference is between a "ported speaker"
and a "bass reflex speaker." (subtle hint: there isn't any)



Surf my web pages at,
http://users.rcn.com/jbyrns/
  #32   Report Post  
John Byrns
 
Posts: n/a
Default Old speaker boxes


WOW! This antique technological backwater has been honored with a post
from Dick Pierce. I haven't seen a post by Dick for years in any of the
groups I frequent, but for my money Dick is easily the most knowledgeable
speaker guy I have encountered. I was troubled by the obvious
inaccuracies of "Sanders" post, but I don't know enough about speakers to
post meaningfully on the subject, thanks to Dick for giving us the
straight scoop.


Regards,

John Byrns


In article ,
(Dick Pierce) wrote:

Sanders wrote in message

...
Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.


Sorry, but this is a load of nonsense on several points:

1. MOST foam surrounds have a lower mechanical compliance or,
equivalently, higher mechanical stiffness than typical "rubber"
(actually one alloy of polybutdene or another) surrounds.

2. In most resaonble high compliance woofers that one would find
in a vented enclosure, the surround is NOT responsible for
most of the mechanical stiffness anyway, it's the centering
spider.

3. Your analysis that "the speaker must get back to '0' as fast
as possible", while it might seem intuitively correct, is wrong.
Once you are above the mechanical resonance of the loudspeaker,
the driver is MASS controlled, NOT stiffness controlled, as you
assert. As such, it is NOT the ability to return to a given
position, but the need for acceleration. Now, as we hopefully
remember:

F = ma

Where F is force applied by the voice coil, m is mass of the cone
and a is it's acceleration. Notice the complete absence of a
stiffness term: the suspension does not playb a dominant role at
all over most of the operating bandwidth of the speaker.

And it does NOT need to accelerate "as fast as possible," but
only at the rate determined by the incoming signal.

At resonance, the speaker is predomintly resistance (either
mechanical or, for the most part electrical) controlled and ONLY
below resonance is it stiffness controlled and only then does the
suspension's stiffness play a role. And, at that point, it is only
the magnitude of the stiffness that counts.

4. If your assertion were correct, all drivers with high compliance,
low stiffness surrounds would have worse transient response than
stiffer drivers. Yet drivers with high compliance/low stiffness
surrounds, as a general rule, tend to go deeper in the bass, for
the simple fact that their mechanical resonances are lower. With
a lower mechanical resonance, the badnwidth of the system is wider,
and wider band systems, all else being equal, have better transient
response, as defined by the fundamental relation:

dT * dF = 1/2

where dT is the uncertainty in time and dF is the uncertainty in
frequency (e.g. bandwidth). What this fundamentally means is that
wider bandwidth systems (large dF) have better transient capabilities
than narrow band systems (small dT).

5. Optimally tuned reflex systems do NOT require suspensions with high
stiffness, as you claim, they require suspensions of the correct
stiffness, which is dependent upon the entire system design. One
can (and many people successfully have) designed reflex systems
using high-compliance drivers. In, for example, the classical lossless
B4 maximally flat alignment, one of the requirements is that the
driver compliance be about the same as the driver compliance. That
means that if you are designing a system with a large cabinet volume,
as a means of positioning your self high on the efficiency side of
the efficiency/bandwidth/volume relation, you MUST have a high-
compliance driver. Otherwise the driver resonance will be too high,
tuning will be significantly compromised and the system will, in fact
have fairly dismal transient response, contrary to your assertion.

6. Improvements in transient response of reflex systems can be had
by moving in the realm of QB3 alignments, which can only be had
with low-Q, low resonance drivers, which is, despite your assertion,
contrary to the notion of stiff suspensions. All other things being
equal, the stiffer the suspe4nsion, the higher the total Q and the
higher the driver resonance.

7. Please explain what the difference is between a "ported speaker"
and a "bass reflex speaker." (subtle hint: there isn't any)



Surf my web pages at,
http://users.rcn.com/jbyrns/
  #33   Report Post  
John Byrns
 
Posts: n/a
Default Old speaker boxes


WOW! This antique technological backwater has been honored with a post
from Dick Pierce. I haven't seen a post by Dick for years in any of the
groups I frequent, but for my money Dick is easily the most knowledgeable
speaker guy I have encountered. I was troubled by the obvious
inaccuracies of "Sanders" post, but I don't know enough about speakers to
post meaningfully on the subject, thanks to Dick for giving us the
straight scoop.


Regards,

John Byrns


In article ,
(Dick Pierce) wrote:

Sanders wrote in message

...
Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.


Sorry, but this is a load of nonsense on several points:

1. MOST foam surrounds have a lower mechanical compliance or,
equivalently, higher mechanical stiffness than typical "rubber"
(actually one alloy of polybutdene or another) surrounds.

2. In most resaonble high compliance woofers that one would find
in a vented enclosure, the surround is NOT responsible for
most of the mechanical stiffness anyway, it's the centering
spider.

3. Your analysis that "the speaker must get back to '0' as fast
as possible", while it might seem intuitively correct, is wrong.
Once you are above the mechanical resonance of the loudspeaker,
the driver is MASS controlled, NOT stiffness controlled, as you
assert. As such, it is NOT the ability to return to a given
position, but the need for acceleration. Now, as we hopefully
remember:

F = ma

Where F is force applied by the voice coil, m is mass of the cone
and a is it's acceleration. Notice the complete absence of a
stiffness term: the suspension does not playb a dominant role at
all over most of the operating bandwidth of the speaker.

And it does NOT need to accelerate "as fast as possible," but
only at the rate determined by the incoming signal.

At resonance, the speaker is predomintly resistance (either
mechanical or, for the most part electrical) controlled and ONLY
below resonance is it stiffness controlled and only then does the
suspension's stiffness play a role. And, at that point, it is only
the magnitude of the stiffness that counts.

4. If your assertion were correct, all drivers with high compliance,
low stiffness surrounds would have worse transient response than
stiffer drivers. Yet drivers with high compliance/low stiffness
surrounds, as a general rule, tend to go deeper in the bass, for
the simple fact that their mechanical resonances are lower. With
a lower mechanical resonance, the badnwidth of the system is wider,
and wider band systems, all else being equal, have better transient
response, as defined by the fundamental relation:

dT * dF = 1/2

where dT is the uncertainty in time and dF is the uncertainty in
frequency (e.g. bandwidth). What this fundamentally means is that
wider bandwidth systems (large dF) have better transient capabilities
than narrow band systems (small dT).

5. Optimally tuned reflex systems do NOT require suspensions with high
stiffness, as you claim, they require suspensions of the correct
stiffness, which is dependent upon the entire system design. One
can (and many people successfully have) designed reflex systems
using high-compliance drivers. In, for example, the classical lossless
B4 maximally flat alignment, one of the requirements is that the
driver compliance be about the same as the driver compliance. That
means that if you are designing a system with a large cabinet volume,
as a means of positioning your self high on the efficiency side of
the efficiency/bandwidth/volume relation, you MUST have a high-
compliance driver. Otherwise the driver resonance will be too high,
tuning will be significantly compromised and the system will, in fact
have fairly dismal transient response, contrary to your assertion.

6. Improvements in transient response of reflex systems can be had
by moving in the realm of QB3 alignments, which can only be had
with low-Q, low resonance drivers, which is, despite your assertion,
contrary to the notion of stiff suspensions. All other things being
equal, the stiffer the suspe4nsion, the higher the total Q and the
higher the driver resonance.

7. Please explain what the difference is between a "ported speaker"
and a "bass reflex speaker." (subtle hint: there isn't any)



Surf my web pages at,
http://users.rcn.com/jbyrns/
  #34   Report Post  
John Byrns
 
Posts: n/a
Default Old speaker boxes


WOW! This antique technological backwater has been honored with a post
from Dick Pierce. I haven't seen a post by Dick for years in any of the
groups I frequent, but for my money Dick is easily the most knowledgeable
speaker guy I have encountered. I was troubled by the obvious
inaccuracies of "Sanders" post, but I don't know enough about speakers to
post meaningfully on the subject, thanks to Dick for giving us the
straight scoop.


Regards,

John Byrns


In article ,
(Dick Pierce) wrote:

Sanders wrote in message

...
Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.


Sorry, but this is a load of nonsense on several points:

1. MOST foam surrounds have a lower mechanical compliance or,
equivalently, higher mechanical stiffness than typical "rubber"
(actually one alloy of polybutdene or another) surrounds.

2. In most resaonble high compliance woofers that one would find
in a vented enclosure, the surround is NOT responsible for
most of the mechanical stiffness anyway, it's the centering
spider.

3. Your analysis that "the speaker must get back to '0' as fast
as possible", while it might seem intuitively correct, is wrong.
Once you are above the mechanical resonance of the loudspeaker,
the driver is MASS controlled, NOT stiffness controlled, as you
assert. As such, it is NOT the ability to return to a given
position, but the need for acceleration. Now, as we hopefully
remember:

F = ma

Where F is force applied by the voice coil, m is mass of the cone
and a is it's acceleration. Notice the complete absence of a
stiffness term: the suspension does not playb a dominant role at
all over most of the operating bandwidth of the speaker.

And it does NOT need to accelerate "as fast as possible," but
only at the rate determined by the incoming signal.

At resonance, the speaker is predomintly resistance (either
mechanical or, for the most part electrical) controlled and ONLY
below resonance is it stiffness controlled and only then does the
suspension's stiffness play a role. And, at that point, it is only
the magnitude of the stiffness that counts.

4. If your assertion were correct, all drivers with high compliance,
low stiffness surrounds would have worse transient response than
stiffer drivers. Yet drivers with high compliance/low stiffness
surrounds, as a general rule, tend to go deeper in the bass, for
the simple fact that their mechanical resonances are lower. With
a lower mechanical resonance, the badnwidth of the system is wider,
and wider band systems, all else being equal, have better transient
response, as defined by the fundamental relation:

dT * dF = 1/2

where dT is the uncertainty in time and dF is the uncertainty in
frequency (e.g. bandwidth). What this fundamentally means is that
wider bandwidth systems (large dF) have better transient capabilities
than narrow band systems (small dT).

5. Optimally tuned reflex systems do NOT require suspensions with high
stiffness, as you claim, they require suspensions of the correct
stiffness, which is dependent upon the entire system design. One
can (and many people successfully have) designed reflex systems
using high-compliance drivers. In, for example, the classical lossless
B4 maximally flat alignment, one of the requirements is that the
driver compliance be about the same as the driver compliance. That
means that if you are designing a system with a large cabinet volume,
as a means of positioning your self high on the efficiency side of
the efficiency/bandwidth/volume relation, you MUST have a high-
compliance driver. Otherwise the driver resonance will be too high,
tuning will be significantly compromised and the system will, in fact
have fairly dismal transient response, contrary to your assertion.

6. Improvements in transient response of reflex systems can be had
by moving in the realm of QB3 alignments, which can only be had
with low-Q, low resonance drivers, which is, despite your assertion,
contrary to the notion of stiff suspensions. All other things being
equal, the stiffer the suspe4nsion, the higher the total Q and the
higher the driver resonance.

7. Please explain what the difference is between a "ported speaker"
and a "bass reflex speaker." (subtle hint: there isn't any)



Surf my web pages at,
http://users.rcn.com/jbyrns/
  #35   Report Post  
cyrus
 
Posts: n/a
Default Old speaker boxes

In article ,
Sanders wrote:

Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.

John



Now that's a bold statement.

Thankfully, another poster has addressed it for the rest of us.

--
cyrus

*coughcasaucedoprodigynetcough*




  #36   Report Post  
cyrus
 
Posts: n/a
Default Old speaker boxes

In article ,
Sanders wrote:

Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.

John



Now that's a bold statement.

Thankfully, another poster has addressed it for the rest of us.

--
cyrus

*coughcasaucedoprodigynetcough*


  #37   Report Post  
cyrus
 
Posts: n/a
Default Old speaker boxes

In article ,
Sanders wrote:

Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.

John



Now that's a bold statement.

Thankfully, another poster has addressed it for the rest of us.

--
cyrus

*coughcasaucedoprodigynetcough*


  #38   Report Post  
cyrus
 
Posts: n/a
Default Old speaker boxes

In article ,
Sanders wrote:

Foam surrounds and ports will never give accurate response. It only
allows for a slower base response to go lower in a smaller box. To
understand that after each note, the speaker must get back to "0" as
fast as possible. Foam surrounds need a sealed box to do this. Good
bass reflex speakers count on a rigid surround and tuned port to
accomplish the same task.

John



Now that's a bold statement.

Thankfully, another poster has addressed it for the rest of us.

--
cyrus

*coughcasaucedoprodigynetcough*


  #39   Report Post  
William Sommerwerck
 
Posts: n/a
Default Old speaker boxes

Foam surrounds and ports will never give accurate response.
It only allows for a slower base [sic!!!] response to go lower in
a smaller box. To understand that after each note, the speaker
must get back to "0" as fast as possible. Foam surrounds need
a sealed box to do this. Good bass-reflex speakers count on a
rigid surround and tuned port to accomplish the same task.


Pardon my bluntness, but you don't know what the h*** you're talking about.

To over-simplify it, a properly designed sealed-box woofer is _less_ resonant
than a bass-reflex design, and the driver "returns to zero" more quickly.

"Good" and "bass reflex" is a contradiction in terms.

  #40   Report Post  
William Sommerwerck
 
Posts: n/a
Default Old speaker boxes

Foam surrounds and ports will never give accurate response.
It only allows for a slower base [sic!!!] response to go lower in
a smaller box. To understand that after each note, the speaker
must get back to "0" as fast as possible. Foam surrounds need
a sealed box to do this. Good bass-reflex speakers count on a
rigid surround and tuned port to accomplish the same task.


Pardon my bluntness, but you don't know what the h*** you're talking about.

To over-simplify it, a properly designed sealed-box woofer is _less_ resonant
than a bass-reflex design, and the driver "returns to zero" more quickly.

"Good" and "bass reflex" is a contradiction in terms.



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