Reply
 
Thread Tools Display Modes
  #1   Report Post  
bsguidry
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

I'm preparing to build an enclosure for the Adire Tempest driver using
Adire's plans called the "Adire Alignment". This will be a 7.56 cu
ft box with two 3" diameter ports. The sub is downfiring.

I have all the plans and needed wood measurements, however, I have
concern about how to stuff the recommended 4 lbs of polyfill. By
filling the entire encolsure evenly with 4 lbs of polyfill, I'm
concerned that there is some risk that the polyfill will settle around
the back of the driver or into the port tubes.

Any suggestions about how to prevent this? Could I use some type of
screen material or perhaps an additional brace (with numberous holes)
placed above the subwoofer?

Thanks,

bsguidry
  #5   Report Post  
gregs
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

In article , (bsguidry) wrote:
I'm preparing to build an enclosure for the Adire Tempest driver using
Adire's plans called the "Adire Alignment". This will be a 7.56 cu
ft box with two 3" diameter ports. The sub is downfiring.

I have all the plans and needed wood measurements, however, I have
concern about how to stuff the recommended 4 lbs of polyfill. By
filling the entire encolsure evenly with 4 lbs of polyfill, I'm
concerned that there is some risk that the polyfill will settle around
the back of the driver or into the port tubes.

Any suggestions about how to prevent this? Could I use some type of
screen material or perhaps an additional brace (with numberous holes)
placed above the subwoofer?


Allthough it will settle some, the stuff holds itself somewhat. You can keep it back
by simple stapling some strands to the sides. I often use black polypropylene
gutter guard, which comes in rolls. Cut it and it can be stapled or tacked to the sides,
holding back the stuffing. Its possible to also glue or tie it around the driver basket.
There are many other things and methods to do the trick. I would not generally
recommend even stuffing a cabnet with ports. I usually just use 2-3 inches of
foam tacked to the sides of the box. By all means, keep the stuffing
away from the ports and drivers unless you want its effects.

greg




  #8   Report Post  
Peter Larsen
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : PolyfillConcerns

bsguidry wrote:

I'm preparing to build an enclosure for the Adire Tempest driver using
Adire's plans called the "Adire Alignment". This will be a 7.56 cu
ft box with two 3" diameter ports. The sub is downfiring.


Redesign the box for vertical placement of the loudspeaker. You will
like having done this in 10 years. Just my opinion, ymmv.

I have all the plans and needed wood measurements, however, I have
concern about how to stuff the recommended 4 lbs of polyfill. By
filling the entire encolsure evenly with 4 lbs of polyfill, I'm
concerned that there is some risk that the polyfill will settle around
the back of the driver or into the port tubes.

Any suggestions about how to prevent this? Could I use some type of
screen material or perhaps an additional brace (with numberous holes)
placed above the subwoofer?


Gregs suggestion on how to keep the polyfill in place will still apply.

bsguidry



Kind regards

Peter Larsen

--
************************************************** ***********
* My site is at: http://www.muyiovatki.dk *
************************************************** ***********
  #9   Report Post  
Peter Larsen
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : PolyfillConcerns

bsguidry wrote:

I'm preparing to build an enclosure for the Adire Tempest driver using
Adire's plans called the "Adire Alignment". This will be a 7.56 cu
ft box with two 3" diameter ports. The sub is downfiring.


Redesign the box for vertical placement of the loudspeaker. You will
like having done this in 10 years. Just my opinion, ymmv.

I have all the plans and needed wood measurements, however, I have
concern about how to stuff the recommended 4 lbs of polyfill. By
filling the entire encolsure evenly with 4 lbs of polyfill, I'm
concerned that there is some risk that the polyfill will settle around
the back of the driver or into the port tubes.

Any suggestions about how to prevent this? Could I use some type of
screen material or perhaps an additional brace (with numberous holes)
placed above the subwoofer?


Gregs suggestion on how to keep the polyfill in place will still apply.

bsguidry



Kind regards

Peter Larsen

--
************************************************** ***********
* My site is at: http://www.muyiovatki.dk *
************************************************** ***********
  #10   Report Post  
Peter Larsen
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : PolyfillConcerns

bsguidry wrote:

I'm preparing to build an enclosure for the Adire Tempest driver using
Adire's plans called the "Adire Alignment". This will be a 7.56 cu
ft box with two 3" diameter ports. The sub is downfiring.


Redesign the box for vertical placement of the loudspeaker. You will
like having done this in 10 years. Just my opinion, ymmv.

I have all the plans and needed wood measurements, however, I have
concern about how to stuff the recommended 4 lbs of polyfill. By
filling the entire encolsure evenly with 4 lbs of polyfill, I'm
concerned that there is some risk that the polyfill will settle around
the back of the driver or into the port tubes.

Any suggestions about how to prevent this? Could I use some type of
screen material or perhaps an additional brace (with numberous holes)
placed above the subwoofer?


Gregs suggestion on how to keep the polyfill in place will still apply.

bsguidry



Kind regards

Peter Larsen

--
************************************************** ***********
* My site is at: http://www.muyiovatki.dk *
************************************************** ***********


  #11   Report Post  
bsguidry
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

Peter Larsen wrote in message ...
bsguidry wrote:

I'm preparing to build an enclosure for the Adire Tempest driver using
Adire's plans called the "Adire Alignment". This will be a 7.56 cu
ft box with two 3" diameter ports. The sub is downfiring.


Redesign the box for vertical placement of the loudspeaker. You will
like having done this in 10 years. Just my opinion, ymmv.

I have all the plans and needed wood measurements, however, I have
concern about how to stuff the recommended 4 lbs of polyfill. By
filling the entire encolsure evenly with 4 lbs of polyfill, I'm
concerned that there is some risk that the polyfill will settle around
the back of the driver or into the port tubes.

Any suggestions about how to prevent this? Could I use some type of
screen material or perhaps an additional brace (with numberous holes)
placed above the subwoofer?


Gregs suggestion on how to keep the polyfill in place will still apply.

bsguidry



Kind regards

Peter Larsen


Thanks to all who have responded. I believe I will use a combination
of sticking the polyfill to the sides and perhaps using cords or twine
as a net above the driver and ports.

As far as mounting the driver for a vertical alignment, I'd like to
know more why I'd appreciate this design in 10 years. Unfortunately,
I have two toddlers who haven't learned to keep out of my
electronics. Having the sub mounted underneath would offer a bit more
protection than if it were side mounted.

bsguidry
  #12   Report Post  
bsguidry
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

Peter Larsen wrote in message ...
bsguidry wrote:

I'm preparing to build an enclosure for the Adire Tempest driver using
Adire's plans called the "Adire Alignment". This will be a 7.56 cu
ft box with two 3" diameter ports. The sub is downfiring.


Redesign the box for vertical placement of the loudspeaker. You will
like having done this in 10 years. Just my opinion, ymmv.

I have all the plans and needed wood measurements, however, I have
concern about how to stuff the recommended 4 lbs of polyfill. By
filling the entire encolsure evenly with 4 lbs of polyfill, I'm
concerned that there is some risk that the polyfill will settle around
the back of the driver or into the port tubes.

Any suggestions about how to prevent this? Could I use some type of
screen material or perhaps an additional brace (with numberous holes)
placed above the subwoofer?


Gregs suggestion on how to keep the polyfill in place will still apply.

bsguidry



Kind regards

Peter Larsen


Thanks to all who have responded. I believe I will use a combination
of sticking the polyfill to the sides and perhaps using cords or twine
as a net above the driver and ports.

As far as mounting the driver for a vertical alignment, I'd like to
know more why I'd appreciate this design in 10 years. Unfortunately,
I have two toddlers who haven't learned to keep out of my
electronics. Having the sub mounted underneath would offer a bit more
protection than if it were side mounted.

bsguidry
  #13   Report Post  
bsguidry
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

Peter Larsen wrote in message ...
bsguidry wrote:

I'm preparing to build an enclosure for the Adire Tempest driver using
Adire's plans called the "Adire Alignment". This will be a 7.56 cu
ft box with two 3" diameter ports. The sub is downfiring.


Redesign the box for vertical placement of the loudspeaker. You will
like having done this in 10 years. Just my opinion, ymmv.

I have all the plans and needed wood measurements, however, I have
concern about how to stuff the recommended 4 lbs of polyfill. By
filling the entire encolsure evenly with 4 lbs of polyfill, I'm
concerned that there is some risk that the polyfill will settle around
the back of the driver or into the port tubes.

Any suggestions about how to prevent this? Could I use some type of
screen material or perhaps an additional brace (with numberous holes)
placed above the subwoofer?


Gregs suggestion on how to keep the polyfill in place will still apply.

bsguidry



Kind regards

Peter Larsen


Thanks to all who have responded. I believe I will use a combination
of sticking the polyfill to the sides and perhaps using cords or twine
as a net above the driver and ports.

As far as mounting the driver for a vertical alignment, I'd like to
know more why I'd appreciate this design in 10 years. Unfortunately,
I have two toddlers who haven't learned to keep out of my
electronics. Having the sub mounted underneath would offer a bit more
protection than if it were side mounted.

bsguidry
  #14   Report Post  
Peter Larsen
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : PolyfillConcerns

bsguidry wrote:

As far as mounting the driver for a vertical alignment,
I'd like to know more why I'd appreciate this design in
10 years.


Gravity will eventually cause the loudspeaker unit to leave its correct
rest position. This is not something that happens fast, but eventually
it will happen.

Unfortunately, I have two toddlers who haven't learned
to keep out of my electronics.


Aha ...

Having the sub mounted underneath would offer a bit more
protection than if it were side mounted.


Indeed. Design sure never is simple .... and even if a metal screen is
used, then the spilled beverage and icecream risk remains. I would try
to find a solution with a hidden loudspeaker unit, but then it becomes a
total redesign. One way of getting the loudspeaker unit hidden is to go
for a bandpass reflex box with a front chamber instead. But you already
appear to have a lock on the target ... or do you?

http://www.tachyon.co.jp may be an interesting passtime if you want to
look for possible solutions that may be somewhat beyond your initial
aim. The also have a subsite for WE555 Replacement Diaphragm ... just as
an a pro pos to a thread in this forum some weeks ago.

bsguidry



Kind regards

Peter Larsen

--
************************************************** ***********
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** ***********
  #15   Report Post  
Peter Larsen
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : PolyfillConcerns

bsguidry wrote:

As far as mounting the driver for a vertical alignment,
I'd like to know more why I'd appreciate this design in
10 years.


Gravity will eventually cause the loudspeaker unit to leave its correct
rest position. This is not something that happens fast, but eventually
it will happen.

Unfortunately, I have two toddlers who haven't learned
to keep out of my electronics.


Aha ...

Having the sub mounted underneath would offer a bit more
protection than if it were side mounted.


Indeed. Design sure never is simple .... and even if a metal screen is
used, then the spilled beverage and icecream risk remains. I would try
to find a solution with a hidden loudspeaker unit, but then it becomes a
total redesign. One way of getting the loudspeaker unit hidden is to go
for a bandpass reflex box with a front chamber instead. But you already
appear to have a lock on the target ... or do you?

http://www.tachyon.co.jp may be an interesting passtime if you want to
look for possible solutions that may be somewhat beyond your initial
aim. The also have a subsite for WE555 Replacement Diaphragm ... just as
an a pro pos to a thread in this forum some weeks ago.

bsguidry



Kind regards

Peter Larsen

--
************************************************** ***********
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** ***********


  #16   Report Post  
Peter Larsen
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : PolyfillConcerns

bsguidry wrote:

As far as mounting the driver for a vertical alignment,
I'd like to know more why I'd appreciate this design in
10 years.


Gravity will eventually cause the loudspeaker unit to leave its correct
rest position. This is not something that happens fast, but eventually
it will happen.

Unfortunately, I have two toddlers who haven't learned
to keep out of my electronics.


Aha ...

Having the sub mounted underneath would offer a bit more
protection than if it were side mounted.


Indeed. Design sure never is simple .... and even if a metal screen is
used, then the spilled beverage and icecream risk remains. I would try
to find a solution with a hidden loudspeaker unit, but then it becomes a
total redesign. One way of getting the loudspeaker unit hidden is to go
for a bandpass reflex box with a front chamber instead. But you already
appear to have a lock on the target ... or do you?

http://www.tachyon.co.jp may be an interesting passtime if you want to
look for possible solutions that may be somewhat beyond your initial
aim. The also have a subsite for WE555 Replacement Diaphragm ... just as
an a pro pos to a thread in this forum some weeks ago.

bsguidry



Kind regards

Peter Larsen

--
************************************************** ***********
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** ***********
  #20   Report Post  
Rusty Boudreaux
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

This is off topic but you might want to consider an infinite
baffle arrangement. It's inexpensive and easy to construct
arrangement that yields incredibly clean, low distortion, very
deep bass at unbelievable SPL. Certainly the cleanest and
loudest bass I've ever heard.

With multiple (hidden) drivers you can literally achieve house
damaging levels with a flat response from below 10Hz to well
above 100Hz...at a fraction of the cost of a comparable box sub.
All this without a monster amplifier and no big ugly box in the
corner (and no polyfill concerns). I usually recommend four high
excursion 15" drivers (Stryke AV15 is the current
performance/dollar leader but the older Adire Tempest and Dayton
15" drivers compete well). For $1k total (drivers, amp,
construction materials) you can blow windows out of their frames
without the drivers breaking a sweat (i.e. still within linear
Xmax).

IB maximizes Hoffman's Iron Law. Hoffman's Iron Law states that
the efficiency of a woofer system is directly proportional to its
cabinet volume and the cube of its cutoff frequency (the lowest
frequency it can usefully reproduce). With any box sub there is a
tradeoff between efficiency, volume, and low frequency response.
With IB the volume is 'infinite' which maximizes the efficiency
and cutoff to simply the properties of the bare driver. It
doesn't get any better. Power compression/distortion isn't an
issue like a box sub and you only need a relatively tiny amp.

FAQ:
https://home.comcast.net/~ttriff/

Gallery pictures pages 1 and 2 with construction links
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

Forum
http://f20.parsimony.net/forum36475/

IB: no box, no box-like sound




  #21   Report Post  
Rusty Boudreaux
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

This is off topic but you might want to consider an infinite
baffle arrangement. It's inexpensive and easy to construct
arrangement that yields incredibly clean, low distortion, very
deep bass at unbelievable SPL. Certainly the cleanest and
loudest bass I've ever heard.

With multiple (hidden) drivers you can literally achieve house
damaging levels with a flat response from below 10Hz to well
above 100Hz...at a fraction of the cost of a comparable box sub.
All this without a monster amplifier and no big ugly box in the
corner (and no polyfill concerns). I usually recommend four high
excursion 15" drivers (Stryke AV15 is the current
performance/dollar leader but the older Adire Tempest and Dayton
15" drivers compete well). For $1k total (drivers, amp,
construction materials) you can blow windows out of their frames
without the drivers breaking a sweat (i.e. still within linear
Xmax).

IB maximizes Hoffman's Iron Law. Hoffman's Iron Law states that
the efficiency of a woofer system is directly proportional to its
cabinet volume and the cube of its cutoff frequency (the lowest
frequency it can usefully reproduce). With any box sub there is a
tradeoff between efficiency, volume, and low frequency response.
With IB the volume is 'infinite' which maximizes the efficiency
and cutoff to simply the properties of the bare driver. It
doesn't get any better. Power compression/distortion isn't an
issue like a box sub and you only need a relatively tiny amp.

FAQ:
https://home.comcast.net/~ttriff/

Gallery pictures pages 1 and 2 with construction links
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

Forum
http://f20.parsimony.net/forum36475/

IB: no box, no box-like sound


  #22   Report Post  
Rusty Boudreaux
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

This is off topic but you might want to consider an infinite
baffle arrangement. It's inexpensive and easy to construct
arrangement that yields incredibly clean, low distortion, very
deep bass at unbelievable SPL. Certainly the cleanest and
loudest bass I've ever heard.

With multiple (hidden) drivers you can literally achieve house
damaging levels with a flat response from below 10Hz to well
above 100Hz...at a fraction of the cost of a comparable box sub.
All this without a monster amplifier and no big ugly box in the
corner (and no polyfill concerns). I usually recommend four high
excursion 15" drivers (Stryke AV15 is the current
performance/dollar leader but the older Adire Tempest and Dayton
15" drivers compete well). For $1k total (drivers, amp,
construction materials) you can blow windows out of their frames
without the drivers breaking a sweat (i.e. still within linear
Xmax).

IB maximizes Hoffman's Iron Law. Hoffman's Iron Law states that
the efficiency of a woofer system is directly proportional to its
cabinet volume and the cube of its cutoff frequency (the lowest
frequency it can usefully reproduce). With any box sub there is a
tradeoff between efficiency, volume, and low frequency response.
With IB the volume is 'infinite' which maximizes the efficiency
and cutoff to simply the properties of the bare driver. It
doesn't get any better. Power compression/distortion isn't an
issue like a box sub and you only need a relatively tiny amp.

FAQ:
https://home.comcast.net/~ttriff/

Gallery pictures pages 1 and 2 with construction links
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

Forum
http://f20.parsimony.net/forum36475/

IB: no box, no box-like sound


  #23   Report Post  
bsguidry
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

"Rusty Boudreaux" wrote in message ...
This is off topic but you might want to consider an infinite
baffle arrangement. It's inexpensive and easy to construct
arrangement that yields incredibly clean, low distortion, very
deep bass at unbelievable SPL. Certainly the cleanest and
loudest bass I've ever heard.

With multiple (hidden) drivers you can literally achieve house
damaging levels with a flat response from below 10Hz to well
above 100Hz...at a fraction of the cost of a comparable box sub.
All this without a monster amplifier and no big ugly box in the
corner (and no polyfill concerns). I usually recommend four high
excursion 15" drivers (Stryke AV15 is the current
performance/dollar leader but the older Adire Tempest and Dayton
15" drivers compete well). For $1k total (drivers, amp,
construction materials) you can blow windows out of their frames
without the drivers breaking a sweat (i.e. still within linear
Xmax).

IB maximizes Hoffman's Iron Law. Hoffman's Iron Law states that
the efficiency of a woofer system is directly proportional to its
cabinet volume and the cube of its cutoff frequency (the lowest
frequency it can usefully reproduce). With any box sub there is a
tradeoff between efficiency, volume, and low frequency response.
With IB the volume is 'infinite' which maximizes the efficiency
and cutoff to simply the properties of the bare driver. It
doesn't get any better. Power compression/distortion isn't an
issue like a box sub and you only need a relatively tiny amp.

FAQ:
https://home.comcast.net/~ttriff/

Gallery pictures pages 1 and 2 with construction links
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

Forum
http://f20.parsimony.net/forum36475/

IB: no box, no box-like sound


I wish I had investigated Infinite Baffles further prior to beginning.
I hadn't envisioned doing an infinite baffle in what appears to be
the standard approach on the websites above. It definitely would lead
to simpler carpentry and no huge boxes in the room. I may move to
this in the near future.

I've already begun work on the 214L box for the Tempest. The wood is
all cut and much of it assembled. I'll go from there.

One question about port tubes. When using flared port kits,
measurements are given for the center tube length. In the case of the
Tempest plans it indicates a center tube length of 11". I'm assuming
this is the actual length of the center tube piece before the flared
ends are attached. The flared ends slip over the center tube so
measuring it afterwards would be about 10.5".

bsguidry
  #24   Report Post  
bsguidry
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

"Rusty Boudreaux" wrote in message ...
This is off topic but you might want to consider an infinite
baffle arrangement. It's inexpensive and easy to construct
arrangement that yields incredibly clean, low distortion, very
deep bass at unbelievable SPL. Certainly the cleanest and
loudest bass I've ever heard.

With multiple (hidden) drivers you can literally achieve house
damaging levels with a flat response from below 10Hz to well
above 100Hz...at a fraction of the cost of a comparable box sub.
All this without a monster amplifier and no big ugly box in the
corner (and no polyfill concerns). I usually recommend four high
excursion 15" drivers (Stryke AV15 is the current
performance/dollar leader but the older Adire Tempest and Dayton
15" drivers compete well). For $1k total (drivers, amp,
construction materials) you can blow windows out of their frames
without the drivers breaking a sweat (i.e. still within linear
Xmax).

IB maximizes Hoffman's Iron Law. Hoffman's Iron Law states that
the efficiency of a woofer system is directly proportional to its
cabinet volume and the cube of its cutoff frequency (the lowest
frequency it can usefully reproduce). With any box sub there is a
tradeoff between efficiency, volume, and low frequency response.
With IB the volume is 'infinite' which maximizes the efficiency
and cutoff to simply the properties of the bare driver. It
doesn't get any better. Power compression/distortion isn't an
issue like a box sub and you only need a relatively tiny amp.

FAQ:
https://home.comcast.net/~ttriff/

Gallery pictures pages 1 and 2 with construction links
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

Forum
http://f20.parsimony.net/forum36475/

IB: no box, no box-like sound


I wish I had investigated Infinite Baffles further prior to beginning.
I hadn't envisioned doing an infinite baffle in what appears to be
the standard approach on the websites above. It definitely would lead
to simpler carpentry and no huge boxes in the room. I may move to
this in the near future.

I've already begun work on the 214L box for the Tempest. The wood is
all cut and much of it assembled. I'll go from there.

One question about port tubes. When using flared port kits,
measurements are given for the center tube length. In the case of the
Tempest plans it indicates a center tube length of 11". I'm assuming
this is the actual length of the center tube piece before the flared
ends are attached. The flared ends slip over the center tube so
measuring it afterwards would be about 10.5".

bsguidry
  #25   Report Post  
bsguidry
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

"Rusty Boudreaux" wrote in message ...
This is off topic but you might want to consider an infinite
baffle arrangement. It's inexpensive and easy to construct
arrangement that yields incredibly clean, low distortion, very
deep bass at unbelievable SPL. Certainly the cleanest and
loudest bass I've ever heard.

With multiple (hidden) drivers you can literally achieve house
damaging levels with a flat response from below 10Hz to well
above 100Hz...at a fraction of the cost of a comparable box sub.
All this without a monster amplifier and no big ugly box in the
corner (and no polyfill concerns). I usually recommend four high
excursion 15" drivers (Stryke AV15 is the current
performance/dollar leader but the older Adire Tempest and Dayton
15" drivers compete well). For $1k total (drivers, amp,
construction materials) you can blow windows out of their frames
without the drivers breaking a sweat (i.e. still within linear
Xmax).

IB maximizes Hoffman's Iron Law. Hoffman's Iron Law states that
the efficiency of a woofer system is directly proportional to its
cabinet volume and the cube of its cutoff frequency (the lowest
frequency it can usefully reproduce). With any box sub there is a
tradeoff between efficiency, volume, and low frequency response.
With IB the volume is 'infinite' which maximizes the efficiency
and cutoff to simply the properties of the bare driver. It
doesn't get any better. Power compression/distortion isn't an
issue like a box sub and you only need a relatively tiny amp.

FAQ:
https://home.comcast.net/~ttriff/

Gallery pictures pages 1 and 2 with construction links
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

Forum
http://f20.parsimony.net/forum36475/

IB: no box, no box-like sound


I wish I had investigated Infinite Baffles further prior to beginning.
I hadn't envisioned doing an infinite baffle in what appears to be
the standard approach on the websites above. It definitely would lead
to simpler carpentry and no huge boxes in the room. I may move to
this in the near future.

I've already begun work on the 214L box for the Tempest. The wood is
all cut and much of it assembled. I'll go from there.

One question about port tubes. When using flared port kits,
measurements are given for the center tube length. In the case of the
Tempest plans it indicates a center tube length of 11". I'm assuming
this is the actual length of the center tube piece before the flared
ends are attached. The flared ends slip over the center tube so
measuring it afterwards would be about 10.5".

bsguidry


  #26   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

On Tue, 23 Dec 2003 04:39:04 -0600, "Rusty Boudreaux"
wrote:

With any box sub there is a
tradeoff between efficiency, volume, and low frequency response.
With IB the volume is 'infinite' which maximizes the efficiency
and cutoff to simply the properties of the bare driver. It
doesn't get any better. Power compression/distortion isn't an
issue like a box sub and you only need a relatively tiny amp.

FAQ:
https://home.comcast.net/~ttriff/

Gallery pictures pages 1 and 2 with construction links
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

Forum
http://f20.parsimony.net/forum36475/

IB: no box, no box-like sound


OTOH, your ceiling will rattle like crazy..........

BTW, if using an open baffle, watch out that you don't rip the
suspension loose at low frequencies, when you can easily drive *way*
beyond Xmax! Note that most of the ultra-long throw drivers are
intended for use in a relatively small sealed boxes, with heavy EQ and
big amps. Go to the Linkwitz Lab website, and run the numbers through
for large box volumes - you get Xmax limiting at low frequencies with
very low power.

BTW, I'm in a similar situation to you, I have a large loft space
above my listening room, but I'm going with a pair of Tempests in a
200 litre sealed box, driven by a 500 watt amp. This works pretty
well, Xmax limited from 30 Hz down so achieving maximum possible SPL,
but without much spare power to overload the driver. Should give a
clean 120 dB in-room from 20 Hz up.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #27   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

On Tue, 23 Dec 2003 04:39:04 -0600, "Rusty Boudreaux"
wrote:

With any box sub there is a
tradeoff between efficiency, volume, and low frequency response.
With IB the volume is 'infinite' which maximizes the efficiency
and cutoff to simply the properties of the bare driver. It
doesn't get any better. Power compression/distortion isn't an
issue like a box sub and you only need a relatively tiny amp.

FAQ:
https://home.comcast.net/~ttriff/

Gallery pictures pages 1 and 2 with construction links
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

Forum
http://f20.parsimony.net/forum36475/

IB: no box, no box-like sound


OTOH, your ceiling will rattle like crazy..........

BTW, if using an open baffle, watch out that you don't rip the
suspension loose at low frequencies, when you can easily drive *way*
beyond Xmax! Note that most of the ultra-long throw drivers are
intended for use in a relatively small sealed boxes, with heavy EQ and
big amps. Go to the Linkwitz Lab website, and run the numbers through
for large box volumes - you get Xmax limiting at low frequencies with
very low power.

BTW, I'm in a similar situation to you, I have a large loft space
above my listening room, but I'm going with a pair of Tempests in a
200 litre sealed box, driven by a 500 watt amp. This works pretty
well, Xmax limited from 30 Hz down so achieving maximum possible SPL,
but without much spare power to overload the driver. Should give a
clean 120 dB in-room from 20 Hz up.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #28   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

On Tue, 23 Dec 2003 04:39:04 -0600, "Rusty Boudreaux"
wrote:

With any box sub there is a
tradeoff between efficiency, volume, and low frequency response.
With IB the volume is 'infinite' which maximizes the efficiency
and cutoff to simply the properties of the bare driver. It
doesn't get any better. Power compression/distortion isn't an
issue like a box sub and you only need a relatively tiny amp.

FAQ:
https://home.comcast.net/~ttriff/

Gallery pictures pages 1 and 2 with construction links
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

Forum
http://f20.parsimony.net/forum36475/

IB: no box, no box-like sound


OTOH, your ceiling will rattle like crazy..........

BTW, if using an open baffle, watch out that you don't rip the
suspension loose at low frequencies, when you can easily drive *way*
beyond Xmax! Note that most of the ultra-long throw drivers are
intended for use in a relatively small sealed boxes, with heavy EQ and
big amps. Go to the Linkwitz Lab website, and run the numbers through
for large box volumes - you get Xmax limiting at low frequencies with
very low power.

BTW, I'm in a similar situation to you, I have a large loft space
above my listening room, but I'm going with a pair of Tempests in a
200 litre sealed box, driven by a 500 watt amp. This works pretty
well, Xmax limited from 30 Hz down so achieving maximum possible SPL,
but without much spare power to overload the driver. Should give a
clean 120 dB in-room from 20 Hz up.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #29   Report Post  
Rusty Boudreaux
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

"Stewart Pinkerton" wrote in message
...
OTOH, your ceiling will rattle like crazy..........


If you use a manifold with opposing drivers it won't be any worse
than a box sub at the same SPL. Rattling, shaking, etc will be
solely from acoustic coupling.

BTW, if using an open baffle, watch out that you don't rip the
suspension loose at low frequencies, when you can easily drive

*way*
beyond Xmax! Note that most of the ultra-long throw drivers are


Sure but that's the beauty of an IB. Driving to Xmax yields the
maximum output regardless of alignment. For an IB you don't need
a monster amp to get to Xmax. Four AV15's will get you nearly
100dB at 5Hz within Xmax and around 120dB by 15Hz or so.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast. With four
drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.

above my listening room, but I'm going with a pair of Tempests

in a
200 litre sealed box, driven by a 500 watt amp. This works

pretty

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


  #30   Report Post  
Rusty Boudreaux
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

"Stewart Pinkerton" wrote in message
...
OTOH, your ceiling will rattle like crazy..........


If you use a manifold with opposing drivers it won't be any worse
than a box sub at the same SPL. Rattling, shaking, etc will be
solely from acoustic coupling.

BTW, if using an open baffle, watch out that you don't rip the
suspension loose at low frequencies, when you can easily drive

*way*
beyond Xmax! Note that most of the ultra-long throw drivers are


Sure but that's the beauty of an IB. Driving to Xmax yields the
maximum output regardless of alignment. For an IB you don't need
a monster amp to get to Xmax. Four AV15's will get you nearly
100dB at 5Hz within Xmax and around 120dB by 15Hz or so.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast. With four
drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.

above my listening room, but I'm going with a pair of Tempests

in a
200 litre sealed box, driven by a 500 watt amp. This works

pretty

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).




  #31   Report Post  
Rusty Boudreaux
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

"Stewart Pinkerton" wrote in message
...
OTOH, your ceiling will rattle like crazy..........


If you use a manifold with opposing drivers it won't be any worse
than a box sub at the same SPL. Rattling, shaking, etc will be
solely from acoustic coupling.

BTW, if using an open baffle, watch out that you don't rip the
suspension loose at low frequencies, when you can easily drive

*way*
beyond Xmax! Note that most of the ultra-long throw drivers are


Sure but that's the beauty of an IB. Driving to Xmax yields the
maximum output regardless of alignment. For an IB you don't need
a monster amp to get to Xmax. Four AV15's will get you nearly
100dB at 5Hz within Xmax and around 120dB by 15Hz or so.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast. With four
drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.

above my listening room, but I'm going with a pair of Tempests

in a
200 litre sealed box, driven by a 500 watt amp. This works

pretty

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


  #32   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

On Tue, 23 Dec 2003 22:21:52 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
OTOH, your ceiling will rattle like crazy..........


If you use a manifold with opposing drivers it won't be any worse
than a box sub at the same SPL. Rattling, shaking, etc will be
solely from acoustic coupling.


Well, unless you have the box on springs, it will also be due to
mechanical coupling. IME, ceilings are not so strongly built as
floors!

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast.


Yup - that was my point. You can certainly do this with an IB, and I
doubt that it does the components much good! :-)

With four
drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.


Or you can just use the correct size of sealed box and avoid the
problem altogether........

above my listening room, but I'm going with a pair of Tempests in a
200 litre sealed box, driven by a 500 watt amp. This works

pretty

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


Unfortunately, I have to use what's available in the UK, which doesn't
include the Stryke AV15 - and I can't afford a pair of Tumults!
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #33   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

On Tue, 23 Dec 2003 22:21:52 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
OTOH, your ceiling will rattle like crazy..........


If you use a manifold with opposing drivers it won't be any worse
than a box sub at the same SPL. Rattling, shaking, etc will be
solely from acoustic coupling.


Well, unless you have the box on springs, it will also be due to
mechanical coupling. IME, ceilings are not so strongly built as
floors!

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast.


Yup - that was my point. You can certainly do this with an IB, and I
doubt that it does the components much good! :-)

With four
drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.


Or you can just use the correct size of sealed box and avoid the
problem altogether........

above my listening room, but I'm going with a pair of Tempests in a
200 litre sealed box, driven by a 500 watt amp. This works

pretty

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


Unfortunately, I have to use what's available in the UK, which doesn't
include the Stryke AV15 - and I can't afford a pair of Tumults!
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #34   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

On Tue, 23 Dec 2003 22:21:52 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
OTOH, your ceiling will rattle like crazy..........


If you use a manifold with opposing drivers it won't be any worse
than a box sub at the same SPL. Rattling, shaking, etc will be
solely from acoustic coupling.


Well, unless you have the box on springs, it will also be due to
mechanical coupling. IME, ceilings are not so strongly built as
floors!

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast.


Yup - that was my point. You can certainly do this with an IB, and I
doubt that it does the components much good! :-)

With four
drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.


Or you can just use the correct size of sealed box and avoid the
problem altogether........

above my listening room, but I'm going with a pair of Tempests in a
200 litre sealed box, driven by a 500 watt amp. This works

pretty

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


Unfortunately, I have to use what's available in the UK, which doesn't
include the Stryke AV15 - and I can't afford a pair of Tumults!
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #35   Report Post  
Rusty Boudreaux
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due

to
mechanical coupling. IME, ceilings are not so strongly built as
floors!


Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm.

The
suspension is designed to handle overdrive without damage up

to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil

former
hitting the backplate sounds like a shotgun blast.


Yup - that was my point. You can certainly do this with an IB,

and I
doubt that it does the components much good! :-)


Stewart, I've always thought your comments were dead on but I
think you're blowing this way out of proportion. With a typical
IB setup you'll never hit Xsus. Even if you do it won't damage
the driver.

For example, I can play Telarc's DVD-A version of Tchaikovsky's
1812 Overture at such volume that I seriously worry my double
sash windows are going to come out the their frames. I'm talking
about pegging the radio shack SPL meter at 126dB before getting
scared and backing off the volume (even with earplugs). Not once
have those 7Hz digital cannons hit Xsus. Now I can hook up a
tone generator and hit Xsus with a 3Hz tone but how realistic is
that? The sub will play several times louder than my mains so
it's a moot point anyway. To get to the SPL numbers above I have
to turn off the main amplifers to keep from toasting the
speakers. Because of the IB's large headroom I can EQ the sub
for flat response from 10Hz up and hit reference levels without
running out of bass.

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".

drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8

Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.


Or you can just use the correct size of sealed box and avoid

the
problem altogether........


Why? What problem? The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


Unfortunately, I have to use what's available in the UK, which

doesn't
include the Stryke AV15 - and I can't afford a pair of Tumults!


Although the Tumult is the king of displacement I doubt anyone
would use on for IB due to cost. Since an IB lends itself to
multiple drivers it's more economical to use 'lesser' drivers.
Four Tempests will get you the same displacement as two Tumults.

Seriously, the Tempest is an excellent driver for an IB. Along
with the Dayton 15" drivers (available internationally through
partsexpress) the Tempest was the most popular IB driver until
the AV15 came along. The AV15 has about 50% more displacement
per driver than a Tempest or Dayton and costs slightly less per
liter. For the same output you just need a few more
Tempests...or fewer AV15s.

If you want an AV15 (or multiple ones) I'll order them from
acoustic-visions and ship them to you at my cost (no added fee).
You've been posting here long enough...I trust you




  #36   Report Post  
Rusty Boudreaux
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due

to
mechanical coupling. IME, ceilings are not so strongly built as
floors!


Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm.

The
suspension is designed to handle overdrive without damage up

to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil

former
hitting the backplate sounds like a shotgun blast.


Yup - that was my point. You can certainly do this with an IB,

and I
doubt that it does the components much good! :-)


Stewart, I've always thought your comments were dead on but I
think you're blowing this way out of proportion. With a typical
IB setup you'll never hit Xsus. Even if you do it won't damage
the driver.

For example, I can play Telarc's DVD-A version of Tchaikovsky's
1812 Overture at such volume that I seriously worry my double
sash windows are going to come out the their frames. I'm talking
about pegging the radio shack SPL meter at 126dB before getting
scared and backing off the volume (even with earplugs). Not once
have those 7Hz digital cannons hit Xsus. Now I can hook up a
tone generator and hit Xsus with a 3Hz tone but how realistic is
that? The sub will play several times louder than my mains so
it's a moot point anyway. To get to the SPL numbers above I have
to turn off the main amplifers to keep from toasting the
speakers. Because of the IB's large headroom I can EQ the sub
for flat response from 10Hz up and hit reference levels without
running out of bass.

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".

drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8

Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.


Or you can just use the correct size of sealed box and avoid

the
problem altogether........


Why? What problem? The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


Unfortunately, I have to use what's available in the UK, which

doesn't
include the Stryke AV15 - and I can't afford a pair of Tumults!


Although the Tumult is the king of displacement I doubt anyone
would use on for IB due to cost. Since an IB lends itself to
multiple drivers it's more economical to use 'lesser' drivers.
Four Tempests will get you the same displacement as two Tumults.

Seriously, the Tempest is an excellent driver for an IB. Along
with the Dayton 15" drivers (available internationally through
partsexpress) the Tempest was the most popular IB driver until
the AV15 came along. The AV15 has about 50% more displacement
per driver than a Tempest or Dayton and costs slightly less per
liter. For the same output you just need a few more
Tempests...or fewer AV15s.

If you want an AV15 (or multiple ones) I'll order them from
acoustic-visions and ship them to you at my cost (no added fee).
You've been posting here long enough...I trust you


  #37   Report Post  
Rusty Boudreaux
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due

to
mechanical coupling. IME, ceilings are not so strongly built as
floors!


Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm.

The
suspension is designed to handle overdrive without damage up

to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil

former
hitting the backplate sounds like a shotgun blast.


Yup - that was my point. You can certainly do this with an IB,

and I
doubt that it does the components much good! :-)


Stewart, I've always thought your comments were dead on but I
think you're blowing this way out of proportion. With a typical
IB setup you'll never hit Xsus. Even if you do it won't damage
the driver.

For example, I can play Telarc's DVD-A version of Tchaikovsky's
1812 Overture at such volume that I seriously worry my double
sash windows are going to come out the their frames. I'm talking
about pegging the radio shack SPL meter at 126dB before getting
scared and backing off the volume (even with earplugs). Not once
have those 7Hz digital cannons hit Xsus. Now I can hook up a
tone generator and hit Xsus with a 3Hz tone but how realistic is
that? The sub will play several times louder than my mains so
it's a moot point anyway. To get to the SPL numbers above I have
to turn off the main amplifers to keep from toasting the
speakers. Because of the IB's large headroom I can EQ the sub
for flat response from 10Hz up and hit reference levels without
running out of bass.

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".

drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8

Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.


Or you can just use the correct size of sealed box and avoid

the
problem altogether........


Why? What problem? The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


Unfortunately, I have to use what's available in the UK, which

doesn't
include the Stryke AV15 - and I can't afford a pair of Tumults!


Although the Tumult is the king of displacement I doubt anyone
would use on for IB due to cost. Since an IB lends itself to
multiple drivers it's more economical to use 'lesser' drivers.
Four Tempests will get you the same displacement as two Tumults.

Seriously, the Tempest is an excellent driver for an IB. Along
with the Dayton 15" drivers (available internationally through
partsexpress) the Tempest was the most popular IB driver until
the AV15 came along. The AV15 has about 50% more displacement
per driver than a Tempest or Dayton and costs slightly less per
liter. For the same output you just need a few more
Tempests...or fewer AV15s.

If you want an AV15 (or multiple ones) I'll order them from
acoustic-visions and ship them to you at my cost (no added fee).
You've been posting here long enough...I trust you


  #38   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

On Wed, 24 Dec 2003 17:28:39 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due

to
mechanical coupling. IME, ceilings are not so strongly built as
floors!


Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.


That's certainly the logical way to minimise box rattle.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast.


Yup - that was my point. You can certainly do this with an IB, and I
doubt that it does the components much good! :-)


Stewart, I've always thought your comments were dead on but I
think you're blowing this way out of proportion. With a typical
IB setup you'll never hit Xsus. Even if you do it won't damage
the driver.


OK, I'll take your word on that, but voice coils slamming into
backplates (as you yourself describe) doesn't sound like a recipe for
longevity!

For example, I can play Telarc's DVD-A version of Tchaikovsky's
1812 Overture at such volume that I seriously worry my double
sash windows are going to come out the their frames. I'm talking
about pegging the radio shack SPL meter at 126dB before getting
scared and backing off the volume (even with earplugs). Not once
have those 7Hz digital cannons hit Xsus. Now I can hook up a
tone generator and hit Xsus with a 3Hz tone but how realistic is
that? The sub will play several times louder than my mains so
it's a moot point anyway. To get to the SPL numbers above I have
to turn off the main amplifers to keep from toasting the
speakers. Because of the IB's large headroom I can EQ the sub
for flat response from 10Hz up and hit reference levels without
running out of bass.


OK, so long as you're happy with it. Since I need 500 watts into 4
ohms to drive a Tempest fully for my target 115dB at 30-100Hz, I see
no harm in cushioning the driver by using a box sized so that max
power just drops below Xmax from 20Hz down. I'm not wasting any power
'cos it's there anyway, and I protect the drivers from any wayward
infrabass accidents.

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".


Yup, I'm familiar with his weapon of house destruction!

drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.


Or you can just use the correct size of sealed box and avoid the
problem altogether........


Why? What problem? The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.


You can still have the box in the loft space, and a Linkwitz transform
equaliser will give you any alignment you want. A small box doesn't
have to mean a high Qts in 2003/4. I guess I'm just hedging my bets.
Besides, SWMBO doesn't want a hole in the ceiling!

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


Unfortunately, I have to use what's available in the UK, which doesn't
include the Stryke AV15 - and I can't afford a pair of Tumults!


Although the Tumult is the king of displacement I doubt anyone
would use on for IB due to cost. Since an IB lends itself to
multiple drivers it's more economical to use 'lesser' drivers.
Four Tempests will get you the same displacement as two Tumults.


In your particular type of IB, this is true, although for 'in-room'
IBs the Tumult and DPL12 are sonically superior due to their rear
basket aerodynamics.

Seriously, the Tempest is an excellent driver for an IB. Along
with the Dayton 15" drivers (available internationally through
partsexpress) the Tempest was the most popular IB driver until
the AV15 came along. The AV15 has about 50% more displacement
per driver than a Tempest or Dayton and costs slightly less per
liter. For the same output you just need a few more
Tempests...or fewer AV15s.

If you want an AV15 (or multiple ones) I'll order them from
acoustic-visions and ship them to you at my cost (no added fee).
You've been posting here long enough...I trust you


Do you have Thiele Small numbers for the AV15? I might take you up on
that if I can't source them any other way. As you say, displacement is
everything at LF.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #39   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

On Wed, 24 Dec 2003 17:28:39 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due

to
mechanical coupling. IME, ceilings are not so strongly built as
floors!


Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.


That's certainly the logical way to minimise box rattle.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast.


Yup - that was my point. You can certainly do this with an IB, and I
doubt that it does the components much good! :-)


Stewart, I've always thought your comments were dead on but I
think you're blowing this way out of proportion. With a typical
IB setup you'll never hit Xsus. Even if you do it won't damage
the driver.


OK, I'll take your word on that, but voice coils slamming into
backplates (as you yourself describe) doesn't sound like a recipe for
longevity!

For example, I can play Telarc's DVD-A version of Tchaikovsky's
1812 Overture at such volume that I seriously worry my double
sash windows are going to come out the their frames. I'm talking
about pegging the radio shack SPL meter at 126dB before getting
scared and backing off the volume (even with earplugs). Not once
have those 7Hz digital cannons hit Xsus. Now I can hook up a
tone generator and hit Xsus with a 3Hz tone but how realistic is
that? The sub will play several times louder than my mains so
it's a moot point anyway. To get to the SPL numbers above I have
to turn off the main amplifers to keep from toasting the
speakers. Because of the IB's large headroom I can EQ the sub
for flat response from 10Hz up and hit reference levels without
running out of bass.


OK, so long as you're happy with it. Since I need 500 watts into 4
ohms to drive a Tempest fully for my target 115dB at 30-100Hz, I see
no harm in cushioning the driver by using a box sized so that max
power just drops below Xmax from 20Hz down. I'm not wasting any power
'cos it's there anyway, and I protect the drivers from any wayward
infrabass accidents.

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".


Yup, I'm familiar with his weapon of house destruction!

drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.


Or you can just use the correct size of sealed box and avoid the
problem altogether........


Why? What problem? The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.


You can still have the box in the loft space, and a Linkwitz transform
equaliser will give you any alignment you want. A small box doesn't
have to mean a high Qts in 2003/4. I guess I'm just hedging my bets.
Besides, SWMBO doesn't want a hole in the ceiling!

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


Unfortunately, I have to use what's available in the UK, which doesn't
include the Stryke AV15 - and I can't afford a pair of Tumults!


Although the Tumult is the king of displacement I doubt anyone
would use on for IB due to cost. Since an IB lends itself to
multiple drivers it's more economical to use 'lesser' drivers.
Four Tempests will get you the same displacement as two Tumults.


In your particular type of IB, this is true, although for 'in-room'
IBs the Tumult and DPL12 are sonically superior due to their rear
basket aerodynamics.

Seriously, the Tempest is an excellent driver for an IB. Along
with the Dayton 15" drivers (available internationally through
partsexpress) the Tempest was the most popular IB driver until
the AV15 came along. The AV15 has about 50% more displacement
per driver than a Tempest or Dayton and costs slightly less per
liter. For the same output you just need a few more
Tempests...or fewer AV15s.

If you want an AV15 (or multiple ones) I'll order them from
acoustic-visions and ship them to you at my cost (no added fee).
You've been posting here long enough...I trust you


Do you have Thiele Small numbers for the AV15? I might take you up on
that if I can't source them any other way. As you say, displacement is
everything at LF.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #40   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns

On Wed, 24 Dec 2003 17:28:39 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due

to
mechanical coupling. IME, ceilings are not so strongly built as
floors!


Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.


That's certainly the logical way to minimise box rattle.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast.


Yup - that was my point. You can certainly do this with an IB, and I
doubt that it does the components much good! :-)


Stewart, I've always thought your comments were dead on but I
think you're blowing this way out of proportion. With a typical
IB setup you'll never hit Xsus. Even if you do it won't damage
the driver.


OK, I'll take your word on that, but voice coils slamming into
backplates (as you yourself describe) doesn't sound like a recipe for
longevity!

For example, I can play Telarc's DVD-A version of Tchaikovsky's
1812 Overture at such volume that I seriously worry my double
sash windows are going to come out the their frames. I'm talking
about pegging the radio shack SPL meter at 126dB before getting
scared and backing off the volume (even with earplugs). Not once
have those 7Hz digital cannons hit Xsus. Now I can hook up a
tone generator and hit Xsus with a 3Hz tone but how realistic is
that? The sub will play several times louder than my mains so
it's a moot point anyway. To get to the SPL numbers above I have
to turn off the main amplifers to keep from toasting the
speakers. Because of the IB's large headroom I can EQ the sub
for flat response from 10Hz up and hit reference levels without
running out of bass.


OK, so long as you're happy with it. Since I need 500 watts into 4
ohms to drive a Tempest fully for my target 115dB at 30-100Hz, I see
no harm in cushioning the driver by using a box sized so that max
power just drops below Xmax from 20Hz down. I'm not wasting any power
'cos it's there anyway, and I protect the drivers from any wayward
infrabass accidents.

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".


Yup, I'm familiar with his weapon of house destruction!

drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.


Or you can just use the correct size of sealed box and avoid the
problem altogether........


Why? What problem? The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.


You can still have the box in the loft space, and a Linkwitz transform
equaliser will give you any alignment you want. A small box doesn't
have to mean a high Qts in 2003/4. I guess I'm just hedging my bets.
Besides, SWMBO doesn't want a hole in the ceiling!

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

Four AV15's in an IB will give you 3x the output capability at
Xmax (15 liters vs 3 liters).


Unfortunately, I have to use what's available in the UK, which doesn't
include the Stryke AV15 - and I can't afford a pair of Tumults!


Although the Tumult is the king of displacement I doubt anyone
would use on for IB due to cost. Since an IB lends itself to
multiple drivers it's more economical to use 'lesser' drivers.
Four Tempests will get you the same displacement as two Tumults.


In your particular type of IB, this is true, although for 'in-room'
IBs the Tumult and DPL12 are sonically superior due to their rear
basket aerodynamics.

Seriously, the Tempest is an excellent driver for an IB. Along
with the Dayton 15" drivers (available internationally through
partsexpress) the Tempest was the most popular IB driver until
the AV15 came along. The AV15 has about 50% more displacement
per driver than a Tempest or Dayton and costs slightly less per
liter. For the same output you just need a few more
Tempests...or fewer AV15s.

If you want an AV15 (or multiple ones) I'll order them from
acoustic-visions and ship them to you at my cost (no added fee).
You've been posting here long enough...I trust you


Do you have Thiele Small numbers for the AV15? I might take you up on
that if I can't source them any other way. As you say, displacement is
everything at LF.
--

Stewart Pinkerton | Music is Art - Audio is Engineering


Reply
Thread Tools
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Newbie Subwoofer questions OodlesoFun General 28 January 12th 04 05:51 PM
Newbie Subwoofer questions OodlesoFun Audio Opinions 23 January 12th 04 05:51 PM
Adire Tempest Downfiring Ported Subwoofer Project : Polyfill Concerns bsguidry Audio Opinions 76 January 4th 04 01:44 PM
"Project Gramophone" discussion group started -- do contribute ... Jon Noring General 0 August 9th 03 03:51 PM


All times are GMT +1. The time now is 08:54 PM.

Powered by: vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AudioBanter.com.
The comments are property of their posters.
 

About Us

"It's about Audio and hi-fi"