[Jack[_6_]]

Good day group,

Perhaps someone can clear something up for me.

I just came into possession of some rather large 3-way speakers and I
took the woofers and midrange and tweeters out to have a look-see.

The hots for the mids and tweeters are connected from the terminals in
back of the cabinets in series respectively with 10 mfd and 4.7 mfd
electrolytic caps to pots on the cabinet face and then to the drivers.
The hots for the woofers are directly connected to the speaker wire
terminals, as are the grounds for all the speakers.

The question I have arises from how the mids are wired. The woofers have
a '+' and '-' stamped near the connector lugs, so its easy to tell which
wire goes where inside the cabinet. The mids have a red band near one
lug and the tweeters have a red dot near one lug. I am assuming that red
means hot or positive and 'no red' means ground or minus. The confusion
arises from the fact that the grounds coming from the amp are connected
to the red side of the connector lugs on the mids. The tweeters have the
hot, or positive, wire connected to the red side and the woofers have
the hot, or positive, wire connected to the side stamped with the '+'.

I checked the woofer against the midrange with 1.5 volt battery and the
red side on the mid corresponds to the '+' on the woofer. Connecting the
plus side of the battery to the red side of the mid caused the cone to
move out, and connecting the plus side of the battery to the '+' on the
woofer moved the cone in the same direction.

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

Can anyone shed some light on this?

Thanks,
Jack
Beautiful Sunny Berkeley

[Scott Dorsey]

Jack wrote:

The hots for the mids and tweeters are connected from the terminals in
back of the cabinets in series respectively with 10 mfd and 4.7 mfd
electrolytic caps to pots on the cabinet face and then to the drivers.
The hots for the woofers are directly connected to the speaker wire
terminals, as are the grounds for all the speakers.

Okay, this isn't a real crossover. The whole signal is going to the woofer
including high frequencies that will make the cone break up. The tweeter
has only a 6 dB/oct high pass with that series capacitor, and the same
goes for the "midrange" driver.

The question I have arises from how the mids are wired. The woofers have
a '+' and '-' stamped near the connector lugs, so its easy to tell which
wire goes where inside the cabinet. The mids have a red band near one
lug and the tweeters have a red dot near one lug. I am assuming that red
means hot or positive and 'no red' means ground or minus. The confusion
arises from the fact that the grounds coming from the amp are connected
to the red side of the connector lugs on the mids. The tweeters have the
hot, or positive, wire connected to the red side and the woofers have
the hot, or positive, wire connected to the side stamped with the '+'.

You're basically talking about a bunch of random drivers thrown into a
box without any engineering. It isn't going to preserve phase anyway, so
it really doesn't matter how they are wired up. This is not a real speaker,
this is "white van" grade stuff.

I checked the woofer against the midrange with 1.5 volt battery and the
red side on the mid corresponds to the '+' on the woofer. Connecting the
plus side of the battery to the red side of the mid caused the cone to
move out, and connecting the plus side of the battery to the '+' on the
woofer moved the cone in the same direction.

Right.

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

It IS very common for speakers with real crossovers to be wired this way,
because the crossover produces substantial phase shift and so the midrange
driver needs to be wired with reverse polarity so that over the crossover
region, the signals from the drivers are more or less in phase.

This requires pretty careful engineering to make sure that the phase shift
of the crossover at the crossover points is carefully matched up, and it
may require one or more of the drivers to be mounted either forward or back
of the front plate in order to get some physical time delay. The speaker
you describe, however, is not carefully engineered.

This speaker is not that way, but in fact this speaker isn't designed so
much as tossed together. This speaker isn't going to preserve phase
across the passband anyway, so it probably doesn't matter much how the
individual drivers are wired up.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Preben Friis]

"Jack" wrote

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

Can anyone shed some light on this?

It is perfectly normal to have the midrange wired that way. It is due to the
phase shift in the cross-over circuit.

Quote from the page below: "Filter outputs are in phase when the midrange
bandpass has reversed polarity."

http://www.linkwitzlab.com/crossovers.htm

/Preben Friis

[Jack[_6_]]

Scott Dorsey wrote:
Jack wrote:
The hots for the mids and tweeters are connected from the terminals in
back of the cabinets in series respectively with 10 mfd and 4.7 mfd
electrolytic caps to pots on the cabinet face and then to the drivers.
The hots for the woofers are directly connected to the speaker wire
terminals, as are the grounds for all the speakers.

Okay, this isn't a real crossover. The whole signal is going to the woofer
including high frequencies that will make the cone break up. The tweeter
has only a 6 dB/oct high pass with that series capacitor, and the same
goes for the "midrange" driver.

The question I have arises from how the mids are wired. The woofers have
a '+' and '-' stamped near the connector lugs, so its easy to tell which
wire goes where inside the cabinet. The mids have a red band near one
lug and the tweeters have a red dot near one lug. I am assuming that red
means hot or positive and 'no red' means ground or minus. The confusion
arises from the fact that the grounds coming from the amp are connected
to the red side of the connector lugs on the mids. The tweeters have the
hot, or positive, wire connected to the red side and the woofers have
the hot, or positive, wire connected to the side stamped with the '+'.

You're basically talking about a bunch of random drivers thrown into a
box without any engineering. It isn't going to preserve phase anyway, so
it really doesn't matter how they are wired up. This is not a real speaker,
this is "white van" grade stuff.

God, I don't believe this. When I describe the speakers to an audio
friend of mine, he said he knew this guy that used to sell speakers like
that out the back of a white van.

That guy must have made quite a name for himself.

Oh well.. since I only paid $20 for the pair and the sound compares
favorably with some much pricier Klipsch speakers that I have and like,
I can live with them not being real speakers.

For what it's worth, here's a link to a picture of the front label
around the pots. No other markings:

http://www.flickr.com/photos/27689880@N00/966447434/

I checked the woofer against the midrange with 1.5 volt battery and the
red side on the mid corresponds to the '+' on the woofer. Connecting the
plus side of the battery to the red side of the mid caused the cone to
move out, and connecting the plus side of the battery to the '+' on the
woofer moved the cone in the same direction.

Right.

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

It IS very common for speakers with real crossovers to be wired this way,
because the crossover produces substantial phase shift and so the midrange
driver needs to be wired with reverse polarity so that over the crossover
region, the signals from the drivers are more or less in phase.

This requires pretty careful engineering to make sure that the phase shift
of the crossover at the crossover points is carefully matched up, and it
may require one or more of the drivers to be mounted either forward or back
of the front plate in order to get some physical time delay. The speaker
you describe, however, is not carefully engineered.

This speaker is not that way, but in fact this speaker isn't designed so
much as tossed together. This speaker isn't going to preserve phase
across the passband anyway, so it probably doesn't matter much how the
individual drivers are wired up.
--scott

[Jack[_6_]]

Scott Dorsey wrote:
Jack wrote:
The hots for the mids and tweeters are connected from the terminals in
back of the cabinets in series respectively with 10 mfd and 4.7 mfd
electrolytic caps to pots on the cabinet face and then to the drivers.
The hots for the woofers are directly connected to the speaker wire
terminals, as are the grounds for all the speakers.

Okay, this isn't a real crossover.

My mistake, I think, in using the term 3-way. I take it that "3-way"
refers to three different crossover circuitries and not the number of
drivers in a system. Thanks for pointing that out.

The whole signal is going to the woofer
including high frequencies that will make the cone break up. The tweeter
has only a 6 dB/oct high pass with that series capacitor, and the same
goes for the "midrange" driver.

The question I have arises from how the mids are wired. The woofers have
a '+' and '-' stamped near the connector lugs, so its easy to tell which
wire goes where inside the cabinet. The mids have a red band near one
lug and the tweeters have a red dot near one lug. I am assuming that red
means hot or positive and 'no red' means ground or minus. The confusion
arises from the fact that the grounds coming from the amp are connected
to the red side of the connector lugs on the mids. The tweeters have the
hot, or positive, wire connected to the red side and the woofers have
the hot, or positive, wire connected to the side stamped with the '+'.

You're basically talking about a bunch of random drivers thrown into a
box without any engineering. It isn't going to preserve phase anyway, so
it really doesn't matter how they are wired up. This is not a real speaker,
this is "white van" grade stuff.

I checked the woofer against the midrange with 1.5 volt battery and the
red side on the mid corresponds to the '+' on the woofer. Connecting the
plus side of the battery to the red side of the mid caused the cone to
move out, and connecting the plus side of the battery to the '+' on the
woofer moved the cone in the same direction.

Right.

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

It IS very common for speakers with real crossovers to be wired this way,
because the crossover produces substantial phase shift and so the midrange
driver needs to be wired with reverse polarity so that over the crossover
region, the signals from the drivers are more or less in phase.

This requires pretty careful engineering to make sure that the phase shift
of the crossover at the crossover points is carefully matched up, and it
may require one or more of the drivers to be mounted either forward or back
of the front plate in order to get some physical time delay. The speaker
you describe, however, is not carefully engineered.

This speaker is not that way, but in fact this speaker isn't designed so
much as tossed together. This speaker isn't going to preserve phase
across the passband anyway, so it probably doesn't matter much how the
individual drivers are wired up.
--scott

And, in fact, I could not tell the difference with the mids wired
forward or backward.

[Jack[_6_]]

Preben Friis wrote:
"Jack" wrote

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

Can anyone shed some light on this?

It is perfectly normal to have the midrange wired that way. It is due to the
phase shift in the cross-over circuit.

Quote from the page below: "Filter outputs are in phase when the midrange
bandpass has reversed polarity."

http://www.linkwitzlab.com/crossovers.htm

/Preben Friis

Thanks, Preben, for the info and the link.

[Bill Dunkenfield]

Preben Friis wrote:

"Jack" wrote

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

Can anyone shed some light on this?

It is perfectly normal to have the midrange wired that way. It is due to the
phase shift in the cross-over circuit.

Quote from the page below: "Filter outputs are in phase when the midrange
bandpass has reversed polarity."

http://www.linkwitzlab.com/crossovers.htm

/Preben Friis

The only thing I can add is that there is a big difference between
ground and common. I seriously doubt that any of this equipment is
connected to ground.

JAM

[Walt]

Jack wrote:
Scott Dorsey wrote:

This is not a real speaker,
this is "white van" grade stuff.

God, I don't believe this. When I describe the speakers to an audio
friend of mine, he said he knew this guy that used to sell speakers like
that out the back of a white van.

That guy must have made quite a name for himself.

For what it's worth, here's a link to a picture of the front label
around the pots. No other markings:

http://www.flickr.com/photos/27689880@N00/966447434/

Yup. Acoustic Monitor brand, aka White Van Speakers.

See:
http://en.wikipedia.org/wiki/White_van_speakers

//Walt

[jakdedert]

Jack wrote:
snip

My mistake, I think, in using the term 3-way. I take it that "3-way"
refers to three different crossover circuitries and not the number of
drivers in a system. Thanks for pointing that out.

snip

I'm glad you like them. Fact is, a 'thrown together' speaker system can
sound 'OK' for uncritical applications. It could probably be improved
in several ways. First off, yes, it is (nominally) a 3-way system. It
has three drivers which get somewhat different frequency ranges sent to
each by the rudimentary crossover network. The use of capacitors only
means however that the mid and low freq' drivers get everything the ones
above them get. Real crossovers contain inductors, in a more complex
circuit, which ensures that each driver gets only the frequencies it was
meant to reproduce. Further, the cutoff frequency is more sharply defined.

Sending the high frequencies to the midrange and woofer causes all sorts
of nasties that may not be apparent on casual listening, but will likely
cause listening fatigue over the long run.

So...the first thing you 'could' do to improve the system would be to
add a 'real' crossover network. This involves some technicalities to
which you might not be inclined; but it's not an impossible task.

Secondly, speakers as you describe usually have inadequate cabinets.
Either they are too thin, not properly sealed, or improperly ported (if
in fact they are ported at all). Adding bracing and/or an extra 'shell'
of dense material (MDF...or even concrete) around the cabinet can
improve the sound. (If you can rap on the cabinet with your knuckles
and hear a definite 'note' they are not thick enough.) Making sure that
they are absolutely airtight (except for whatever port they might
employ). Often, there is no internal damping material. A layer of
acoustical fiberglass on the interior cabinet walls is desirable. If
the cabinets have no port, filling the entire box loosely with the same
can improve the sound (perhaps at the expense of some low-end
efficiency...but an improvement overall, nonetheless).

Lastly, the drivers themselves are often deficient and can be replaced
with matched units of higher quality.

OTOH, the only reason to do all this is for fun, self-satisfaction, or
to improve them over a period of time, without laying out a huge chunk
of money all at once.

Doing all of the above will probably make the speakers 'better' but
might never make them really 'good'...from an accuracy/efficiency point
of view.

YMMV....

jak

[Jack[_6_]]

Walt wrote:
Jack wrote:
Scott Dorsey wrote:

This is not a real speaker,
this is "white van" grade stuff.
God, I don't believe this. When I describe the speakers to an audio
friend of mine, he said he knew this guy that used to sell speakers like
that out the back of a white van.

That guy must have made quite a name for himself.

For what it's worth, here's a link to a picture of the front label
around the pots. No other markings:

http://www.flickr.com/photos/27689880@N00/966447434/

Yup. Acoustic Monitor brand, aka White Van Speakers.

See:
http://en.wikipedia.org/wiki/White_van_speakers

//Walt


I'll.........be..........damned

[Jack[_6_]]

jakdedert wrote:
Jack wrote:
snip
My mistake, I think, in using the term 3-way. I take it that "3-way"
refers to three different crossover circuitries and not the number of
drivers in a system. Thanks for pointing that out.

snip

I'm glad you like them. Fact is, a 'thrown together' speaker system can
sound 'OK' for uncritical applications. It could probably be improved
in several ways. First off, yes, it is (nominally) a 3-way system. It
has three drivers which get somewhat different frequency ranges sent to
each by the rudimentary crossover network. The use of capacitors only
means however that the mid and low freq' drivers get everything the ones
above them get. Real crossovers contain inductors, in a more complex
circuit, which ensures that each driver gets only the frequencies it was
meant to reproduce. Further, the cutoff frequency is more sharply defined.

Sending the high frequencies to the midrange and woofer causes all sorts
of nasties that may not be apparent on casual listening, but will likely
cause listening fatigue over the long run.

So...the first thing you 'could' do to improve the system would be to
add a 'real' crossover network. This involves some technicalities to
which you might not be inclined; but it's not an impossible task.

Secondly, speakers as you describe usually have inadequate cabinets.
Either they are too thin, not properly sealed, or improperly ported (if
in fact they are ported at all). Adding bracing and/or an extra 'shell'
of dense material (MDF...or even concrete) around the cabinet can
improve the sound. (If you can rap on the cabinet with your knuckles
and hear a definite 'note' they are not thick enough.) Making sure that
they are absolutely airtight (except for whatever port they might
employ). Often, there is no internal damping material. A layer of
acoustical fiberglass on the interior cabinet walls is desirable. If
the cabinets have no port, filling the entire box loosely with the same
can improve the sound (perhaps at the expense of some low-end
efficiency...but an improvement overall, nonetheless).

Lastly, the drivers themselves are often deficient and can be replaced
with matched units of higher quality.

At this point, we're talking about building a speaker set from scratch.

I like the concrete idea. Form 'em up and pour 'em in place.

The circuitry part sounds intriguing. I'm sure I could work something
out with the help of websites like this:

http://www.lalena.com/Audio/Calculator/APCXOver/


OTOH, the only reason to do all this is for fun, self-satisfaction, or
to improve them over a period of time, without laying out a huge chunk
of money all at once.

Doing all of the above will probably make the speakers 'better' but
might never make them really 'good'...from an accuracy/efficiency point
of view.

YMMV....

jak

[Jack[_6_]]

Bill Dunkenfield wrote:
Preben Friis wrote:
"Jack" wrote

But the the speakers were wired inside with the negative wire from the
amp going to the red or positive side of the midrange driver.

Is it normal for a 3-way speaker box to be wired this way? I would think
that all the individual drivers in a box should be phased the same. I am
basing that on absolutely nothing but pure logic and a knowledge of how
a speaker moves air to create sound and that if two speaker boxes are
connected out of phase, their individual output of sound would tend to
cancel each other out.

Can anyone shed some light on this?
It is perfectly normal to have the midrange wired that way. It is due to the
phase shift in the cross-over circuit.

Quote from the page below: "Filter outputs are in phase when the midrange
bandpass has reversed polarity."

http://www.linkwitzlab.com/crossovers.htm

/Preben Friis

The only thing I can add is that there is a big difference between
ground and common. I seriously doubt that any of this equipment is
connected to ground.

JAM

The word "ground" is used synonymously with the word "common" where I am
from.

[Scott Dorsey]

Jack wrote:
Scott Dorsey wrote:
Jack wrote:
The hots for the mids and tweeters are connected from the terminals in
back of the cabinets in series respectively with 10 mfd and 4.7 mfd
electrolytic caps to pots on the cabinet face and then to the drivers.
The hots for the woofers are directly connected to the speaker wire
terminals, as are the grounds for all the speakers.

Okay, this isn't a real crossover.

My mistake, I think, in using the term 3-way. I take it that "3-way"
refers to three different crossover circuitries and not the number of
drivers in a system. Thanks for pointing that out.

Well, it is in fact SOME kind of three-way system, since there are crude
high-pass networks on the midrange and tweeter. It's just not a very
good one, because there are no low-pass networks anywhere, and because
the high-pass networks are so wide that they aren't very useful other
than to prevent the drivers from being damaged.

This speaker is not that way, but in fact this speaker isn't designed so
much as tossed together. This speaker isn't going to preserve phase
across the passband anyway, so it probably doesn't matter much how the
individual drivers are wired up.

And, in fact, I could not tell the difference with the mids wired
forward or backward.

Right, which is a sign these speakers are not even vaguely phase coherent.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Melodious Thunk[_2_]]

On Jul 31, 3:00 pm, Jack wrote:
Walt wrote:
Jack wrote:
Scott Dorsey wrote:

This is not a real speaker,
this is "white van" grade stuff.
God, I don't believe this. When I describe the speakers to an audio
friend of mine, he said he knew this guy that used to sell speakers like
that out the back of a white van.

That guy must have made quite a name for himself.

For what it's worth, here's a link to a picture of the front label
around the pots. No other markings:

http://www.flickr.com/photos/27689880@N00/966447434/

Yup. Acoustic Monitor brand, aka White Van Speakers.

See:
http://en.wikipedia.org/wiki/White_van_speakers

//Walt

I'll.........be..........damned

I'm (a bit) ashamed to be able to point out, that in California, this
was a common scam for kids just released from "juvie." Guys would hire
kids coming out of detention centers to do just this; I sold "Acoustic
Response," I think, around Venice and Santa Monica, out of the back of
someone's van, circa 1976 (when Acoustic Research had some respect).

[Jack[_6_]]

Melodious Thunk wrote:
On Jul 31, 3:00 pm, Jack wrote:
Walt wrote:
Jack wrote:
Scott Dorsey wrote:
This is not a real speaker,
this is "white van" grade stuff.
God, I don't believe this. When I describe the speakers to an audio
friend of mine, he said he knew this guy that used to sell speakers like
that out the back of a white van.
That guy must have made quite a name for himself.
For what it's worth, here's a link to a picture of the front label
around the pots. No other markings:
http://www.flickr.com/photos/27689880@N00/966447434/
Yup. Acoustic Monitor brand, aka White Van Speakers.
See:
http://en.wikipedia.org/wiki/White_van_speakers
//Walt
I'll.........be..........damned

I'm (a bit) ashamed to be able to point out, that in California, this
was a common scam for kids just released from "juvie." Guys would hire
kids coming out of detention centers to do just this; I sold "Acoustic
Response," I think, around Venice and Santa Monica, out of the back of
someone's van, circa 1976 (when Acoustic Research had some respect).


Think of the history!

I'm bowled over by the whole phenomenon. I bet it was a sweet moment
when the deal went over. I feel like I bought a piece of history for
$20! And they are not really that bad. I could throw some crossover
circuitry on them for another $15 and see what that does. Hell, I might
have the caps in old circuits laying around. I'll probably have to buy
the coils or wind some out some magnet wire I got somewhere.

The pots were scratchy and one was loose but I fixed that already with
some switch cleaner and a hammer :--)

I love the names of the fake companies at Wikipedia. Did you get that
site link? Here it is:

White van speakers
http://en.wikipedia.org/wiki/White_van_speakers

Acoustic Response is in there, along with Acoustic Monitor (mine),
Acoustic Image and Acoustic Lab Technology.

And that's just the A's.

I'll bet there's a book in there somewhere, if only someone would write it.

[Jack[_6_]]

Scott Dorsey wrote:
Jack wrote:
Scott Dorsey wrote:
Jack wrote:
The hots for the mids and tweeters are connected from the terminals in
back of the cabinets in series respectively with 10 mfd and 4.7 mfd
electrolytic caps to pots on the cabinet face and then to the drivers.
The hots for the woofers are directly connected to the speaker wire
terminals, as are the grounds for all the speakers.
Okay, this isn't a real crossover.
My mistake, I think, in using the term 3-way. I take it that "3-way"
refers to three different crossover circuitries and not the number of
drivers in a system. Thanks for pointing that out.

Well, it is in fact SOME kind of three-way system, since there are crude
high-pass networks on the midrange and tweeter. It's just not a very
good one, because there are no low-pass networks anywhere, and because
the high-pass networks are so wide that they aren't very useful other
than to prevent the drivers from being damaged.

This speaker is not that way, but in fact this speaker isn't designed so
much as tossed together. This speaker isn't going to preserve phase
across the passband anyway, so it probably doesn't matter much how the
individual drivers are wired up.
And, in fact, I could not tell the difference with the mids wired
forward or backward.

Right, which is a sign these speakers are not even vaguely phase coherent.
--scott

Me being deaf in one ear doesn't help, either.

[Mr.T]

"Scott Dorsey" wrote in message
...
Jack wrote:

The hots for the mids and tweeters are connected from the terminals in
back of the cabinets in series respectively with 10 mfd and 4.7 mfd
electrolytic caps to pots on the cabinet face and then to the drivers.
The hots for the woofers are directly connected to the speaker wire
terminals, as are the grounds for all the speakers.

Okay, this isn't a real crossover. The whole signal is going to the
woofer
including high frequencies that will make the cone break up.


Not necessarily, it will depend on the woofer roll-off and possibly it's
impedance increase with frequency.
Some reasonable designs have used the woofer this way, as well as a huge
number of lousy designs.

The tweeter
has only a 6 dB/oct high pass with that series capacitor, and the same
goes for the "midrange" driver.

Yep, and I note the "midrange" is only one octave below the tweeter,
assuming both have a similar impedance.


The question I have arises from how the mids are wired. The woofers have
a '+' and '-' stamped near the connector lugs, so its easy to tell which
wire goes where inside the cabinet. The mids have a red band near one
lug and the tweeters have a red dot near one lug. I am assuming that red
means hot or positive and 'no red' means ground or minus. The confusion
arises from the fact that the grounds coming from the amp are connected
to the red side of the connector lugs on the mids. The tweeters have the
hot, or positive, wire connected to the red side and the woofers have
the hot, or positive, wire connected to the side stamped with the '+'.

You're basically talking about a bunch of random drivers thrown into a
box without any engineering. It isn't going to preserve phase anyway, so
it really doesn't matter how they are wired up. This is not a real
speaker,
this is "white van" grade stuff.


And some expensive brands don't do much better unfortunately.

MrT.

[Mr.T]

"Preben Friis" wrote in message
k...

It is perfectly normal to have the midrange wired that way. It is due to
the
phase shift in the cross-over circuit.

Perfectly normal for a 12dB/octave crossover. In this case however, the
phase error will be approx 90deg however you wire them. Just as Jack has
found.

MrT.

[William Sommerwerck]

White van speakers
http://en.wikipedia.org/wiki/White_van_speakers

About 10 years ago I was accosted by such a seller in an Office Despot
parking lot. When I told him that I owned Apogee speakers -- and what they
cost -- he practically screamed at me: "You bleeping own speakers that
cost as much as a used car?" He was not a happy fellow.

[Arny Krueger]

"William Sommerwerck" wrote in
message
White van speakers
http://en.wikipedia.org/wiki/White_van_speakers

About 10 years ago I was accosted by such a seller in an
Office Despot parking lot. When I told him that I owned
Apogee speakers -- and what they cost -- he practically
screamed at me: "You bleeping own speakers that cost as
much as a used car?" He was not a happy fellow.

I'm surprised that he knew what Apogees are and cost.

[Arny Krueger]

"Jack" wrote in message


And, in fact, I could not tell the difference with the
mids wired forward or backward.

Ouch!

BTW the *right way* to check the polarity of drivers in a speaker like this
is to play pink noise over the speaker in a really reverberent room, and
listen for cancellation notches and phasiness.

At least that what I recall Jim Long saying when he was delivering papers
in the 70s about this interesting effect.

[Arny Krueger]

"Jack" wrote in message


Me being deaf in one ear doesn't help, either.

Maybe, maybe not. Remember that it is good form to block one ear when
walking around a sound source, listening for good mic locations. Your
situation leaves boths hands free! ;-)

[Mark]

BTW the *right way* to check the polarity of drivers in a speaker like this
is to play pink noise over the speaker in a really reverberent room, and
listen for cancellation notches and phasiness.



that seems like a good idea excpet why in a reverberent room, I would
think you want to use a dead room so any "phasiness" you might hear
would be due to the speakers and not the room...

Mark

[Arny Krueger]

"Mark" wrote in message
ups.com

BTW the *right way* to check the polarity of drivers in
a speaker like this is to play pink noise over the
speaker in a really reverberent room, and listen for
cancellation notches and phasiness.

that seems like a good idea excpet why in a reverberent
room,

The stated goal (Mr. Long's) was to optimize the speaker's power response,
as opposed to its on-axis response.

I would think you want to use a dead room so any
"phasiness" you might hear would be due to the speakers
and not the room...

In even a medium-sized room, the phasiness due to crossover problems, and
that due to the room, have quite different sonic signatures.

[Arny Krueger]

"Arny Krueger" wrote in message

"Mark" wrote in message
ups.com

BTW the *right way* to check the polarity of drivers in
a speaker like this is to play pink noise over the
speaker in a really reverberent room, and listen for
cancellation notches and phasiness.

that seems like a good idea excpet why in a reverberent
room,

The stated goal (Mr. Long's) was to optimize the
speaker's power response, as opposed to its on-axis
response.
I would think you want to use a dead room so any
"phasiness" you might hear would be due to the speakers
and not the room...

In even a medium-sized room, the phasiness due to
crossover problems, and that due to the room, have quite
different sonic signatures.

BTW I want to emphasize the use of pink noise, as a lot of music has
built-in notches and phasiness. Also, the method was supposed to be applied
to just one speaker at a time.

[Scott Dorsey]

Jack wrote:
Scott Dorsey wrote:

You're basically talking about a bunch of random drivers thrown into a
box without any engineering. It isn't going to preserve phase anyway, so
it really doesn't matter how they are wired up. This is not a real speaker,
this is "white van" grade stuff.

God, I don't believe this. When I describe the speakers to an audio
friend of mine, he said he knew this guy that used to sell speakers like
that out the back of a white van.

That guy must have made quite a name for himself.

It's an international combine doing it, and they have been doing it since
the early seventies. Their marketing has changed a little over the years,
but not by much. In fact, one of the regular posters here was an expert
witness against them a few years back.

Oh well.. since I only paid $20 for the pair and the sound compares
favorably with some much pricier Klipsch speakers that I have and like,
I can live with them not being real speakers.

That's sure damning of the Klipsch.

For what it's worth, here's a link to a picture of the front label
around the pots. No other markings:

http://www.flickr.com/photos/27689880@N00/966447434/

This does have the signs of a white van special. The fake frequency range
information should be enough to warn you off. But it sounds like you at
least didn't get the version with the piezo tweeters. The guy who owned
our local Vietnamese restaurant got scammed with a pair of the carpet-padded
ones with the piezo tweeters... it was like having nails jammed in your ears
listening to those...
--scott



--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Jack wrote:
Scott Dorsey wrote:

This speaker is not that way, but in fact this speaker isn't designed so
much as tossed together. This speaker isn't going to preserve phase
across the passband anyway, so it probably doesn't matter much how the
individual drivers are wired up.
And, in fact, I could not tell the difference with the mids wired
forward or backward.

Right, which is a sign these speakers are not even vaguely phase coherent.

Me being deaf in one ear doesn't help, either.

Doesn't matter, you should be able to judge group delay and comb filtering
problems just as easily with one ear. My wife has one ear, and she is
remarkably good at that. She can't judge imaging at all, though, and she
even has problem with height cues, which you'd think you'd only need one
ear for.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Arny Krueger wrote:

BTW the *right way* to check the polarity of drivers in a speaker like this
is to play pink noise over the speaker in a really reverberent room, and
listen for cancellation notches and phasiness.

At least that what I recall Jim Long saying when he was delivering papers
in the 70s about this interesting effect.

That's an okay way. Looking at square wave response on a scope is better,
but requires a measurement mike that is pretty decent. It's fascinating
to watch how it changes off-axis too.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Bill Dunkenfield]

Jack wrote:

Bill Dunkenfield wrote:
Preben Friis wrote:


The only thing I can add is that there is a big difference between
ground and common. I seriously doubt that any of this equipment is
connected to ground.

JAM

The word "ground" is used synonymously with the word "common" where I am
from.

Must be a very confusing place.

Mixing the two in actual circuits can cause all kinds of trouble.

JAM

[William Sommerwerck]

About 10 years ago I was accosted by such a seller in an
Office Despot parking lot. When I told him that I owned
Apogee speakers -- and what they cost -- he practically
screamed at me: "You bleeping own speakers that
cost as much as a used car?" He was not a happy fellow.

I'm surprised he knew what Apogees are and cost.

He didn't. I told him.

[Scott Dorsey]

Bill Dunkenfield wrote:
Jack wrote:

Bill Dunkenfield wrote:
Preben Friis wrote:

The only thing I can add is that there is a big difference between
ground and common. I seriously doubt that any of this equipment is
connected to ground.

The word "ground" is used synonymously with the word "common" where I am
from.

Must be a very confusing place.

Mixing the two in actual circuits can cause all kinds of trouble.

We got ground, local ground, chassis ground, earth, safety ground,
analogue signal ground, digital signal ground, module ground, unit
ground. Which one is ground?
--scott

| | |
His ----- is my | which is your -----
///// - ---
-
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Arny Krueger]

"William Sommerwerck" wrote in
message
About 10 years ago I was accosted by such a seller in an
Office Despot parking lot. When I told him that I owned
Apogee speakers -- and what they cost -- he practically
screamed at me: "You bleeping own speakers that
cost as much as a used car?" He was not a happy fellow.

I'm surprised he knew what Apogees are and cost.

He didn't. I told him.

Right, you said that the first time. I just didn't read it.

[Arny Krueger]

"Scott Dorsey" wrote in message

Arny Krueger wrote:

BTW the *right way* to check the polarity of drivers in
a speaker like this is to play pink noise over the
speaker in a really reverberent room, and listen for
cancellation notches and phasiness.

At least that what I recall Jim Long saying when he was
delivering papers in the 70s about this interesting
effect.

That's an okay way. Looking at square wave response on a
scope is better, but requires a measurement mike that is
pretty decent.

It also requires either a strong stomach or a speaker that is already pretty
good.

It's fascinating to watch how it changes
off-axis too. --scott

BTW, I got my Longs wrong. I was thinking of Edward M. Long, not Jim Long
of EV.

E.M. Long developed these ideas and methods while working for Pacific
Stereo, of all people. My comments are based on his lecture at a Midwest
Acoustics conference.

[Matt Ion]

Jack wrote:

I'll bet there's a book in there somewhere, if only someone would write it.

Nah... you'd only be able to sell it out the back of a white van

Oddly enough, the last time I was hit up by some of these "white van"
guys, they were driving a red Caravan. Guess they're trying to go
incognito.

[Bill Dunkenfield]

Scott Dorsey wrote:

Bill Dunkenfield wrote:
Jack wrote:

Bill Dunkenfield wrote:
Preben Friis wrote:


The word "ground" is used synonymously with the word "common" where I am
from.

Must be a very confusing place.

Mixing the two in actual circuits can cause all kinds of trouble.

We got ground, local ground, chassis ground, earth, safety ground,
analogue signal ground, digital signal ground, module ground, unit
ground. Which one is ground?
--scott

| | |
His ----- is my | which is your -----
///// - ---
-
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

It depends on whether the conductor is carrying power supply current,
signal current, noise current, no current or carrying current only in a
fault condition.

JAM

[William Sommerwerck]

About 10 years ago I was accosted by such a seller in an
Office Despot parking lot. When I told him that I owned
Apogee speakers -- and what they cost -- he practically
screamed at me: "You bleeping own speakers that
cost as much as a used car?" He was not a happy fellow.

I'm surprised he knew what Apogees are and cost.

He didn't. I told him.

Right, you said that the first time. I just didn't read it.

I'm just as guilty. I sometimes delete mail I was about to send because a
re-read shows that I misread the original.

[jakdedert]

Scott Dorsey wrote:
Bill Dunkenfield wrote:
Jack wrote:
Bill Dunkenfield wrote:
Preben Friis wrote:
The only thing I can add is that there is a big difference between
ground and common. I seriously doubt that any of this equipment is
connected to ground.
The word "ground" is used synonymously with the word "common" where I am
from.
Must be a very confusing place.

Mixing the two in actual circuits can cause all kinds of trouble.

We got ground, local ground, chassis ground, earth, safety ground,
analogue signal ground, digital signal ground, module ground, unit
ground. Which one is ground?

Right under your feet...what the grass is growing out of.

g

jak

--scott

| | |
His ----- is my | which is your -----
///// - ---
-

[jakdedert]

Jack wrote:
jakdedert wrote:
snip


Lastly, the drivers themselves are often deficient and can be replaced
with matched units of higher quality.

At this point, we're talking about building a speaker set from scratch.

Well, that's kind of the point. There's rarely much of any real use in
speakers of that ilk.

I like the concrete idea. Form 'em up and pour 'em in place.

Yeah, that's what they're good for: concrete forms (or molds, as it
were)....
g
jak

[Paul Stamler]

"Mr.T" MrT@home wrote in message
u...
The question I have arises from how the mids are wired. The woofers
have
a '+' and '-' stamped near the connector lugs, so its easy to tell
which
wire goes where inside the cabinet. The mids have a red band near one
lug and the tweeters have a red dot near one lug. I am assuming that
red
means hot or positive and 'no red' means ground or minus. The confusion
arises from the fact that the grounds coming from the amp are connected
to the red side of the connector lugs on the mids. The tweeters have
the
hot, or positive, wire connected to the red side and the woofers have
the hot, or positive, wire connected to the side stamped with the '+'.

This would be correct wiring for a real 12dB/octave crossover. Of course,
these speakers don't have that, so they're wired wrong.

You're basically talking about a bunch of random drivers thrown into a
box without any engineering. It isn't going to preserve phase anyway,
so
it really doesn't matter how they are wired up. This is not a real
speaker,
this is "white van" grade stuff.

Yep.

Peace,
Paul

[Paul Stamler]

"Scott Dorsey" wrote in message
...

This does have the signs of a white van special. The fake frequency range
information should be enough to warn you off. But it sounds like you at
least didn't get the version with the piezo tweeters. The guy who owned
our local Vietnamese restaurant got scammed with a pair of the
carpet-padded
ones with the piezo tweeters... it was like having nails jammed in your
ears
listening to those...

A pot of boiling pho poured into the tweeters should help.

Peace,
Paul