On 18 Jan 2004 23:27:18 GMT, (Nousaine) wrote:



As Arny Krueger mentioned we have a friend who built a DIY unit dating back to
the mid-70s. But as far as commerical products my memory suggests that the
first time I saw one it was called a "Volkswoofer" or something similar and was
being made by M&K and dates back to the late 70s (I think.)

I remember some sub+satelite systems from the Swedish Dux and German
Braun, but that must have been earlier, probably late sixties. Both
units was mono sub if I am not mistaken (Svante, have you seen the Dux
units?), crossed over at some 150-200Hz. I did build one myself, using
a 300 Hz passive filter, but my power amp did not like to parallell
the outputs below 300Hz and went south, with destroyed output
transitors. Twice! Really silly of me.

The data at the time suggested that signals under 300Hz was not
directional, hence the high crossover frequency.

Per.

Per Stromgren wrote in message . ..
I remember some sub+satelite systems from the Swedish Dux and German
Braun, but that must have been earlier, probably late sixties. Both
units was mono sub if I am not mistaken (Svante, have you seen the Dux
units?), crossed over at some 150-200Hz.

Nope. My first contact with subs was DIY projects in various books and
magazines. I built my own first sub in the late 70's at age 16 or
something. It sounded wonderful... I thought. Those were happy,
ignorant days! My first contact with commercial subs was the Audio pro
B2-50.

Per Stromgren wrote in message . ..
I remember some sub+satelite systems from the Swedish Dux and German
Braun, but that must have been earlier, probably late sixties. Both
units was mono sub if I am not mistaken (Svante, have you seen the Dux
units?), crossed over at some 150-200Hz.

Nope. My first contact with subs was DIY projects in various books and
magazines. I built my own first sub in the late 70's at age 16 or
something. It sounded wonderful... I thought. Those were happy,
ignorant days! My first contact with commercial subs was the Audio pro
B2-50.

Per Stromgren wrote in message . ..
I remember some sub+satelite systems from the Swedish Dux and German
Braun, but that must have been earlier, probably late sixties. Both
units was mono sub if I am not mistaken (Svante, have you seen the Dux
units?), crossed over at some 150-200Hz.

Nope. My first contact with subs was DIY projects in various books and
magazines. I built my own first sub in the late 70's at age 16 or
something. It sounded wonderful... I thought. Those were happy,
ignorant days! My first contact with commercial subs was the Audio pro
B2-50.

Per Stromgren wrote in message . ..
I remember some sub+satelite systems from the Swedish Dux and German
Braun, but that must have been earlier, probably late sixties. Both
units was mono sub if I am not mistaken (Svante, have you seen the Dux
units?), crossed over at some 150-200Hz.

Nope. My first contact with subs was DIY projects in various books and
magazines. I built my own first sub in the late 70's at age 16 or
something. It sounded wonderful... I thought. Those were happy,
ignorant days! My first contact with commercial subs was the Audio pro
B2-50.

(Stewart Pinkerton) wrote in message ...
On 18 Jan 2004 13:26:35 -0800, (Svante)
wrote:

(Stewart Pinkerton) wrote in message ...
On 17 Jan 2004 21:32:56 -0800, (Jean) wrote:

Hi everyone

I have several doubts regarding subwoofer and its amplifier

-1- What is the basic difference(in construction,working and
performance) between a subwoofer and an ordinary woofer ?

None, although a subwoofer may reasonably be expected to extend to the
15-20Hz region, whereas a woofer can cut off at 30Hz without disgrace.

Also, a subwoofer rarely works above 100-200 Hz, whereas a woofer
could commonly is used up to 2-4 kHz.

Well, a true woofer, as used in a 3-way speaker, wouldn't be
expected to work much above 3-400 Hz, you are thinking of the
ubiquitous 2-way bass/mid unit.

Yes. Upper limit would be lower in the 3-way design, like you say.

-3- How can I detect a distorted output from a subwoofer ?

Measure or listen. Listening is the only *relevant* test.

Coming from the manufacturer, a THD measurement would be a more
relevant, rather than him/her saying that his/her subwoofer sounds
better than brand yyy.

Agreed, but you very seldom see useful information in that regard.

Mmm... I see what you mean. Still I think measurement has it's place.

-5- Is the shape of the box significant ? Or is that the volume of the
box that matter ?

Volume is what matters, and a cube or sphere are the most logical
shapes.

Sphere??? If shape doesn't matter, why bother making a sphere?

Maximum wall rigidity for any given material and wall thickness.
Agreed a cube is *much* simpler!

Assuming symmetrical excitation, yes. But in the case where the driver
is actually mounted in the ("surface" of the) sphere, resonances can
occur propagating from the mounting point.
BTW, my teacher in electroacoustics once suggested to me that a
"bass-reflex" speaker could be built using a rubber sphere, where the
entire case would be a passive radiator. I don't think he ever built
it.

(Stewart Pinkerton) wrote in message ...
On 18 Jan 2004 13:26:35 -0800, (Svante)
wrote:

(Stewart Pinkerton) wrote in message ...
On 17 Jan 2004 21:32:56 -0800, (Jean) wrote:

Hi everyone

I have several doubts regarding subwoofer and its amplifier

-1- What is the basic difference(in construction,working and
performance) between a subwoofer and an ordinary woofer ?

None, although a subwoofer may reasonably be expected to extend to the
15-20Hz region, whereas a woofer can cut off at 30Hz without disgrace.

Also, a subwoofer rarely works above 100-200 Hz, whereas a woofer
could commonly is used up to 2-4 kHz.

Well, a true woofer, as used in a 3-way speaker, wouldn't be
expected to work much above 3-400 Hz, you are thinking of the
ubiquitous 2-way bass/mid unit.

Yes. Upper limit would be lower in the 3-way design, like you say.

-3- How can I detect a distorted output from a subwoofer ?

Measure or listen. Listening is the only *relevant* test.

Coming from the manufacturer, a THD measurement would be a more
relevant, rather than him/her saying that his/her subwoofer sounds
better than brand yyy.

Agreed, but you very seldom see useful information in that regard.

Mmm... I see what you mean. Still I think measurement has it's place.

-5- Is the shape of the box significant ? Or is that the volume of the
box that matter ?

Volume is what matters, and a cube or sphere are the most logical
shapes.

Sphere??? If shape doesn't matter, why bother making a sphere?

Maximum wall rigidity for any given material and wall thickness.
Agreed a cube is *much* simpler!

Assuming symmetrical excitation, yes. But in the case where the driver
is actually mounted in the ("surface" of the) sphere, resonances can
occur propagating from the mounting point.
BTW, my teacher in electroacoustics once suggested to me that a
"bass-reflex" speaker could be built using a rubber sphere, where the
entire case would be a passive radiator. I don't think he ever built
it.

(Stewart Pinkerton) wrote in message ...
On 18 Jan 2004 13:26:35 -0800, (Svante)
wrote:

(Stewart Pinkerton) wrote in message ...
On 17 Jan 2004 21:32:56 -0800, (Jean) wrote:

Hi everyone

I have several doubts regarding subwoofer and its amplifier

-1- What is the basic difference(in construction,working and
performance) between a subwoofer and an ordinary woofer ?

None, although a subwoofer may reasonably be expected to extend to the
15-20Hz region, whereas a woofer can cut off at 30Hz without disgrace.

Also, a subwoofer rarely works above 100-200 Hz, whereas a woofer
could commonly is used up to 2-4 kHz.

Well, a true woofer, as used in a 3-way speaker, wouldn't be
expected to work much above 3-400 Hz, you are thinking of the
ubiquitous 2-way bass/mid unit.

Yes. Upper limit would be lower in the 3-way design, like you say.

-3- How can I detect a distorted output from a subwoofer ?

Measure or listen. Listening is the only *relevant* test.

Coming from the manufacturer, a THD measurement would be a more
relevant, rather than him/her saying that his/her subwoofer sounds
better than brand yyy.

Agreed, but you very seldom see useful information in that regard.

Mmm... I see what you mean. Still I think measurement has it's place.

-5- Is the shape of the box significant ? Or is that the volume of the
box that matter ?

Volume is what matters, and a cube or sphere are the most logical
shapes.

Sphere??? If shape doesn't matter, why bother making a sphere?

Maximum wall rigidity for any given material and wall thickness.
Agreed a cube is *much* simpler!

Assuming symmetrical excitation, yes. But in the case where the driver
is actually mounted in the ("surface" of the) sphere, resonances can
occur propagating from the mounting point.
BTW, my teacher in electroacoustics once suggested to me that a
"bass-reflex" speaker could be built using a rubber sphere, where the
entire case would be a passive radiator. I don't think he ever built
it.

(Stewart Pinkerton) wrote in message ...
On 18 Jan 2004 13:26:35 -0800, (Svante)
wrote:

(Stewart Pinkerton) wrote in message ...
On 17 Jan 2004 21:32:56 -0800, (Jean) wrote:

Hi everyone

I have several doubts regarding subwoofer and its amplifier

-1- What is the basic difference(in construction,working and
performance) between a subwoofer and an ordinary woofer ?

None, although a subwoofer may reasonably be expected to extend to the
15-20Hz region, whereas a woofer can cut off at 30Hz without disgrace.

Also, a subwoofer rarely works above 100-200 Hz, whereas a woofer
could commonly is used up to 2-4 kHz.

Well, a true woofer, as used in a 3-way speaker, wouldn't be
expected to work much above 3-400 Hz, you are thinking of the
ubiquitous 2-way bass/mid unit.

Yes. Upper limit would be lower in the 3-way design, like you say.

-3- How can I detect a distorted output from a subwoofer ?

Measure or listen. Listening is the only *relevant* test.

Coming from the manufacturer, a THD measurement would be a more
relevant, rather than him/her saying that his/her subwoofer sounds
better than brand yyy.

Agreed, but you very seldom see useful information in that regard.

Mmm... I see what you mean. Still I think measurement has it's place.

-5- Is the shape of the box significant ? Or is that the volume of the
box that matter ?

Volume is what matters, and a cube or sphere are the most logical
shapes.

Sphere??? If shape doesn't matter, why bother making a sphere?

Maximum wall rigidity for any given material and wall thickness.
Agreed a cube is *much* simpler!

Assuming symmetrical excitation, yes. But in the case where the driver
is actually mounted in the ("surface" of the) sphere, resonances can
occur propagating from the mounting point.
BTW, my teacher in electroacoustics once suggested to me that a
"bass-reflex" speaker could be built using a rubber sphere, where the
entire case would be a passive radiator. I don't think he ever built
it.

On Mon, 19 Jan 2004 00:56:38 GMT, (gregs)
wrote:

The first separate woofer I remember was a JBL unit, a 3 piece set.
The woofer crossed over at 70 Hz. Probably didn't go much lower than 40 Hz
which typical woofers go. Later 70's.

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Kal

On Mon, 19 Jan 2004 00:56:38 GMT, (gregs)
wrote:

The first separate woofer I remember was a JBL unit, a 3 piece set.
The woofer crossed over at 70 Hz. Probably didn't go much lower than 40 Hz
which typical woofers go. Later 70's.

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Kal

On Mon, 19 Jan 2004 00:56:38 GMT, (gregs)
wrote:

The first separate woofer I remember was a JBL unit, a 3 piece set.
The woofer crossed over at 70 Hz. Probably didn't go much lower than 40 Hz
which typical woofers go. Later 70's.

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Kal

On Mon, 19 Jan 2004 00:56:38 GMT, (gregs)
wrote:

The first separate woofer I remember was a JBL unit, a 3 piece set.
The woofer crossed over at 70 Hz. Probably didn't go much lower than 40 Hz
which typical woofers go. Later 70's.

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Kal

"Kalman Rubinson" wrote in message

On Mon, 19 Jan 2004 00:56:38 GMT, (gregs)
wrote:

The first separate woofer I remember was a JBL unit, a 3 piece set.
The woofer crossed over at 70 Hz. Probably didn't go much lower than
40 Hz which typical woofers go. Later 70's.

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Right, thanks for the memory jog. Of course the w\Weathers shared bass
speaker wasn't really a subwoofer. It was called a shared bass unit as I
recall.

The Infinity Servo-static sywstem included what I'd call a true subwoofer
and is dated to 1975 by
http://www.audiocircuit.com/9041-esl...ty-INF/9041CMI
NF.htm.

But, I clearly remember auditioning them years at least a couple of before
that.

This source
http://oellerer.net/infinity_classic...o_static_i.htm
l
says 1968, which seems more like it. I first heard a set in 1970 or 1971.

"Kalman Rubinson" wrote in message

On Mon, 19 Jan 2004 00:56:38 GMT, (gregs)
wrote:

The first separate woofer I remember was a JBL unit, a 3 piece set.
The woofer crossed over at 70 Hz. Probably didn't go much lower than
40 Hz which typical woofers go. Later 70's.

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Right, thanks for the memory jog. Of course the w\Weathers shared bass
speaker wasn't really a subwoofer. It was called a shared bass unit as I
recall.

The Infinity Servo-static sywstem included what I'd call a true subwoofer
and is dated to 1975 by
http://www.audiocircuit.com/9041-esl...ty-INF/9041CMI
NF.htm.

But, I clearly remember auditioning them years at least a couple of before
that.

This source
http://oellerer.net/infinity_classic...o_static_i.htm
l
says 1968, which seems more like it. I first heard a set in 1970 or 1971.

"Kalman Rubinson" wrote in message

On Mon, 19 Jan 2004 00:56:38 GMT, (gregs)
wrote:

The first separate woofer I remember was a JBL unit, a 3 piece set.
The woofer crossed over at 70 Hz. Probably didn't go much lower than
40 Hz which typical woofers go. Later 70's.

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Right, thanks for the memory jog. Of course the w\Weathers shared bass
speaker wasn't really a subwoofer. It was called a shared bass unit as I
recall.

The Infinity Servo-static sywstem included what I'd call a true subwoofer
and is dated to 1975 by
http://www.audiocircuit.com/9041-esl...ty-INF/9041CMI
NF.htm.

But, I clearly remember auditioning them years at least a couple of before
that.

This source
http://oellerer.net/infinity_classic...o_static_i.htm
l
says 1968, which seems more like it. I first heard a set in 1970 or 1971.

"Kalman Rubinson" wrote in message

On Mon, 19 Jan 2004 00:56:38 GMT, (gregs)
wrote:

The first separate woofer I remember was a JBL unit, a 3 piece set.
The woofer crossed over at 70 Hz. Probably didn't go much lower than
40 Hz which typical woofers go. Later 70's.

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Right, thanks for the memory jog. Of course the w\Weathers shared bass
speaker wasn't really a subwoofer. It was called a shared bass unit as I
recall.

The Infinity Servo-static sywstem included what I'd call a true subwoofer
and is dated to 1975 by
http://www.audiocircuit.com/9041-esl...ty-INF/9041CMI
NF.htm.

But, I clearly remember auditioning them years at least a couple of before
that.

This source
http://oellerer.net/infinity_classic...o_static_i.htm
l
says 1968, which seems more like it. I first heard a set in 1970 or 1971.

On Mon, 19 Jan 2004 12:45:35 -0500, "Arny Krueger"
wrote:

"Kalman Rubinson" wrote in message

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Right, thanks for the memory jog. Of course the w\Weathers shared bass
speaker wasn't really a subwoofer. It was called a shared bass unit as I
recall.

The Infinity Servo-static sywstem included what I'd call a true subwoofer
and is dated to 1975 by
http://www.audiocircuit.com/9041-esl...ty-INF/9041CMI
NF.htm.

But, I clearly remember auditioning them years at least a couple of before
that.

This source
http://oellerer.net/infinity_classic...o_static_i.htm
l
says 1968, which seems more like it. I first heard a set in 1970 or 1971.

Agreed but, of course, the issue then as now is the distinction
between what is a woofer and what is a sub. The Weathers books
probably, iirc, did not get quite to 100Hz, so the 'module' is more
properly a woofer, as you say.

Kal

On Mon, 19 Jan 2004 12:45:35 -0500, "Arny Krueger"
wrote:

"Kalman Rubinson" wrote in message

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Right, thanks for the memory jog. Of course the w\Weathers shared bass
speaker wasn't really a subwoofer. It was called a shared bass unit as I
recall.

The Infinity Servo-static sywstem included what I'd call a true subwoofer
and is dated to 1975 by
http://www.audiocircuit.com/9041-esl...ty-INF/9041CMI
NF.htm.

But, I clearly remember auditioning them years at least a couple of before
that.

This source
http://oellerer.net/infinity_classic...o_static_i.htm
l
says 1968, which seems more like it. I first heard a set in 1970 or 1971.

Agreed but, of course, the issue then as now is the distinction
between what is a woofer and what is a sub. The Weathers books
probably, iirc, did not get quite to 100Hz, so the 'module' is more
properly a woofer, as you say.

Kal

On Mon, 19 Jan 2004 12:45:35 -0500, "Arny Krueger"
wrote:

"Kalman Rubinson" wrote in message

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Right, thanks for the memory jog. Of course the w\Weathers shared bass
speaker wasn't really a subwoofer. It was called a shared bass unit as I
recall.

The Infinity Servo-static sywstem included what I'd call a true subwoofer
and is dated to 1975 by
http://www.audiocircuit.com/9041-esl...ty-INF/9041CMI
NF.htm.

But, I clearly remember auditioning them years at least a couple of before
that.

This source
http://oellerer.net/infinity_classic...o_static_i.htm
l
says 1968, which seems more like it. I first heard a set in 1970 or 1971.

Agreed but, of course, the issue then as now is the distinction
between what is a woofer and what is a sub. The Weathers books
probably, iirc, did not get quite to 100Hz, so the 'module' is more
properly a woofer, as you say.

Kal

On Mon, 19 Jan 2004 12:45:35 -0500, "Arny Krueger"
wrote:

"Kalman Rubinson" wrote in message

I had a similar set made by Weathers back in the early 60s(!!!): Two
book-shaped satellites and a central woofer.

Right, thanks for the memory jog. Of course the w\Weathers shared bass
speaker wasn't really a subwoofer. It was called a shared bass unit as I
recall.

The Infinity Servo-static sywstem included what I'd call a true subwoofer
and is dated to 1975 by
http://www.audiocircuit.com/9041-esl...ty-INF/9041CMI
NF.htm.

But, I clearly remember auditioning them years at least a couple of before
that.

This source
http://oellerer.net/infinity_classic...o_static_i.htm
l
says 1968, which seems more like it. I first heard a set in 1970 or 1971.

Agreed but, of course, the issue then as now is the distinction
between what is a woofer and what is a sub. The Weathers books
probably, iirc, did not get quite to 100Hz, so the 'module' is more
properly a woofer, as you say.

Kal