Bass speaker / reflex cabinet observation

  • Thread starter robin.pain@tesco.net
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robin.pain@tesco.net

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I had suggested that the bass speakers be anti-phase because I
presumed that they would aid and abet each other and thus move more
air.

He tried it and lo, they were audibly quieter even though the cones
were now visibly moving *further*.

So we had a think about it and for the first time I realised that the
point of "Helmholtz resonance" was "impedence matching".

(When the speakers aid and abet, they are stealing each other's load
and cannot impart as much energy into the air).

Robin
 
robin.pain@tesco.net wrote:
I had suggested that the bass speakers be anti-phase because I
presumed that they would aid and abet each other and thus move more
air.

He tried it and lo, they were audibly quieter even though the cones
were now visibly moving *further*.

So we had a think about it and for the first time I realised that the
point of "Helmholtz resonance" was "impedence matching".

(When the speakers aid and abet, they are stealing each other's load
and cannot impart as much energy into the air).

Robin
Click to expand...
What do you want to say? What are your questions? I cannot make any sense of
your post. Maybe you start with a short description of what you were trying
to do.
--
ciao Ban
Bordighera, Italy
 
I read in sci.electronics.design that Ban <bansuri@web.de> wrote (in
<eCBac.127608$z23.5384595@news3.tin.it>) about 'Bass speaker / reflex
cabinet observation', on Wed, 31 Mar 2004:
What do you want to say? What are your questions? I cannot make any sense of
your post. Maybe you start with a short description of what you were trying
to do.
Click to expand...
There is obviously at least one previous post that we haven't seen.
Maybe it went to another newsgroup.

The question is, 'Have we missed anything significant?' (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
"Ban" <bansuri@web.de> wrote in message news:<eCBac.127608$z23.5384595@news3.tin.it>...
robin.pain@tesco.net wrote:
I had suggested that the bass speakers be anti-phase because I
presumed that they would aid and abet each other and thus move more
air.

He tried it and lo, they were audibly quieter even though the cones
were now visibly moving *further*.

So we had a think about it and for the first time I realised that the
point of "Helmholtz resonance" was "impedence matching".

(When the speakers aid and abet, they are stealing each other's load
and cannot impart as much energy into the air).

Robin

What do you want to say? What are your questions? I cannot make any sense of
your post. Maybe you start with a short description of what you were trying
to do.
Click to expand...
Yes, well, too explicit is boring and too implicit is only clear if ya
know already, hence the weirdo style.

This impedance-matching-thing was a big moment for me because
previously I had vaguely assummed that resonance == loud (but how can
it? Energy is conserved) because, probably, it's a general
misconception.

Robin "the patronising bastard" Pain
 
I read in sci.electronics.design that Ken Smith
<kensmith@violet.rahul.net> wrote (in <c4ha4c$uts$3@blue.rahul.net>)
about 'Bass speaker / reflex cabinet observation', on Thu, 1 Apr 2004:
In article <fMKSV5CX3uaAFwps@jmwa.demon.co.uk>,
John Woodgate <noone@yuk.yuk> wrote:
[.. bass speaker..]
The question is, 'Have we missed anything significant?' (;-)

The answer is certainly yes and we will not know what it is until it is
just about to bite us.

I think the OP was remarking "Aha I just discovered something!". He has
discovered one of the basics of speaker design.
Click to expand...
Have they not already been discovered, some of them several times?
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
On Wed, 31 Mar 2004 17:12:07 +0100, John Woodgate wrote:

I read in sci.electronics.design that Ban <bansuri@web.de> wrote (in
eCBac.127608$z23.5384595@news3.tin.it>) about 'Bass speaker / reflex
cabinet observation', on Wed, 31 Mar 2004:
What do you want to say? What are your questions? I cannot make any sense of
your post. Maybe you start with a short description of what you were trying
to do.

There is obviously at least one previous post that we haven't seen.
Maybe it went to another newsgroup.

The question is, 'Have we missed anything significant?' (;-)
Click to expand...
Maybe. When I was maybe 12, just getting into electronics, I read in
a Tab book or some crap RS book that speakers should be driven out
of phase. That made sense to no one I ever mentioed it to and
eventually I saw the opposite in print.

--
Best Regards,
Mike
 
On Thu, 1 Apr 2004 10:56:09 -0500, the renowned Active8
<reply2group@ndbbm.net> wrote:

On Wed, 31 Mar 2004 17:12:07 +0100, John Woodgate wrote:

I read in sci.electronics.design that Ban <bansuri@web.de> wrote (in
eCBac.127608$z23.5384595@news3.tin.it>) about 'Bass speaker / reflex
cabinet observation', on Wed, 31 Mar 2004:
What do you want to say? What are your questions? I cannot make any sense of
your post. Maybe you start with a short description of what you were trying
to do.

There is obviously at least one previous post that we haven't seen.
Maybe it went to another newsgroup.

The question is, 'Have we missed anything significant?' (;-)

Maybe. When I was maybe 12, just getting into electronics, I read in
a Tab book or some crap RS book that speakers should be driven out
of phase. That made sense to no one I ever mentioed it to and
eventually I saw the opposite in print.
Click to expand...
I think that sort of advice should go in one ear and out the other.
But maybe it was good advice when it came to RS speakers of that era.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
I read in sci.electronics.design that Spehro Pefhany <speffSNIP@interlog
DOTyou.knowwhat> wrote (in <1mgo60t4ulj44hu9063c3tersj7dbgbcpv@4ax.com>)
about 'Bass speaker / reflex cabinet observation', on Thu, 1 Apr 2004:

I think that sort of advice should go in one ear and out the other.
Click to expand...
That's PRECISELY why you drive the loudspeakers 'out-of-phase'. If you
didn't, the sound energy would build up in your head and it would
explode. It applies even more to headphones.

I thought that was obvious.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
In article <fMKSV5CX3uaAFwps@jmwa.demon.co.uk>,
John Woodgate <noone@yuk.yuk> wrote:
[.. bass speaker..]
The question is, 'Have we missed anything significant?' (;-)
Click to expand...
The answer is certainly yes and we will not know what it is until it is
just about to bite us.

I think the OP was remarking "Aha I just discovered something!". He has
discovered one of the basics of speaker design.

--
--
kensmith@rahul.net forging knowledge
 
On Thu, 1 Apr 2004 17:36:56 +0100, John Woodgate
<jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Spehro Pefhany <speffSNIP@interlog
DOTyou.knowwhat> wrote (in <1mgo60t4ulj44hu9063c3tersj7dbgbcpv@4ax.com>)
about 'Bass speaker / reflex cabinet observation', on Thu, 1 Apr 2004:

I think that sort of advice should go in one ear and out the other.

That's PRECISELY why you drive the loudspeakers 'out-of-phase'. If you
didn't, the sound energy would build up in your head and it would
explode. It applies even more to headphones.

I thought that was obvious.
Click to expand...
Push-Pull

--

Boris Mohar
 
I read in sci.electronics.design that Boris Mohar <borism_-void-
_@sympatico.ca> wrote (in <j9jo605a5ni9dumiksbd5jib71ptv1pbp2@4ax.com>)
about 'Bass speaker / reflex cabinet observation', on Thu, 1 Apr 2004:
On Thu, 1 Apr 2004 17:36:56 +0100, John Woodgate
jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Spehro Pefhany <speffSNIP@interlog
DOTyou.knowwhat> wrote (in <1mgo60t4ulj44hu9063c3tersj7dbgbcpv@4ax.com>)
about 'Bass speaker / reflex cabinet observation', on Thu, 1 Apr 2004:

I think that sort of advice should go in one ear and out the other.

That's PRECISELY why you drive the loudspeakers 'out-of-phase'. If you
didn't, the sound energy would build up in your head and it would
explode. It applies even more to headphones.

I thought that was obvious.

Push-Pull
Click to expand...
Or the low-cost version, 'shove-heave'. (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
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