Testing that speakers in phase?
 

In article ,
Eeyore wrote:


David Looser wrote:

"GSV Three Minds in a Can" wrote

Sure it can. You just need something around 0.1hz.

You won't get 0.1Hz through an audio amplifier!

You won't get 0.1Hz through a speaker either !

You may not hear it but should be able to see it. After all a speaker
reacts to DC.

Graham

--
*OK, who stopped payment on my reality check?

Dave Plowman London SW
To e-mail, change noise into sound.

Testing that speakers in phase?
 

Terry Pinnell wrote:
Could someone remind me of the simple test involving placing 'left'
and 'right' speakers close together facing each other please? Am I
right in recalling that they are in correct 'phase' when the volume
sounds reduced/muffled? Or is it the reverse?

(I have some cable extensions to do on the speakers that came with my
new PC, and both wires are identical, so I want to be sure I get it
right.)

Terry,
Cable with absolutely no polarity identification is unusual, though not
impossible to find. In some cases the identification is not obvious and
can be something like a rib on one side that may just look like a flash
from a moulding process.
Roger Thorpe

Testing that speakers in phase?
 

"Don Pearce" wrote in message
...
On Tue, 06 May 2008 08:10:28 +0100, Eeyore
wrote:



David Looser wrote:

"GSV Three Minds in a Can" wrote

Sure it can. You just need something around 0.1hz.

You won't get 0.1Hz through an audio amplifier!

You won't get 0.1Hz through a speaker either !

Graham

Fan-based subwoofers will do it.

What's a "fan-based" subwoofer?, and what will they "do"?

David.

Testing that speakers in phase?
 

On Tue, 6 May 2008 10:41:03 +0100, "David Looser"
wrote:

"Don Pearce" wrote in message
...
On Tue, 06 May 2008 08:10:28 +0100, Eeyore
wrote:



David Looser wrote:

"GSV Three Minds in a Can" wrote

Sure it can. You just need something around 0.1hz.

You won't get 0.1Hz through an audio amplifier!

You won't get 0.1Hz through a speaker either !

Graham

Fan-based subwoofers will do it.

What's a "fan-based" subwoofer?, and what will they "do"?

David.


A rotating fan with variable pitch blades whose angle is modulated by
the bass signal. What they will do is reproduce 0.1Hz quite nicely.

d

--
Pearce Consulting
http://www.pearce.uk.com

Testing that speakers in phase?
 

"Don Pearce" wrote in message
...
On Tue, 6 May 2008 10:41:03 +0100, "David Looser"
wrote:

"Don Pearce" wrote in message
...

Fan-based subwoofers will do it.

What's a "fan-based" subwoofer?, and what will they "do"?

David.


A rotating fan with variable pitch blades whose angle is modulated by
the bass signal. What they will do is reproduce 0.1Hz quite nicely.


Is this something you've just invented? because it seems utterly pointless
to me. And I don't know what you mean by "reproduce". 0.1Hz isn't "sound" by
any stretch of the imagination, it cannot be heard, and is actually too low
a frequency even to be readily sensed as movement. The only sort of device I
can imagine that will "reproduce" 0.1Hz, in the sense of doing something
that a human could detect (other than by sight), would be a moving platform.

David.
..

Testing that speakers in phase?
 

On Tue, 6 May 2008 11:05:28 +0100, "David Looser"
wrote:

"Don Pearce" wrote in message
...
On Tue, 6 May 2008 10:41:03 +0100, "David Looser"
wrote:

"Don Pearce" wrote in message
...

Fan-based subwoofers will do it.

What's a "fan-based" subwoofer?, and what will they "do"?

David.


A rotating fan with variable pitch blades whose angle is modulated by
the bass signal. What they will do is reproduce 0.1Hz quite nicely.


Is this something you've just invented? because it seems utterly pointless
to me. And I don't know what you mean by "reproduce". 0.1Hz isn't "sound" by
any stretch of the imagination, it cannot be heard, and is actually too low
a frequency even to be readily sensed as movement. The only sort of device I
can imagine that will "reproduce" 0.1Hz, in the sense of doing something
that a human could detect (other than by sight), would be a moving platform.

David.
.


Isn't everything ultimately pointless? And by reproduce I mean "cause
to be present in the listening environment". I mean, does a Hi Fi make
any noise if there is nobody there to hear it?

Anyway, you can read about it here. Some interesting links to follow
too.

http://www.eminent-tech.com/RWbrochure.htm

d
--
Pearce Consulting
http://www.pearce.uk.com

Testing that speakers in phase?
 

Bitstring , from the wonderful
person David Looser said
"GSV Three Minds in a Can" wrote in message
...
Bitstring , from the wonderful person
David Looser said
"GSV Three Minds in a Can" wrote in message
...

Sure it can. You just need something around 0.1hz.

You won't get 0.1Hz through an audio amplifier!

Who was talking about using an audio amp?

That's what this thread was about. We were talking about speaker phase, and
speakers are only ever driven by audio amplifiers!

Nope, speakers are driven by whatever you connect to them. A Battery
works fine.

I was musing between a frequency generator, and maybe just a battery and
switch. I did say it was a dumb idea though, since you can only test at
the terminals on the back on the speaker (unless you knock it to pieces),
and with cheap speakers they are just as likely to be mis-wired inside.

Well it IS a dumb idea, a particularly dumb idea, but not for that reason.
I've never come across mis-wired speakers and frankly I don't believe that
any factory-made speakers, even the very cheapest, would have the two
speakers of a stereo pair wired differently.

Believe what you like .. just don't visit any Chinese factories.

--
GSV Three Minds in a Can
11,517 Km walked. 2,259 Km PROWs surveyed. 40.9% complete.

Testing that speakers in phase?
 

"GSV Three Minds in a Can" wrote in message
...

Believe what you like .. just don't visit any Chinese factories.


So do you have any anecdotes of pairs of speakers with opposite connections?

David.

Testing that speakers in phase?
 

"Don Pearce" wrote in message
...

Isn't everything ultimately pointless?

No, I don't think so!

And by reproduce I mean "cause (what?)
to be present in the listening environment". I mean, does a Hi Fi make
any noise if there is nobody there to hear it?

Ah, that old chestnut!

Anyway, you can read about it here. Some interesting links to follow
too.

http://www.eminent-tech.com/RWbrochure.htm


Well I stand corrected, it does exist, interesting beast!. But I notice that
the hearing threshold crosses it's maximum output at around 3Hz, so it
doesn't "do it" below that frequency, certainly not at 0.1Hz.

David.

Testing that speakers in phase?
 

In article ,
David Looser wrote:
"GSV Three Minds in a Can" wrote in message
...

Believe what you like .. just don't visit any Chinese factories.


So do you have any anecdotes of pairs of speakers with opposite connections?

My Spendor BC1s (early '70s) came with one HF1300 connected in the wrong
phase. Very difficult to put 'your finger on' by listening as the
crossover frequency is so high.

If I remember correctly they are designed to have the HF 1300 wired out of
phase with the bass unit.

--
*OK, so what's the speed of dark? *

Dave Plowman London SW
To e-mail, change noise into sound.