How do the sound of negative-wiring speaker?

presscot

Member
2010-07-27 12:24 pm
I’m curious about the sound when I swapped speaker cable, between positive and negative, at speaker terminal. At first, I believed the sound would be the same whatever wired conventionally or reversed polarity. After trial, however, I can hear the different of sound! Could anyone please confirm me that the wiring polarity, at terminal, is matter? Also, I used to see some speaker’s schematics, not sure if they were vintage AR speakers, were put the passive network components on negative line. It would be very helpful if anyone has a microphone setup for doing a frequency swap, please assist to measure the response and phase for both cases. Thanks in advance.
 

Galu

Member
2018-04-17 6:50 pm
Also, I used to see some speaker’s schematics, not sure if they were vintage AR speakers, were put the passive network components on negative line.
The designations 'negative' and 'positive' are a misnomer as the audio input to the speaker terminals is an alternating voltage which is constantly changing in polarity.

Note that, on the attached AR4x crossover circuit, the legends '1' and '2' are more approprately used to designate the input 'lines'.

It makes no difference whether the passive components are in the '1' line or in the '2 line'.

For example, the inductor in series with the bass driver could equally be placed in front of the bass driver as behind i.e. in the '2' line instead of the '1' line.

An added complication of the attached crossover is that the tweeter is connected in reverse phase compared to the bass driver i.e. the + terminal of the tweeter is connected in the '1' line while the + terminal of the bass driver is connected in the '2' line.

(You should be aware that the + terminal on a driver indicates that its cone or dome will move in the forward direction when a positive going voltage is applied to that terminal.)

Confused? I wouldn't blame you if you were! :D
 

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Although total sum of the music signal is zero (positive plus negative portion of the wave), some listeners may be sensitive to the absolute polarity of the music signal. Some musical instruments produce asymmetrical acoustic wave-forms.
Multi-way loudspeakers may have different (mixed) polarity of the drivers, obscuring this effect. Single fullrange loudspeakers (or headphones) or planar (ESL, magneplanar) speakers are the only choice for testing this.
 
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diyiggy

Member
2019-01-16 12:22 am
Is it related to the claim some designers always try to use the positive terminals of the drivers just with the positive of the binding post, I mean to avoid to reverse a drivervis a vis the overs unit while it's limiting the choice of slope and order choices ?
 
The debate whether the absolute phase (or polarity) can be recognized or not is ages old and will probably never come to an end. Personally, I rather doubt it, but don't want to rule it out completely under all circumstances. Sonce has pointed out the one reason why it could make a difference, at least in theory.

Trouble is, you cannot even be sure that all the other components in your equipment do preserve the absolute phase. There have been living examples of amplifiers that do reverse polarity (although I cannot name one from the top of my head). The same goes for recording equipment used in the studio. Hell, what if some tracks have been recorded with "correct" polarity and some have not?

The example provided by Galu is not a rare one. Depending on filter order and type, tweeters and/or midrange drivers rather often must be reversed in polarity to achieve a flat response at the crossover frequency. This soon leads to further questions of if and how an unsteady phase response is recognizable. Some believe that multi-way speakers are generally not able to reproduce music faithfully for such reasons ... ;)

All in all, this is a typical case of "it's not worth it", at least in my book. Just make sure to not reverse the polarity of just one speaker, as Bill Coltrane has explained in powerful words.


Here's a little fun experiment:
Reverse the polarity of just one tweeter. Some listeners will be taken away by the "airy" and "spacious" representation. :) This is a BS test, of course, but can be entertaining as a reality check.
 
The debate whether the absolute phase (or polarity) can be recognized or not is ages old]

Some can perceive absolute phase, particularily evident in percussion instruments, and if you switch and it sounds better, then good. But keep in. ind that with each recording — even if it preserves absolute phase — could be in a different direction. If absolute phase is somethign important to you, you need a handy switch (like on a remote) so that each album can be checked and marked as to the way it sounds best.

dave
 

presscot

Member
2010-07-27 12:24 pm
After read on all comments, I had gone further for a test. I tried to swap all of the polarity of the drivers in my speaker - it’s a commercial one, not diy, and a 3-way configuration. The original polarity connections are as follows:

Tweeter: -
Midrange: +
Woofer: +

Note: Calling it + if the positive terminal of the driver is connected to positive terminal of the network.

You won’t believe that once reversing the connections;

Tweeter: +
Midrange: -
Woofer: -

The sound is big different! I affirm. You probably believe my ears because I have did it many times to ensure.

This is for your information. What do all of you think?
 

jdarg

Member
2005-08-27 4:52 pm
You can switch polarity instantaneously if using PC with the right app or something like a minidsp (these switch slower though.) There is absolutely a difference but I don't think I'd ever be able to pick one from the other in a dbt unless I trained myself on that particular piece of music first. Then I'm pretty sure I could after a bit.

Keep in mind the upstream components might flip absolute polarity too. So connecting it to the amp as indicated might actually be reversed unless you verify the signal at the terminals.
 
I also had tried to do that too and found sound different but not as big as reversing on all drivers. I affirm!

Reversing the polarity of all the drivers is EXACTLY the same as reversing the connections at the input terminal...no difference at all, so if you heard a difference, it originated between your ears, not outside of them.

Mike