'correct' driver polarity doesn't agree with my ears...

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According to the Stereophile article I cited, the higher-caliber the speaker, the harder it is to distinguish the correct vs the incorrect polarity. They surmised the reason is that lesser speakers introduce their own asymmetry, which is audible. The best speakers exhibit highly symmetrical behaviour, and it becomes hard to distinguish the polarity. They concluded that in and of itself, the ear cannot hear absolute polarity, what is heard instead is the imperfection of the speaker. (Otherwise it can't explain the fact that they couldn't tell polarity with the best speakers, but they could with lesser ones.)

The moment I uttered it, that no evidence exists to confirm audibility of absolute polarity other than what Stereophile found, I knew it - it was a highly controversial topic, and certainly going to attract a good debate. I enjoy debating with intelligent people such as all of you, so thank you! But think of this: Stereophile is advocacy for an industry which makes money out of a "difference" no matter that "difference" is really audible or not, so it is unusual for them to say the ear cannot hear absolute phase, and if it could what you are really hearing is a speaker imperfection. If even them says so, they must be onto something.

And if you can tell polarity by listening your speakers are not symmetrical enough and should be upgraded.
 
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To be honest, some threads are so weird and full of inaccuracies to my strictly Mathematical Mind that I just sit on the sidelines and eat popcorn!

But this one I cannot resist! :D

Here's my testbed of experiment:

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This to the interested student of loudspeakers is a LR4 crossover. It does the usual LR4 thing of low distortion and strict phase alignment:

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Because I am interested, I just wired the tweeter in opposite polarity, AKA out of phase. 5 minutes work made easy by the sensible Morel convention of the tweeter spade connectors being identical. How did it sound? :confused:

The theory says it has a huge hole in frequency response around 3kHz. Below diagram.

How did it sound? TBH, not bad. But a bit hollow IMO on orchestra. I noticed certain notes on violin arpeggio went completely missing. :boggled:

But I have a very highly trained musical ear. And I know what the live sound sounds like. Most of you just don't know what to listen for. :cool:
 

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FWIW, Here are my definitions and thoughts on polarity (and phase)

"Absolute" polarity....simply means a (+) pulse makes driver moves outwards, away from coil. Acoustic polarity.
Note that the (+) pulse is at the driver terminals, and is the sum of crossover phase combined with original drive polarity.
Which means, drive polarity must often be reversed to maintain a (+) pulse, depending on xover type and order.

Relative polarity....simply means all drivers or speakers are in "absolute" polarity or not.
This is where most folks debate about polarity...between separate speakers, or between drivers.
It's really simple stuff, but it totally matters, pls see thoughts below...


Thoughts.....
If all drivers or speakers are in "absolute" polarity, or all are in "inverse absolute polarity"......... is entirely immaterial...both are acoustically and audibly equivalent.

What matters is whether all drivers or speakers share the same acoustic polarity. This is relative acoustic polarity, and is entirely audible.

Polarity and phase, are entwined to the point of inseparability. Polarity is simply a relatively coarse 180 degree expression of phase.
The truest expression of phase alignment is when the initial rise time of all frequencies occurs at the identical time. IOW, all frequencies begin their initial outward pulse together (or inward pulse together ;))
IME, this degree of phase alignment is very audible and rare.
 
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Natural sounds particularly voice have peaks asymmetry.
The initial peak describes direction and enables us to locate sound sources.
This absolute polarity property is clearly and always audible on the right speakers.


Dan.

Dan,

Natural sounds are asymmetrical, of course. However, the mirror image of that asymmetry sounds just as sweet.

The ear is excellent at timing when a sound arrives. It is not so good at telling apart whether that arrival is a rarefaction or a compression. If you study the anatomy of the cochlea and how the hair cells work, then it is going to make sense to you why this is so. (There are specific hair cells for different frequencies and they only tell the brain if a frequency is present or not, it does not tell the brain if it is a compression or a rarefaction. The ear is no oscilloscope, and there is no evolutionary advantage to be able to tell absolute polarity apart.)
 
As soon as your mic is a foot from the violin, the phases across the tone compass get rotated differently. Isn't that perfectly obvious to all? Not to mention that between the mic diaphragm and your speaker terminals, there are possibly thousands of non-linear silicon junctions and much else besides, not to mention a recording engineer who has been exposed to damaging sound levels for many years and never had the nerve to get tested.

While you can picture a highly asymmetric pressure pulse from a cymbal, nothing like that in the train of sine waves of which it is composed. While I have also heard reports like krivium's about the violin player* (or other instruments too), I think its pretty hard to reject cyberstudio's basic premise and his explanations why one polarity might comes across as better, more accurate, or more pleasing some of the time with some drivers.

I've spent a lot of time measuring and listening to polarity choices for subs at 140 Hz and not located too close to the main speakers. I don't think I ever found one polarity definitively better in all respects than another. Talking of mid-ranges is different than subs but the room isn't less of an influence.

Given that measuring an FR with REW tells you only part of the story of perceptual FR, I'd say it is entirely plausible that somebody in some room would prefer a mid-range with the wrong polarity and even say it sounds more like their really-hard-to-define memory of "real instruments" than does the right polarity. In all my years of listening to quality systems, I've never thought there was even just little flute or recorder playing in my room**... even if people listening to Edison cylinders did.

Really a pity there's no acoustic sub-forum yet.

B.
*I guess it didn't occur to krivium (who I truly respect) that the last person who can tell you what a "real" violin sounds like is a person who listens 5 hours a day from 2 inches above the sound box
** I have thought there were real satisfying recordings of instruments and even the gigantic band, large chorus, and soloists in Mahler's 2nd Sym playing in my room
 
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Hi,
Ben, it did occurs to me but i have a different approach about the 'all actors of pro audio are deaf' ( engineers, musicians,etc,etc,...) than yours.
We could talk about it but not here as it is far off topic ( and i don't think this would interest most or there is a dedicated place to do so, maybe we'll do in pm ).

I'm not thinking that Cyberstudio reasoning is wrong, my remark (as pointed by Earlk) was just that phase and absolute polarity should not be mixed for ease of understanding or if done with the correct words designing each case.

Anyway i may kept my collection of 'weirdos or wtf' anecdoct ( i've got a lot of them about individuals 'super powers' in audio, ranging from people not hearing some defined notes, to the girl which hear the bats comings!).
Those are not the norm in any ways and as interesting they are ( because they make you think about what happen or not) they don't help discussion.

This is interesting in how the Audiophile argicle is interpreted by different people.
For me it is a case of more money spent makes a problem a non issue! Spend more money ( on adviced brands within the article!).
;)
 
@System7: ... wouldn't the LR4 crossover introduce an impedance peak at the crossover point?
Yup, a good observation. But not in this case. The 8" bass is not flat at 3kHz. It's already rolling off mechanically so needs more power.

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This is actually old hat. The BBC Rogers LS5-9 used this sort of impedance corrected Zobel network 30 years ago. Doesn't much matter if you do it LR4 or BW3 negative polarity. It ends up pretty flat impedance. Michael Chua reinvented it recently: Seas ER18RNX with 27TDFC

Very amp friendly IMO. Sounds good. TBH, I haven't decided if I prefer third order BW3 or fourth order LR4 on the tweeter, but I'm veering towards BW3. The bass is second order. The BW3 can have the +3dB peak, but it sounds OK. Power response matters as much as frequency response IMO.

IMO, if you get polarity wrong, the imaging goes wrong. It sounds phasey. I have no idea what Sage12 is talking about here. A hit and run post. If it's a BW3 design, phase doesn't matter. Only the lobing above and below axis changes. My current negative polarity 8" designs sound better below axis.
 

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Here's an example of EQ I have to apply to make my 3 ways listenable on bright / forward recordings.

The top example applied to R.E.M's greatest hits works well

The 2nd example - one of the BBC dip flavours works well on a variety of 80s compressed rock and pop.

The images were taken from Equalizer APO (on windows). This great piece of software allows you to run and combine multiple equalizers (fixed or variable bands) and also notch filters (fixed or varying Q):
Equalizer APO download | SourceForge.net

Highly recommend this if you want to isolate problematic frequencies or source material.

The Q notch filter is great as you can dial up or down the frequency as you play a problematic track to "Centre" on the frequency of most annoyance.
 

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