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Why does a solo sound sound different when inverted?

EPC

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#1
When soloing sounds and flipping phase, it sounds a little different, what's the reasoning for this?
Should the phase be a 'correct' way for the punchiest sound?
 

threni

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#2
When soloing sounds and flipping phase, it sounds a little different, what's the reasoning for this?
Should the phase be a 'correct' way for the punchiest sound?
Not sure what a "solo sound" is, or the context of your question, but if the phase is wrong on loudspeakers then you run the risk of the soundwaves from the left and right speakers interfering with each other, cancelling/boosting certain frequencies. An effect popular in the '60s but Beethoven probably wouldn't have approved.
 
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EPC

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Thread Starter #3
Not sure what a "solo sound" is, or the context of your question, but if the phase is wrong on loudspeakers then you run the risk of the soundwaves from the left and right speakers interfering with each other, cancelling/boosting certain frequencies. An effect popular in the '60s but Beethoven probably wouldn't have approved.
I probably should have put individual sound
I meant a sound on its own, not the phase relationship between 2 sounds, i.e kick and bass
If you listen on a mono speaker and flip the phase of say, a synth, it sounds slightly different
 

threni

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#4
I probably should have put individual sound
I meant a sound on its own, not the phase relationship between 2 sounds, i.e kick and bass
If you listen on a mono speaker and flip the phase of say, a synth, it sounds slightly different
Sure, what I put makes more sense related to a single, stereo instrument/sound/etc sample.
 
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EPC

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Thread Starter #5
Sure, what I put makes more sense related to a single, stereo instrument/sound/etc sample.
I was under the assumption that because waveform peaks and troughs aren’t parallel, when you flip the phase the speaker is pulling in as apposed to pushing out, and thus sounds slightly different
 

threni

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#6
I was under the assumption that because waveform peaks and troughs aren’t parallel, when you flip the phase the speaker is pulling in as apposed to pushing out, and thus sounds slightly different
In physics it's called "interference". In your example, with a perfect system, you'll cancel out the signal entirely, leaving you with silence. It's how noise cancelling works.
 

LTig

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#7
I probably should have put individual sound
I meant a sound on its own, not the phase relationship between 2 sounds, i.e kick and bass
If you listen on a mono speaker and flip the phase of say, a synth, it sounds slightly different
Run a test with 2 files carrying the same sound but one is inverted. Then do a blind ABX test and post the results.
 
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EPC

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Thread Starter #8
I’m not referring to phase cancellation
I mean, if you have a mono snare, and you’re listening out of 1 single speaker, and you flip the phase of the snare, it sounds different to the original polarity
 
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EPC

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Thread Starter #9
Run a test with 2 files carrying the same sound but one is inverted. Then do a blind ABX test and post the results.
I have tested this many times already, I assume it sounds different because the waveform heights aren’t parallel to the dips, but I didn’t know if there was a term for it
 

anmpr1

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#12
Not sure this is what you mean, however if you Yandex 'Clark Johnson absolute polarity' you can find some history on the question of the audibility of polarity, pro and con. Clark (may he RIP) made somewhat of a splash in the '70s (might have been '80s) claiming that absolute polarity (he called it the 'Wood Effect'--I don't remember why) was a huge issue in home stereo listening, and began at the recording front end. He wrote a self-published book about it. The Stereophile and Absolute Sound gang appreciated his 'important research', others such as the Audio Critic took the position of, "Well, theoretically I guess everything in the recording chain from microphone to mixer to tape recorder to multi-track console to home stereo preamp to amplifier to your loudspeakers ought to be one way, but if it's not you won't hear any overall effect on real music."

I guess if your listening habits turn on solo snare drums and/of hi-hats over a single speaker it might be something important. Otherwise...
 
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EPC

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Thread Starter #13
Not sure this is what you mean, however if you Yandex 'Clark Johnson absolute polarity' you can find some history on the question of the audibility of polarity, pro and con. Clark (may he RIP) made somewhat of a splash in the '70s (might have been '80s) claiming that absolute polarity (he called it the 'Wood Effect'--I don't remember why) was a huge issue in home stereo listening, and began at the recording front end. He wrote a self-published book about it. The Stereophile and Absolute Sound gang appreciated his 'important research', others such as the Audio Critic took the position of, "Well, theoretically I guess everything in the recording chain from microphone to mixer to tape recorder to multi-track console to home stereo preamp to amplifier to your loudspeakers ought to be one way, but if it's not you won't hear any overall effect on real music."

I guess if your listening habits turn on solo snare drums and/of hi-hats over a single speaker it might be something important. Otherwise...
Haha I used that just for an example, but I do regular mixing for people and it is something i've noticed...

You should try it in a DAW, play a sound back on a loop and flip the phase and you will notice one doesn't sound as punchy, it has this like slight sucking sound... hard to explain

It is very very slight
 

anmpr1

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#14
It is very very slight
I think that was the overall conclusion of most people who investigated it. With any reproduced audible effect, generally the simpler the tone(s) the easier it will be to isolate problems.

In a recording venue, with a simple set up, it is easier to control these variables. If you were working for Deutsche Grammophon or RCA in the '70s there was so much electrical wiring in the signal chain that it was probably impossible to make things 'right'. For processed pop it's not even worth talking about! o_O
 

somebodyelse

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#15
There was a long discussion/argument about absolute phase in one of the Topping DAC threads (E30?) complete with synthetic and acoustic test samples, and some theory on what sort of signals it would make a difference to.
 

anmpr1

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#16
An associated 'problem' (I first heard about it from the engineers at Rectilinear--a loudspeaker maker in the '60s) and later Aczel in his magazine was 'pulse coherence' of loudspeaker drivers. That is, the tweeter and mid drivers should both operate in time--a positive pulse from the signal should make both drivers go out, and so forth (I don't think the LF bass was considered that critical). However, later in his career I believe he downplayed that criterion as an important design characteristic, at least in the overall scheme of loudspeaker engineering.
 

tjf

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#17
An associated 'problem' (I first heard about it from the engineers at Rectilinear--a loudspeaker maker in the '60s) and later Aczel in his magazine was 'pulse coherence' of loudspeaker drivers. That is, the tweeter and mid drivers should both operate in time--a positive pulse from the signal should make both drivers go out, and so forth (I don't think the LF bass was considered that critical). However, later in his career I believe he downplayed that criterion as an important design characteristic, at least in the overall scheme of loudspeaker engineering.

Aczel's infamous "Best Value" reccomendation of the infamous DCM Time Window speakers with their "Pulse Accurate" impulse response graphs and "Phase Matched" utterly crappy Philips dome tweeters and similarly utterly crappy Philips 8" paper cone drivers --

...and yes...I admit to be taken in by his reviews and DCM's cleverly "scientific" literature showing scope images of the "fantastic" and "coherent" impluse response tests...nevermind the lack of any output above 12 khz (those awesome poly cabonate Philips domes) or the poorly controlled bass from the equally awesome Philips 8" paper cones tuned to a port res well below what they were intended for, so DCM could claim "30 hz bass" response!!!

Oh the shame....

But, OTOH....they did look cool....

Anybody up for starting a "recovering Time Window owner's" support group???
 
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anmpr1

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#18
1) Aczel's infamous "Best Value" reccomendation of the infamous DCM Time Window ... 2) utterly crappy Philips 8" paper cone drivers -- 3) ...nevermind the lack of any output above 12 khz 4) ...or the poorly controlled bass ...tuned to a port res well below what they were intended ...
1) In the context of 1977 and at their price point the DCM TW was good overall value. Certainly it was the best of the cheap speakers he had tested, which was all he claimed.

2) The Phillips cones were 6" by the way (did they change them out in later models?).

3) There was 'no output' above 12KHz? None?

4) LF signal in a ported design is a function of box size in addition to port tuning. DCM was a small speaker, thus necessarily showing design trade offs. Some good, some questionable. That is true.

I checked the review you mentioned and didn't find it as you suggested. Below is his comment on bass:

If we were pressed to designate a nominal corner frequency of the TW's rather bumpy composite bass roll-off we'd place it at 50Hz. After all, it's not a large box. We say 'composite' because the bass response of a vented box is the sum of the outputs produced by the woofer and the vent. Ideally, these would be complementary, arithmetically adding up to flat response. In the case of the DCM they aren't. Each woofer exhibits the classic vented box response you'd expect, but the vents by themselves have perfectly flat output down to about 18Hz instead of filling in for the woofers with a humped response where the woofers drop out. Somebody obviously thought that this was a very good thing, but of course it doesn't add up to flat bass response...

So, if you bought the TW after reading his review, you should have been aware of the loudspeaker's problems. To blame Peter for any subsequent dissatisfaction with your purchase is misguided and not fair.
 

andreasmaaan

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#19
When soloing sounds and flipping phase, it sounds a little different, what's the reasoning for this?
Should the phase be a 'correct' way for the punchiest sound?
Yep, absolute polarity inversion is audible.

However, the process of inverting polarity itself is far more audible than the effects of the inversion.

I'm not sure how you're testing it atm, but if you're switching without any gap in playback, you may find that, when you pause playback briefly to make the switch, the differences are far less obvious than you thought.
 
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EPC

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Thread Starter #20
Yep, absolute polarity inversion is audible.

However, the process of inverting polarity itself is far more audible than the effects of the inversion.

I'm not sure how you're testing it atm, but if you're switching without any gap in playback, you may find that, when you pause playback to make the switch, the differences are far less obvious than you thought.
I've been leaving gaps between, I have 2 tracks that alternate back and forth, one has the phase flipped
The difference is so slight that it probably isn't even worth talking about, but I did notice a difference.

Is there a general preference to having the peak of the waveform pushing the speaker out as apposed to being pulled in?
My logic is that if the peak pushes the speaker out, then there might be more punch, but maybe it makes no difference...
 
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