I first discovered the critically of this when working on a two way speaker, some design methods suggest reversing the polarity of drivers, when I listened to designs using this method, you would hear correct reproduction with some instruments only in one polarity but not the other. Quite a weird experience.
So how would you? I assume the only way would be by looking at the beginning of a sound with an oscilloscope, and seeing if the wave starts with an up- or downgoing slope - but what is "correct"? Have you looked at different instruments, and determined if the sound starts with a high or a low air pressure? Doesn't it depend on the microphone position?
What about multiple instruments/voices/microphones?
Do you think studio engineers spend any time worrying about maintaining absolute polarity?
How do you think the ear actually detects polarity? A human ear is sensitive to frequency, intensity and *relative* timing of sounds. How would the neurons in the ear detect the absolute polarity?
In all the cases I have come across where the sound changed when switching polarity, the circuit was asymmetric in some way, and the polarity switch actually affected the circuit topology (usually ground/earth).
It is rare that i agree with soongsc but in this case his observations about audibility are spot on
As in "sometimes detectable with selected single-source mono signals".
Even then, considering how few successful tests there have been, and how there has been very little independent verification/replication, I think "proven" is a bit too strong.
You got a link where someone can show this for a symphony orchestra at full chat to be proven?
Or is anyone brave enough to take a BBC recording, invert it and place both copies for us to vote on?
Or is anyone brave enough to take a BBC recording, invert it and place both copies for us to vote on?
Actually I would like to find software that will make track polarity inverting convenient instead of having to do it every time I listen.
I think it was Ethan Winer who made the observation that some woofers have very asymmetric clipping - they bottom out in one direction, but not the other.
You remind me of a thread where the discussion of ITD and IID, lead to someone posting a few different files for people to listen to a respond. I think I was the only one brave enough to respond which lead to revealing of unannounced. Tweaks he did to the tracks. Let me see if I can find it.
Most BBC are VERY well recorded. I loved lots of their recordings from the vinyl days. Was listening to a demonstration CD yesterday, loved it.
OK, I worded myself badly - I guess we all know that woofers bottom asymmetrically, but Ethan observed that that can explain why a transient could sound different when you reverse the polarity.
There are certainly lots of valuables, but the Hong Kong magazine author went through some 3000 CDs and found consistent preference for the brands he reviewed. I tried, and found a similar trend. Since my preference was the same as the author, I just started to supplement his list with the brands I have. I would be glad to post the list if there is any interest.
I guess it wouldn't have made much of a story if he hadn't...
Were both done under double-blind listening conditions?
Personal preference. As a matter of fact, frequently after I make a polarity switch during normal listening, I cross check to see if my preference matches the list, I don't think there was once it did not.
Modulus-86: Composite amplifier achieving <0.0004 % THD+N.
I seldom spend time to do ABX, if I hear it, it matters, if not, I just don't worry about it. If I hear a difference but do not form a preference, that means more work to get to the source of the cause.
I seldom spend time to do ABX, if I hear it, it matters, if not, I just don't worry about it. If I hear a difference but do not form a preference, that means more work to get to the source of the cause.