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Sonically, what should I expect to be the difference if the polarity of the speaker wires were reversed?
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Backwave reflections coalescing with frontwave ones in the room can make it hard to distinguish between nuances such as these.
Many speakers have different polarity on individual drivers in which case this question becomes essentially moot. I have friend whose 1st question is whether all the drivers have the same polarity and if they don't he has no interest in them.
Actually, I'm prompted to ask the question because some pre-amplifiers invert the electrical signal; consequently, it's recommended that you reverse polarity of the amplifier output terminals to the speaker terminals.
Speaker polarity is a contentious issue but I understand blind tests using test signals have proven that people can distinguish between sound with "normal" and "reverse" polarity. Unfortunately test signals aren't necessarily a good indicator of what we hear with the more complex signal that a musical track presents and results with music have been much less clear cut. There is some indication that it is easier to hear a difference with some sorts of music than with others.
Unfortunately the issue is even more complex than it first appears. There are lists around which purport to tell you which companies release discs in correct polarity and which in reverse polarity. That assumes that all discs a given company releases are mastered identically which isn't true. It is apparently possible to find discs with both 'flavours' of polarity in any given label's catalogue. The situation is compounded further when you realise that polarity can be reversed at various stages in the recording/mixing/mastering process and, given the way individual tracks are processed and mixed when making a record produced from a multi-channel tape, it's possible for some instruments/voices on a disc to be in "correct" polarity and others in "reversed" polarity. How do you then determine what the "right" polarity for playback of the disc is when whatever choice you makes ensures that part of the music is being reproduced in the opposite polarity to other parts of the music?
I think I can hear a difference with some records when I reverse the polarity of my speakers but it's a small difference and, in the end, I simply gave up worrying about polarity. Others are fanatical about it and report that getting it right makes a big difference. Perhaps speaker choice and how phase coherent over the whole frequency range the speaker is overall accounts for some of the differences in how big a difference those who claim to hear a difference report hearing. There are still others who reject the audibility of any difference whatsoever.
Try it and see. You may hear something and you may not. If you hear something you may consider it a big change and you may not, but some discs will sound better in one polarity and others in the opposite polarity. Results are going to be highly dependent on the discs you play, the speakers you use, how well your signal chain preserves polarity (some components reverse polarity and some don't), and on your personal hearing acuity and sensitivity.
David Aiken
"Speaker polarity is a contentious issue but I understand blind tests using test signals have proven that people can distinguish between sound with "normal" and "reverse" polarity. Unfortunately test signals aren't necessarily a good indicator of what we hear with the more complex signal that a musical track presents and results with music have been much less clear cut. There is some indication that it is easier to hear a difference with some sorts of music than with others."
Sorry I don't recall the publication/date, but one study on this showed that a limited number of people (mostly professional musicians) COULD consistently hear polarity differences, ONLY on minimalist recordings of certain instruments with sharp transient attacks (such as snare drum and trumpet).
Again, it depends far more on the speakers and recordings than on anyone's ability to discern polarity effects per se.
Many or most speakers are not sufficiently polarity-coherent to allow you to hear the effect. Complex crossovers don't help.
NT
David Aiken
I guess it was a question of emphasis. Without phase-coherent, minimum-crossover speakers most people will never hear the effect. I remember playing test CDs with tracks that "supposedly" demonstrated "normal" and "inverted" polarity. They all sounded the same to me no matter how hard I focused on hearing a difference. Then I got Gallo Ref 3s, and some discs and open reel tapes sounded distinctly odd until I started experimenting with speaker cable switching. Querying Gallo tech support I heard back that these speakers are "extraordinarily sensitive" to polarity. I eventually gave up and bought a line stage with a polarity switch (accessible via remote, thank heaven).
Likely nothing if BOTH speakers of a Stereo pair are identically connected. A Mono system is of no matter in this regard. Since signal current is alternating vs direct, the reason for polarity markings IS to ensure both woofer cones move back & forth in sync with each other lest out-of-phase sound production between Left & Right channels create nulls in low frequiency sound (which has longer wave lengths & thus more affected by phase nulls) that would reduce heard Bass amplitude. Try it for yourself. The physical ability to hear Absolute Phase is not so common & electrical circuts often reverse such phase, too. Thus speaker markings of + & -, or Red & Black, or #1 & #2 are only to ensure same Stereo connection.
Edits: 07/27/09
Frank Sinatra will sound like Barry Manilow,
and vice versa.
Since recordings ignore polarity standards.
reversing the polarity at home is most likely
to have no audible effect.
Ask a friend to swap cables in both speakers
based on a coin toss and see if you can identify
normal and reversed polarity without knowing how the
speakers are actually connected. If you score well in
the first few trials, and think you can hear a difference,
see if you can be right in 12 of 16 trials = a positive single-blind test result.
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RG...Banned from Critics Forum for daring to ask why high-end reviewers get no hearing or listening skills tests before being hired to review audio gear & pointing out negative points in reviews get reversed by "Happy Face" conclusions
i don't think recordings "ignore polarity standards" but there is a lot of out of phase information on some recordings due to bleed, poor mic placement etc.
If both speakers are reversed, a change in bass may be most noticeable.
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