[ctviggen]

Wayne from Bolder Cables was nice enough to send me a CD having a phase test.  The CD has two versions of two different songs.  Each version was recorded in phase and then out of phase.  So, you play the first version (in phase) then the second version (out of phase).  Yesterday, I played each song (two versions of each song) at least 4 times each.  I'll be darned if I can tell which is better.  However, I did not set up my Realtraps in front of my RPTV, and this really does help.  For instance, comparing the Ack Dack D/A with the D/A in my Proceed AVP, without the Realtraps, it's hard to tell the difference; with the Realtraps, the differences are much more apparent.  I'll do more testing today.

I think that the way my system is currently set up, my R/L front speakers are out of phase (i.e., the chain of components from my transport, though the Ack Dack D/A, and to the speakers yields out of phase).  I say this because I recently changed speaker wire and reversed the phase (actually hooking the wire up red to red and black to black, instead of vice versa), and I used the test tones on Avia to determine that the rear and center channel are now wired out of phase relative to the R/L front speakers.  I believe that the rear and center channels are wired with correct phase.

I think the "in phase" versions of the songs were minorly better than the "out of phase" versions.  But if my system (R/L front speakers) is wired out of phase, wouldn't the "in phase" versions of the song actually be out of phase?  If so, shouldn't I really prefer the "out of phase" versions, as they'd really be in phase?  Or should I switch phase again on my speakers and try the test again (so that "in phase" versions of the song would really be "in phase")?

[AndrewH]

Try playing AM radio static in mono, and if your speakers are out of phase they should cancel out in the plane halfway between the speakers.

[konut]

Can someone more knowlegable than myself please explain the difference between relative phase and absolute phase?

[Davey]

A typical example:  Relative phase is when two adjacent drivers (maybe a woofer and midrange) in the same speaker are connected with opposite polarity....ie....if the crossover networked were removed and a positive-going voltage were applied to both drivers one would move out and the other in.  This is commonly done so that the drivers will sum together correctly when the crossover and its associated phase shifts is connected.  Obviously this "relative" difference exists in other forms besides this simple speaker example.

Absolute phase (or polarity as it should be called) is something totally different and is simply a 180 degree flip (of both channels) in the polarity anywhere along the recording or playback chain.  Example:  Flipping the polarity of the speaker cables connected to both speakers.  There is no way to know which way is "correct" or "incorrect" because there were probably hundreds of such changes that happened in the recording chain before the music was mastered.  A person would have to audition every piece of software he/she has with both polarities and note a difference (if there is one) and then return to the preferred setting at each playing.
I believe the current thinking by knowledgeable folks on this subject is that playback systems with higher orders of even-harmonic distortion will accenuate the audible effect of absolute polarity.

I hope that helps.  This is one of those subjects that most folks have weighted with more importance than it deserves....relatively speaking.  

Cheers,

Davey.

[PhilNYC]

A typical example:  Relative phase is when two adjacent drivers (maybe a woofer and midrange) in the same speaker are connected with opposite polarity....ie....if the crossover networked were removed and a positive-going voltage were applied to both drivers one would move out and the other in.  This is commonly done so that the drivers will sum together correctly when the crossover and its associated phase shifts is connected.  Obviously this "relative" difference exists in other forms besides this simple s ...

"Relative phase" can also refer to your left and right speaker channels.  Most test CDs have a track that lets you test whether your left and right channels are hooked up in-phase relative to each other.  If your left and right channels are out of phase, then you will lose your imaging...

[Davey]

Phil,

Yes, you're correct.  There are many examples of "relative phase."  I was making an assumption that what Konut was referring to was relative phase between drivers within a single speaker.  Maybe I was wrong with that assumption, but it was keeping with the subject of a few other recent threads regarding "phase coherent" and "time aligned" speaker systems.

Cheers,

Davey.