[al128]

hi there,

just a quick Q.

I understand that some (all?) tripath amps have their fase inverted ... this means you would hook your speakers up correctly connecting the RED speaker post on the amp to the BLACK post on the speaker (fase 180deg inverted)

IS THIS TRUE FOR THE VIRTUES?

or do I just connect red to red?

thx, and cheers
Al

[JimJ]

Easy way to make sure is to listen to a vocal phase test... Very apparent if something is wrong.

[eclein]

I have a TWO.2 and have no phase issues whatsoever..red is red, black is black..I checked with a THX disk via DVD and it all sounds most excellent!!

[srb]

I have a TWO.2 and have no phase issues whatsoever..red is red, black is black..I checked with a THX disk via DVD and it all sounds most excellent!!

AFAIK, the THX disc is testing for relative phase between speakers, meaning that the speaker diaphragms are moving in the same direction at the same time, so that a cancellation of frequencies is not ocurring, most apparent to the listener in the bass frequencies.
 
This is different from absolute phase, which means that the initial compression of the recording microphone diaphragm which resulted in a positive voltage is maintained through the playback electronics and speaker chain without being inverted.
 
The Stereophile Test CD Track 8 is an absolute polarity track which inverts polarity in the middle of the track.  Absolute polarity is much harder to discern by many people, but is supposed to be more readily discernible on voice and piano.
 
As Al pointed out, the Tripath chips do invert polarity, as do some other preamplifiers, amplifiers and DACs.  But if a polarity-inverting input stage is added internally inside a Tripath based amplifier, then the output would be non-inverted.
 
Audio Research tube preamplifiers, for example, have a phase inversion switch on them, as their output is normally inverted.  Of course, if the inverted preamp signal is sent through another electronic component that also inverts phase, the output will be back to non-inverted.
 
Beyond the more subtle difference in sound between absolute polarity or not in a stereo setup, it becomes more important when an inverting amplifier is combined with a non-inverting amplifier, as could happen with a subwoofer.  Because there will always be some doubling of frequencies between high-passed mains and a subwoofer near the crossover frequency, an inverting mains amplifier combined with a non-inverting subwoofer amplifier will result in some bass cancellation, similar to when a left and right speaker are out of phase with each other.
 
Steve

[eclein]

So basically I wasn't even close!!  LOL....
AFAIK = ??

[srb]

AFAIK = ??

Sorry, AFAIK = "as far as I know".  I don't use phrase abbreviations too often, but occasionally AFAIK or FYI = "for your information".
 
What I meant is I don't have a THX disc here for verification, but I don't remember any track addressing "absolute phase" on a disc I had borrowed a couple years ago.
 
Steve

[guest1632]

hi there,

just a quick Q.

I understand that some (all?) tripath amps have their fase inverted ... this means you would hook your speakers up correctly connecting the RED speaker post on the amp to the BLACK post on the speaker (fase 180deg inverted)

IS THIS TRUE FOR THE VIRTUES?

or do I just connect red to red?

thx, and cheers
Al

Hi Al,

Let me give this to you from one blindman's perspective. Hook up your speakers like you normally would. If you have access to a tuner, put it in between stations with white noise. Now, ... if all is not! well, and you need to walk so you are 90 degrees walking from left to right/right to left, if you are out of phase, you will hear a nice hole of sound in between your speakers. If all is well, then you will hear a wall of sound building up as you are walking towards the middle between the speakers. Sorta like a Shevron/arch. Music is a lot harder to detect this, but with a bit of practice you should be able to discern this effect. Hope that helps.

Ray Bronk

[srb]

Let me give this to you from one blindman's perspective. Hook up your speakers like you normally would. If you have access to a tuner, put it in between stations with white noise. Now, ... if all is not! well, and you need to walk so you are 90 degrees walking from left to right/right to left, if you are out of phase, you will hear a nice hole of sound in between your speakers. If all is well, then you will hear a wall of sound building up as you are walking towards the middle between the speakers. Sorta like a Shevron/arch. Music is a lot harder to detect this, but with a bit of practice you should be able to discern this effect. Hope that helps.

Ray,
 
I think the phenomena you are describing is whether the speakers are in phase or out of phase with each other.
 
As far as absolute phase versus inverted phase (the speakers are still in phase with each other in both scenarios), I don't think the difference can be discerned with wide spectrum constant amplitude white noise.  I believe that it would require a waveform that has attack, decay and dynamics.
 
Steve

[guest1632]

Ray,
 
I think the phenomena you are describing is whether the speakers are in phase or out of phase with each other.
 
As far as absolute phase versus inverted phase (the speakers are still in phase with each other in both scenarios), I don't think the difference can be discerned with wide spectrum constant amplitude white noise.  I believe that it would require a waveform that has attack, decay and dynamics.
 
Steve

Hi Steve,

Well, he was asking about hooking up his speakers to the amp, Red to Red ETC. So I just told him how to discern if that was a problem or not. It would be a question to ask on the virtuae audio forum. Oh, this is the virtuae forum. haha. maybe Seth can chime in here to answer this question.

Ray

[Nuuk]

Steve has explained it well but if it needs simplifying ( ) then basically it doesn't matter much which way you connect the speakers providing that it is a single-amped system (and you hook up each speaker in the same phase).

To make matters a bit more complicated, recordings are not always engineered with the same absolute phase so which ever way that you connect your speakers, it is possible that the sound will be 180 degrees out of phase on some albums.

Even if your ears can detect that, it isn't really practical to hop up between tracks/albums, and swap your speaker cables over. Some equipment like the Scott Nixon DacKit has a phase inversion switch but I have only played with it a couple of times in five or six years, and then more for my own amusement than making a recording sound 'better'.

So there you have it, something else to worry about that many of you didn't even know existed! 

But as Steve pointed out, it is worthwhile to understand the difference between absolute phase, and relative phase. If you have the relative phase wrong, you will most likely notice a reduction in bass output. Or if you have multi-amped systems, and they are out of phase, it won't sound right either.

And don't forget the phase-shift issue with (ALL) class-T amps. If you have a multi-amped system make sure all the amps are class-T(D).

Plenty more reading at http://www.google.co.uk/search?hl=en&client=firefox-a&hs=8ES&rls=org.mozilla%3Aen-GB%3Aofficial&q=absolute+and+relative+phase+loudspeakers&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= for those who are interested.

[guest1632]

Steve has explained it well but if it needs simplifying ( ) then basically it doesn't matter much which way you connect the speakers providing that it is a single-amped system (and you hook up each speaker in the same phase).

To make matters a bit more complicated, recordings are not always engineered with the same absolute phase so which ever way that you connect your speakers, it is possible that the sound will be 180 degrees out of phase on some albums.

Even if your ears can detect that, it isn't really practical to hop up between tracks/albums, and swap your speaker cables over. Some equipment like the Scott Nixon DacKit has a phase inversion switch but I have only played with it a couple of times in five or six years, and then more for my own amusement than making a recording sound 'better'.

So there you have it, something else to worry about that many of you didn't even know existed! 

But as Steve pointed out, it is worthwhile to understand the difference between absolute phase, and relative phase. If you have the relative phase wrong, you will most likely notice a reduction in bass output. Or if you have multi-amped systems, and they are out of phase, it won't sound right either.

And don't forget the phase-shift issue with (ALL) class-T amps. If you have a multi-amped system make sure all the amps are class-T(D).

Plenty more reading at http://www.google.co.uk/search?hl=en&client=firefox-a&hs=8ES&rls=org.mozilla%3Aen-GB%3Aofficial&q=absolute+and+relative+phase+loudspeakers&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= for those who are interested.

Hi, Well, I was just again pointing out how to know if your speakers are hooked up in phase in the first place. Sheesh. Thanks Steve for the explanation. Yep, did know that about the recordings.

As for further reading: ... joy.

Ray Bronk

[dvenardos]

We probably wouldn't be doing this if we didn't love to pick nits (that is half the fun), but don't forget that the vast majority of receivers are class a/b and a good percentage of subwoofers are class D and are often calibrated with software, so I wouldn't worry about phase issues with class d / ab unless something doesn't sound right.

[JimJ]

We probably wouldn't be doing this if we didn't love to pick nits (that is half the fun), but don't forget that the vast majority of receivers are class a/b and a good percentage of subwoofers are class D and are often calibrated with software, so I wouldn't worry about phase issues with class d / ab unless something doesn't sound right.

Most of the high-end auto sound installs I've heard have been like that, Class D on sub(s) and A/B on the front stage - and phase issues are just as apparent.

[srb]

We probably wouldn't be doing this if we didn't love to pick nits (that is half the fun), but don't forget that the vast majority of receivers are class a/b and a good percentage of subwoofers are class D and are often calibrated with software, so I wouldn't worry about phase issues with class d / ab unless something doesn't sound right.

There is a reason that many subwoofers have an inverting phase switch or variable phase control.  Knowing that the Tripath chip does invert, I don't know what other circuitry is inside the Virtue amps, so I couldn't definitively say whether the output is inverted or not.
 
All the OP really wanted to know was if the Virtue amps inverted phase or not.  He didn't ask how important it was or that he was neccesarily worried about it, and many of us like to provide whatever information we have, but I wouldn't call it nitpicking.
 
I suppose if Virtue was watching this thread, they could have responded with a simple "Yes" or "No"!

[virtue]

We flipped the output at the terminus.  So no phase issues on this amp.

[dvenardos]

There is a reason that many subwoofers have an inverting phase switch or variable phase control.

Which is exactly why it doesn't really matter if you have a class a/b sub with a class d amp or vice versus.

All the OP really wanted to know was if the Virtue amps inverted phase or not.  He didn't ask how important it was or that he was neccesarily worried about it, and many of us like to provide whatever information we have, but I wouldn't call it nitpicking.

Actually he was just wanting to know whether to hook up his speakers positive to positive or positive to negative and you are telling him that he needs to make sure he has a class d sub with a class d amp.

[srb]

Actually he was just wanting to know whether to hook up his speakers positive to positive or positive to negative and you are telling him that he needs to make sure he has a class d sub with a class d amp.

That is not at all what I said.  I merely said that absolute phase is a consideration when combining an inverting mains amp with a non-inverting subwoofer amp or vice-versa, hence the phase switch on most/many subwoofers.

Much of the further discussion was addressing other posters who were confusing relative phase between L and R speakers with absolute phase of the stereo signal.
 
Steve

[al128]

We flipped the output at the terminus.  So no phase issues on this amp.

 

that was my guess, otherwise 95% of all your customers would be listening out of phase, right?
 

[Nuuk]

Which is exactly why it doesn't really matter if you have a class a/b sub with a class d amp or vice versus.

If only life were that simple!    This is an issue of phase shifting with frequency so no amount of phase shifting (at the crossover point) will redress the issue properly.   

[classicjt2]

Sonic Impact amps were all absolute phase inverting, but the Virtue amps are clearly (to my hearing) not phase inverting. It does take listening through a speaker that has a crossover that phase correct- 2nd order, 12dB/oct are notorious in that the drivers are out of phase with one another (except at the crossover point). Once you've identified the condition of correct phase, you really don't want to listen when it's 180 degrees out of phase. Some popular audiophile recordings that are clearly 180 degrees out of phase are "Mary Black", and Holly Cole's "Don't Smoke in Bed" CDs, the American release (the Canadian is phase correct). The reverse phase sound is brighter, edgier, and echoey. Flip the speaker leads around (+ to -, - to +) and the sound becomes smoother and more natural (though I know some who prefer the added "reverb" of the Holly Cole in reverse phase).

James