Phase Inversion?

I read a post at another site where a guy found out his CJ PV12L pre amp could be placed in Phase Inversion in an attempt to change the sound by moving the + and - leads on the speaker.

He was/is not using ML but the thought occured to me to try this. What am I risking by attempting this swap? I have no idea what it means and the limited search I've done left me blank.

Comments?

Gordon

As far as I know, some CJ amps invert absolute phase due to an odd number of gain stages. (Not sure about this model in particular). The recommended way to get absolute phase back is with the swapping of + and - speaker terminals, but the success of this depends on whether you have another phase inverting component in your system.

Gordon,

I had that preamp and I now have the Premier 18LS.

I think all CJ preamps are phase inverting and the manual clearly states that this is the case.

If you have no other phase inverting piece in the signal path, you have to switch the speaker leads to listen to music "in phase".

However, there are also recordings that are recorded out of phase. I think OPUS is one (1) label that does this. Go figure.

GG

Phase invert

I have denon AVC-A1XVA european version, (i think it`s avr 5308 US version or somting like that 10channel amp.)
Well when using the audyssey correction it "said" the phase is wrong.. I did know what to do.. But then I tried what you are asking of.. So I switched the cable terminals on one speaker (front).. and did a new audessey correction, and that problem was solved. And not only that I`ve noticed a small improvement in sound!

My speaker are bi-wired.. and soon planning to bi-amp to get more juice to my Request and to use the other channels of my amp. So I wonder how the issue of phase problem.. Should I Phase invert both terminals in one speakers? or only on stators or woofer Maybe stupid to ask.. anyone have a comment on that?

reybent said:

I have denon AVC-A1XVA european version, (i think it`s avr 5308 US version or somting like that 10channel amp.)
Well when using the audyssey correction it "said" the phase is wrong.. I did know what to do.. But then I tried what you are asking of.. So I switched the cable terminals on one speaker (front).. and did a new audessey correction, and that problem was solved. And not only that I`ve noticed a small improvement in sound!

My speaker are bi-wired.. and soon planning to bi-amp to get more juice to my Request and to use the other channels of my amp. So I wonder how the issue of phase problem.. Should I Phase invert both terminals in one speakers? or only on stators or woofer Maybe stupid to ask.. anyone have a comment on that?

Click to expand...

I had a similar problem. I have a Denon 3808 receiver running the pre outs to my amplifier powering my CLS and when I ran the audyssey it told me just my right speaker was out of phase. I checked my connections and ran it again because I didn't believe it, same result. So i swapped the terminals at the speaker and ran audyssey and everything checked out fine. I still find it very strange.

Phase invert

I heard that some speakers may be wrong connected so that`s way i did gave it a chance.

Note to the Audyssey users:

Phase error reports are driven by either of these possibilities:

1. Your speaker is really out of phase and reversing the leads to it is the fix
2. Your big dipole radiator energizes reflections that fool Audyssey into thinking the speaker is out of phase when it's not. Re-measure.

To confirm it's one or the other, do a 'test', re-measure with the mic placed in the near-field of the speaker in question. That is, within six or eight feet of the panel, and as directly aligned with its center as possible

Always take the phase error with a bit of skepticism, look into it but often, it’s just fooled by reflections.

Remember, our MartinLogans are large, linesource dipole radiators, and the rear wave from the panels is out of phase. If that rear wave energy has a short enough reflected path to the measurement mic (typically six or so feet relative to the front direct energy), then Audyssey can miss-read the phase on that channel.

Again, that can be verified by placing the mic closer to the speaker in question, and re-doing a measurement and checking phase on that speaker.
If that speaker is good, then leave it alone, and re-do the entire Audyssey measurement for the rest of the speakers.

Audyssey totally depends on a well executed measurement run for its accuracy. Practice makes perfect, so don’t be afraid to redo these several times.

My question is this! Why manufacture a high end product that you need to do something so un rule y as reverse the phase on speaker leads to sound good.
I am no Electrical engineer but inst there something they could do internally. I am amazed that there have not been any issues with this.

Chris, the only way to "fix" this internally would be to add another phase-inverting stage, i.e. more electronics and more money. In addition, for purity of the signal you want to minimize the number of stages. It is easier and cheaper to just switch the leads.

Why not just mark the (+ as -) and the (- as +). It should be this simple, or am I missing something?

Yes , Why not do it at the factory ! Reverse them internally !

The (-) may be tied to ground, and so it is best to identify it as such.

What has me wondering is this: I've always been taught left to left, right to right, black to black and red to red.

Is that guidance now suspect? Does one move one speakers pair of leads or both? It would seem unusual to me to have one one way and the other another.

I may play with this over the weekend.

Gordon

You need to change phasing for both the left and right speakers.
I run all CJ gear so lucky for me I have an even number of phase inversions so it fixes itself. When I did not run all CJ gear I did have to correct for phasing, and I did hear a difference. It was small but noticeable.

Industry standards are not clear...some brand recordings like Philips are out of absolute phase. This is why on some records you have a nice stage and others do not. Just reverse the speakers cables, black to red on both speakers, so absolute phase is 180 degrees, and usually that particular recording with non stage, now you can have it right with stage. Try this, you might like it!...happy listening,
Roberto.

There used to be a scheme that was popular in England many years ago, called OOPS (Out Of Phase System). Using a turntable as an example, the cartridge leads for one channel were connected normally, while the other channel was reversed, and the same thing was done with the speakers.

The thinking behind this (IIRC) was that the two channels were drawing power from the amplifier out of phase with each other, hence putting less stress on the amplifier. It was supposed to improve the sound, but I never did try it.

Bernard said:

There used to be a scheme that was popular in England many years ago, called OOPS (Out Of Phase System). Using a turntable as an example, the cartridge leads for one channel were connected normally, while the other channel was reversed, and the same thing was done with the speakers.

The thinking behind this (IIRC) was that the two channels were drawing power from the amplifier out of phase with each other, hence putting less stress on the amplifier. It was supposed to improve the sound, but I never did try it.

Click to expand...

Hola Bernard...I did try it...the system that I was using at that time was a Golmund Studio turntable with the T3 Tonearm (still have it, but not in use)...and I could not tell the difference or a benefit. I envy those who did!!!...went back to the the normal connection...and everything was as good either way...my power amp at that time was Mark Levinson Model 2 mono blocks with the CLSs and the ML-6A preamps (still have these, but not in use)...tons of fun doing all the testing and learning to listen (I think)...happy listening,
Roberto.

roberto said:

Hola Bernard...I did try it...the system that I was using at that time was a Golmund Studio turntable with the T3 Tonearm (still have it, but not in use)...and I could not tell the difference or a benefit. I envy those who did!!!...went back to the the normal connection...and everything was as good either way...my power amp at that time was Mark Levinson Model 2 mono blocks with the CLSs and the ML-6A preamps (still have these, but not in use)...tons of fun doing all the testing and learning to listen (I think)...happy listening,
Roberto.

Click to expand...

Roberto, the difference was supposed to be apparent if you were using a stereo amplifier, not monoblocks, as you were then supposed to be putting less stress on the amplifier.

Bernard said:

Roberto, the difference was supposed to be apparent if you were using a stereo amplifier, not monoblocks, as you were then supposed to be putting less stress on the amplifier.

Click to expand...

...
Yes, I do understand that perfectly...we try the ML-3 also...and we could not tell the difference...perhaps because I was the ML-3 so powerful that we could not hear the difference...but makes sense what you are saying, one channel out of phase with the other, but the truth, no difference in my ears...that is why I envy those who did!!!...happy listening,
Roberto.

I swapped the speaker leads today and listened to some of the disks I know well. There was a seemingly bit more of air and a slightly forward presentation which did not appeal to me at all. It sounded appealing for a couple minutes but quickly became irrating to my ears.

So my assumption is that all my pieces are in phase without moving anything outside the "norm".

Everything is back to + to + and - to - and I prefer this much more!

Gordon