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Got an Avia "In Phase/Out Phase" question. (1 Viewer)

John Pine

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OK, I just purchased the Avia CD and an analog "Shack" meter. Avia showed my left front and right front speakers to be "out of phase". I swapped the leads at the right front as suggested and it cleared up the problem. How can the speakers be out of phase if they are wired properly (pos-pos neg-neg)? I think I'm missing something here. Will someone enlighten a "newbie"!
 

Royce H

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Mar 10, 2001
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It's possible that one of them was accidentally wired out of phase internally at the factory. Mistakes do happen!
 

John Pine

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Royce: Thanks for the feedback. I'm using the same wire for all 5 speakers. It's Home Depot 12 gauge clear with the thick jacket.

Clear 12/2 Speaker Wire
Model: #C13631590
SKU: #551893

This wire was all cut at the same time right in front of me. If this was the problem I think it would have shown up on the other runs as well.
 

Jeffrey Chin

Second Unit
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May 22, 2001
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John,
If the sub is "out of phase" with the mains, the sub's
driver is making a forward motion when the main drivers are making a
backward motion. When both units are producing the same frequency, the net
result is a cancellation of the sound waves at this frequency.

The short answer to your basic question is to set the sub's phase switch
such that you hear slightly MORE bass -- this means that the sub and mains
are "in phase" with each other since the sound waves are combining , rather
than cancelling, one another. If you hear less bass, sound waves are
cancelling each other out and you are in effect "missing" some frequencies.
When your sub and mains are out of phase and you increase the sub's volume,
you aren't really compensating for the lower level of bass. What you're
doing is increasing OTHER bass frequncies below the crossover region,
therefore getting the illusion of "compensating."
 

John Pine

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Jeff and Chris thanks for the feedback! Here's my budget system: Yamaha RX-V530, X-Box, JBL L40's(mains) Boston Acoustics 424v(cen) JBL N24II's(rears). My mains are two-ways, each with a 10" woofer. I don't even have a sub. Jeff, I understand what you are saying about the drivers moving in opposite directions thus canceling each other out. Now that I've crosssed the leads on the right front I can hear the phantom test tone in the middle for 1 1/2 seconds as described by the Avia disc. The speakers are "in phase" now according to Avia. But, now the right front is cross connected to the receiver. I have NO PROBLEM leaving it connected the way it is but, can this "out of phase" problem occur even when the leads are wired properly?(red to red/black to black)
 

Paul Clarke

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John,

Go back and read Royce's post again. He is speaking of the INTERNAL wiring connections on your drivers. They do get mismarked at the factory at the time of assembly. That is why it is important to check your system with test/calibration discs as sometimes it is what is unseen that causes the problem.
 

John Pine

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Paul, that has to be it because the speakers were physically wired properly externally! But........that means I've been running them "out of phase" for 20 years! Could this have cause any damage internally?

p.s.......Thanks again Royce!
 

Paul Clarke

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I wouldn't worry about any damage except to the music. :) I recommend you get a test CD for two channel. I have one from Ubid...CD Laser 2000 or something like that. It will check everything from top to bottom. As of right now, you still don't know which of your drivers may be the culprit(s). Could be the highs...or the lows...or both.
 

Chris Tsutsui

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Switch the left one to out of phase and listen to it.. I should be very obvious that one channel is out of phase. If it's not obvious to you then you may have listened to music like that for 20 years. :)
Are the labels correct for red/black?
Also... the big question is do the speakers sound better after they've been setup for AVIA. Or do they sound better when you wire the other channel according to label?
Maybe try an alternate test like using a simple THX test found on many DVDs such as Star wars, Titan AE, fight club, etc.
 

John Pine

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Paul: You right, I don't know! I'll see if I can find one on fleaBay. Thanks for the suggestion!

Chris: I'll try switching the left front and see what happens. There are no labels, the connectors are red and black and are some kinda of twisting post. I don't know what they are called. You strip down the wire, insert then twist the entire connector to lock them in place. The hole was barely large enough, it took quite a bit of effort to get the 12 gauge wire through it.

To me the speakers do sound better, but that might be my new receiver I'm hearing. I recently replaced my old Pro-Logic Kenwood with a Yamaha RX-V530, the different is stunning! I'll to do an A-B test and see which way sounds better.
 

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