# AVIA II LR Surround Phase Test Question



## Philm63 (Jan 1, 2015)

Hopefully I'm posting this one in a suitable place - tried searching this one on the web and several forums - spent a lot of time - and did not get my answer, so here it goes: 

Just got my AVIA II DVD and started running through the various tests, and when I got to the phase tests, the front three checked out fine, but the surrounds didn't seem to work properly for me based on what the screen said I should have been hearing. 

Here's what I know: Denon AVR-X2000, Panasonic BDP, 5.1 system, large irregular living room (two open walls, tall ceilings). A/V connections are HDMI. BDP is set to output its audio for True HD. Identification tones show all speakers are playing 5.1 properly. Levels are calibrated to 85 dB from MLP. Speakers are all wired + to + and - to -.

When playing AVIA phase test tones, the AVR shows DD+PLIIxC, and both LR surrounds are playing the tones simultaneously, as I'd expect during a phase test. However, the screen says I should face the surrounds (with my back to the display) and I should hear 3 seconds of a phantom image centered between the two surround speakers, and for 1 second I should hear a sound that is "difficult to localize". 

This worked fine for my front three, with the levels of each tone being about equal. When the tones go to my surrounds, it is real quiet for the 3-second burst, and normal level (same level as all other phase tests) for the 1-second burst. Because the levels between the tones are so different, I cannot say for sure if it images correctly during the 3-second burst or the 1-second burst as it is difficult to compare.

Not sure if I am understanding how all of this works yet, still new to the hobby. But it seems there is something about the phase test to the surrounds that is not consistent with what I hear when I do this test on the front three. My initial thought is that the audio out from the BDP is not what it should be to properly play these tones, but I've double-checked all settings, including the BDP, and it's all set to play True HD. 

Is this perhaps an AVIA II issue and NOT my system? As far as I can tell, everything is set correctly, and all connections are confirmed to be OK. Am I interpreting this test correctly, or is there possibly an issue with my setup? Or with AVIA II?

I'll also be playing with REW soon - should I even be putting much emphasis on AVIA's phase test, or...?


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## AudiocRaver (Jun 6, 2012)

You have described your situation very well. Your expectations is correct that you should get the same basic result for any adjacent pair of speakers in your circle of mains, center, and surrounds. The test sounds should all be at the same vo!ume !level, and the phantom source should be midway between whatever pair is under test _once your distances and levels are properly set._ You have interpreted the test properly, speaking in general terms - I am not familiar with your specific hardware.

Sounds like you have completed the initial setup procedure as you should. My only suggestion is to check the surround hookups one more time.


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## Philm63 (Jan 1, 2015)

AudiocRaver said:


> You have described your situation very well. Your expectations is correct that you should get the same basic result for any adjacent pair of speakers in your circle of mains, center, and surrounds. The test sounds should all be at the same vo!ume !level, and the phantom source should be midway between whatever pair is under test _once your distances and levels are properly set._ You have interpreted the test properly, speaking in general terms - I am not familiar with your specific hardware.
> 
> Sounds like you have completed the initial setup procedure as you should. My only suggestion is to check the surround hookups one more time.


Confirmed - surrounds are connected correctly. Distances for all 5 speakers were measured to the MLP with a tape measure, and the measured distances were set into the AVR. Levels for all 5 speakers are calibrated to the MLP at 85 dB using a calibrated SPL meter. The thing I can't quite put my finger on is the fact the test tone varies in level between the 3-second and 1-second bursts, while all other phase test tones are equal in level. 

I tried reversing the connection on one of the surrounds - no change. I tried reversing the connection on both surrounds - no change. Sounds exactly the same with all combinations leading me to think it has something to do with the BDP or AVIA II. BDP has been gone through several times, and is outputting audio in True HD - confirmed by watching a few blu rays and the AVR display shows DTS indicating it is in True HD - and the 5.1 sounds natural and correct.

When AVIA II is in the BDP, the AVR display shows PLIIxC when idling, and when playing a test tone the AVR display shows Dolby Digital+PLIIxC for all phase test tones, including the one sent to the surrounds. If it plays (sounds) correct when testing the Front LR, Front L and Center, Front L and Surround L, why not when testing the two surrounds? That one test is the only one that doesn't seem to be cooperating.


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## willis7469 (Jan 31, 2014)

I think Dolby digital +pliixc is indicating:
Dolby digital (2.0pcm) 
PLIIxc(pro logic matrixed with "c"enter. 
The PLII designation tells us that even though the signal is DD, it's only 2channel. That's why PLII is in use. I've never used the avia disk but its well regarded. (don't recall if you said,sorry). Is there a setting in the Avia menu for "soundtrack "(lack of terms) output, similar to a bd movie? I'm gonna try to find out a little more, when I can sneak it in. (Sunday family day).


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## willis7469 (Jan 31, 2014)

Also, when it's playing the test, try to manually select a different sound mode. Maybe auto detect is flagging it wrong.


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## Philm63 (Jan 1, 2015)

^^ Got it! Tried something everyone should do, but most of us engineering types do not - I read the directions!! In with the AVIA II DVD is a set of instructions that has a note pertaining to Dolby Digital EX 6.1 or 7.1 decoding - says all audio tests "except for the Left/Right-Surround Phase" tests will operate correctly with the EX processing activated, and it goes on to tell the reader to turn EX off for that one test. Per your second response, I did try manually changing the AVR settings while the tone was playing and I found one that allowed both the 3-second and 1-second bursts to come in at the same level. All is well in the world. Well, sort of...

Thanks, willis7469!


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## willis7469 (Jan 31, 2014)

Nice work Philm! You're going the right way. I'm a jr engineer myself, but I'm personally guilty of reading owners manuals, and "destructions", even though through experience I don't need to so much. I just find that each manufacturer has their own nomenclature, and mumbo jumbo, and understanding the lingo helps. Yes, my wife gives me____about it lol. Glad to help you along. Btw, how many movies/clips have you been through in the last 4-5 days? Lol


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## Philm63 (Jan 1, 2015)

willis7469 said:


> ...Btw, how many movies/clips have you been through in the last 4-5 days? Lol


Too many, apparently - wife getting a little irritated...


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## willis7469 (Jan 31, 2014)

Philm63 said:


> Too many, apparently - wife getting a little irritated...


 lol! This I understand all too well. We also have drums, guitars and a piano. ...oh the poor thing.


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