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Rear speakers silent, except during phase test

post #1 of 19
11/20/08 at 10:53pm
Thread Starter 
I have an elderly Kenwood receiver (about 7 years old), model VR-209 that I have been using in Stereo mode for years. This week, I got a deal on some open-box Klipsch Synergy bookshelf speakers and a Polk center channel speaker. Shazam! instant low-cost surround sound, I think. I carefully followed manual regarding the wiring connections to receiver, keeping polarity consistent. The Kenwood has a test mode that runs white noise sequentially through left, center, right and rear surround speakers, allowing me to confirm that all was correct and to balance volumes across all speakers. All good so far.

I have a Panasonic plasma TV, model TH-50PX80U that has 3 HDMI inputs and an optical digital audio output. Since my receiver has no HDMI but does have an optical digital input, I have both my PS3 and my Apple TV connected to TV with HDMI, and then run the optical digital audio out from TV to receiver. I'm under the impression that this arrangement will get me 5.1 digital audio from those two units, right?

My problem revealed itself when I inserted a Star Wars DVD into the PS3 (my only disk player) to use the THX tests for audio included on that disk. When the audio test ran through the channels with white noise, no sound came from my rear speakers! When the rear speakers were indicated on screen, it seemed as if sound emanated from the center channel (or well-centered signal from right and left front speakers)! After rechecking my connections and settings on the receiver, I tried again with same result. But this time I continued to the next test for "phase", and when the screen indicated that the audio signal was "out of phase" from the front speakers I heard sound from my rear speakers!! WTF??

I don't know that this is relevant, but I also noted that when I initially switched Listening Mode from Stereo to Pro Logic after connecting up the new speakers, the volume from the front speakers was dramatically reduced. Since I'm thinking that there are separate amps for each channel, this dramatically lower volume in Pro Logic makes no sense to me either.

Its midnight, and I'm tired and frustrated, so I'm going to leave this until tomorrow with a fresher brain. But I would sure appreciate some ideas about what to look for when I begin again tomorrow.
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post #2 of 19
11/21/08 at 6:13am
Quote:
Originally Posted by Mykl4now View Post

...I have both my PS3 and my Apple TV connected to TV with HDMI, and then run the optical digital audio out from TV to receiver..

Its early and I'm running out myself, but I think you would want to connect both the PS3 and Apple TV optical out to the receiver.

PS3, Apple TV, HDMI out to the TV. PS3, Apple TV, digital out to the receiver. You should be good to go. Why would you want to route audio through the TV??
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post #3 of 19
11/21/08 at 7:06am
Quote:
Originally Posted by Mykl4now View Post

...when the screen indicated that the audio signal was "out of phase" from the front speakers I heard sound from my rear speakers!! WTF??

When movies were encoded using Dolby Surround, the surround information was matrixed into the mix as an out of phase signal. During playback, Pro Logic decoding would be applied to the 2-channel soundtrack and any information that was out of phase would be sent to the surround speakers. Simple encode/decode scheme.

So it is completely normal behaviour for your receiver to extract out of phase information from a 2-channel signal and sent it to your surround speakers. After all, the decoder doesn't know whether the 2-channel signal was Dolby Surround encoded or just regular stereo.

But this does point out that your receiver is getting a 2-channel signal, not 5.1 as you may have orignally thought (Pro Logic can't be applied to multi-channel signals, only 2-channel sources). One of the reasons may be HDMI handshaking: your TV is telling the PS3 that it is a 2-channel device, so the PS3 outputs a 2-channel signal.

Try connecting the optical out from the PS3 directly to the receiver, as atdamico suggested, and see if you get actual 5.1 signals.

Sanjay
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post #4 of 19
11/21/08 at 8:06am
First, the television will not pass surround sound with the exception of OTA television from it's tuner. This is a DRM concession.

Second, that receiver is old, I don't think it has DD decoding does it? Doesn't it only have matrix decoding? If so sending the PS3 directly to the receiver will not help.

So what is probably happening is you have your DVD set to output multichannel digital over hdmi. The TV passes that to the receiver as 2 channel. Then your receiver has no choice but to use matrixing. The multichannel digital track of the DVD you are playing is not matrix encoded so you will not get any surround. Of course the test tones play because the receiver just sends tone to each amplifier separately, probably not even going through the decoder.

Possible solutions: 1 Switch the DVD to play the Dolby 2 channel track if the disc has it. 2 use the analog out of the DVD into the receiver. 3 get a new receiver with more digital inputs and multichannel decoding.
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post #5 of 19
11/21/08 at 9:50am
Quote:
Originally Posted by atdamico View Post

Why would you want to route audio through the TV??

Some people do it for ease of setup, or to have the option of just using TV speakers. Unfortunately, like said above, most TVs won't pass 5.1 audio to the receiver over optical. (Some reportedly do, though, but they're not numerous enough to recommend this setup.)
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post #6 of 19
11/21/08 at 10:18am
Quote:
Originally Posted by Harrypt View Post

First, the television will not pass surround sound with the exception of OTA television from it's tuner. This is a DRM concession.

Second, that receiver is old, I don't think it has DD decoding does it? Doesn't it only have matrix decoding? If so sending the PS3 directly to the receiver will not help.

So what is probably happening is you have your DVD set to output multichannel digital over hdmi. The TV passes that to the receiver as 2 channel. Then your receiver has no choice but to use matrixing. The multichannel digital track of the DVD you are playing is not matrix encoded so you will not get any surround. Of course the test tones play because the receiver just sends tone to each amplifier separately, probably not even going through the decoder.

Possible solutions: 1 Switch the DVD to play the Dolby 2 channel track if the disc has it. 2 use the analog out of the DVD into the receiver. 3 get a new receiver with more digital inputs and multichannel decoding.

You are correct. That receiver is only Pro-Logic, not DD. Connecting via the receiver will not do anything. You really need to take option 3 above and buy yourself a new reveiver. There are some great deals around right now and for a few hundred you can get the sound you want. I don't think the PS3 has 5.1 analog out so if it is being used as a DVD player then option 2 will not work either.
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post #7 of 19
11/21/08 at 4:11pm
Thread Starter 
Quote:
Originally Posted by atdamico View Post

Its early and I'm running out myself, but I think you would want to connect both the PS3 and Apple TV optical out to the receiver.

Thanks for the reply. I only have one optical input on receiver to serve both units.

Quote:
Originally Posted by atdamico View Post

PS3, Apple TV, HDMI out to the TV. PS3, Apple TV, digital out to the receiver. You should be good to go. Why would you want to route audio through the TV??

First, I thought the digital audio WAS present in the HDMI, why would I also run another audio signal in addition?

Secondly, because I only have one optical input on receiver, but two HDMI inputs on the TV. The Panasonic tech support seemed to support my impression that the TV would relay the digital input from each HDMI input into the Optical Output that was then accepted by the (sole) optical input on the receiver.

Are you saying that the digital audio signals from each HDMI inputs are not actually 5.1? Or are you saying that the TV alters those signals before outputting them to the optical digital output? Or.... what?
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post #8 of 19
11/21/08 at 4:23pm
Quote:
Originally Posted by Mykl4now View Post

Thanks for the reply. I only have one optical input on receiver to serve both units.



First, I thought the digital audio WAS present in the HDMI, why would I also run another audio signal in addition?

Secondly, because I only have one optical input on receiver, but two HDMI inputs on the TV. The Panasonic tech support seemed to support my impression that the TV would relay the digital input from each HDMI input into the Optical Output that was then accepted by the (sole) optical input on the receiver.

Are you saying that the digital audio signals from each HDMI inputs are not actually 5.1? Or are you saying that the TV alters those signals before outputting them to the optical digital output? Or.... what?

Part of what I am saying is that if you want discreet 5.1 sound then there is no answer to what you are trying to accomplish other than to purchase a new receiver. Your TV will not decode 5.1 audio. Further, if you want discreet 5.1 audio via HDMI, then not only will you need a new receiver but you will need one that accepts audio via HDMI, usually v1.3. Fortunatly your PS3 can pass all the new codecs via LPCM so your receiver does not need to decode the newer codecs but it MUST accept audio via HDMI, usually v1.3.

If your receiver does not accept audio via HDMI, but can decoded DD or DTS via digital, (the one you have now will not) then you will need to run a seperate digital cable from your sources to capture discreet 5.1 audio. The most common way would be to run HDMI to the TV (video) and digital to the receiver (audio)

You have a great display, great sources, and an old, outdated receiver.
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post #9 of 19
11/21/08 at 5:10pm
Funny thing is that My recently aquired RCA reciver is 7 years old and it has Digital coax in and out and 2 optical inputs, must be older than 7 years if yours dosent.

Mine decodes DD, Prologic and DTS in full 5.1 and has 2 subwoofer outs so I can go into 5.2

You definately need a NEW receiver (or at least a newer used one) Harman Kardon makes an EXCELLENT one, and so does Onkyo and Yamaha.
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post #10 of 19
11/21/08 at 8:20pm
Thread Starter 
Quote:
Originally Posted by Harrypt View Post

First, the television will not pass surround sound with the exception of OTA television from it's tuner. This is a DRM concession.

Well, damn. That explains why I'm not getting surround sound.

Quote:
Originally Posted by Harrypt View Post

Second, that receiver is old, I don't think it has DD decoding does it? Doesn't it only have matrix decoding? If so sending the PS3 directly to the receiver will not help.

The manual states that it has DD (AC-3), Pro-Logic, 3-Stereo and Stereo. I have discovered that in addition to VCR-3 input being optical digital audio, VCR-2 has a coaxial digital audio input. Is that just a RCA connector, or something more exotic?

Quote:
Originally Posted by Harrypt View Post

So what is probably happening is you have your DVD set to output multichannel digital over hdmi. The TV passes that to the receiver as 2 channel. Then your receiver has no choice but to use matrixing. The multichannel digital track of the DVD you are playing is not matrix encoded so you will not get any surround. Of course the test tones play because the receiver just sends tone to each amplifier separately, probably not even going through the decoder.

Possible solutions: 1 Switch the DVD to play the Dolby 2 channel track if the disc has it. 2 use the analog out of the DVD into the receiver. 3 get a new receiver with more digital inputs and multichannel decoding.

If I use analog audio out of PS3/DVD, will I get 5.1 channels?
Or, If I use optical digital audio out from PS3, coax digital out from Apple TV, will that generate 5.1 channel audio from both sources? Having just unexpectedly spent $400 for my bargain Klipsch rear surrounds, stands and Polk center channel, I'm really not ready to spend yet another $400 or more on a receiver right now. This was an impulse/unexpected bargain purchase. Nothing else until next year.

I really appreciate all the feedback.
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post #11 of 19
11/22/08 at 12:03pm
Quote:
Originally Posted by Mykl4now View Post

Well, damn. That explains why I'm not getting surround sound.

Probably. If your receiver IS capable of 5.1 (you say below that it is).


Quote:
Originally Posted by Mykl4now View Post

The manual states that it has DD (AC-3), Pro-Logic, 3-Stereo and Stereo. I have discovered that in addition to VCR-3 input being optical digital audio, VCR-2 has a coaxial digital audio input. Is that just a RCA connector, or something more exotic?

If one of your components has a digital coax output, you're set. Most likely you will need a 75ohm RCA cable to pass the digital signal competently. A yellow-ended video cable is usually 75ohm, so that will be fine. As will many nicer audio RCA interconnects. If you need to buy a cable, there is no need to spend a lot for something marketed as a "digital coax" cable. IF you have a cable on-hand that you think will work, give it a shot. If it passes 5.1 audio with no dropouts (etc.), then it's fine.


Quote:
Originally Posted by Mykl4now View Post

If I use analog audio out of PS3/DVD, will I get 5.1 channels?

No. Not true, discrete 5.1 audio. You can apply Pro-Logic and get matrixed surround from the 2 channels.


Quote:
Originally Posted by Mykl4now View Post

Or, If I use optical digital audio out from PS3, coax digital out from Apple TV, will that generate 5.1 channel audio from both sources?

Yes. With DD5.1 material. Provided your receiver IS capable of it (again, you seem to be indicating that it is).
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post #12 of 19
12/1/08 at 6:05pm
Thread Starter 
Its been awhile, but I wanted to follow up after having experimented with the suggestions I received here. I am now running the optical digital audio out from the PS3 to my ancient receiver and am actually getting Dolby Digital (AC-3) 5.1 surround sound! Unfortunately, the Apple TV and my Pannasonic TV have only HDMI and optical to transmit digital audio, no co-ax digital audio. I am forced to choose only one component for true 5.1 surround sound (currently my PS3). So although my rented movies downloaded through iTunes are HD, I must listen to only analog stereo audio. My broadcast HD TV also offers many HD programs in surround sound, but I have no way to input that into my receiver, unless...

Any possibility that there is a "hub" (like there is for USB cables) for optical digital audio? All my components can output optical digital audio, but my receiver only has one such input.

Anyway, thanks for all the input and suggestions.
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post #13 of 19
12/1/08 at 7:05pm
Quote:
Originally Posted by Mykl4now View Post

Any possibility that there is a "hub" (like there is for USB cables) for optical digital audio? All my components can output optical digital audio, but my receiver only has one such input.

Can't vouch for the quality, but it's certainly cheap enough to give it a try.

http://www.monoprice.com/products/pr...seq=1&format=2


There are much more expensive switchers available, too, some of which have remote control capability.
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post #14 of 19
12/2/08 at 6:55pm
Quote:
Originally Posted by sivadselim View Post

Can't vouch for the quality, but it's certainly cheap enough to give it a try.

http://www.monoprice.com/products/pr...seq=1&format=2


There are much more expensive switchers available, too, some of which have remote control capability.

Had a friend that tried this cheap swtch. It seemed to work well but I haven't kept in touch so don't know if he was happy long term. Rather than shoot for a expensive switch, might as well sell the older receiver, add the cost of the switch, and spring for a newer receiver. Hell, even a used last year's model of any good receiver would work well and you could pick one up pretty cheap on the used market. (Audiogon or Ebay)
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post #15 of 19
12/2/08 at 10:08pm
Quote:
Originally Posted by atdamico View Post

Rather than shoot for a expensive switch, might as well sell the older receiver, add the cost of the switch, and spring for a newer receiver. Hell, even a used last year's model of any good receiver would work well and you could pick one up pretty cheap on the used market. (Audiogon or Ebay)

Why not buy the switch w/shipping for $10 or so and keep his current receiver if it works?
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post #16 of 19
12/2/08 at 11:36pm
Thread Starter 
Although the switch is suspiciously cheap, I agree its worth a try. The switch, two 6' optical cables and shipping from Monoprice is $13.05! Its a manual switch, but if it lasts me a few months until I can recover from Christmas expenses and then scrape up the cash for a receiver, it will be well spent. I'll report back after I've had time to set it up and play with it. Thanks again for all the time and effort on everyone's part. I appreciate the guidance/opinions/comments.
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post #17 of 19
12/11/08 at 11:49am
Thread Starter 
Well, I bought the suggested optical switcher and it seems to work. I have both the PS3 and the Apple TV connected through the switcher. Playing Star Wars III DVD demonstrated that full 5.1 surround sound was available. When I switched to Apple TV and played a HD trailer, I heard nothing from surround speakers, but I'm not clear whether those trailers are offering surround sound. But the digital audio input doesn't light up the DD (AC3) light as the Star Wars III disk does. I selected "Digital Audio" setting on the Apple TV, and have no idea what else (if anything) I might have missed to obtain surround sound from the Apple TV.

Any thoughts here?

Second observation, I rented and played Indiana Jones & Crystal Skull Blu-Ray disk which displayed Dolby True HD logo rather than AC3. My receiver did not light up the surround sound indicator light and played it in Pro Logic instead. Is Dolby True HD not backward compatible with DD AC3? Or is my receiver too stupid to know what to do with it?

Thanks for the input so far. Any additional insight or speculation welcome.
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post #18 of 19
12/11/08 at 12:50pm
Quote:
Originally Posted by Mykl4now View Post

I rented and played Indiana Jones & Crystal Skull Blu-Ray disk which displayed Dolby True HD logo rather than AC3. My receiver did not light up the surround sound indicator light and played it in Pro Logic instead. Is Dolby True HD not backward compatible with DD AC3?

Pro Logic can only be applied to stereo sources, so it sounds like you're getting the 2-channel lossless core of the TrueHD soundtrack. Make sure the optical out is set to 'bitstream' or 'raw' or any setting that is not PCM. This should make your player transmit the companion DD (AC3) stream to your receiver.

Sanjay
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post #19 of 19
12/11/08 at 12:59pm
Quote:
Originally Posted by Mykl4now View Post

...Second observation, I rented and played Indiana Jones & Crystal Skull Blu-Ray disk which displayed Dolby True HD logo rather than AC3. My receiver did not light up the surround sound indicator light and played it in Pro Logic instead. Is Dolby True HD not backward compatible with DD AC3? Or is my receiver too stupid to know what to do with it?

Thanks for the input so far. Any additional insight or speculation welcome.

To get Doly True HD sound you would need to set your PS3 to output PCM and connect it to your receiver via HDMI, provided that your receiver is capable of receiving HDMI audio and it isn't. There is no way that you can get lossless audio with your current setup, sorry. If your PS3 is connected via digital to your receiver and set to output bitstream it should have played in DD. If it didn't then you need to select DD from the audio menu of the disc or manually select the input from the receiver. It may not auto select.
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