Axiom Home Page Forums General Discussion Home Theater Audio Format Question

Our basement refinishing project finally is almost done (hope to post pictures at some point), and this past weekend I set up the home theater system. Watched Dark Night last night on BluRay, and now have a question (I'd never watched BluRay at home before). The player I use is the PS3, connected to my AVR via HDMI. While watching I noticed that the audio format was displayed as PCM, and I could not change that on the AVR. Doing some research today, it appears that PCM is actually a good format (it certainly sounded good). The question I have is this. When looking at the PS3 manual, it says: "When using an HDMI cable, only [Linear PCM 2 Ch.] audio will be output from PlayStation®2 and PlayStation® format software. To output Dolby Digital or DTS audio, you must connect the PS3™ system and the audio device using a digital optical cable and switch to [Digital Out (Optical)] under [Audio Output Settings]." This language confuses me, since it switches from talking about the PS2 in the first sentence to the PS3 in the second. In any event, my concern is the reference to 2 Ch. Output--am I losing something by using HDMI and apparently limiting the output to 2 channel output? If it matters, my AVR is the Panasonic Elite 72TXV.

As in the past, your thoughts are much appreciated. I have to say, the Axioms sound incredible in my new space.

You shouldn't be losing anything with Blu-ray when you're outputting as PCM over HDMI. I don't have any PS1 or PS2 games, so I can't verify whether or not it limits PCM output to 2-channel for those. I don't have time at the moment to look into your receiver, so hopefully someone else can do that.

Thanks CV. I am not particularly concerned about the PS2 games. Really my concern is about when I am watching movies and, I suppose, when playing PS3 games. And, it's always possible I just have no idea what the manual is saying and/or my understanding of any/all of this!

PS1 games used 44.1kHz, stereo audio, and PS2 games are 48kHz. There were a few (very few) PS2 titles which had live-mixed DTS, and a couple with Dolby-Digital tracks for pre-rendered video.

When I read that same text I wondered if they meant that games which used those special features would not output their audio correctly over HDMI. I don't have any of the DTS games, but I do have Final Fantasy X-2 which has Dolby Digital for its movies. Maybe I'll try that over HDMI this weekend.

I'm a bit confused for which I apologize. During the BluRay movie, were you experiencing 5.1 surround sound or just stereo. I'm not familiar with your Panny AVR but will it tell you what type of audio is being output while it receives the PCM input? This would give us a good clue.

Also, PCM is not so much a format but a method of transport to get your sound format from one box to the next.

One thing you are correct about is that it can get very confusing with what options to pick to ensure you get a surround sound format to play via a PS3. Works seamlessly after you get it right though.

I'll be back with correct settings once I remember where I put them or looked them up.

there is not much to configure, when using the PS3's HDMI connection. You need to go in the ps3's system menu and make sure that the AUDIO OUTPUT is set to PCM or LPCM.

From that point, the majority of receivers will display PCM on their display and won't be able to tell more information. The decoding of the audio track will be done by the ps3 and the resulting decoded audio stream will be played by the receiver (which has no clues regarding the format it was encoded).

To find out what you are really listening to, you need to bring the information page (on the ps3) and from there you can find out which audio codec is in use.

To send an unprocessed audio signal that an AVR could decode, you would have to use an optical cable but that would be limiting you to 5.1 audio tracks.

So PCM (LPCM), is the way to go but you will never see the audio format listed on your receiver's display.

This is also an advantage for people which aren't equipped with a recent AVR. The ps3 is doing all the decoding, so the AVR only needs to support LPCM over a hdmi port.

OK, got lazy and cut and pasted from a FAQ.

<snip>
Case 4: PS3 connected to a recent model AVR, with HDMI inputs, and the AVR HDMI output is connected to your recent vintage HDTV.

In this case you can simply use an HDMI cable to connect from the HDMI output on your PS3 to an available HDMI input on your AVR. Then use another HDMI cable to connected the HDMI output of your AVR to an available HDMI input on your HDTV. Your AVR will receive the digital audio data (decoded and provided in multi-channel LPCM format) from the PS3, will process it then output the audio to the connected speakers. The AVR will also pass the digital video data on to your HDTV for display.

Suggested PS3 Audio and Video additional Settings for Case 4 (starting from XMB and Settings drop down menu):

* XMB >>> Settings >>> Display Settings >>> Video Output Settings = HDMI >>> Setting Method=AUTOMATIC

* XMB >>> Settings >>> Video Settings* >>> BD/DVD Audio Output Format (HDMI)=LINEAR PCM

* XMB >>> Settings >>> Sound Settings >>> Audio Output Settings >>> HDMI >>> Method for Setting the Output Format=AUTOMATIC

* "Video Settings" was called "BD/DVD Settings" with PS3 firmware prior to version 2.50

<endsnip>

In short, if you are set up as above,
whatever fancy audio format you choose from your Bluray disk will automatically get decoded in the PS3 so that the AVR doesn't have to deal with it. Only the newest AVRs will decode the new HD formats so this is a great thing as you wont need to upgrade your current one.

It then takes the decoded data and sends it out via the HDMI to the AVR as PCM data (think of it as a universal digital format or transport layer.) Because the AVR is receiving generic digital data, it doesn't have to decode it nor does it know or even care what fancy HD format it was in originally. That's why the AVR doesn't tell you anything except "PCM". My Denon, simply says "Digital" or something like that.

But in the end, you still get true HD surround sound out of your speakers. The only thing it won't do in is way is 7.1 formats if you are set up for that. It will however, automatically strip it down to 5.1 for you automatically. To get true 7.1 you would need to invest in a receiver that is capable of doing the decoding of HD formats on the AVR side side.

The 7.1 part is incorrect. The PS3 will decode the 7.1 formats and send them as 8 channels of LPCM to the AVR if it advertises support (mine does).

There really is no reason at all to send undecoded audio to the AVR. There's even a plus to doing it in the player, in that it can mix secondary steams (like menu beeps or commentaries) on the fly. Without the player doing the decoding you'd not hear these things at all.

What you've encountered here is one limitation to using a PS3 as a BluRay player. It cannot output HD audio (DolbyTrueHD or DTSHD) in a raw (bitstream) format. All it can do is process the signal and output it as PCM. I'm pretty sure that it can do 7.1 channel PCM, but I know from personal experience that it can do 5.1 PCM.

So you're still going to get the soundtrack in full, real, and exquisite surround sound, even though your AVR just says 'PCM' instead of 'Dolby Digital' or 'DTS' or whatever.

With that 72TX, it doesn't matter anyway because the 72TX doesn't know how to decode a DD-HD or DTS-HD bitstream. So even if the PS3 could output the bitstream, you wouldn't be able to use it with your receiver. You'd have to tell it to output it in PCM.