HD 101: How to use Dolby TrueHD and DTS-HD with your PS3

If you read Engadget HD, it's safe to say that you're ahead of the curve when it comes to home audio/video. You do your homework before picking out gear, and you know that the PS3 can deliver Blu-ray audio bliss courtesy lossless Dolby TrueHD and DTS-HD MA tracks. One look at all the configuration options in the PS3's XMB (Xross Media Bar) interface, however, and you might find yourself wondering how to unlock the those audio codecs. In this installment of HD 101, we'll briefly cover the reason for the confusion and then go through setting up your PS3 for lossless audio step-by-step.

We recently got an email from Mike, who has a new receiver that decodes Dolby TrueHD and DTS-HD MA, but was stumped about how to get it to play nicely with his PS3:

"I hooked up my PS3 to it with the HDMI and changed the settings to output audio as Linear PCM instead of Bitstream via the HDMI and it doesn't appear the receiver is getting the Dolby True HD or DTS HD signals. When I was outputting sound via an optical cable as bitstream, my receiver would display "Dolby Digital" or "DTS" on the front LED, but now all it displays is "PCM" and not Dolby True HD or DTS HD, which is what I expected after upgrading the receiver and running audio through the HDMI. What gives? Am I doing something wrong? I do have this thing hooked up for optimal sound by setting it to linear PCM over bitstream? I'd hate to think I wasted a bunch of money on gear i don't have connected correctly."

First off, there's nothing wrong with your setup, and your equipment is perfectly capable of delivering sonic nirvana of the new lossless codecs. Before we get into the step-by-step process, though, we'll recap some essential information from a post we did a while back, but with a very PS3-specific viewpoint.

First off, S/PDIF transmission -- over either optical TOSLINK or coax -- does not have the bandwidth to carry Dolby TrueHD or DTS-HD MA signals. If you connect your Blu-ray player to your receiver with optical or coax, the audio will "fall back" to Dolby Digital, DTS or two-channel PCM (lossless, but only two channels). What you'll need is an HDMI connection. Note that with the PS3, you don't specifically need a HDMI 1.3 receiver or cable -- even HDMI 1.0 will suffice.

TOSLink and HDMI

Many modern receivers can decode Dolby TrueHD and DTS-HD MA right in the receiver. This feature is making its way down to even modestly-priced models for many manufacturers, and we're happy to see it. When using a PS3, however, Dolby TrueHD and DTS-HD MA codec support in the receiver will go unused. If you paid extra just for the extra two logos, sorry. Whatever you do, don't panic -- you can still enjoy all the quality of these lossless codecs with your PS3.

Dolby TrueHD / DTS-HD MA and the PS3
It is helpful to think of Dolby True HD and DTS-HD MA as "zipped" versions of the audio tracks that allows the Blu-ray disc to store more data (useful when space has to be reserved for other stuff -- like video, for example). Just like zip files, when you decode the Dolby TrueHD / DTS-HD MA tracks, you get an identical copy of the original audio -- this is why it's called "lossless." On Blu-ray discs, the Dolby TrueHD and DTS-HD MA codecs can bundle up to eight channels of lossless audio information, each channel with up to 24-bits resolution at a 96kHz sampling rate, commonly referred to as "24/96." However, the PS3 cannot send these formats over HDMI for decoding in your receiver.

First, the good news. What the PS3 can do is decode (unzip) the Dolby TrueHD / DTS-HD MA lossless audio and send it to your receiver as a multichannel linear PCM (LPCM) stream, which just about any modern receiver can decode. The LPCM audio is identical to the Dolby TrueHD / DTS-HD MA original format, so no quality is lost.

Now, the bad news. An annoying side effect of sending the "unzipped" LPCM rather than the "zipped" Dolby TrueHD / DTS-HD MA is that the receiver's Dolby TrueHD / DTS-HD MA indicator will not light up because it's not decoding Dolby TrueHD / DTS-HD MA -- the PS3 already did the decoding. Instead, the receiver will (correctly) indicate that it is receiving a LPCM signal.

Set up
Enough background -- let's get the good audio flowing. It sounds like our friend Mike currently has things set up so the PS3 is sending bitstream audio to his receiver, which unfortunately means he's not taking advantage of the the lossless codecs. In this case, information about the audio format sent from the PS3 (accessed by pressing the "Select" button) and being decoded by the receiver will show up like this:

Even though you might be comforted by the nice red "DTS" indicator on your receiver and the "DTS Multi-Channel" in the PS3's info area, you're not getting DTS-HD MA lossless audio, and it's a similar story for Dolby TrueHD.

Go back out to the PS3's XMB interface and go to Settings -> Video Settings. Once there, scroll down to the BD/DVD Audio Output Format (HDMI) and set the PS3 to stream Linear PCM. This will force the PS3 to decode the Dolby TrueHD / DTS-HD MA tracks and send them out as lossless LPCM on the HDMI connection.

Now, just to be sure everything is hooked up correctly, go to the Settings -> Sound Settings in the XMB. From there, make sure the PS3 audio is set to go out over the HDMI connection and that the necessary LPCM formats (24-bits at 96kHz) are enabled.

You're all done! If you fire up a Blu-ray disc with one of the lossless codecs now, your receiver will no longer show the Dolby or DTS logos. Remember -- the PS3 is decoding the lossless audio and sending to the receiver as LPCM. So even though you're not seeing the fancy lights that you might have paid for, you're getting higher quality audio. What you really want to check out is the PS3's info, which should now show that you are indeed getting the lossless audio.

Got a basic HD topic that you'd love for us to explain? Tired of Google's complicated answers when you asked for a simple explaination? Hit us up at ask at engadgethd dawt com and keep an eye on this space -- your topic could be next.