5.1/7.1 PCM, HDMI, and DSP - An Explaination of the Future-Proof receiver - Page 4

SPDIF was a huge mess when it came out too. Considering that HDMI was just introduced, I think we're doing fairly well. Technical documentation is horrible in any consumer product. Usually it's a copy-and-paste job from the older manuals, which is why PCM HDMI specs are missing. Remember, these are gigantic companies trying to pass information to highly segregated groups. It should take a lot of support calls and another generation before they figure it out. I'm pretty sure the 604 doesn't do processing on HDMI PCM, but the 674 does. Check the manuals under the surround-sound format, see if multi-channel PCM is listed. If it can do DPLIIx on the PCM stream, then it can certainly do bass management. We're used to an unusually long period of stability in home audio, so a lot of people entering the market in the last few years think stability is the mainstay, when in fact, for many years, things were very chaotic. With HDMI and the high-def formats bringing the thundering herd of change, no one should be expecting a good execution in first-generation (or even second-generation) technology. Give it time.

If they won't know, they'll contact the engineering department and find someone who will. Documentation is usually the first thing to suffer when companies try to compress the budget or compress the timeline. Poor documentation rarely means they don't know what the product does, it almost always means they did a cut back on the budget and schedule for the documentation, resulting in a half-assed job (which is all too common, unfortunately). I agree, it sucks and I wish it was different, but it's always been that way. It makes it a pain for us, customers, but thats the price we pair for early adoption.

Using the information you provided and doing a little bit of extra reasearch, it looks like all latest HDMI Denons are level 6 (accept 7.1 PCM and do processing). I've updated the first post to reflect this. Thanks for the info!


As Sanjay said, no current receivers can do this, you need a receiver that has HDMI 1.3. But the great thing is, you don't need this type of receiver! The high-def DVD players can decode the signals for you and send them as multichannel PCM signals either over an analog connection, or, preferrably, over HDMI 1.1.

This is actually preferrable since special decoding can be done on the player, for example director comments overlaid on the original soundtrack. These types of special decoding can't be done on the receiver since it doesn't have access to the necessary information on the disc.

Believe it or not, providing the new DD and DTS formats over HDMI 1.3 is actually a step backwards and will only cause more confusion and problems. I really don't have a clue what they were thinking.

EDIT (added): They should have spec'd all HDMI versions to only carry uncompressed lossless audio (PCM) at various resolutions (24/192, etc.) from the very beginning, like they did with video. It was extremely boneheaded of the HDMI consortium to do what they did with multiple audio formats. They only thing they did was give receiver manufacturers opportunities to screw things up. Not only that, but if we move to HDMI only receivers, you won't need all those Dolby and DTS encoders anymore, making them a whole lot cheaper. All you'd have would be a PCM processor.


I'm not familiar with the Denon A1-SRA, but you can certainly connect 7.1 analog outputs to your 7.1 analog inputs to achieve nearly the same thing (obviously, there's a DAC involved, and possibly an ADC involved too). If it has an HDMI input, it may be able to receive 7.1 over HDMI (or 5.1).

Your explaination is correct.

In addition, the Denon may be able to provide processing on the analog inputs (after an ADC and DAC - see my next response). If it can't, or you decide not to do processing on the analog inputs, then you'll have to set up your HD-DVD/BR player to do the processing for you (bass management, time delay, level trim). While annoying, it is a trivial task.


Nearly the same thing as 7.1 PCM over HDMI. The PCM over HDMI will be completely digital, whereas the PCM over analog connections will be analog in nature, meaning you'll need to digital and analog conversions (DAC/ADC). Whenever a conversion takes place, there's an opportunity for unwanted coloration of the audio signal.

DAC = digital to analog conversion
ADC = analog to digital conversion

The player will perform a DAC and send the PCM over your analog connections. The receiver may or may not perform an ADC to be able to perform processing (bass management, etc.) on the analog inputs. If this happens, then another DAC will need to happen after the processing before sending the processed signal to the amplifier section.

I believe all Denons allow you to choose whether or not to apply the ADC, processing and the final DAC before amplification. You'll have to look at the manual for how to do this, but I believe it's the Pure Direct option.


It's far better than tech support at HP (had to send in my laptop for repairs yesterday).

If you have >5.1 speakers, you'll want to send the older DD & DTS streams out as bitstreams (not PCM), since the Toshibas (not sure about BDs) can't do the 6.1 decoding for DTS-EX and DD's equivalent. Otherwise, there's no difference between doing the legacy (older format) decoding on the receiver or the players.