5.1/7.1 PCM, HDMI, and DSP - An Explanation of the Future-Proof ReceiverIntroduction:
With the recent introduction of high resolution sound provided from both Blue-Ray and HD-DVD players, a lot of people have been inquiring about buying a future-proof receiver - one that can handle the lossless and higher resolution lossy formats (TrueHD, etc.) even though HDMI 1.3 is not here yet. There seems to be a lot of confusion here surrounding these topics so I've taken a moment to sit down and write a little bit about it all. First things first, HDMI 1.3 is unnecessary for a receiver, a future-proof receiver with HDMI 1.1 is all you need.Words of caution:1)
Only some receivers with HDMI currently on the market output audio over HDMI, others simply ignore the audio signal and act as a switcher (i.e. Pioneer 1016tx).2)
Movie soundtracks are recorded with the .1 (LFE) channel 10db quieter than the rest of the channels. It is a receiver's job to increase the .1 channel by 10 db, when fed a Dolby or DTS signal. Some receivers do NOT apply this 10 db increase to PCM signals over HDMI, reproducing the bass much quieter than the rest of the soundtrack. See here for more information (including which receivers do what).3)
Some PS3 games (Ridge Racer 7) will only output 7.1 and 2.0 PCM, and thus, will only output 2.0 PCM when settings indicate a 5.1 channel setup. For such games, setting the output to DD will allow 5.1 channel setups to experience properly downmixed 5.1 channels of audio.4)
My examples of receivers with various support is only a small sampling and may not be entirely accurate. As new information emerges, I will try to keep them updated as much as possible. If you have any corrections or additions to the list, please post them in this thread. Use the examples list as a guideline, but be sure to double check support in the receiver's specific thread.Defintions:
These aren't rigorous, so cut me some slack. Simple Processing
- Level trimming (volume balancing)
- Distance adjustment
- Bass managementSurround Processing
- Dolby Pro-Logic IIx provides surround upmixing from 5.1 pre-HDMI Dolby formats and two channel formats to 6.1 and 7.1 channels.
- DTS EX provides surround upmixing from specially encoded 5.1 pre-HDMI DTS formats into 6.1 channels (7.1 too?).
- Some receivers also have THX Select2 provides advanced THX processing that attempts to improve sound quality for small rooms from sound formats that were originally mixed for theaters. Also provides surround upmixing from 5.1 channels to 7.1 channels.EQ Processing
- Some receivers provide advanced equalization, or adjustment of the volume of specific frequency bands, to help correct room acoustical problems (some even in the time-domain, i.e. Audessy).Analog
- Provides one analog channel of lossless uncompressed PCM audio.
- Most receivers have 5.1 analog inputs, some have 7.1.SPDIF
- Provides two channel lossless uncompressed PCM audio.
- Provides all pre-HDMI Dolby and DTS formats (5.1/6.1).HDMI 1.1
- Provides up to 8 (7.1) channels of lossless uncompressed PCM audio.
- Provides all pre-HDMI Dolby and DTS formats (5.1/6.1).
- Provides DVD-Audio streaming as PCM.HDMI 1.2
- Adds SACD streaming as proprietary DSD format.HDMI 1.3
- Adds up to 8 (7.1) channels of post-HDMI Dolby and DTS formats (TrueHD, etc.).Current HD-DVD and Blue-Ray Players
- Provides pre-HDMI and post-HDMI formats through analog outputs in lossless uncompressed PCM format.
- Provides pre-HDMI and post-HDMI formats through HDMI output in lossless uncompressed PCM format.
- Provides pre-HDMI formats through HDMI output in bitstream compressed format (Dolby/DTS).
- Limited to 5.1 channels (7.1 channels will come with later players).PS3
- Provides 7.1 channels.
- 7.1 titles include: Resistance of Man (7.1 discrete video game), Descent (6.1 matrixed to 7.1), and Crank (6.1 matrixed to 7.1).Levels of Receivers:Level 1
5.1 receivers that provide SPDIF, 5.1 analog input channels and provide all three processing stages on digital sources.Examples:
Virtually all 5.1 receivers.Level 2
7.1 receivers that provide SPDIF, 5.1 analog inputs, and provide all three processing stages on digital sources.Level 3
7.1 receivers that provide SPDIF, 5.1 analog inputs, and 5.1 HDMI PCM but can't perform surround processing on PCM digital sources.Examples:
Panasonic XR57 (no processing at all).Level 3.5
(added late in the game)
7.1 receivers that provide SPDIF, 7.1 analog inputs, and 5.1 HDMI PCM but can't perform surround processing on PCM digital sources.Examples:
Onkyo x04 series.Level 4
7.1 receivers that provide SPDIF, 5.1/7.1 analog inputs, and 7.1 HDMI PCM but can't perform surround processing on PCM digital sources.Examples:
Panasonic XR700 (no processing at all). Onkyo 605. Sony STR-DG810 and higher.Level 5
7.1 recievers that provide SPDIF, 5.1/7.1 analog inputs, 5.1 HDMI PCM, and allow all three processing types on all digital signals.Examples:
HK 645 and higher. Marantz SR6001 and higher (only with latest firmware?).Level 6
7.1 receivers that provide SPDIF, 5.1/7.1 analog inputs, 7.1 HDMI PCM, and allow all three processing types on all digital signals.Examples:
All HDMI Denons. Yamaha RX-V661/HTR-6060 and higher. Pioneer Elite 81TXV and higher. Onkyo 705 and higher. Integra *.8 series.Future-proof decisions:
If you don't care about 7.1 surround sound, then all receivers are future proof.
If you don't care about 7.1 surround sound for post-HDMI Dolby and DTS formats, or using generally inferior DACs in your player for post-HDMI Dolby and DTS formats, then receivers Level 2 and higher are future proof.
If you don't care about 7.1 audio for post-HDMI Dolby and DTS formats, then receivers Level 3 and higher are future proof.
If you don't care about 7.1 audio for 5.1 post-HDMI Dolby and DTS formats, then receivers Level 4 and higher are future proof.
If you don't care about being at the mercy of the generally inferior DACs in your player (vs the DACs in your receiver) for 7.1 audio and switching between HDMI and Analog output for 5.1 and 7.1 sources, then receivers Level 5 and higher are future proof.
If you want a true future proof receiver with full processing on post-HDMI Dolby and DTS formats, and true digital 7.1 channel support, then Level 6 receivers are future proof (see annotation).Annotation:
The only current 7.1 PCM HDMI source is the PS3. Receiver manuals are notoriously vague on HDMI audio support. Therefore, there are very few confirmed Level 6 receivers. Some Level 5 receivers may be Level 6 receivers. Contacting the manufacturer is the best way to confirm Level 6 receivers until people begin testing with the PS3.