Picture and Sound via HDMI

Just sound via HDMI:
Here's where things get really tricky: What do you do if you want to use the Blu-ray's HD-audio formats, but there's no HDMI-compatible screen in the signal chain? The problem here is that audio and video always travel together via HDMI - the interface is not meant to carry a lone audio signal. This limitation can cause a lot of trouble.

Along with the normal HDMI signal, nearly all players only deliver a reduced resolution via YUV - in general, just 576i. If the digital connection is active, the YUV will transmit neither 720 nor 1,080 lines, and if you deactivate the digital (HDMI) connection, there's obviously not going to be any sound via HDMI. In addition, the AV receiver generally won't allow you to allocate the HDMI audio to a YUV picture.

So far only in the USA: The Emotiva UMC-1 pre-amp can decode the sound from HDTV signals and deliver YUV video.

But there's another obstacle: No AV receiver can conjure up a YUV signal from HDMI video. The processing can only ever move "upwards" - that is, with analog signals being up-scaled and digitized. Converting downwards is impossible, for one, because it would involve bypassing the HDCP copy-protection. But in the USA, the company Emotive has announced its UMC-1 pre-amp that's supposed to be able to do exactly that. It'll be interesting to see whether the content suppliers tolerate this in the long term - if the claim is indeed true - and whether other manufacturers will follow suit.

In a nutshell: the only sensible option for HD audio if you've got an analog display is an analog connection. You'll need a player with an analog 7.1-channel output and to connect the YUV output to the receiver or pre-amp - or directly to your TV or projector.

Extra devices such as the DVI Fix from Spatz allow you to influence what signals a player delivers.

Many people are unaware of this: You cannot use HD audio if the picture is being supplied in the standard 576i resolution via HDMI. In this case, the player only supplies conventional Dolby Digital or DTS, and sometimes only in stereo - all thanks to Hollywood and its security measures!

We also advise caution when connecting an HDMI splitter between the player and AV receiver or pre-amp - for example, if you want to connect further displays, or if the AV receiver cannot relay 24p signals. The player asks, via the cable, which audio format the TV needs, and then delivers only stereo sound - and therefore not HD audio in a form that's useful for the sound system. You would only get the correct audio with the screen switched off, but there's not a lot of point in that!

A so-called EDID manager (an external HDMI device) can be of some assistance, but that's an expensive solution. In some cases, the HDMI stream can simply pass through the receiver intact, but this generally only works with newer devices.