Originally Posted by wernerleitmann
please allow two questions that came up recently:
1) Although I've read the manual, I do not completely understand the "mixdown mode" options in the speaker configuration settings. Does it make any difference in terms of what's the ouput of the DX-5 through HDMI audio-only when the mixdown mode, or general speaker configuration, is set to "7.1" or "5.1"? I'm using a 5.1 speaker setup. and I'm wondering why the signal input detector of my processor preamp always detects a "7.1", independent of the disc inserted (a stereo CD or SACD, or a 5.1 DVD, for example). I've had the chance to try with an (also Oppo-based) Primare player, here the processor detects the correct format of what's on the disc. So what's the best setting in my configuration for the "mixdown" (btw, I never use mixdown of multichannel sources to stereo output)?
2) Is there a way to play CDs, DVD-As, or multichannel SACDs, "gapless", without interrupting sound between tracks? Since many discs, classical, but also many rock albums have tracks that flow from one to the next without separation, it would be a valuable option to have "gapless" playback. Interestingly, when playing a DVD-Video or BD-Video, the playback is gapless!
Question #1 actually has several separate questions. I will try to answer them in an order that makes sense.
a) If you use the HDMI A/V output of the DX-5 the sound quality will not be as good, but your processor will indicate the proper number of channels coming from the DX-5. With the Audio-Only HDMI output, there is no simple way for us to detect which channels are active. Therefore we set the HDMI signal header to indicate the MAXIMUM number of channels that are available from that format. Otherwise, the processor would cut off the active channels that were not indicated. So your processor should indicate the following:
CD = 2.0
SACD = 5.1
DVD-Video = 5.1
DVD-Audio = 5.1
Blu-Ray = 7.1
It is a quirk of the DX-5 that cannot be fixed, I am sorry for that. Also, the Audio-Only HDMI can only output PCM (and DSD). So your surround processor will always indicate PCM (or DSD), regardless of the type of compression used on the disc. The advantage of this is that even older processors that cannot decode the newer lossless formats will still play them correctly. And again, if you use the A/V HDMI output, the processor will indicate the type of compression that is used, but it will not sound as good.
However if your processor is always indicating 7.1 channels, even with a CD, there is something wrong somewhere. It could be a bug in the DX-5 firmware, or a defect in the HDMI transmitter PCB, or it could be some quirk or that particular processor. It may take some time to figure out the exact problem. How close are you to München, where the importer is located? Also if you are planning to have the DSD upgrade installed, we could send an extra HDMI transmitter PCB and connector cable so that while they are working on your machine they could confirm the problem and repair it while they perform the other work.
b) It's been too many years since we developed the DX-5 for me to recall all the exact details of what we had to do to ensure that everything worked properly. The Audio Only HDMI signals are taken from the signals that are normally sent to the 7.1 analog outputs. These are either PCM (or in the case of an SACD when the on-screen menu is set to NOT convert SACD to 88.2/24 PCM) DSD. All of the compressed (lossless or lossy) Dolby and dts formats are decoded to PCM. It's been too long for me to remember what happens when you listen to a 7.1 channel soundtrack on a 5..1 channel system. The two extra channels must either be mixed in with the active channels or else discarded. I believe that they are discarded as mixing them in would raise a lot of issues. I am sure that whatever is done by Ayre with the Audio-Only HDMI output is AT LEAST as good as what Oppo does with their audio section of the A/V HDMI output. It is not like us to degrade anything. Evidence of this is the LFE Mixdown mode. Oppo does not offer this, and when several forum participants gave us examples of discs that were authored incorrectly and required the LFE Mixdown mode to play back properly, we added this. I don't know of any other player that offers this feature.
To conclude, I would strongly recommend setting the on-screen setup menu EXACTLY as described in the manual. There will be some quirks in the display regarding the number of channels that is playing. For example all Blu-ray discs will show as 7.1 channels, even if they are not all used on a particular disc. And it may be that since your processor is either only capable of 5.1 channels (or is set to 5.1 channels) that it is causing the mis-indication of number of channels being transmitted.
Please let me know the make and model of the processor that you are using and I will investigate this issue further. (Our digital programmer can help answer some of your questions, but he is currently on vacation.) Thank you for your kind assistance and patience.
Ayre Acoustics, Inc.