On the other hand, I will not get into the craziness of SACD producers for using 5.1, especially when designated in metadata as 6 channels. There is no earthly reason I am aware of for the .1 channel to even exist on any Mch source media, even BD video in this day and age. Yet, it does continue to exist and cause nothing but confusion.
I think the rationale for the existence of the .1 channel on SACD is as follows :
- physical SACD disc players are often connected to preamps/receivers via 6-channel analog output
- most receivers/preamps don't do any bass management on the 6-channel analog input
Since not everyone has a subwoofer, or wants to use one, this means the bass management has to be done in the SACD player itself. This is the way it works in my Sony SCD-CE775. I have to tell it my actual speaker configuration in there. And then it decides how to mix, and which of the 6 cables of the analog output will get a signal.
If you are streaming digitally however, then you don't need to do bass management in the player. But most SACD players don't stream DSD digitally. My SCD-CE775 SACD changer was audio only and didn't have an HDMI interface. I bought it in 2001, and it actually predates the existence of the HDMI interface which was introduced in 2002.
I think at the time, there were some short lived attempts to stream DSD over Firewire. Unfortunately, even in 2017, there is no proper standard solution for bitstreaming DSD to preamps.
Many AVRs support DSD over HDMI - my Yamaha RX-A1000 does.
But most SACD players won't send it over. No GPU I know can send bitstream it either.
Even with bitstreaming, it would seem to me that there would still need to be some indication in the bit stream of which channels are which, ie. whether the 6th channel is an LFE channel or not. I would assume that's in the HDMI specs for bit streaming DSD somewhere.
The SACD ISO specs would dictate how the designation for the 6th channel is encoded, whether it's designated as an LFE channel or not. I'm not aware of 6-channel SACD discs that are not actually 5.1 .
I don't have any way to bitstream DSD digitally to my AVR, and I don't have a USB DAC that takes DSD.
I do have an Asio interface with plenty of channels. Actually, a pair of them. Audiofire 12 + Audiofire 8a daisy channed. It presents itself has a 28-in / 28-out ASIO interface. By giving the right channel offset , I am able to use ASIO to play DSD in Media Center on the interface I want. There is no way to assign specific ASIO channels to specific speakers, however.
The only thing that selects the order is designated the numbers of channels to not just the proper number for your system, but the proper order ...
In practice, on my ECHO, no particular output jack is assigned to left, right, center, surround, etc. It's not a home theater DAC - it's for professional audio recording. But works nicely as DAC. I had to figure out which order the channels are packed and plug the right jacks in . I think the channel packing order is even different between ASIO and WASAPI.
In WASAPI, I have a bunch of different devices - a couple of 7.1 analog devices, 2 pairs of stereo devices, and a few more for the SPDIF plugs. Ie. it's not a single 28 channel WASAPI device at all.
Basically, for consumer equipment like a receiver or player, the jacks are clearly assigned to certain speakers, and the content is clearly labeled on disc/files for certain channels. When it comes to audio interfaces, it's not as clearly defined, especially so in the case of ASIO. What would really be needed is some kind of channel map. The player software itself isn't the most logical place for it to be. Yet I find myself wishing for that.
I have built in speakers in almost every room of my house. I think about 16 pairs of them between the two floors. The speaker plugs are concentrated in 2 locations - one on each floor. I have a bunch of multi-channel amps near them, daisy chained, so I get to play stereo content on either floor. Usability is limited though - I can't turn music on/off in each room. There is only one volume control per receiver, and it affects 6 channels at once. I can't adjust volume for each room either. And I can only play 2 sources - one per floor. Some of the speakers are outdoors as well. Those are powered by the last amp in each amp chain, so I just power off those amps when I don't want to play outdoors.
It's really not very usable overall, and I wish I had something better. I think the combination of a multi-channel DAC (like the ECHO) and those receivers would work well, if I could adjust volume digitally in JRiver. But I would still need to have some kind of channel router/mixer. Ideally I would want for example to partition the 28 channels in 4-6 separate zones. Some zones might be stereo, and others not. But all playback would be from a single ASIO audio device. I don't think JRiver MC can do this today unfortunately. But perhaps I'm missing something with the zoning feature. I see choices for outputting up to 32 channels, so perhaps I'm really missing something - not sure how the routing works in that case.
Author
Topic: Problem playing back SACD ISO (Read 7049 times)