Sync/dropout observation on UMC-1 with HTPC

[Nemesis.ie]

Hi all,

I'm still a bit jet-lagged so please excuse me if I am a bit incoherent!

Anyway, I've not had the UMC-1 running for 3 days and am STUNNED by the difference over the Yamaha RX-V2500. Every time I watch something I am amazed at the sound positioning and clarity.

To the point (at last!), configured using the ATI HDMI output device, I was not seeing PLIIx processing from 2 channel (Stereo music files on the HTPC, played over HDMI) and was getting very slow sync times (several seconds), 5+ second drop out/re-sync when pausing music or movies etc. etc.

All streams were running through apparently bit-streamed, i.e. when playing DTS Master demos I was seeing DTS MA on the UMC-1.

I then thought would try installing the Realtek HDMI driver (it's an add-on to the sound driver to pipe the sound through the ATI (or other brand presumably) HDMI port. With this installed things changed dramatically. Instant sync on all files, 2 channel is receiving PLIIx (and sounds fantastic). I can pause, play, rewind, FF, move to another part of the movie/music and it syncs/plays instantly. The down-side is that DTS MA is no longer displaying, it shows DTS, 48KHz.

I figure the Realtek driver is doing some kind of decoding/encoding to the stream, possibly playing back in some kind of PCM (yet it does show the type of stream to some extent, not just PCM or MCHPCM) and whatever it is outputting is more "compatible" or something.

One constant on either method, from time to time when I STOP a stream (not sure it matters what type, I have seen it with both drivers (ATI/MS and Realtek) I get a "clicking", sometimes a repeating tone, sometimes sort a musical rhythm for about 7 seconds, it's like the buffer is not cleared or something and the UMC-1 is playing noise - this could be the PC and not the UMC-1 of course.

Anyway, I was thinking it might be an idea for Lonnie to buy an ATI 5 series card (Mine is the 5750, quite cheap and cheaper than a PCH C-200 anyway <G>). They could then test the outputs of the different streams and see what is being done differently by the realtek driver, it might shed some light on the differences in presentation/hand-shaking that are causing the drop-outs/slow sync etc?

Food for thought I hope. ;D

Cheerio!

[BillBauman]

ATI uses Realtek's chipset for the audio on this solution. It's the same driver/company packaged with the ATI software, you just downloaded the (majorly) updated version of it. The udpate adds both functionality and fixes. I have used a similar setup in the past, but no longer do, so I can't help with any testing here.

[epsomd2]

I have the same problem with my UMC-1 and my Aspire Revo 3610 box. I wouldn't put this on the UMC-1 it appears to be a problem with the decoding in the computer through HDMI. Still looking for good drivers that correct the issue. The problem also changes based on the program I use for playback. So there are loads of factors here not like a bluray player or other source device.

If I figure something out I'll post.

S-P

[Nemesis.ie]

Apr 29, 2010 8:57:16 GMT -5 BillBauman said:

ATI uses Realtek's chipset for the audio on this solution. It's the same driver/company packaged with the ATI software, you just downloaded the (majorly) updated version of it. The udpate adds both functionality and fixes. I have used a similar setup in the past, but no longer do, so I can't help with any testing here.

Yes, but I think the "default" driver may be an MS one or something, either way, the behaviour is very different. HD Master/DTHD should be being passed through I would think even in a newer driver - even more so actually.

[Nemesis.ie]

Apr 29, 2010 10:39:10 GMT -5 epsomd2 said:

I have the same problem with my UMC-1 and my Aspire Revo 3610 box. I wouldn't put this on the UMC-1 it appears to be a problem with the decoding in the computer through HDMI. Still looking for good drivers that correct the issue. The problem also changes based on the program I use for playback. So there are loads of factors here not like a bluray player or other source device.

If I figure something out I'll post.

S-P

The thing is, the audio works superbly and with instant response (i.e. there is no problem, it "just works") with the latest Realtek drivers, other than it's not showing the HD audio, hard to say if its's playing it as I don't have any high res stuff to try to see if it says anything other than 48Khz - anyone with a link to some free HR/HD samples in >48KHz?

[loopinfool]

Apr 29, 2010 12:23:26 GMT -5 Nemesis.ie said:

anyone with a link to some free HR/HD samples in >48KHz?

Here are a couple:
www.gimell.com/musicstore-download-test-files.aspx
www.2l.no/hires/index.html

- LoopinFool

[Nemesis.ie]

Thanks LF!

[loopinfool]

Apr 29, 2010 14:26:44 GMT -5 Nemesis.ie said:

Thanks LF!

You're welcome.

I forgot to add that if anyone here is looking to purchase high-res computer-based audio, check these guys out:
www.hdtracks.com

They're doing it the right way, IMO.

- LoopinFool

[Nemesis.ie]

Quick update, more detail when I get a chance to do more testing:

I uninstalled the Realtek HDMI driver and confirmed that the default Win7 driver is attributed to ATi and seems to be from January 2010 (need to check the exact date).

With the Realtek driver, the hires files from LF's links playback with "2 channel, 48KHz" and the multi-channel test from the Gimell site has the 2 surround channels appearing in the Fronts.

With the ATi driver, the Gimell test has them in the back surrounds which seems more correct for multi-channel music.

Playing the HR audio with ATi, the pop-up does not appear at all (bug?), but the VFD display shows Multich PCM or something and when pressing the info button, although the sample rate is not shown (can this be added?) the format says DTS-HD Master.

I can only conclude that the Realtek driver does not offer the same functionality as the default driver. There is a "Dolby live" option in the RT drivers and I will experiment with that enabled but I suspect all it does is encode to 5.1 48KHz on the fly, i.e. doing the same thing PLIIx on the UMC-1 does, which is of no benefit.

The other thing the ATi driver has is the ability to set the number of speakers you have an also the "room correction" enhancement, I ran it (will update the other thread at some point) and it sends out a LOT of test tones and comes up with some delays for the channels and such, need to compare SQ after using it (it can be ticked on and off easily once run) to see if it offers any benefit.

I still think it may be of benefit to Emotiva to get a card and run the various formats through their test equipment to see where the differences are and see if they can get things to lock on quicker and more consistently with the ATi (which seems to be bitstream) driver.