Sound card out of sync

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jddavid123
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Joined: April 19, 2011

Hey guys, new here but been using Audiomulch for my car audio needs for well over a year now. I am having an issue that I havent seen posted anywhere or at least my search skills need some work. I have had just one sound card in my PC for a while and everything is working great, I can do a time alignment through Smaart and I get consistent, reliable results, the sound card is an Asus Xonar D2x.

The way I have it setup is the audio from my media player is rerouted through Virtual Audio Cable -> Audiomulch -> ASIO4ALL-> Asus Sound Card. Again, never had any problems with just that setup and being able to do time alignment through Smaart using M-audio Mobile Pre USB with EMC8000. Have a 3-way with sub setup so all outputs on the Asus card are being used.

I recently am switching to setup a 4.1 surround setup through this PC, but since the Asus card has no available slots I had to add in another sound card. I have an old Creative Audigy 2 sound card that I threw in the PC and setup ASIO4ALL for both sound cards and I got everything to work sound wise, but when I try to setup Time Alignment through Smaart the delay on the Audigy 2 sound card is not consistent, its consistent in that when I reset Audiomulch the delay will be say 150ms, just as an example, and say if I check the delay immediately after it will read 1 or 2 ms higher, the longer I wait the longer the delay will be until it reaches some point and then resets and goes back down to the original 150ms. I never checked how high the delay reaches before it resets, because its a pain to let it run through that long. I hope that is clear.

It seems as though the Audigy 2 sound card and audiomulch have a clock difference or something? I dont really understand much about clock differences to troubleshoot it. Can anyone point me in the right direction on how to figure this out so I can get both cards to work properly?

I was curious on if I picked up either a second Asus card (needs to be PCI rather that PCI express like the D2x is) like the D2 if that would fix the issue? I just dont know if that would even fix the issue and I dont know if I want to spend that much money on a sound card for just the rear speakers when they will only be on during movies.

I would appreciate any help. If I left any other information out please let me know. Thanks in advance!

Ross B.
Ross B.'s picture
Joined: April 11, 2009

Hi There. So, let me see if I got this right: you are trying to output with some sound channels coming out of the Asus card, and some coming out of the Audigy 2. Is that correct?

Setups like that, or using 2 Audigy cards are not going to work. As you've realised there is a clock difference between the cards. This is normal, and due the the slight variation in clock rates from different quartz crystals -- no two sound cards will run at _exactly_ the same speed, although you might find that some are more closely aligned than others (either due to better crystals or luck).

In pro-audio setups you would use a word-clock cable to share one clock between two cards. I have heard of people doing this with Creative cards but since there isn't a word-clock connector it probably involves some hardware hacking. Even in this case there would probably still be some variations in alignment due to unpredictable startup delays.

I recommend you use a single soundcard for all channels if at all possible.

Does that answer your question?

Best wishes

Ross.

jddavid123
jddavid123's picture
Joined: April 19, 2011

Thanks for the quick reply!

Yes, that is correct. I am attempting to use the outputs on both cards.

I was afraid of that answer :( And yes it does answer my question.

A follow up question for you: Would I have a better chance of finding a more closely aligned clock rate if I purchased an identical card and tried to use both? Or are you saying that even identical sound cards have different quartz crystals in them and having two identical cards would still have a clock rate variation?

I ask because unfortunately my goal of having a 4.1 setup for this PC requires 12 channels of output (3 way front, 2 way rear and sub) and no single sound card has that many outputs so I am forced to require at least two sound cards if I am going to succeed at this.

If the option of grabbing another Asus card is possible then I would certainly like to try that.

Ross B.
Ross B.'s picture
Joined: April 11, 2009

> Or are you saying that even identical sound cards
> have different quartz crystals in them and having
> two identical cards would still have a clock rate variation?

That's what I'm saying. I don't know enough about manufacturing tolerances to give you a more accurate answer but I think it would be more likely luck if they matched.

My recommendation is to always try to use one card and one driver. For 12 channels this may mean switching to something in the "prosumer" category if you can afford it (like something with 2x ADAT optical outputs for example). Brands I trust:
http://www.motu.com/products
http://www.rme-audio.de/en_products.php
Older second hand models that only do 48kHz sample rate tend to be dirt cheap.

Others here may be able to recommend specific hardware models for 12 channel output.

Another option is to investigate wiring the word clock together on two consumer cards. I don't know anything about that. But even if you get it to work you will still have issues with drivers being out of sync. I don't recommend it.

jddavid123
jddavid123's picture
Joined: April 19, 2011

Thanks for the recommendation, but unfortunately those are pretty pricey :( Honestly spending an additional $200 on this system is more than I want to do. Plus this is in a car environment so alot of that equipment wouldnt work, it would need to be something that could run and be powered entirely off the PC and be 12 analog outputs.

Unfortunately I jumped the gun and already fiberglassed some enclosures for 3" wide bands in the C-pillars, 8" midbasses in the rear doors, and bought/installed two more amps for under the two front seats so either I just scratch the idea of rear surround in the car and call it a loss or continue looking at other more affordable sound card options that can support 12 channels. I will look around at some options, especially maybe some older used models that you mentioned. I really appreciate the help! Thanks again Ross!

jddavid123
jddavid123's picture
Joined: April 19, 2011

Just an update, after a little bit of research the pro audio cards were well beyond what I wanted to pay but I did find that M-Audio has a card that you can clock sync up to 4 of them. The 1010LT is very affordable, pretty easily can find these for $100 or less used. So I am going to try and pick up two of these suckers and hopefully that will solve my little dilemma.

Ross B.
Ross B.'s picture
Joined: April 11, 2009

Beware that according to the website the 1010LT drivers don't support linked operation so although the word-clock linked cards will not drift out of time, they may not start exactly synchronised (ie each time you start AM the time alignment may be slightly different:
http://www.m-audio.com/index.php?do=support.faq&ID=ff41c8e9c30d8205c72d46a8db947eb4

jddavid123
jddavid123's picture
Joined: April 19, 2011

Hmmm, that might be an issue. The link you provided doesnt say they cant link/synchonize together, it just said that the program being used has to support using multiple cards, but if I am using ASIO4ALL then it shouldnt be a problem with Audiomulch right?

Either way its certainly cheap enough just to try. Already found two cards for pretty cheap on craigslist (less than $150 for both). If not then I can probably get rid of them quick too. The other thing I saw about these cards is that they dont like hibernate or standby and for a Car PC thats pretty inconvenient. Not a deal breaker, but audio/video wouldnt resume where it left off when the car started.

I talked with Dave Roberts over at MOTU and he suggested a pair of the Ultralite mk3 Hybrids, but considering they run $550 each new, thats more than I have in the budget for car audio.

If these dont work does anyone else have any recommendations for discontinued cards that I might be able to find for under $200 as a plan B?

Ross B.
Ross B.'s picture
Joined: April 11, 2009

> The link you provided doesnt say they cant link/synchonize together,
> it just said that the program being used has to support using multiple cards

True.. hard to say without seeing it in action.

> but if I am using ASIO4ALL then it shouldnt be a problem with Audiomulch right?

I'm not sure how ASIO4ALL handles multiple cards, sorry can't answer that one. Did you already have that working with two different cards?

Worst-case you should be able to get AM to talk to two cards by selecting the Windows Multimedia driver type and assigning each card to different sets of SoundOut/AusOut contraptions on the Audio Output settings page.

Please do let us know whether you succeed. I'm quite interested...

jddavid123
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Joined: April 19, 2011

Alright I picked up the two M-Audio sound cards and they do link together and play in sync everytime when audiomulch starts up which is great, solves my earlier problem but now I got another issue I cant seem to solve. Playing through AM there is a ton of crackling, typically at the peaks in audio, the weird thing is that I can decrease the dB through Gdelay or another plugin (usually about 7-10 dB) and the clicking/crackling is much less, still there but much less. Its weird, I tried several different combinations of sampling, buffer, etc...

If I just take AM out of the equation and play straight out to the cards it sounds perfect. I can either reroute the audio through the M-Audio cards or use VAC then through AM, both have the same outcome of crackling mentioned above. A little frustrated at the moment so I kind of gave up for a while, but wanted to ask you guys here if anyone have any suggestions on what I can try next to figure this out.

Ross B.
Ross B.'s picture
Joined: April 11, 2009

> Playing through AM there is a ton of crackling, typically at the peaks in audio, the
> weird thing is that I can decrease the dB through Gdelay or another plugin
> (usually about 7-10 dB) and the clicking/crackling is much less, still there but much less.

It may be that the crackling is still there but just sounds quieter when you turn down the volume.

Increasing your buffer sizes sounds like a good idea. Are you still using ASIO4ALL or something else? Did you try different driver types (WMME, DirectSound)?

When you say it's working fine without AM, what are you using to play the sound?

First test I would try is getting a patch with just a TestGen to play a tone out cleanly.

jddavid123
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Joined: April 19, 2011

Well I turned up the volume on the amplifier to compensate for the decrease in volume via plugin just to see if that was the case, but if doesnt appear to be. I maxed out the buffer size using ASIO and using Windows Multimedia both with the same results.

I am just using a standard audio player, foobar, winamp, and WMP going straight out to the M-Audio card, tested both cards too. I use Smaartv6 as well to output straight test tones and pink noise. I can try TestGen too, never used that one tho.

jddavid123
jddavid123's picture
Joined: April 19, 2011

ALright I was mistaken. Going straight out to the sound card it still does it, I just couldnt hear it when I first tested it. So I guess its the sound cards themselves, prolly a driver thing. Hopefully I can find a solution from M-audio.

I will update when/if I can get this working and fully tested.

Edit: Well that looks like it was it. Rolled back to some much older M-Audio drivers and sure enough fixed the problem, only difference with the solder drivers is the volume is lower than with the newer drivers, maybe that was the issue, the new drivers were pushing it past clipping? No idea but it looks good so far :) Hopefully I wont run into any other surprises.