Duo problems (IRQ?)

A

Aren

New member
Hi People,

Good to be back home, and good to see that this place hasn't changed much...
My latest purchase on my trip to the US, is a M-Audio Duo USB thing. I installed it today, and I'm getting a lot of pops, clicks and so on while playing back. After a short search, I found out that the USB port thing, is using the same IRQ as my old SB-Live card.
Could this be the source of all my misery?
If so, what can I do about it?

Thanks!

Oren
 
Depending on what O/S you're using, you may need to disable ACPI (especially if the shared IRQ is 9). Windows 2k and XP like to put lots of things shared on IRQ 9, but audio cards usually don't like it that much :)
 
Hmm....
I'm using Winsows ME, and the IRQ in question is 11.
No idea what ACPI is...

Thanks anyway!

Oren
 
ACPI is (basically) power management. This is how the computer shuts it's own power off when you click "Shut Down". ACPI does other things as well, one of them being IRQ sharing (bad idea on Microsoft's part IMO).

I'm not sure how WinME handles it, or if it uses IRQ sharing at all.

The thing is, I can't imagine that 2 sound cards can exist on the same IRQ without having boocoo problems (especially in WinME). Usually Win9X/ME systems are more flexible in allowing you to manually assign IRQ's to devices, which is what you probably need to do. See if Control Panel will allow you to change either of these.
 
There could be pleanty of reasons for your problems.

First off, USB bandwith is very limited and 2 tracks of 24bit audio could lead to problems under certain circumstances.

Secondly, I have seen posts here and elsewere whre peolpe have had hardware compatability and driver issues with the M-Audio Duo and Quattro.

Finally, Sean is correct about IRQ's. I actually discovered that USB devices share bandwith with the PCI bus. You could have a compunded problem with it sharing an IRQ with your SB.

My personal opinion is that the marketting manager from the audio card manufacturer who decided to develop a USB audio interface in the first place should be shot. That was a ridiculous idea and not very well thought out.

USB was never intened to be an interface for high bandwith usage/peripherals. If you have that need either use Firwire or stick with PCI.

Thats my $.02
 
brzilian -
I didn't even try to use 24 Bits. There should be no problems with 2 channels of 16 bit audio.
I heared of a lot of problems with the first batches of the Quatro, but according to what I heared, the Duo drivers are pretty decent.

Apparently, I can't change the IRQ settings for the SB-Live via software. Should I just move it to a different PCI slot?

Oren
 
You could try, but I doubt it will help. Windows decides what IRQ each device uses at bootup. You might not be able to use them both at the same time, and be forced to use multiple boot configurations or remove the SB altogether.

Brzilian does has a point - USB audio interfaces are usually riddled with problems because USB isn't designed for the kind of throughput that audio recording requires. I'm sure that's not something you want to hear after the fact, and many people do use them without problems if all the ducks are lined up.

Do you need to have the SB in there at all? That's probably the simplest answer.
 
Yep. I need the SB for MIDI, which the Duo doesn't provide.

I'll try M-audio's tech support...

Oren
 
Usually when I have had IRQ problems, the symptom was a stuttering sound, not pops and clicks. When I get pops and clicks, it was always an inadequate buffer.

Easiest way to check would be to just increase the DMA buffer a bunch through your M-Audio control panel. If that doesn't work, try taking the SoundBlaster out completely, and then see if it still does it; if it stops after taking the SB out, you know it was an IRQ conflict. If so, start putting it in different PCI slots until it works.
 
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