[PlanetCCRMA] sound card IRQ and crackling sound on F7

Hector Centeno hcengar@gmail.com
Tue Jun 12 16:31:01 2007

Hi Fernando,

Thank you for your advice. It says the Audiophile has a latency of 64
which is what it's set at in the BIOS. Should I reduce this?


On 6/12/07, Fernando Lopez-Lezcano <nando@ccrma.stanford.edu> wrote:
> On Tue, 2007-06-12 at 16:56 -0400, Hector Centeno wrote:
> > Hi,
> >
> > I'm having problems with my new motherboard (Asus P5B-VM with an Intel
> > Core 2 Duo) and a M-Audio Audiphile PCI audio interface. My problem is
> > mainly with Csound and getting crackling sound on one channel. If I
> > set jack buffers to anything higher than 512x2 the crackling gets
> > worse. I tried switching the card to the other PCI slot (it has only
> > two) and the problem got even worse as I would get crackling audio
> > always. I noticed that both PCI slots are sharing IRQ with other 3
> > devices (usb, video card, libata). In the motherboards manual it says:
> >
> > 1.8.2 Configuring an expansion card
> > After installing the expansion card, configure it by adjusting the
> > software settings.
> > 1. Turn on the system and change the necessary BIOS settings, if any. See
> > Chapter 4 for information on BIOS setup.
> > 2. Assign an IRQ to the card. Refer to the tables on the next page.
> > 3. Install the software drivers for the expansion card.
> >
> > There is no more details about how to perform step 2, Chapter 4 only
> > talks about reserving IRQ for ISA interfaces and in the bios there is
> > no way to manually assign IRQs and it looks like it's something you
> > are supposed to do va software, so I was wondering if anyone knows how
> > to do IRQ assignment in Linux using the CCRMA kernel. With my older
> > motherboard and FC6 it was possible to get the Audiophile to have it's
> > own IRQ and I never had any problems with the audio (until the hard
> > drive controllers in the mobo started to fail and had to replace it).
> I would check the pci latency settings just in case that's the problem.
> Do a "/sbin/lspci -v" and see what numbers you have for the latency
> parameter for the cards installed (included the video card).
> -- Fernando