Why do sound cards click and pop?

[Bump Music]

I've used a lot of soundcards over the years... and at one point or another most of them click, pop or add tiny gaps while tracking (printing the clicks onto the audio file).

For certain, this has happened with the Apogee Rosetta 200 w/ Firewire using Logic. And the Fireface 800 using Logic. Buffer at 128 with no other tracks or plugins running.

I've never had a problem with Pro Tool HD so I'm wondering if it's a software (driver) or hardware issue. Firewire or PCI. Etc etc.

The main reason I'm asking is cuz I'm probably going to get the Lynx Aurora and want to know if I should go with Firewire or AES16. Btw.... Is the AES16 card compatible with G5's and Mac Pro's?

Thanks in advance.

[Reptil]

because...


























they are made of popcorn!















quick and dirty answer - it's because the chips on the card or in the computer cannot process all the data fast enough and gaps appear. it's called "buffer underrun".

[Bump Music]

Are there any sound cards that DON'T click, pop or gap out?

Anyone with Pro Tools HD or Lynx Aurora ever experience gaps, clicks or pops?

[Reptil]

your fireface (with the newest drivers - which have a larger safety margin 2.59) should be working without plops and clicks.
if it does, pull up the latency, eg. the buffer in your audio software.
if you use too many plugins in "real time" you can expect more processing, so, more chance of trouble. Although I read here that the lucky ones with mac pros have to put in a lot of effort to bring their system to it's knees..

hope this helps..

[dkatz42]

It's not really the card's fault (other than perhaps poor architecture that makes the CPU work harder), but rather it's usually the driver or the o/s.

As was mentioned, the sound card will run happily so long as it always has samples to send, but if the pipe ever runs dry, you lose. You then have the tension between stability and latency. If the pile of software (app, o/s, driver) delivers the data in bigger chunks, the amount of time to go get the next chunk of data goes up, but so also does the latency.

Since the o/s's we use are not true real-time systems (there is no guaranteed scheduling of processes) there always exists the possibility that the software won't get around in time with more data because it's busy doing something else. Faster systems, better tuning, and better drivers mitigate this.

For example, the Symphony/Mac Pro combo is capable of very low latencies partly because of the architecture of the Symphony card, but mostly because the MacPro is so wildly overpowered that the card doesn't underrun, even with very small sample buffers.

[Bump Music]

Originally Posted by dkatz42

It's not really the card's fault (other than perhaps poor architecture that makes the CPU work harder), but rather it's usually the driver or the o/s.

As was mentioned, the sound card will run happily so long as it always has samples to send, but if the pipe ever runs dry, you lose. You then have the tension between stability and latency. If the pile of software (app, o/s, driver) delivers the data in bigger chunks, the amount of time to go get the next chunk of data goes up, but so also does the latency.

Since the o/s's we use are not true real-time systems (there is no guaranteed scheduling of processes) there always exists the possibility that the software won't get around in time with more data because it's busy doing something else. Faster systems, better tuning, and better drivers mitigate this.

For example, the Symphony/Mac Pro combo is capable of very low latencies partly because of the architecture of the Symphony card, but mostly because the MacPro is so wildly overpowered that the card doesn't underrun, even with very small sample buffers.

That's a great explanation. Thanks! But with all that being said: Does Pro Tools HD ever click and pop? I've never had a problem with it. Is it because of a good driver, good power cards, etc?

What about the Lynx Aurora?