Repeatedly getting garbled audio while recording.

[fragmental]

I keep getting garbled recordings using audacity.

Here is an example:
http://soundcloud.com/stewart-james-mar ... ug/s-kc45D

Not ever recorded track is garbled. I thought it only happened when I left a browser window open, or a media player. Today though I'm getting garbled recordings and I don't have anything open.

I am using version 2.0.2 or audacity. I have windows 7 home premium 64 bit and my computer is relatively fast. The cpu and memory are never any where near maxed.

[kozikowski]

Some part of the system is not going fast enough to handle real time audio. Each of those little ticks and crunches is the system gasping for air. If you have a new or relatively new computer, then we need to look somewhere else.

Did you run your USB microphone through a hub with your keyboard and mouse? Don't do that. Audio doesn't go through hubs well. Audio USB should go direct.

Koz

[fragmental]

I am using a usb microphone. I had it plugged into the ports on the front and I thought that might be the problem so I moved the microphone to the ports on the back. That's where it is now.

[Gale Andrews]

Also take a look at
http://wiki.audacityteam.org/wiki/Manag ... nd_Drivers .



Gale

[fragmental]

I closed most processes. The only processes open were using very few resources. The only windows open were audacity, notepad, windows task manager, and calculator. I watched the windows task manager while recording, and the cpu never went over 20%. The memory stayed around 1 gb(out of 3). No new processes started while recording.

Still, at a little after 2 minutes...maybe 2:15 the garbled audio started again. It usually starts around 2 minutes or shortly after.

[fragmental]

Ok....I read the website you linked to. I loaded up dpc latency checker and it's fine most of the time but gets occasional red spikes. I guess that means that one of my drivers is causing problems? I'll try updating them all and see if that helps.

[ragnar.jensen]

Check out LatencyMon. It can help you pinpoint which driver(s) that are causing problems.
http://resplendence.com/latencymon

--
Ragnar

[ragnar.jensen]

Another one to try:
Start > Settings > Control Panel > System > Advanced settings.
Click on the Advanced tab, and under Performance, click on Settings.
When the Performance Options window opens, click on the Advanced tab and for Processor Scheduling, choose "Background Services."

Control Panel Performance options

bgservices.jpg (46.94 KiB) Viewed 2169 times

This change alone cut latency in half on one of my systems.

--
Ragnar

[fragmental]

I think I've solved it. Thanks for all the help.

I looked for updates to all my drivers and the only one I could find was an updated driver for my nvidia chipset. I installed it and it didn't seem to help the dpc latency issue.

A while back I installed a creative sound blaster x-fi music to see if it would help me get my latency down so I could do realtime monitoring. So, last night I took out the x-fi and switched back to the built-in audio. I upgraded the realtek hd-audio drivers and restarted.

The dpc latency seems to be gone!

If I had tried latencymon from the beginning it might have told me it was the x-fi drivers. I had my suspicions just because it's creative.

I'm still getting a lot of pagefaults with really long resolution times but I'm going to assume that's normal.

Realtime monitoring probably isn't possible on this computer with windows 7 unless I get some other hardware or use a different OS. I'm just happy to be able to record again without having to worry about whether or not the track will be garbage when I finish.

[Gale Andrews]

If I had tried latencymon from the beginning it might have told me it was the x-fi drivers.

I added a link to LatencyMon and the tip about processor scheduling to http://wiki.audacityteam.org/wiki/Manag ... nd_Drivers . Thanks for the tips as always, Ragnar. That said, Latency Mon is probably not the easiest tool for a computer beginner to use.

I'm still getting a lot of pagefaults with really long resolution times but I'm going to assume that's normal.

So-called page faults are indeed normal.

If you have a lot of installed RAM (at least 6 GB or more depending on what you use your computer for) and problems recur, you could try removing the paging file.

Realtime monitoring probably isn't possible on this computer with windows 7 unless I get some other hardware or use a different OS.

Windows isn't a real-time system. But it can get close enough for audio purposes with an ASIO-enabled sound device. Unfortunately Audacity as shipped does not support ASIO protocol due to licensing issues. Please see this page for more:
http://wiki.audacityteam.org/wiki/ASIO_Audio_Interface .



Gale