Audacity Forum

Hey,

Some of you may have seen my post about a week ago about lag problems in Audacity, I have an Acer Aspire 5520 and am trying to record using a mixer through the line in. Despite taking all the the tips I'm having no luck in sorting the problem, and am convinced it must be a setting somewhere on my notebook because others with the same model arne't getting this problem.

I've noticed on other computers using Audacity that when you stop recording, the track moves back slightly and is perfectly in time on playback. My notebook isn't doing this, and I'm wondering if there is some kind of auto time shift or something.

Anyone know anything?

Thanks in advance, Matt.

It could be to do with "latency correction".

(not a guaranteed solution, but possible)...
Hardware is fast, but not instantaneous (particularly consumer grade / laptops / etc) therefore it is quite normal to get a bit of "lag" or "latency". Audacity has the ability to compensate for this. Latency compensation is set up in "Preferences => Audio I/O"

Have a twiddle with those and see if it makes any difference.

Good luck.

This post is a bit long, but it explains how to set the Latency Correction in 1.3.x:

http://audacityteam.org/forum/viewtopic ... 5562#p5562

Nice tutorial alatham.
Regarding the "Audio to Buffer field", this is how much audio data should be buffered before playback. If insufficient data is buffered, the audio buffer will run out of data before the following data has been written to the buffer and the audio that you hear will have gaps in it. If the value is borderline you will hear glitches, but if it is way to small you will hear a horrible kind of distortion.

There are times when you want this to be as small as possible (for example if you are using VSTi's).

When you set your latency correction, this includes the audio buffer latency. So for your system with audio buffers set to 100ms and latency correction of 143 milliseconds, that's 100 ms latency from the audio buffer + 43 ms. If you needed to, you could probably reduce the audio buffers to 50 ms without any problem, and then the latency correction would be around -93 ms.

I'm not sure why, but the amount of audio buffers seems to be largely independent of the number of audio tracks. With my setup (P2 500MHz Sound-Blaster Live Win XP) I need a minimum of 36ms, but that's the same if it's one track or 12 tracks.

Steve,

I know this is an old post, but I can explain why the number of tracks doesn't make a difference in the audio-to-buffer setting. All the computer has to do is add together floating point numbers n times (where n is the number of tracks). It doesn't take very long to do that at all.

I think the overriding factor for the lower limit of the audio-to-buffer setting is going to be the sound card and OS settings. The amount of time Audacity needs to process the signal is much smaller than even the most efficient sound card.

Thanks alatham. I was having a blond moment