Buffer question/Playback engine

[Pointbreakd]

Ok so I use pro tools LE and an MBOX...but I've had a lot of latency issues.


What is the best setting for PlayBack Engine (IE buffersize etc)?

Also, I can only boost my computer usage up to 85%. I'm using a g4 powerbook 1.67 ghz and 1 gig of ram.

thanks for the help.

[Pointbreakd]

very helpful. thanks

[max cooper]

Don't forget that the as the sample rate goes up, the latency at a given buffer size gets smaller.

[Pointbreakd]

Originally Posted by max cooper

Don't forget that the as the sample rate goes up, the latency at a given buffer size gets smaller.

Im an idiot. explain?

[JoeyB]

Originally Posted by Pointbreakd

Im an idiot. explain?

This was an unexpected bonus, but yes it is true. Since the buffer size remains the same, but the sample rate is doubled, it takes half the time to process the buffer packet, so latency is halved.

[max cooper]

Originally Posted by JoeyB

This was an unexpected bonus, but yes it is true. Since the buffer size remains the same, but the sample rate is doubled, it takes half the time to process the buffer packet, so latency is halved.

Right, in cases where the samplerate is indeed doubled, like 44.1 to 88.2 kHz

But the USB will only to 48k so you are confusing the lad...

The reason you can only use 85% is the pCPU has to manage the USB buss, so you can't have it for audio.

USB is a very limited way to do audio, even with USB 2 which neither Mbox will do.

[Pointbreakd]

Ah i get it.

Yah I hate the mbox/USB thing. But I don't have the cash for an 002. I can deal with the latency...For pre-production/low budget demos it works pretty well.

Hey, I have both; they each have their uses. Currently I use the Mbox as an input device for my Powerbook to run SpectraFoo to look for noises and balances visually... while mixing and such with the 002R.

[max cooper]

Hey didn't mean to confuse the issue.

You'll even notice a slight difference in latency going from 44.1 to 48.

If the buffer is 128 samples, and you're at 44.1 kHz, there are fewer samples/second than at 48kHz, so the buffer length of 128 samples takes longer when the samples are more spread out.

Did that make sense?

[Pointbreakd]

yup cool stuff, makes sense.

Max Cooper wrote:
"I'm infinitely baffled."

Don't worry, it's just a bass reflex.

<L>