View Full Version : latency via an USB audio interface?

04-27-2010, 03:48 AM
Hey Guys - wanted to check in since my last post asking about mics and audio interface suggestions. I had been looking for an audio interface.

Well it turns out I managed to buy the one version of Macbook without a firewire port. So that limits me to USB interfaces.

Since I don’t have firewire,- I think I’m leaning towards this M-Audio Fast Track Ultra. http://www.sweetwater.com/store/detail/FastTrkUltra/
It’s $150 more than the lower model – but it has 4 pre-amp inputs and two of em have both 2 XLR/TRS inputs. So it sounds like I’ll have way more flexibility on what I can hook up. Plus it sounds like the pre-amps are much better in this one than the lower model for $200. All in all – it sounds like a big step up for the extra $150 and I’ll have some room to grow into it.

I’m all new to this really – but from I’m reading, one concern I’ve had with USB 2 (vs. firewire) is with latency issues with the monitoring and headphones. Do you guys think I’ll have to worry about latency issues with the monitoring if I’m using all 4 inputs plus playing back tracks all at once on the M-Audio? I'm not sure what to expect here... I know how there's other adjustments that will affect this - but is there any estimate on how many tracks you can typcially work simaltaneously with a USB 2 vs. firewire?

04-28-2010, 04:02 AM
crickets? lol.

04-28-2010, 06:49 AM
You will get latency whether you use FireWire or USB. Latency comes from the signal going into your interface, having to go into your computer, then coming back out of your computer, through your interface and back out of the headphones. The long signal path causes the delay in what you play vs. what you hear in the headphones. To address this, almost all interfaces have a mix/monitor knob. When in the monitor position, the interface splits the input signal. Along with sending it to the computer, it also redirects the signal straight to the headphone output to (almost) eliminate any latency.

In order to hear both the tracks you have recorded as well as the current track, you'll have to have the mix/monitor knob somewhere in the middle. Also make sure you don't have any plug-ins running (EQs, compression, delay, reverb, etc.) as that will add latency. Record everything first, then mix and add the effects.

As far as FireWire vs. USB, FireWire is a more stable transfer protocol which can handle recording more simultaneous tracks than USB. I think the most I've recorded simultaneously with my FireWire interface is 13 tracks (I'm sure it can handle more, I've just never needed to do anymore). With USB, I think 4 simultaneous tracks should be fine...not sure I would trust USB with much more than that though.

04-28-2010, 08:44 AM
great! I cant imagine I'd need to record more than 4 tracks simaltaneously. Great insight all around - thanks for the input!!