Observation made with USB mics and Audition CC on OSX and Windows

Question

Hi all,
I have Audition CC installed on both my desktop (running Windows 7 pro x64) and my Macbook air (OSX Mavericks). 
I noticed that when I use my USB microphone (Audio Technica AT2020) on the desktop, with latency set as low as possible, there is still a slight bit of lag when monitoring.
On the other hand, when I use the USB microphone with the Macbook Air, with i/o buffering at 32 samples [and sometimes higher], I get what seems like zero lag when monitoring.
Does this have to do with hardware or drivers differences between both machines?
Thanks!

Answer 1

Yeah.
One of the big drawbacks with most USB microphones is that most don't provide any monitoring--they rely on you using whatever is built into your computer.  (There are a few USB mics that do include monitoring but they're fairly rare.)
In most cases, this'll just be whatever sound card is installed in the computer--and the standard ones on most PCs are a 65 cent chip designed for the simplest of playback duties and Skype calls, not recording.  This would mean that the only way to monitor is for your signal to do a round trip via the computer which inevitably introduces some latency even with very low buffer settings.
Once you get to more specialist audio interfaces (even fairly basic ones) they have a feature called "direct hardware monitoring" which lets you create a monitor mix in the interface itself before the signal even goes into the computer.  I'm not a Mac user but I have to assume that the audio hardware in your Apple provides some form of direct monitoring without the "round trip".