Perhaps this will work for you, too
Hi,
I'm running a MacBook (2.4Ghz, 4G, 250G) with Parallels 3.0 Build 5600.0 in OS X 10.5.5. I'm run XP patched to SP3 and the current (November 2008) evaluation copy version of Camtasia 5.0 running, of course, in XP. I have a Sennheiser PC-156 USB headset. I do not run in Coherence, keeping the XP side in a different OS X 'Space.' Here is what gets me good Camtasia audio:
1. With the Sennheiser not connected, launch Parallels in its 'Space' (don't go into XP yet) and in the configuration/launch window, click 'Sound' to open those setting options; select 'Default Audio' for both 'Input' and 'Output.' Click 'OK' to close the dialog, returning to the configuration/launch window.
2. Return to the Mac 'Space' and plug in the Sennheiser. Use 'System Preferences' to make sure that the Sennheiser is selected for both 'Input' and 'Output' under 'Sound.' Set the microphone level to about 2/3 of the way to max in 'Input.'
3. Return to the XP 'Space' and launch XP by clicking the green arrow. Launch Camtasia Studio. Under the 'Tools' pulldown, select 'Camtasia Recorder.' In the dialog box that displays, click the 'audio options' link. In the dialog box that displays next, click the 'Audio Format' button. In the dialog box that displays next, open the 'Attributes' pulldown and pick a high bit rate digital audio sampling protocol that's appropriate to your recording. In my case (I'm doing Help videos for an application), mono is fine, so I select '48 kHz, 16 Bit, Mono 93kb/sec'. Click 'Ok' all the way back to wherever you want to go next in Camtasia.
4. Here is something NOT to do: use the Camtasia auto volume-level setting wizard. For some reason it radically undersenses what's coming to Camtasia from the Sennheiser through OS X, Parallels, and XP. I think the best place to mess with the raw microphone input level is probably in OS X 'System Preferences.'
My guess as to what's going on here has to do with how USB connections get handled by Parallels. For most data transfer bursty, asynchronous pass-through isn't particularly noticeable.
Jeff