Today I picked up a Samson C01U mic so that I can have better audio in my WindowsClient.net videos than I had in some previous screencasts. The mic is the same one that Scott Hanselman has used when recording podcasts from his setup.
I spent the better part of the afternoon messing around with the mic, trying to get something with usable audio. The gain just seemed way too low, barely registering one bar in the Windows 7 audio device setup dialog.
I made sure to crank up the gain in that dialog (it’s set really low by default). but that made only marginal difference.
I tried it on my netbook to check levels (which seemed slightly higher there, but still not usable) I even tried switching it around between different USB ports on my PC in case power was an issue. I tried it both on-board and in an external powered USB hub. The tip for that came from Bill Reiss in the Camtasia forums here (excerpted below, emphasis mine).
I had an issue with the Samson C01U microphone levels on Windows 7 (Vista should be very similar), the microphone was very quiet. It turns out that it was the USB port I was plugging it into, it must not provide enough power. I switched to another USB port on the other side of the laptop and it was fine.
If you try switching to another USB port and this doesn't help, you may want to consider a USB hub that has external AC power.
Hope this helps, I didn't find any advice like this online and was about to give up on this microphone before I figured it out. Now I'm very happy with it.
So, before I completely gave up on what I was sure would be a good mic, I decided to try some other ports. My external powered hub has two ports sticking out of the top which look like they might be special. I tried one of those and bam! I suddenly had sound levels in the red. I guess those two are the only ones getting additional juice.
Condenser mics need external power because they rely on voltage changes in a capacitor to capture sound. This makes them more sensitive than other types of mics, but also means they need power where others do not.
In Windows XP you can use the special pre-amp software to work around this, but I imagine the USB power issue remains simply masked.
It appears that not all USB power is created equal. Now the mic sounds great.
