Originally Posted by kosdion
Since TM700 has an internal 5.1 microphone, I am searching for an external 5.1 or at least 4channel microphone. Do you know if such a microphone exist?
Would it matter if the input jack is only stereo? I would also hazard a guess that the onboard mic is only stereo as well, it's just the audio format is saved in 5.1, which might include the appropriate delay between front and rear speakers or not. But is likely not true 5.1. Even if it is, it's not likely input-able through the input jack.
A stereo image helps isolate sounds in a noisy environment. But it doesn't really remove noise.
Plug-in power / bias voltage / whatever you want to call it is provided by most cheap recorders. In the neighborhood of 2V - 9V in strength. Not normally enough to drive 12V - 48V phantom powered mics. And coming from a device that is doing other things, it can be inconsistent on it's voltage and yield results that are otherwise noisier than they would be. Putting a battery box in there to supply the voltage guarantees that it's there and that's it's more consistent. But still a cheap mic on a cheap interface.
Beachtek and Juiced link make preamps to run more pro like mics and feed a camcorder. You can also go the Zoom H4n, H2, H1 route. All of which increase the size of your recording device by stacking multiple devices. Plus mics, hotshoes, and other things. And don't forget to turn those devices on before starting to record the video.
Mics come in various flavors. OMNI is sort of the lantern of audio. Shotgun being the laser beam. Hyper cardioid more flashlight like. Cardioid more headlight like. Some mics let you choose the pattern on mic, most don't. A S/N towards 80dB is desireable, something towards 50dB will have a noticeable self noise. There an A weighted version where 15dB is desireable, and 30dB is a noticeable self noise.
You could go with something cheap like this one:http://www.giant-squid-audio-lab.com...-minigold1.htm
Or something more high end like these:http://soundfield.com/products/products.php
Or just stick with the usual suspects: azden, sony, .......