DIY USB Microphone Array

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Hi All,
This is my first post here, so sorry if it is in the wrong place.

I would like to build a microphone array (eg. 4 microphones) for my group's conference room. Ideally, I would somehow convert the analog signal to USB so it can be plugged into anybodies laptop.

Can anyone rate the difficultly of this project? Is it just as simple as buying a few (cheap?) mic components and soldering them together and then plugging this into a usb soundcard?

Cheers
 
What you need is a small basic 4 channel mic mixer with USB output. making a basic mixer is simple, but to spit out the results over USB means you now have to add analog to digital conversion and whatever USB interface requires, plus the mixer part would likely run on different power supply voltages than the digital part. I wouldn;t consider that a project for a novice.

You could make a very basic audio mixer and then plug that into a sound card on a computer, then use the resulting USB for anyone who needed it.

There are commercial products on the market. A quick look and I found some basic two channel versions. SOmething like this for $80:
ART USB Dual Pre | Sweetwater.com
Pricier at $300 but having 8 channels and other features:
TASCAM US-1641 | Sweetwater.com

Ah, perfect, and from the good guys at Peavey, the Peavey PV6 USB, at $130 a bargain:
Peavey PV6 USB | Sweetwater.com
It has four mic inputs, it mixes, and it has a USB interface on the rear panel.


And have you looked into microphones yet? Are you all sitting around a conference table? Or are you scattered around a room in comfortable chairs? You can close mic everyone and record that. If you are using conventional mics trying to pick up the whole room, you get recordings with that "off-mic" sound and a lot of room noise. There are mics specifically designed for picking up around a conference table. Look up "boundary" mics, or "pressure zone" mics. Crown and others make them, and I think there are inexpensive ones out too. They lay flat on the table top and are designed to pick up the sound without sounding distant. And you might get good results with fewer mics using them.

And there are USB mics on the market. A regular microphone with USB converter inside, it plugs direct into your computer. Get a USB hub and four of those and there you are.

And there are Single mic USB converters you can plug any mic into:
Blue Microphones Icicle | Sweetwater.com

SOme things to consider.
 
Thanks for the info Enzo,

So making a basic audio mixer sounds like a good idea. I got this schematic for a FET audio mixer,
FET Audio Mixer

The conference room is long and skinny, with a long and skinny table in it. I was thinking of hanging 4~6 mics from the ceiling over the table. After making the audio mixer, I would just plug the analog input signal into a USB soundcard, along with some speakers that I planned to install at one end of the long skinny room.

Would the mics and speaker be a problem in terms of feedback, or is this specific to the application (eg Skype calls)?
 
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