Preamplifiers
Measurement grade microphones
usually require a pre-amplifier in order to be used with computer sound
cards.
The preamp should supply the phantom
power required by its companion microphone. It must have enough gain in
order to amplify the microphones output to usable levels. It should also
have a relatively flat frequency response, a relatively high signal to
noise ratio (SNR) and a low Total Harmonic Distortion plus Noise (THD +
Noise) figure.
The following table compares three
low cost preamplifiers.
|
Mike
|
M-Audio DMP3
|
Studio Projects VTB1
|
ibf-akustik
MP-1r
|
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Channels
|
2
|
1
|
1
|
|
Power
|
100-125 VAC
|
100-125 VAC
|
9 Volt battery with plug in for
external supply
|
|
Phantom Power
|
48v
|
48V
|
Bias supply for EMM-8 microphone
|
|
Connectors
|
TRS
|
XLR
|
RF phono jacks
|
|
Input
|
Balanced 3k?
|
2k?/300?
|
Unbalanced 2k?
Capacitor coupled
|
|
Response
|
20-80000Hz; +1 dB
|
20-20000Hz, +0.25 dB
|
20-20000Hz, +0.2 dB
|
|
Gain
|
66dB
|
72dB
|
52dB
|
|
SNR
|
115dB
|
|
70dB
|
|
THD + Noise
|
0.02%
|
0.0015%
|
0.04%
|
|
Output
|
Balanced XLR 550?
|
Balanced XLR 100?
|
Unbalanced 2k? minimum load
|
|
Photo
|
|
|
|
|
Cost
|
US$199, 127€
|
US$220, 141€
|
US$266,171€
|
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What We Do
Sonic beacon produces
electrical and acoustical data acquisition and analysis software for the
Windows operating system.
|
About Us
Sonic beacon is a Canadian organization
founded in 1997. It is located in Pakenham Ontario which is near Ottawa, Canada. Ottawa is also home to
the National Research Council of Canada's anechoic chamber, a key
facility for acoustics testing. The chamber has been instrumental in the development
of Canadian loudspeakers, hearing aids and microphone arrays.
|
News and Events
July
8, 2009: Sonic beacon Version 1.1.0.6 released. Data-Logger
can now save in .FRD and .ZMA file format. Data-Logger and Spectrum
Analyzer can perform .FRD and .ZMA clipboard copy transactions. Signal
generator can output signal complements on each sound card channel to
allow bridging in many consumer audio interfaces. Module status bar shows
current data type, FFT size and sample rate.
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