are three reason might cause the problems,
1. Lower sensitivity
- The sensitivity of
the condenser microphone is from -36 dB to -48 dB (0dB= 1V/Pa).
If we use -44 dB microphones, the sound will be lower.
design of amplifier
- The impedance for
the amplifier will affect the sensitivity and the frequency response.
- Normally, the higher
the impedance is, the better the sensitivity will be. However
if the impedance is too high to get enough voltage/current, the
high frequency response may get worse.
- The lower the impedance
is, the lower the SPL will be. The too much current will cause
the insufficient voltage.
- Input higher voltage
will increase the sensitivity. Depend on the design of the amplifier
and the frequency, the sensitivity might increases around 0.3
dB to 0.6 dB by 1 V.
3. Defective design of mechanism
- The over-length or
curved sound receiving holes leads to lower or unnatural sound.