PreAmp

Hello.

I’ll try to keep my question shot.

I researched for some basics about recording.
At some point you come to a point, where you
will try to eliminate the noise, since it’s the
only interference, which keeps you away from
recording the most silent tone you can find.

Till now i understod, that it is a physically problem
which can’t be solved completely.

But, there are some things you can do about it.
First thing is, trying to cool the capsula (microphone)
a bit which i will try later. (Pretty simmilar to Superconductivity)
See here

Another thing is to increase the signalpower with a preamp.

I’m just about to buy such a thing and need a confirmation, if
the answer i got is correct.

“A preamp powers up the microphone signal, so that the noise
to signal ratio is raised. This way, signal and the noise has gotten
louder, but because the noise to signal ration is raised, the signal
has gotten louder than the noise. A software can’t do this, since
everything is raised up (noise and signal) so everything is louder
but you still can’t understand the quiet signal, because the noise
to signal ration hasn’t raised.”

Is this correct?
Thanks in advance.

Forget about cooling the capsule - it has virtually no effect until you get down to extremely low temperatures (much colder than a freezer) and then the extreme cold can start doing damage to things.

The main factors for achieving clean recordings of quiet sounds are the microphone and the pre-amp.

Different microphones have different “sensitivities”. Sensitivity is how big a signal the microphone will give for a given sound level. For recording very quiet sounds you need a sensitive microphone. The other relevant feature of the microphone is the “signal to noise ratio” (SNR). This is the ratio of maximum signal level compared with the noise level. Microphones with a low noise level will have a high SNR.

The pre-amp can also be a major source of noise. Again, a high SNR will have a lower proportion of noise compared to the signal. For recording low level sound you also need to have a pre-amp with “high gain”. “Gain” is the amount of amplification that the pre-amp can supply.

Standard microphone inputs in computers have very poor quality pre-amps built in that produce a lot of noise (very low SNR). Upgrading the sound card is the bigest improvement that you can make for microphone recording on a standard PC. There are high quality sound cards (including USB devices) that have high quality pre-amps built in. If these are used in conjunction with a high quality microphone, high quality recordings can be achieved.

When making high quality recordings, the noise of the computer can be significant, so it important that the microphone can be sufficiently isolated from the computer to avoid picking up too much noise from computer fans.

Well first of all thank for the complete explaination!

I guess this means in short: Yes/No.

The PreAmp just amplifies the signal as software would,
but if i use it instead standard pc soundcard i will get
less noise with amplified signal because the noise comes
from the soundcard whose amplifier is crappy and produces
the noise.

I will have a look for usb soundcards, it is said they work
pretty well and aren’t much expensive.

BTW
I’m using the Vivanco EM 35 Elektretmicrophone.
It’s actually pretty good, but i want to hear more!
It’s like a digi cam, mine got 10x zoom. :wink:

Vivanco EM 35
Type: Electret microphone
Characteristic: Omnidirectional
Frequency: 20 - 20000Hz
Impedance: 2x 500 ohm (Stereomicrophone)

NSR isn’t measured or mentioned.
Maybe because it’s poor consumer electronics.

You may have trouble finding a suitable pre-amp/USB sound card to fit that microphone. Most sound cards have mono inputs for the microphone socket.

Won’t be a serious problem.

Thought that Stereo sounds nice, but if
you have a look at the characteristic,
stereo means nothing at all for this mic…

It is actually double mono.

But on the other hand, i’ve read mic-in
is always mono, so maybe i never have
had Stereo because i couldn’t use the
linein, yet.

Maybe i find a surprise.
Stereo recording may be nice, even if
only one person is talking. :wink:

<<<Stereo recording may be nice, even if only one person is talking.>>>

No, it’s not. Back in the dark ages when Stereo FM first took off, they experimented with stereo performers on the air. It didn’t last long. If you happened to lean over to pick up a piece of paper while you were talking, it sounded like you were leaping across the room in someone’s house. And then leaping back.

If you were wearing headphones, the effect was even worse. It sounded like you were listening to a ghost who could move very rapidly and didn’t weigh anything.

Koz

Must have been shotgun characteristics.