i need major help....math geniuses welcome!

I

ikon

New member
ok now i need help on how to figure this math hahaha...sorry guys....but if i want to connect my large condensor mic with these specs:

Type: Condenser pressure gradient mic with large 20mm diaphragm
Frequency Range: 30Hz-20kHz
Polar Pattern: Cardioid
Sensitivity: 15mV/Pa
Impedance: 150W
S/N Ratio: 74dB (Ref. 1Pa A-weighted)
Equivalent Noise Level: 20dB (A weighted IEC 268-4)
Max SPL for 0.5% THD: 137dB

High Pass Filter 6dB/octave, 150HZ
Attenuator Switch 0/-10dB

to a preamp with these specs:

Input Connections XLR (balanced), ¼”TS
Output Connections XLR (balanced), ¼”TS
Input Impedance XLR, ¼” 2K ohms, 840k ohms
Output Impedance XLR, ¼” 600 ohms, 300ohms
Maximum Input Level, XLR +14dBu
Maximum Input Level, ¼” +22dBu
Maximum Output Level, XLR +28dBu
Maximum Output Level, ¼” +22dBu
CMRR >75dB (typical @ 1kHz)
Frequency Response 10Hz to 30kHz, +/-.5dB
Dynamic Range >100dB (20-20kHz) typical
Total Harmonic Distortion (THD) <0.1% (typical)
Maximum Gain
XLR to XLR 60dB (typical)
¼” to ¼” 44dB (typical)
XLR to ¼” 54dB (typical)
¼” to XLR 50dB (typical)
Equivalent Input Noise (EIN)
XLR to XLR -129dBu (A weighted)
¼” to ¼” -105dBu (A weighted)
Tube Type 12AX7A, Dual Triode, Hand Selected

how would i find the input gain to get it to +4dbu, then! to make sure ones its leaves my preamp amp.....how much outgain should i boost to make sure its hits my m-audio fastrack wich records at 24bits st the correct levels? i know thres some math involved which is what i would like some help on please.
 
The number we're missing is how loud the source is.

Anyway, in general, gain is set by turning up the pre while it's being used, ie, someone's singing or playing, stopping somewhere short of overdriving the pre. The pre output goes into the fastrack which has its own gain stage that you have to adjust. You'd have to monitor that level in your computer. I usually try to track keeping it around -6 dB. Some like a little lower than that.
 
thank you sir..i will try that out....but i was hoping there woulda been an easier explained answer on how to do the math properly...ive read alot of stuff and thats the major thing that confuses....is matching the specs...i may just be confusing myself...and again thank you!
 
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ikon said:
thank you sir..i will try that out....but i was hoping there woulda been an easier explained answer on how to do the math properly...ive read alot of stuff and thats the major thing that confuses....is matching the specs...i may just be confusing myself...and again thank you!
Click to expand...

The meter in your software kinda does the math for you, along with any clipping LEDs on your pre.

It's like your savings account balance. What matters most is the total, not where it all came from.
 
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