CAD m177

[Monkey Allen]

Anyone know what power (is that the right word?) is required to bring this mic up to unity? (unity = 0db? I am guessing).

It's a condenser mic, so it needs that 48v boost. But for me, in my software, I can't get the input levels to hover around/ just below 0db. It has been suggested I turn on my soundcard's 12db input boost.

So I figured, right, well this condenser mic needs more than that 48v...I've only ever read that a condenser mic simply needs the 48v.

Does what has been suggested to me sound ok? Or should I be getting unity without the 12db boost?

 

[bigwillz24]

You need a preamp to boost the signal up to a decent level...

The 48v applies to the voltage needed to power the mic not make it loud.

 

[Monkey Allen]

Ok, I thought something sounded wrong there. Got it now. Presonus, when I contacted them said...

You should be aiming for just below 0dB in the software, however, your
mic requires 56dB of gain to reach unity (0dB)...the Firebox has about 57dB
of gain with the +12dB boost engaged, so you should have just enough gain to record...make sure that on our control panel, you have the +12dB boost
engaged.

It's just the maths that's bothering me.

In my Firebox manual, it says:

Microphone Input XLR: 45db of variable gain (+14db to +55db)

I don't really understand that. Both those figures are above 0db, which I thought was the level you wanted.

Then, on the actual Firebox, the gain knob gives a range from -10 (hard left) to +30 (hard right)

I can't get my head around those figures.

Then the Presonus fella told me to use the extra 12db level boost on the control panel....so does that 12db add to the +30 to make +42, or to the +55 to make +67??

Niether of those figures are in the message he sent me about the Firebox having about 57db of gain.

If anyone is a gain expert, or can help me, I'd love it

thanks

edit: I get it now. The preamp has a pump up range of +14 to +55 making a total of 45db preamp boost. My mic needs 56db of gain to deliver a good signal. So, I need to use the extra 12db boost.

I can only guess that the numbers -10 to +30 on the gain knob refer to the gain for 1/4" cables?

 

[Adam P]

Try this: turn the trim knob all the way down for the channel you are using. Plug in your mic. Press the button that says "48v" so that it is on. Now while singing or playing back into the mic as you would to record, slowly turn the knob to the right while watching your meters. Since you're recording digitally I wouldn't try to ride just below 0db, since a transient could cause clipping which will sound awful. I'd shoot to stay around -6db on your meters. If you get the knob turned all the way to the right and you're still not there, turn it all the way back to the left, engage this 12db boost that you speak of, and try again. The Firebox should have no problem providing enough gain for your M177, provided that you gain stage it properly.

 

[Monkey Allen]

Ok, sounds like a good idea