Mixer gain control - minus DB is louder?!?

[Wilco]

So the main input gain level controls on my PA mixer have a scale of 0db to minus 50db.

 

When turning the control clockwise therefore increasing the minus db, the sound through the speakers gets louder.

 

I’m sure there’s a logical explanation why increasing the minus db level increases the sound output, but I don’t get it.

 

Anyone able to explain? 
 

The mixer is an RCF

 

Many thanks. 

[Bill Fitzmaurice]

It's adjusting the input sensitivity to match the dBv output of the source. All input pots do, but seldom do you see it shown that way.

[itu]

It is most likely done so, that the mixer can push levels to its max (headroom), which is around 0 dB in this case. There can be some extra available, depending on the technology: analogue mixers may be able to push some more while digital units do not.

 

It is pretty common way of telling you where the max is, as digital units reach their 16/24/whatever bits. Anything over that will result distortion, because all headroom is used.

 

This is something like you dive to -50 m and the surface is at...

[Bill Fitzmaurice]

I should have been more clear. If the input device, like an active electric bass, provides 0dBv then the OdB mark would be the right position for the pot. If it provides -50dBv, as might be the case with a mic, then the -50dB mark would be the right position. This may help: https://radio.co/blog/differences-between-mic-level-and-line-level

[TimR]

That's the way I read it. It's not the amount of gain you're getting, it's the amount of gain the range of the source can provide.

 

From the manual:

 

"The Balanced XLR Microphone preamp input supports sources with a gain range from  0 dB to -50 dB (see section [11] of this manual)."