Mixer PFL level very different from compressor

[jasonprice07]

Hello All,

I manage the sound for a 6 piece covers band in Kent. Last night I had an issue with the LED indicators on the mixer not matching the compressor used for lead vocals.

The mixer is a Soundcraft LX7ii and the compressor is a Behringer MDX1600 and is inserted in channels 1 and 2 which are the for the 2 lead vocalists.

I noticed at one point one of the vocalists channel clip was active, so I checked the PFL on the channel and the bar segments were at the max. However the compressor when I checked both the input and output was centered around 0 with only a few illuminations of the +3 LED.

I know the basics of the gain structure but cannot understand how the 2 pieces of equipment indicate such different levels?

 

Cheers

Jason

[p.k.roberts]

There are a few things which are potentially giving the results you describe - the prefade monitoring on the mixer is post-eq, but the insert point is pre-eq, so any boost added in the eq section of the mixer would increase the level at the the PFL point without increasing the level at the insert point. There is also no indication on the mixer specs as to what the level at the insert point actually is and additionally, the MDX 1600 can be operated at +4dbU or -10dBV.