Dear Denon Staff,
I have the a big problem with my X1850: volume is ducking inconsistently on channel 2…mic is off, master limiter is off, fx limiter is off. Source player can be anything mp3, SC6000, wax…completely irrelevant.
This is extremely annoying…I’m about to sell the mixer and buy a Pioneer…
Any suggestions? Newest firmware is installed, cables double changed and checked, this MUST be the mixer…
Have you ruled out the amplifier?
Are you running direct into active monitors or into a powered amp or compressor, Equaliser ?
Are you pushing it hard or running at moderate neighborhood friendly levels?
Never had any issues with my x1850 
–Sorry just noticed it’s only on channel 2 you mentioned–
It could be a bad runner connection in the channel fader itself. Bit of dust build up or debris has fallen in
No, the effect occurs, even if the fader isn´t moved…same position for several minutes, even then the pumping occurs…
You can hear the effect in the headphones, the master and even the booth, so it´s channel related and only on channel 2.
My 1850 does this aswell (And it also happens on the record out (Via digital) - Thought it was my PA at first untill i noticed it on a recording!
this needs to be fixed
Yes, you hear it on EVERY “out”, because it’s the fader as mentioned…this seems to be a common problem and is very dissapointing…hope your mixer has still guarantee as mine and the affected fader could be replaced…
Mine (FW 1.7 but also 1.6) does do this as well on all channels when i play Vinyl and some louder crackle comes up its ducking the sound instantly. All limiters e.g. switched off. I really don`t believe its some fader issue.
PLEASE Denon, take a look on this!