+4dBu or -10dBV with 3000?

So I finally managed to free up 4 inputs on my RME Fireface for a total of 6 I can connect the 3K to (2 stereo out + 4 individual). My question concerns levels.

AFAIK the individual outputs on the 60 are louder (or quieter?) than the mains. On the 3K however, at least according to the manual, they all output the same level of 6dBm (600Ω). Basically what I want to know is whether I should use an input sensitivity of +4dBu or -10dBV at the Fireface inputs. I've tried using an online db converter to see what 6dBm correspond to but didn't really manage to understand if I'm using it correctly.

Perhaps the fact that the outputs are unbalanced means that -10dBV is a wiser choice?

I know this isn't a big deal, and I've never had the feeling that my 3K isn't giving me enough volume, but I'd feel better with the sensitivities matched correctly.

I think -10 is pro and + 4 is "consumer"

Edit: assbackwardslikecrisskrosszzz

+4 dBu is standard operating level for most professional audio equipment. -10dBv is the standard operating level for most consumer audio equipment. +6 dBu for most broadcast equipment.
This pretty much means that a "pro" equipment's input can handle a higher maximum voltage than it's "consumer" equivalent.
Therefore giving you a better signal to noise ratio and headroom.

Had a look in the 60's manual, and it says the stereo mix outs are -3dBv at 600 Ohm... So if you set the interface's input to -10dBv then you're alright.. If -3dBv is maximum for the Mpc then it should read around 7 dB above standard operating level on your interface....depending on where 0 dBfs is calibrated at for your soundcard you should have enough headroom.

oh sorry just saw you where asking the question about the 3000...

6 dBm is around 6 dBu at 600 Ohm ...so setting you're inputs to +4dBu should be correct.

Thanks Marek2kxl.