I read the manual a bit more and figured out that the above scenario is not a problem because it's (strangely enough) the pan that decides which subgroup(s) that channel routes to. If it is set to L it routes to the odd subgroup number and if it is set to R it routes to the even subgroup number. If the pan is set to mid, the channel is transmitted to both subgroups. Therefore you can connect 8 tracks on the mixer to 8 input tracks on the audio interface in this way by the sub groups:

Channel1:
Mic1 PAN L Button1 (-> sub group 1)

Channel2:
Mic2 PAN R Button1 (-> sub group 2)

Channel3:
Mic3 PAN L Button2 (-> sub group 3)

Channel4:
Mic4 PAN R Button2 (-> sub group 4)

Channel5:
Mic5 PAN L Button3 (-> sub group 5)

Channel6:
Mic6 PAN R Button3 (-> sub group 6)

Channel7:
Mic7 PAN L Button4 (-> sub group 7)

Channel8:
Mic8 PAN R Button4 (-> sub group 8)

It's also cool that the 8 buses are duplicated onto 16 jacks so you can route each channel to two differently manipulated signal paths into a 16 channel audio interface (for instance a clean and a crunch guitar all in one) without having to re-patch or re-record. Another very nice feature in the Behringer MX9000 is that you can use the direct outs on the rest of the channels(with predefined recording channels) and get up to 24 channels out, which is very good if you expand with an additional RME interface or external D/A A/D converter interface. But if you need 2 outputs back from the computer you can only use 22 of these direct outs effectively since two are required for the computer's main outs.

Overall I think I need an 8 Bus mixer, especially since I then also can specialize each bus and route it out however I want to. For instance if I buy some guitar amps I might run a Fender amp and a Marshall amp on the same bus and always be able to setup different guitars onto several setups without having to repatch anything! In a greater context I would even be able to dedicate several buses to the the same signal type e.g. with 2 buses for guitar get 4 different amps available on any of the 24 channels on the mixer! I am not made of money, so the Behringer is a good choice for me even though it might add some noise in the signal path. I read that it's only the mic pre amps that can get a little noisy when run on max level. The mics for vocals might be best routed directly to the RME.

[This message has been edited by YamahaAndy (edited 03-06-2005).]

[This message has been edited by YamahaAndy (edited 03-06-2005).]