A little more info too...  I have a tuned mastering room with big B&W mains.  The mastering rig is flat to around 27Hz.

   When mixing though, I like to use nearfields.  BUT...  nearfields without a sub are tough.  If I had a speaker management system like this, I could use my mastering mains as a subwoofer with my nearfields...  just by having that be one of the speaker "setups" with bass management set up to do it.  These features would also allow me to use different crossover points and delays (for time alignment) with my sub if I wanted to use one subwoofer system for multiple speaker systems.  I suppose I could put together a complicated system to do all of this, but it would be far easier if these features were built into Totalmix.

   Basically, I would like to be able to dedicate a specific totalmix output channel for each "speaker" in my rig...  and each "speaker" could have it's own crossover/filter and/or delay...  and then if we could save "speaker setups"...  and then switch between setups like Cranesong Avocet, or Grace M905, Presonus Central Station, etc.

This would be AWESOME.  Please consider this...  I think you guys could do it so well...  Totalmix is amazing, and these features in Totalmix would really put it over the top.

No - you totally missed what I'm talking about.  I'll try to be more concise:

All I'm really asking for is new features in Totalmix (which could possibly require more DSP on RME cards).  Imagine you have two monitor sets...  Auratones, and Mackie HR824...  and you want to switch between them.  You could use a monitor switcher (Cranesong Avocet, Grace M905, etc)...  BUT why is this necessary?  Totalmix could handle this.  Imagine you have a 8 channel D/A.  Well, connect 2 channels to the amp going to the Auratones, and two channels to the Mackie HR824.  Now how do you switch between the "speaker sets"?  Totalmix could do it with mutes, etc.  BUT if Totalmix was "designed" to do this, it could handle it more gracefully.  Now imagine you add a subwoofer.  Just dedicate another D/A to the sub (channel 5, as your first 4 are used for the other speakers).  If totalmix had the option to add delay and/or crossover filtering to each output, you could use the same sub with both your Auratones, AND your Mackie HR824.  You'd just save one "speaker set" in Totalmix with the sub configured to work well with the Auratones.  Then save another "speaker set" with the sub configured to work well with the HR824s.  You wouldn't have to buy a separate subwoofer for each speaker system.  You could just configure the crossover/delay differently within Totalmix for each speaker "set".  The delay would be helpful for time aligning the sub to the mains, so if you could save the delay, that we be awesome too.

   Now using the ARC USB, if Totalmix could do everything I just described, you would no longer have a need for an expensive dedicated monitor controller.  Totalmix and the ARC usb could perform the same functions (speaker set switching, volume control, etc)...  probably BETTER.  The only hardware change I was suggesting is I'd prefer CAT5 to USB for the ARC, as CAT5 can travel much farther.

Exactly.  That's the basic idea...  but I'm using a $50,000 tuned mastering speaker system which I use for mastering work...  along with a few different nearfield monitoring systems I use when I'm doing mixing work.  Currently I'm using a Cranesong Avocet as a speaker switch, which works well.  I've been thinking of adding a subwoofer to my nearfield systems, but I got thinking, if Totalmix had these abilities, I could use my big mastering system as a subwoofer whenever I have to work on my nearfields...  and technically, a system like this could replace the Avocet as well - although the volume control in Totalmix would obviously be digital rather than analog as on the Avocet.

Thanks would be kind of a rigged way to do speaker switching, but it would do nothing for bass management.

   I'd like filters on each speaker/output channel that can be used as crossovers for subwoofer integration.  I'd also like delay on each channel for time alignment.  I think if it was designed to function as a monitor controller/switcher like the Avocet or M905, and it also had the delay and filters, it would work.

I would not want to use an analog volume control that works without relay switches, otherwise l/r imbalances will happen. And relay based controller are very expensive.

I think totalmix with the existing external knob is pretty great. One just have to make sure that the volume of the monitor speaker is no way to high that you must turn down totalmix like -40db all the time - but mainly because a reasonable volume limit for 0dbfs is a safety measures in case you have a computer crash..

I think RME explained somewhere that this resolution loss with digital volume control in totalmixis a myth.