Sub hookup in a 2ch/HT system with preamp passthru

Can anyone tell me the best way to hook up a Velodyne DD-12 to my system that uses the preamp (Mcintosh C2200)for 2 channel control and also as a passthru for my processor when listening to HT/satellite. The sub has 1 XLR input and 2 RCA inputs. Do I need to run cables from both the processor and the preamp to the sub? Can I run just one pair off the preamp outputs into the sub and that will work in both 2 channel and when the preamp is passed through? The C2200 has 3 sets of outputs. ANy help is appreciated. In speaking with Velodyne (who thought I was a minority using a preamp as a passthru for HT) they were no help what so ever. He told me the sub was meant for just one input from EITHER a receiver, processor, or preamp and that adding other components to input would sum all the signals and degrade the performance. THanks again. Dave
I do what you are looking for by running the LFE out from my processor to the L RCA input on my Velodyne HGS-12 and a second pre out (My pre has dual outputs which is convenient for this configuration) to the R RCA input of the Sub. I then Set the crossover on the Sub to around 70 or so. I set everything up optimal for two channel and then adjusted the processors LFE output level to match that. I'm know I am loosing a little of the LFE signal by applying the crossover to that signal but the loss is worth it in my opinion to get the sub to work for 2-channel as well as HT.

Hope this helps.
Hard to answer. Are you using the sub for LFE or for bass-management?

Kal, more for bass management and trying to get a bit more bottom end in the 2 channel listening. Of course the sub will also be used secondarily in the HT setting. Did that answer you question? Thanks for your help.
Simplest arrangement is to tell the processor that you have no sub and that the front L/R are large. Then connect the output of the 2200 to the L/R inputs of the DD-12 with the main amp fed from the DD-12's RCA outputs. This will impose an 80dB HP filter on your main speakers but all the bass and LFE will go to the DD-12.

Use the setup/EQ on the DD-12 to configure the rest of the crossover options.

I have the same setup as you:
a preamp for 2 channel with HT passthru and 2 outputs, a separate surround processor and one subwoofer. I agree with Kr4 above and set up my system the same way. The key is setting both L and R front speakers speakers on the processor to 'large' and the subwoofer to 'none' - this will direct all low frequencies to your front channels, which your subwoofer is a part of. You can then set the crossover on the sub to your liking. I find I like the crossover lower (40hz)on music and a little higher with movies.
Also, you can set your center to 'small' if you'd like to direct center channel low frequencies to your mains and subwoofer.
Thank you fellas for your help. I really didn't want to use a sub BETWWEN my pre and amp since I'm using XLR's (Aqueous Anniv. from Purist) between preamp and amp. THe amp is 2 channel and accepts either RCA's or XLR's. Can I not go:

2 channel - source with XLR's > preamp > output with XLR's to amp. I would use a pair of RCA's outputted from preamp (I have main, output1, output2 pairs in RCA and XLR as outputs on this preamp) to subwoofer in (RCA L/R)

When in HT can I not just take a y-cable with 1 RCA out from SUB OUT on the processor and input into any pair of inputs on the preamp. I don't know if the preamp (since it is in passthru mode at this point) will pass the sub signal through as well. As it is now the front channels (L/R) come out of the processor into the preamp's 2 AUX inputs. Can I not just Y from the processor to another set of inputs on the preamp and the signal will work in HT? As an additional note, I CAN switch OUTPUT 1 and OUTPUT 2 on and off manually or remotely but on the MAIN preamp outs I cannot. Any other options guys? Might have to send the unit back and buy the new REL Britannia 2 which is inputted right from the speaker outputs on my 2 channel amp and could connects right to the processor via 1 cable to get the .1 in HT. THanks very much for taking time to correspond. Velodyne thought I was a freak when I mentioned my setup (2ch/HT hybrid) to them and didn't have anything valuable advice to add. Thanks. Dave
Your stereo preamp cannot do anything with the SUB OUT if you are using it for L/R. It is only 2 channels.

The only other suggestion with your present equipment is to use the sub only for HT and not for stereo.

Well guys here's the method that works and no need to connect using the speaker out on the sub.

2 channel - paired RCA's from preamp out to sub in. No problem here and I can save a 2 channel preset with this sub. Can also switch sub on and off from preamp (OUTPUT2 in my case)

HT/Satellite - Simply run a Y-cable from the processor SUB OUT single into any pair of inputs on the preamp.(In my case I used the TAPE, but all inputs work). I know the sub signal still passes through another component but it gets too tricky doing the other methods. I can still use the crossover from either the pro or the sub in this case and can also switch the sub on/off with the OUTPUT2 button on the front or the remote. Can also save a preset for HT and satellite in the sub's memory to default there even time HT is needed.