I just ordered the ICBM-1 today and was curious about the setup for my particular system.

I am using a McIntosh MX-132 for DTS/Dolby Digital processing with a Parasound CSE-6.1 piggybacking it for the EX/ES processing.

On the Mac I have a Subwoofer output, and on the the Circle Surround (i.e. CSE-6.1) there is also a subwoofer output for the rear surround channels. I currently have a front sub and added a rear sub, how would you suggest setting up my system? As I think there is a ever slight delay on the rear sub from the front sub.... Is the answer to just NOT route the rear sub through the ICBM-1?

My speaker setup is this:
(2) NHT SuperTwo's for right/left (flat to 40 Hz)
(1) NHT SuperOne for center (flat to 60 Hz)
(2) NHT HDP-2's for right/left surround (flat to 60 Hz)
(2) NHT SuperOne's for rear center (flat to 60 Hz)
(1) Velodyne ULD-18II for front sub (20 Hz)
(1) NHT SW3P for rear sub (23 Hz)

My thought would be to do just what you said -- not route the rear sub through the ICBM-1. The choice is made somewhat easier by the presence of only one LFE input on the ICBM-1. So if you have two subs that each get a separate input, as in your case, you can only connect one of the subs to the ICBM-1 (people with two subs that both use the same input are a different story, of course). It would also make the most sense to me to have the bass management for your speakers rely on the "main" sub (the front sub, your Velodyne) to handle the low-freq work for them.

<>

I think this would be due to the delay on the rear speakers, if the sub is a dedicated rear sub from the processor. Maybe you could play with the delays and see if that homogenizes the sound more.

<>

I'm not sure about the specs on the NHT's, but if the rears are small and that's why you added the rear sub, you could still get some bass management on that channel by using line level inputs to the sub and the outputs to the rears, assuming the NHT sub has these features. If the sub is to function as a rear sub for 3 channels instead of two, this scheme would not work satisfactorily.

A setup question I have is are you using the ICBM between the McIntosh and Parasound, or at some other position? My only concern was if you would get the cascading crossover problem if there is bass management included in the other processors. I could be totally off base, but have been bitten by that before.

S.

Sandman,

Yes those are my exact concerns... I was reading the .pdf owner's manual for the ICBM and on page 11 it says:

"The ICBM works not only with 5.1-channel systems, but also with 6.1 channel systems like Lucasfilm THX Surround EX and DTS ES-Matrix/Discrete. We have included an extra channel of bass management to accomodate these systems. That extra channel also lets the ICBM work with the 6.0 channel systems now being championed by Chesky Records and others. These systems repurpose two of the channels in DVD-Audio or multi-channel SACD, using the center channel as a left/front/side "height" channel, and the LFE channel as a right/front/side "height" channel."

Can someone explain to me this paragraph???

The rear and surround speakers I have are quite large and are supposedly rated to go down to 57 + or - 3 dB, so I would think a safe cross over point would be the 60 Hz setting.

I am going to use the ICBM-1 for bass management AFTER the Mac and Parasound units. Both units have pass thru signals which send the full 20Hz-20kHz, which is the reason for this unit...

I think what I will end up doing is really only using half of the in/outputs... The Front L/R/C and the Front Sub.

For the rear I will just leave it as is, and keep the Parasound doing it's thing, as it's bass management will take all the Side/Rear signals below 80 Hz and play them through the Rear Sub. As opposed to going through the ICBM and having the Side and Rear Surrounds' bass signals being mixed in with the Front L/R and Sub. This way I won't have destructive or interfering bass waves emmanating from the front to the rear of the room.

Does this make sense at all??? I AM having a hard time keeping it all straight. Any suggestions or tips are greatly appreciated.

I guess my next suggestion would be to have a Side/Rear Surround Sub in/output...

What you propose does sound correct to me. I was unaware of the extra channel in the ICBM, but with the two subs, I think your plan makes the most sense. I think the result would likely be better than using the crossover in the NHT sub as I originally suggested. I'm guessing you would get a better db per octave curve from the processor.

Sounds like you've got some fun on your hands. Let us know how it works out!

S.