Sorry, curegeorg if you thought I was not supporting you by asking questions.

I am not saying SVS is 'wrong' but they do make subs, so I might question their objectivity.

Anyway, thanks for the HK white papers which I have read before. The question of using different subs is not really addressed, although the other information is priceless, as always.

Here is a differing opinion on mixing subs, and though I think the answer is quite 'obvious' if you have read any of the information from the website before you would know the staff is very knowledgeable.

"Does one have to purchase the same subwoofer if they want to have two subwoofers (i.e., how would it sound if I purchase a M&K V75 {sealed subwoofer} with a Paradigm P-1000 {ported subwoofer})? Also, what do you think about the subwoofer external crossovers if I decide to purchase another subwoofer to complement my Paradigm P-1000?"

"Two different brand subs will not cause a problem, because low frequencies don't have an audible tonality. We use three different brands in the home theater test lab. As far as crossovers go, you may have to set each sub at a different low pass frequency if you run one from the LFE output on the AC-3 decoder and the other from the subwoofer output on the receiver, or if you run one with the rear speakers and the other with the front speakers."

here is the entire page:

http://www.hometheaterhifi.com/qa/qa9798/qa28.html