I have added a second sub to my 7.1 system. My AVR h/k 645 has a sub stetting that calls for a 12/10/8 inch driver. My main sub is a duel 8 inch drive and the other sub has a 12 inch driver. What setting sould the AVR be at?

Quite frankly, other than perhaps maybe suggested crossover and/or LFE level settings I am not exactly sure what is meant by an AVR "sub setting". Depending on the size of your L/R speakers, the usual crossover is 80hz. The different size drivers in each sub is pretty irrelevant. I have a couple of old Yamaha subs in another system in my house with "dual 8s" that, although they can't be played quite as loud, give me better bass extension than a Paradigm I have with a 12" driver.

Just get the crossover, volume balance between the two subs and phase setting right and you will be good to go.

I challenge you to a dual!

Hehe

I would set it for the 12" driver as dual 8's is pretty close to a 12" cone area.

I dunno, it seems to me that each size of speaker playes a certain frequency 'optimally' (as in, you don't see very many 12 inch tweeters)... sure they can engineer different sized speakers to play frequencies that may otherwize not be best reproduced by that particular size. The 6 1/2 inch divers in my M80's are a great example. In all my car audio days I never, and I mean NEVER heard speakers that small produce such impressive bass. So my guess would be that your AVR is trying to send the bass signal to your subs that best suits the size of your sub. But with todays subwoofers, that just might be a non-issue.

Either way, I'm sure JohnK will be along shortly to tear apart my theories and set you straight!

Just forget about this issue, keep the BIC and FedEx the Bravus 8D to Buffalo.

Uhhh.... you guys brothers?

Never heard of that setting. There are some HK owners on this thread, maybe they can contribute to your question..

Strange indeed. I wonder if it does both a high and lowpass filter?

Yes we are brothers. Twin brothers. To be at Axioms 30 year bash!!

My H/K doesn't have that feature. Rick?

Robert, welcome and an appreciation for your service in law enforcement. You should generally rely on the settings arrived at by EzSet/EQ, but a manual setting for a high pass filter to the subs is available on the 645. This rolls off the frequencies delivered to the sub below certain frequencies(30Hz, 25Hz, 20Hz, etc.)depending(somewhat simplistically)on their cone sizes. This is to keep ultra-low frequencies that the sub supposedly couldn't handle well out of the way. I'd forget it or just set it at the highest size. Oh, and yes, Micah's theories suck(just kidding, Micah!).