Sub cross over settings?

CinderLyon

I have a Onkyo tx-nr809 receiver I am trying to set up. I have read that I should set the frequency cross over on my sub all the way up and then calibrate with audyssey and let the receiver determine room corrected frequency response.

Is that correct?

(the things i do to get my count up to 100 hehe)

ZLTFUL

That is indeed correct. As long as you are using the LFE connection from the AVR.

CinderLyon

by lfe connections i am assuming you mean the rca sub out connection or is it something different?

John K.

Yes, by "LFE" was meant the sub out on the receiver which accepts an RCA plug. To clarify a point, subs don't have internal crossovers. The frequency control is a low-pass filter which rolls off the response of the sub above the frequency set, but has no effect on the speakers, even if they're wired through the sub.

CinderLyon

i always wondered what the speaker connections are on the back of some subs. I take it they are just pass throughs. what does the freq knob on a sub do? work in connection with the lfe settings in the receiver? Or is it a separate band pass cut off. or is it meant for reciverss that do not have an LFE setting option?

John K.

Yes, in nearly all cases the speaker level outputs on a sub are simply a straight-through connection which is the same as if the speakers were wired directly from the receiver terminals. A very few subs have a separate high-pass filter on the speaker level outputs which roll off the connected speakers below a fixed frequency of 100Hz or so. Even on these the sub's frequency control has nothing to do with the speakers. It rolls off the sub to "blend" with the speakers when used with a receiver which has no internal crossover which affects both the sub and the speakers. When the receiver is doing a crossover, the sub's low-pass filter should be by-passed by using its "LFE" input(if available)or setting it at its highest frequency so it won't interfere in the frequency range where the receiver is doing the crossover.