I am hoping one of the knowledable pppl on this board can comment on this.

My goal is to add a sub to my rear speakers (Axiom QS-8s).

What I can do, using my Marantz SR4400 AV receiver is:

1) set rear speakers to large in receiver
2) cable from rear L/R pre-out to the sub. Use the sub's builtin variable low pass to mesh with the Axiom sateliites.

What I can NOT do is filter the signal going to the satellites (i.e use a high pass filter).

The only solution I can find is to use an inline, speaker level, high pass filter, like those used in the car audio biz.

ex: http://www.partsexpress.com/webpage.cfm?...758810&desc=ASC

My question: would use of one of these filters be acceptable in a mid-range home theatre? would it be equivalent, in terms of signal degradation, to the crossover network in a cheap receiver?

Any comments welecome.

regards Colin

I don't know much about the Parts Express components you linked to, I'm afraid, although others around here may have some better info. Paradigm makes a product called the X-30 that may do what you are looking for (I haven't looked at it in a long time, and I'm not sure exactly what sort of I/O it offers), and of course Outlaw's ICBM could do it as well, but in both cases you would need to locate the unit between pre-amp output and amp input for the surrounds, which may not be an option if you are using the Marantz's internal amps to drive those speakers.

Paradigm's X-10 might work best for you, though - speaker level inputs for two channels along with speaker level outputs for both channels and a line level output for a powered subwoofer.

Do you not have a separate amp channel available as it would be better to use inline RCA type filters than these you show which will be more lossy.

For instance, I have the two rear speakers on one channel of my 770, but they are 8 ohms and since the back channel is really combined in most cases, using the same channel works.

I have used both these:
http://www.partsexpress.com/webpage.cfm?...=195&manuid=265
and the filters you pointed out and both work fine.

It also appears that your trying to use the Marantz to power the sub and rear channels and you might want to consider using the Marantz to power the rear channels and get a plate amp for your sub since you can get a good one for $100-$200 just to power the sub.

To clairfy, ... I am using a powered sub with no speaker level high pass filter builtin.

It appears that the Paradigm x-10, x-20 external crossovers will solve my problem. Now if I can only find more info on the frequency of the high pass...

regards Colin