subwoofer setup problem

I would try 3) first since it is relatively inexpensive, and ACI has a good return policy. I have also read ACI owners who have commented very favorably. Plus a simple capacitor (which is really all the filter is) is not going to cause much sonic degradation in frequencies above 65Hz.

If that doesn't work I'd bite the bullet and get a REL. I have a strata3 with the rolloff frequency set to 28Hz to complement Spica Angelus. If I set the frequency much above 30Hz it sounds awfully muddy ... could be just like you're describing.

As a REL owner I should tell you to dump the ACI and buy REL, but I won't because I think that the ACI might work just as well.

The above threads are interesting physics descriptions ported vs vented etc etc but I think your best advice (from Sean I think, no not the same Sean) was to make sure the sub is well away from the corners ... I agree that subs in corners sound awful boom, boom boom).

I think you are correct to state that the overlap is the problem and I agree with all other posters that subs should underlap rather than overlap the mains in order to avoid muddy bass.

So I still think that 3) should be your first step for the following reasons :

1) ACI wouldn't sell the filters if they didn't think they work.
2) it's cheap and they are returnable if you don't like them.
3) It will stop any overlap, and might even improve the clarity of the main speakers since the drivers are not trying to reproduce low bass (leave it to the sub).
3) buying a different subwoofer is much more expensive, and may not be necessary after adding the filters.

I would try to resolve the issue with ACI before anything else. My REL sub is great but I'm sure your ACI is just as good if correctly set up.

Good luck, and please post back to let us know if you solve the problem.