Subwoofer Blending

The Velodyne's have an excellent high pass filter, the REL's don't. I'd suggest you look at the Velodyne SPL line. There's a 8", 10", and 12". The SPL 800 (8") does a great job for audio as long as you're not playing real loud. I agree that filtering your speakers is much better than full range, much less distortion and more dynamic.
Good Luck,
Curt

Hi Tomryan. Most powered subwoofers usually include both a variable adjustable low pass filter for your sub and a switchable high pass filter with three or so settings for the feed to your mains. I can understand you wanting to lessen the load on your SET amp, but I would try as much as possible to avoid running your 2.5s through the high pass circuitry of the subwoofer's crossover.

I own ProAc Tablette 50 Signatures and Response 1SCs and love the midrange of these monitors. I have never even gotten close to acceptable results running any of my monitors through my sub's high pass filtering. The beautiful midrange of the ProAcs and Sonus Fabers I tried this with were completely lost with this method. It's tough enough retaining the midrange quality of these speakers and not muddying them up running them full range and rolling the sub off at 35-40Hz, so filtering both the mains and the sub at least for me is not acceptable.

I should note that using the method you're considering does work for me in my all NHT home theater system. To my ears they blend pretty seemlessly, but audiophile speakers can be another issue. My ProAcs are much more revealing of musical detail and soundstaging than my NHTs, so it's easier to compromise their qualities if I'm not careful in the setup.

For music I would probably avoid the Velodyne and look for a REL Storm III to match with your 2.5s. Once you get a powered sub you can always experiment with integrating it both ways, but I'm sure you'll prefer running your ProAcs full range. Is buying a second amp like the one you have and biamping a feasible alternative? Good luck!

I don't have a specific answer, but I would strongly suggest demoing subs and picking whichever one sounds more musical, regardless of the sub's ability to provide a high-pass output. REL does not feature a high-pass output, but they are very good subs and should not be struck off your list for this reason.

ACI speaker manufacturer offers a passive high-pass filter to go between the preamp and amp (at line level). This would only work if you connect the sub to the preamp at line level, and would clearly not work if you connect the sub to the power amp at speaker level (REL's favored approach).

Lastly I have heard of people getting a very large non-polarized capacitor and connecting in series with the main speakers. Off the top of my head I think you'd need a non-polarized capacitor, rated to at least 100 volts (to be safe) and with a capacitance of around 200 millifarads. Not sure how easy this is to find.

I think it may be best to run full range .. but if you can get the capacitors cheaply try it out.