Another Sub Q: Is my sub mismatched with speakers?


I have floorstanding speakers that go from 35Hz on up. I have a subwoofer that the lowest it will crossover is 50Hz. Are my speakers and subwoofer competing at some of the same frequencies? I read that the subwoofer should start crossing over at about 5Hz below the lowest the mains will go. In other words, my sub should be crossing over at 30Hz to match up better with my mains, right?

Am I nuts here?
matchstikman
Find the point where your speakers start to roll off their bass, maybe the point where they are down 3db. and cross over at a point above this. Some overlap between the mains and sub will sound best, find this by listening. Subs work best for music if they are near the mains and I have found that is somewere between the mains in most cases but not all cases. Get a cheap rat shack spl meter (nice to have anyway) and a must for hometheater.
beside, all the points above, dont forget that many speakers claim to reproduce music in low Hz, but they dont sound as good as quailty sub,, the best is to do comparision and hear, even cross at 125 Hz , may sound more solid and richer bass
Are you using the crossover in the sub? Does your preamp have a crossover built in? If you are running full range to your speakers and full range to the sub, you will get some overlap with a crossover at 50hz. Remember that most crossovers are not 1st order, so you will get a gradual roll-off over a 12db to 18db range. The only way to avoid this is to have the system crossed over between the pre and power amps or between the amp and the speakers so the sub won't get too much of the same signal.
Some very high end subs will allow you to adjust for a good blend.
I think that if you run your main speakers full range you have to set the sub crossover below the mains. So I think 30Hz is a fair guess for where you would have to cross.
My guess is that the crossover at 50Hz will result in boomy, muddy bass. It's pretty clearly audible if there's too much overlap, and it doesn't sound good.

As I see it you have two choices ... either put a high pass filter on the main speakers to take them to about 60Hz cutoff (I think that ACI, makers of the Titan sub sell passive filters for this purpose). Another filter option is to get an active crossover, but these can be expensive.

The second option is to get a new sub like a REL which can crossover at 30Hz or below. REL goes to 22Hz as its lowest crossover frequency, and I think this is a key reason for REL works so well with so many speakers.