New subwoofer!.. now what?

exlvit

Well, I picked up a JBL ES150P from costco for $125 today, thought it was a good deal. I've got it hooked up through an HK3490, paired up with some Monitor 60's. It should really complete the stereo, since the M60's lack some bass imo.

Anyway, I don't really know how to set this thing up correctly. The crossover on the back goes from 50-150Hz, but the frequency response in the spec sheet says 27-150Hz! I'm also pretty much clueless what to do with the phase switch, since I can't really tell a difference in the sound in 0? or 180?

pyrocyborg

Well, I do not know if the HK3490 has a crossover option, in the menu. If so, you could set it at 80 hz, and do the same on the sub; and set your speakers to large, so they will still go deep! (I do not know if your receiver has either of these options).

The frequency indicated on the spec sheet is what the sub is capable to handle (here, 27 to 150 hz). However, as bass are directionnal (you can tell where they came from) near the 100 hz level, you don't want your sub to reproduce frequencies ranging from 100 to 150 hz, except if you have tiny speakers unable to do lower frequencies.

Anyways, as your floorstander sure goes deep in bass, all you should do is turn the knob on your sub so the crossover is set to 80 hz. This way, your sub will reproduce frequencies under 80 hz, which it is "specialized" into.

As for the phase, there is a way to find out which sounds better. First of all, let's say it all depends on your room acoustics: for someone, 0 degree is better, for someone else, it's 180. To find out which one suits you best, go to your listening position and try a song you know, with a lot of bass. After a try, change the phase to the other option, and listen again. Choose whatever one has the stronger bass.

exlvit

Well, the HK3490 doesn't have any from of bass management/settings, but I did set the crossover on the subwoofer to around 70-80 hz (the dots that represent hz are not labeled, so I just set it two higher than 50), and there has been a big improvement! I can't hear the direction the bass is coming from, which is what it's supposed to sound like. I also flipped the phase back and forth, and still, couldn't tell a difference, so I just left it on 0.

Thanks for the help though, I guess I had the crossover set too high, which didn't sound right.

Syndil

If the subwoofer is out of phase, there will be a null at the crossover point between the mains and the sub. Easiest way I have found to determine the phase is with a tone sweep. If you have a DVD with the THX optimizer on it, it will have a subwoofer test with a tone sweep. Set the phase to whichever position gives you more consistent volume throughout the sweep.