One note sub-woofers

[luxmanlover]

I have a couple of non-jbl subs I built a while ago. I was messing around around with them now that I have a decent active cross-over to split the signal with. Problem is the result is pretty much the same as when i was using the old crossover...poor intergration and one note bass. What are some of the causes of this.
Thx Kelly

[GordonW]

The two main causes of one-note bass are:

1) cabinet volume too small/not enough stuffing. If you don't have any or much fiberglass stuffing in the cabinet, I'd at least have 4" on each wall.

2) Port tuned too high. I'd try lengthening the port, probably by a couple inches at first, and adjust to taste.

Either of these conditions can result in a high-Q peak near port resonance. The idea is to get enough box volume that the natural box resonances are low enough, and tune the port low enough so that it doesn't cause things to become peaky.

Regards,
Gordon.