4648 Port Stuffing

[jdubs]

Guys

I'm running a pair of JBL 4648s for the bass in my Oris horn setup.

I'd love to tighten up the bass and also increase its extension if possible.

I was told that stuffing one port in each cabinet would be a good way to accomplish this.

What are the best ways of port stuffing? I.e., what material(s) should I use to accompish it?

Thanks!!

Jim

[edgewound]

You could use rolled up open cell foam, dacron batting, or fiberglass...I'm sure there's more too.

The foam seems to be the cleanest to work with, but the dacron is cheap....find at upholstery shops....and the fiberglass is cheap but itchy .

Stuff to your liking...but it will change the alignment of the cabinet to leakage damped.

[jdubs]

You could use rolled up open cell foam, dacron batting, or fiberglass...I'm sure there's more too.

The foam seems to be the cleanest to work with, but the dacron is cheap....find at upholstery shops....and the fiberglass is cheap but itchy .

Stuff to your liking...but it will change the alignment of the cabinet to leakage damped.

Much obliged...thanks edgewound!!

[wpod]

I've also got a pair of 4648A and if my memory (and notes) serve me correctly, I had the best results lowering the tuning by lengthening the two ports by 2 inches each, giving a total length of 6 1/2 inches long each. This gave me a box tuning of 36 Hz, which seemed to work the best in my room (12x26x9 ft.). I beleive that by stuffing one port, you end up with a 28.5 Hz tuning , which was a little too low for that cabinet in my room. The only hassle is that the vents in this cabinet are 5 inch inside diameter, so you will probably have to roll your own (as I did) to add on to the original. Experiment, take notes, have fun.