Terminal Port Experiments on a 2 cu ft cab

Here’s an example of me getting too excited about a project or experiment to document the process along the way. So here are a couple’after’ photos of a recent experiment adding vents to my used-to-be-a-combo closed cab. I modeled the frequency response along the way with WinISD, working backward: tweaking the tuning frequency until the length of vents matched the thickness of the baffle for a given number & diameter of ports. The results were not good. As soon as I started making ports, the cab got louder, but the treble became obnoxious. Adding more ports increased bass response, but did nothing about the harsh treble. By the time I had six ports I had stopped modeling, figuring I was pretty close to an open cab at that point. It definitely sounded better the more ports I put in it, but nowhere near as good as it sounded sealed. So I got out the PL Premium and glued the plugs back in, and now the cab is extra crazy looking. Sounds great though.

Speaker is an Eminence Private Jack. Amp used was an AX84 SEL, more or less. Cab was once a Fender London Reverb combo, and is about 2 cubic feet. It’s lined, back and sides, with 1.5″ polyester batting.

Sound clips would have been a good idea, huh? As I said, I tend not to think of documenting until it’s too late.