Speaker Box Building Software

[skyboltone]

Greetings Lads and Laddies:
I've been using the registered version of Boxplot 3 for some time but it doesn't address open back cabinets or even single driver boxes very well. Are any of you familiar with box modeling software that is usefull to those of us here that build amps and boxes?

Thanks in advance
Dan

[jaysg]

I attempted to use Boxplot for a ported bass cabinet. It yeilded all sorts of seemingly useful information, however, I ended up taking the advice of a guy who runs the engineering department at a high end car sound speaker manufacturer...which was, "Copy something you know is good."

The reasoning is that these programs won't tell you how it will sound. This isn't sound reinforcement, it's sound production. In the bass cabinet world, mostly they're stealing from SWR, Bag End or Bergantino. Improvements are often as not created by experimenting with geometry and port depths and judged by listening tests, not technical acoustics.

If you look a lot of newer (since the 80's) open back designs, I think you'll see an attempt to partially restrict the flow of air via half-backs, slots, or round/oval openings. In comparison, a 60's Fender combo is almost completely unrestriced. all opinion of course, ymmv, etc, hth

[skyboltone]

I think there must be some at least minor science out there for open backs. Dumble gave me strict dimensions for the cabinet and the hole in the back when he built my amp. I built the cabinet of course. He called for a lumber core box and a couple of 6" +/- circles some distance which I don't recall apart and tied together with horizontal cuts. If you look at the interview page he's leaning on one that looks exactly like mine size wise. He had me put an Altec 417-8C inside.

Anybody around have one of those cabinets? Sure would like to know the dimensions of the hole.

Dan