Hey guys i'm playing with kerf port design. But i'm clueless on how big the kerf needs be, compared to the size of the port. The port i'm using is 2.5 x 37.5. Should the kerf be the the same size as the port width or half the port width? Here is the design so everyone can see how i'm tring to get the kerf.

Since nobody else has chimed in, I'll give you my experience with kerfing.

I originally tried a 2" id, 2 3/4" od, it didn't work out so well. I couldn't get all of the cuts to bend the same before one of them split (no matter how thin/thick the material I left was). I believe the radius was too small and this was my first attempt at kerfing.

I'm a steel fabricator by trade, so I went with what I know and nipped some 11 gauge steel to the radius needed so I didn't have to redesign the enclosure. I've found a very limited amount of information on this subject.

My advice to you is to start with a 4" or 5" radius (practicing) and try to go smaller form there.

You'll find your limits and can redesign your enclosure with the smallest kerf you can achieve, if necessary. Your only kerfing the end of your port so a larger radius shouldn't change your tuning much.

Any radius you can achieve will be better than the port just stopping as you're only creating a smoother transition to the environment outside of the enclosure.

I remember seeing Jacob post a thread, on sundown audio's forum, where he used bending plywood and spacer blocks to achieve his kerf (like a sandwich).

Good luck and post back with pics when you get something working.

Edited August 19, 201015 yr by cobra93