The Rocket sub

Posted in My projects

One reason for this project (beside the other 50 projects I'm working on ;-) ) is Floyd Tool's book "Sound Reproduction" where he discusses multiple subwoofers in a room to diffuse or spread out room resonance modes to greatly improve low frequency response flatness and accuracy. There is also an excellent thread on this subject here, where, among others, Earl Geddes offers an empirical method to set up such a system with multiple subs.

The cone is about 80 cm high, with an internal volume of some 78 liters. I have designed a wooden adapter ring that accepts the excellent Peerless XXL 12 inch woofer. I had them painted in a body shop in BMW Arctic Gray...

A word about the enclosure: these are rejected missile nose cones from the HAWK air defense missile system. The material is glass fiber, about half an inch thick. They are very stiff constructions and yet relatively light (which is good if you have to loft it up into the air!). They have a resonance at about 1kHz; this frequency is well above the cut-off frequency of about 80Hz so it will never be excited. I've been using them for several years now and they produce strong, well controlled bass with an elegant form factor. Swords to ploughshares, isn't that the expression ;-) ?

Want to build one of my designs?

I am flattered but would also like us to agree on a few rules.

My designs are the best I can make them, including reliability and safety. A lot of effort, time and money goes into them, and I enjoy doing it.

Nevertheless, I have obviously no control over how, where or when somebody would use a design of me. Therefore, I cannot guarantee that it will do as advertised in all cases and circumstances. I also have to decline any and all responsibility for any damages, direct or consequential, resulting from the use of my designs. Sorry about that, but that's how my lawyer wants it...

If you want to build one for your own use, go ahead. It would be nice if you would let me know how it all works out.

If you like to use one of my designs for a commercial product, we can discuss the terms of such use. If you plan to make money out of them, I would like to have some compensation for my work and effort as well. Or, if you are in need of a design consultant for a project, let me know. I’m sure we can work something out to mutual benefit.