Home High Efficiency Speaker Asylum

Need speakers that can rock with just one watt? You found da place.

Here is a picture of the enclosures that were used

I received an inquiry about what enclosures were used . . . sorry for not making that clear. When ever I mention "Dimension 5" or "Dimension 5nf" or "Dimension 5e" (for the special-order field coil version), I'm referring to the corresponding Feastrex fullrange driver housed in an enclosure like the ones shown in the photo.

The D5 driver installs from the rear of the baffle and has a ring protruding from the flange, right around the surround, that just fits into the baffle hole. Then the driver is supported at the back of the motor by a brace with a hole in it. A bolt (M8) passes through the hole in the brace into a corresponding threaded hole in the back plate of the motor. There is also a paper gasket between flange and the baffle.

In the case of the D5nf, the driver mounts more conventionally, from the front of the baffle. However, it too has a threaded hole in the center of the back side of the yoke, and it too is supported by a brace. In the case of the D5nf, a sorbothane or cork gasket goes between the frame and the baffle, and the baffle screws can be left a little loose. (Rubber or cork washers could also be used with the screws.)

These methods of affixing the driver help to decouple the driver and the baffle.

The enclosures for the different drivers are very similar to each other but not identical. First, the side wall mounting position of the rear brace varies for the different drivers. Second, the finishing of the baffle hole obviously varies depending on whether the driver is mounted from the front or from the rear. Third, the tuning of the round port is different depending on the driver. However, the round port is just a section of PVC 3" water pipe (3.2" actually, but 3-inch *drain* pipes have thinner walls than 3-inch *supply* pipes and thus the inner diameter should measure 3.2 inches) and tuning is a matter of cutting the length differently. And it could be designed as a force fit into the baffle allowing the user to change it depending on the driver used.

There is a slight problem of standing waves inside a box with parallel walls like this but 2.5 sheets of newspaper lightly crumpled up and put inside are enough to keep those down . . . you could also get fancy and use traditional handmade Japanese "washi" paper but after all the money you spent on the drivers maybe you don't have anything left to budget for fancy paper to crumple up and toss inside . . . :-D

P.S. The round port is rather short but the rectangular opening in the bottom is actually two ports that are bent in an L shape on the bottom and running up the back of the inside of the enclosure, and tuned to two different frequencies, although I'm not sure I know why Feastrex did it that way . . . basically you've got an enclosure that is rather large for the size of the drivers (although fairly small compared to what most people expect of a high-performance, high fidelity loudspeaker) and the bass reflex tuning set to roughly 1/2 the resonance frequency . . . a lot of cut-and-try went into these, I am told.


This post is made possible by the generous support of people like you and our sponsors:
  Parts Connexion  


Follow Ups Full Thread
Follow Ups
  • Here is a picture of the enclosures that were used - Christopher Witmer 20:42:44 03/07/07 (0)


You can not post to an archived thread.