Beam Blockers

[skyboltone]

Strange phase issues are cool. Leslie speakers are designed to screw up phase altogether.

[drhulsey]

I have adapted Jay Mitchell's foam PDM for a 1x12 Ear Candy cab with a Warehouse VIntage 30 clone speaker. The challenge was to use the foam on cab with a front-loaded speaker covered by a clamp-on grill. I used 3/4" foam from McMaster/Carr (85735K72) suggested on TGP's thread. The full 3/4" thickness was too much to clamp at the grill's edge and touched the surround. I altered the edge contour and that seemed to fit fine. I have yet to hear the result.

[drhulsey]

The last three pictures.
The type of foam seems to be important. Makes sense.

[Sonny ReVerb]

Nice work, Doc! Hopefully, it sounds as good as it looks.

[Structo]

How were you able to cut that foam so nice Doc?

Looks good, how do you think it performs?

[andrew]

I use an Ampdoc1 Speaker Tweaker on a Tone Tubby Alnico with my Rocketish build. Smoothes things out a bit.

[drhulsey]

How were you able to cut that foam...

I cut the 12" circle on a band saw. The 3" whole I cut with a 3" whole saw on a drill. The edge I cut on a router table, first with a rabbet, then a chamfer bit.
I hope to hear how it sound this weekend.

[Structo]

The foam must be pretty firm to be able to use power tools on it?

Did you get the density #4 foam?

[drhulsey]

Yes, I used the #4 foam (Mcmaster/Carr # 85735K72).
I have cut foam for years on the band saw. The circular hole saws work great, as well. This was only my second attempt at using a router with foam. The type of foam certainly affects the result, but with sharp bits and careful feed rates, it seems to be a reasonable option. A Dremel tool with router bits works well if you're trying to cut out foam for cradling an item for shock absorption.

[Structo]

How are you liking the tone from the speaker with the foam?

Of course the metal grill thing is a little off the reservation but it may work ok.

I've been wanting to try it.

At the end of that Gear Page thread there was another foam supplier that somebody posted that looked like it might be closer to what Jay uses.
But I haven't been back to that thread to see how that turned out.

[drhulsey]

The grill presented a problem in just how to implement the idea. I don't think it changes the concept appreciably. I PM'd Jay, but haven't heard from him. I still haven't had a chance to play through it.