I theorize: "Convergence".....

[Wolf]

Eric- I already have about 4 subs I can pair them with. In my room though, I really don't need the sub with them with the F3 as low as it already is.

Wolf

[Wolf]

Now that the Entertainment Center is constructed and in place currently, awaiting a few more things to make it all as I want it finale, it's time to progress on some other builds...

Got the boards cut out for the Convergence today. I ended up not using 2 full boards for the center partition. The driver mounting board is solid except for the hole, but the second layer I pieced together with scraps so I don't have to waist so much material. The method of active driver mounting should allow for removal, so the framed layer will be closer to a square cutout. This way I can grab an edge of the driver frame from the opening. The recessed amp mounting on the rear and possibly an added handle on the top will allow easy movement of the completed structure.

Driver mounting double-board, recently glued up:


Later,
Wolf

[Wolf]

Okay...

It only required 2(!) 1.5" steel fender washers to tune the PR down from 51 Hz to 49Hz. I did not expect the PR to be that close to tuning inherently. I'll test it out tomorrow before work so I don't wake up the family.
Here's the measured impedance up to 300Hz:



I used the hex-head screws so I could use the 0.25" nut driver from most magnetic bit sets. Being a bandpass, the sealing of the chambers is paramount for performance. Normally, I use the poly-glue to seal the gaps as it expands, and nothing else is required. I used caulking of the center partition, as well as weather stripping on both the TB and the Eminence PR. The Plate amp has a seal tape on it already, so that sufficed. I lightly stuffed the sealed chamber with polyfil, and lined the perimeter of the reflex chamber with 0.5" thick open-cell foam.

The suspension on this thing is TIGHT! I can't wait to try it out tomorrow before work!

More photos...








Later,
Wolf

[Wolf]

Oh, forgot-

The Euro block was only used as a test-point for the impedance measurement. One side is the amplifier, and the other the sub. I'll likely remove it later....

Later,
Wolf

[marvin]

Come on , Ben, plain black drywall screws will look better than those silver hex heads to mount the plate amp!

[philthien]

Looking forward to a report on how this sounds.

[dynamo]

I like the silver sheet metal screws, gives a tough industrial look

[Wolf]

Dynamo- yes- this is what I was going for!

As to a test report, I had to reduce the level on the Crowns because this is RCA level input. I have it in the middle of the room, so it's in free-space. Nothing really major there in terms of capable output. I have it maxed out just to meet up, so 200W is about right. I suspect less would be applicable in an all RCA signal driven system. I've been playing some various music, and even some Bass Mechanik. Moonstone is mostly 27 cycles, and in free-space, it does not hit the fundamental. I imagine against a room boundary it just might succeed. Everything above that seems to be really nice and tight. I have the xover set about 1:00 on the dial adjusted by ear, and nothing untoward seems to be coming from it. 30Hz up in free space is pretty decent, and it's shaking the couch and everything else in the room.

I'm pretty happy with how this turned out!
Wolf