BillFitzmaurice.info

chjade84 wrote:I didn't have any clamps that could reach to the middle

Can be done with clamps, although 4 hands come in handy. Put something like a smallish block, stack of a few ply cutoffs or whatever in the middle, then lay e.g. a 2x4 or 4x6 across the cab and clamp at both sides. It will push down the block in the middle, just as if you did have that super reach clamp.

That looks like a very solid Table Tuba to me. I bet you can hardly wait to get it fired up

Yea... that would have worked, too.

I want to fire it up tomorrow afternoon. That will be 24 hours since I laid the PL. Hope that's ok. I can't imagine it wouldn't be.

Well, she's all done and in behind my couch. (EDIT: It's not really "done" yet. I'm not sure what I want to do finish-wise and I couldn't wait to hear it.)





It sounds great! There are several spots in the room where the bass drops compared to the rest, but fortunately none of those spots are where people sit. It shakes the cabinets in the other room so I'll have to fix those.

The only thing I'm concerned about is blowing the speaker with too much voltage. I only have the Foster plate amp turned up about half of the way and I'm still hitting 20v at times depending on the bass track of the particular song/movie I'm listening to. Of course that means the rest of the "quieter" bass is pretty limited just to keep the harder hits from overpowering the driver - which isn't ideal.

What do you guys use/do to prevent overvoltage to the driver? I remember reading about limiters but I can't find any anymore.


Good work on the design Bill! I know where I'll be coming for my subwoofers from now on...

Save yourself from a blown driver and get a pair of these: http://www.parts-express.com/pe/showdet ... er=266-248 when they get back in stock.

You lose just a tiny bit of response on the low end, but will save you having to replace the driver when it goes.

NCDaveD

NCDaveD wrote:Save yourself from a blown driver and get a pair of these: http://www.parts-express.com/pe/showdet ... er=266-248 when they get back in stock.

You lose just a tiny bit of response on the low end, but will save you having to replace the driver when it goes.

NCDaveD

From my plate amp:

"Unit has a 3rd order (18dB/octave) high pass filter at 29Hz with a Q of 0.707 built into the subwoofer section."


So I should be good in the high pass department. I just need to keep my voltage to the driver under 21 volts.

What about this one?

Behringer MDX1600 2 channel expander/gate/compressor/peak limiter

http://www.behringer.com/EN/Products/MDX1600.aspx

Peak Limiter Section:
Type: IGC
Level: Variable (0db to OFF)
Ratio: infinity:1
Level 1 limiter Type: clipper
Attack: "zero"
Release: "zero"


That seems like it should do the trick, right?

NCDaveD wrote:Save yourself from a blown driver and get a pair of these: http://www.parts-express.com/pe/showdet ... er=266-248

IMO Fmods have insufficient slope to offer much protection. They're frequency corner is also imprecise, being dependent on the input impedance of the supplied device. They may be better than nothing, but if so barely.

Bill, thanks for the edification. At least they kill the start up thump of the amp...

NCDaveD