home sub too cheap to fix

[tedmich]

I got a free Monitor Audio Bronze BRW-10 subwoofer off C list



Power LED comes on but no output. Thing is HEAVY so I figured I could at least use the box and/or speaker if the amp is dead.

Opening it up the onboard amp is full of crappy Jun Fu caps, pretty reviled at Badcaps.net so I pulled all the big ones. They were rated at 85C and very close to the 4 output devices, the closest cap even had heavy gauge shrink tube on it try to keep it from being BBQd. The MOSFETs (Mospec f12c20c) are all in little silicone bags and awkwardly clamped to the faceplate.

The solder is all Pb free and barely flows at the highest setting of my 35w solder station.
The speaker has only 4 screws, a tip there is nothing heavy duty going on

sure enough its a stamped frame lightwight with a cool looking cone

inside is very thin 15mm MDF and the internal "brace" is particle board to save more $, and there at the bottom is a HUGE steel slab accounting for the majority of the weight.

Its pretty amazing what ~$300 buys some places...
this thing wasn't worth the gas I spent picking it up!

on the bright side the speaker looks perfect for the corn starch / water stuff

[Enzo]

Wow, I haven't seen speakers do that since oh, about 1968. Then they usually looked like that.

[Leo_Gnardo]

Hilarious! Mosh pit, right in the speaker. It's been a while since I've found steel chunks added to a piece of gear to give the illusion of "it must be good - it's heavy."

Do you drive the speaker with one frequency or what? I want to do that to entertain my "while you wait" crustomers, or scare away Halloweeners next year.

Gets my best laugh of the day, you outdid George H W Bush's new book.

[elipsey]

I got a crappy sub like that from my room mate a few years ago. I cut a new baffle, put a cheap bench power supply, a car stereo amp, and a sub in it that I had lying around. The power supply and car stereo amp happend to fit nicely into the plastic molding that the old amplifier's PCB was installed in. Then I modeled it with WinISD, and added a tuned port. It works OK and had a marginal cost of $0. Also, now all of my dinner parties sound like a disco.

They say MDF has good acoustic properties, especially for subwoofers, because it is very dense. Why not up-cycle the cabinet?

[tedmich]

Wow, I haven't seen speakers do that since oh, about 1968. Then they usually looked like that.

I can dig it Enzo! Since my brain is done with such things this is as close as I get to hallucinations now



stare at center for 60 sec then whatever you look at next bubbles

[Enzo]

yeah well, in the '60s everything bubbled all the time anyway.

[tedmich]

I may just drop $100 on a KRK Rockit 10S plate amp as it interfaces with my existing Tascam monitors better, since they all have balanced inputs.

Steve at ApexJr has the 12" KRK drivers for $50 (YELLOW!) and 3 versions of KRK plate amps for $56-$120

[olddawg]

Check out MCM for a replacement power module first. Or better yet.... Check out Frys and Amazon. I got a 12" 100 watt Sony powered Sub from Frys a while back for $89 free shipping to add to my home theater setup. It will drive you out of the room. The one pictured in this thread looks like a computer system sub. The Sony is a big black box.

[Mick Bailey]

Wow, I haven't seen speakers do that since oh, about 1968. Then they usually looked like that.

Were they pulled from a porn cinema?