BillFitzmaurice.info

Having nearly fineshed my pair of T30's im looking for a new project over the summer and i was thinking along the lines of a mini 12V BFM rig!
Im not too clued up about this kind of thing so any help would be greatly appreciated.
I was thinking of maybe building an O15 or O12 tall boy as it could easily fit on a sack barrow and be wheeled around.
Will i be able to install a plate amp and batteries to power it into the speaker without degrading performance?
also, could anyone give me advice on what batteries to use and how to wire them to get desired voltages and to power my little rig properly. and if possible i would like to be able to use rechargeable batteries, rarther than having to replace them.

This will be used to play anything from modern DnB and Dubstep to chilled out jazz, i am asuming bill's O15 tall boy will suit my needs, but i was also thinking of the possibly of an AT/OTop combination as i already have the OTop and i could do with a AT for my car, would this combination work? also, can the AT be fired into the floor?

If anybody else has made a 12v BFM system it would be great to see pictures!

Think Rubicon is your man for these questions...

ok, lets hope rubicon can chip in at some point.

Has anybody got anything to say about using the tall boys for this application?

I dunno how your dubstep will come out. Might be better with a sub and a DR for efficiency on the batteries.

Gregory East wrote:I dunno how your dubstep will come out. Might be better with a sub and a DR for efficiency on the batteries.

haha, well im not expecting to feel my bones shake from the bass 50 feet away, but im sure it will be better than the 2x2" woofers in my current portable ipod speakers!

there is an ever growing 12v movement out there
check out this thread
http://forum.speakerplans.com/show-off- ... 30511.html
although fun and interesting even inspiring it plays on the old adage that people will eventually do the right thing, after they have exhausted all other possibilities.
You are lucky because you have found BFM, the others are all mired in inefficiency.
The O15 is not a bad choice because it is very efficient, but it is an 8 ohm cab, and you are
limited from the 12V to only 18W per channel (P=V²/R), theoretically, much less in practice.
For added headrom the jack212 would be a better vhoice, and also lighter, but with less bass, but that in turn means you need less battery power. It's all about how much weight and volume you are happy to carry.
Don't use a plate or car amp, get a class-d amp from ebay, or if you are able, build your own.

these are the set of three 12v amps I have made so far from kits by http://www.41hz.com

amp32PS and amp32 sitting on amp9, note the AA battery, these things are tiny, but really perform.

Battery choice is either a seald lead acid battery or if you feel wealthy, lithium iron phosphate (LiFePO4), with a 7Ah (1,5Kg) SLA battery I get about 6 hours of music from my DR250 at very good volume.

For lower impedance O15, use two 3012LF's instead of 3015LF.

horst wrote:people will eventually do the right thing, after they have exhausted all other possibilities.

My challenge is not to run out of life before possibilities.

thats great, thanks for the replies.

will the o15 be afected by the battery and amp being inside or will it be a minimal difference?

im going to have a look into those little amps, any idea of how loud that would take me?
a video of your DR's would be reat aswell!

george

just make a seperate wooden enclosure for the amp and battery. I think it might have been leland who posted a picture of his Plate amp in a wooden case, and it was awesome looking.

It was Drey.

ah, must have been in the same thread. All I could remember is those cabs were sexy hahaha.

How long are you expecting to run system before batteries are dead?For cost and efficiency why not run car audio amps that are allready 12 volt?You will not be happy to see how fast you batteries will drain before needing charge.I run 2-dr250's(200 watts each) and a dual Tuba 36(36" wide 600watts).I have 2- 6 volt forklift batteries(100 pounds each ,650AH each as they last the longest before charge and can run 6 hours at war volumes before recharging.

shawn b wrote:How long are you expecting to run system before batteries are dead?For cost and efficiency why not run car audio amps that are allready 12 volt?You will not be happy to see how fast you batteries will drain before needing charge.I run 2-dr250's(200 watts each) and a dual Tuba 36(36" wide 600watts).I have 2- 6 volt forklift batteries(100 pounds each ,650AH each as they last the longest before charge and can run 6 hours at war volumes before recharging.

+1 car amplifiers are cheaper than P.A.'s and they can handle dust, heat, mud, almost anything, and they have active crossovers already.

well, ive picked up a car amp, built in crossover, 2 x 100w for only £5 off ebay

when i get round to building, hopefully soon, ill start a little build thread for anyone who's interested.

thanks for all the responses.

george

well, ive picked up a car amp, built in crossover, 2 x 100w for only £5 off ebay

when i get round to building, hopefully soon, ill start a little build thread for anyone who's interested.

thanks for all the responses.

george

I am VERY interested in watching this thread. I have a reason myself for wanting to build something like this. Please post updates as you continue your build and good luck.