Help me build an active monitor for dj'ing

[lunchmoney]

(also posted in "everything else", wasn't sure of best place to put it)

Hey there,

Total noob here...

I'm looking to build one self-powered monitor specifically for mobile dj'ing. This is for putting in the dj booth with me, pointed towards me, so I can hear what I'm doing. Essentially, whatever the crowd is hearing is what I'll be hearing through this monitor.

Requirements:

- 8" or 10" woofer
- not sure what size or type of tweeter I should use
- INTERNAL amplifier(s), ideally bi-amped
- 100 Watts rms minimum (combined power of both amps)
- bass, treble, and volume gains
- RCA inputs at the very least, 1/4" would be nice too
- rugged construction for mobile dj'ing
- don't want to spend more than $300 on components and materials
- doesn't need to be studio monitor quality, it just needs to get the job done and be reliable

The holy grail would be to duplicate a Mackie SRM350 (obviously not the molded ohusing). I'm sure it's unrealistic for me to build a speaker of this caliber, but check it out and it'll give you a sense of the basic specs I'm after:

http://www.mackie.com/products/srm350/index.html

I'm new to the world of building speakers, but I have a lot of experience in a model shop, and I have a model shop at my disposable with every tool under the sun. The tools and the craftsmanship are there, just not the specific know-how for speakers. I'm sure it's unrealistic for me to get into the hardcore intricacies that you guys do, but I'm sure that if I had the right components and some advice on assembly I could get it done.

Please kindly help me with:

- recommended components and where to get them
- how-to advice or links to how-to advice
- an assessment of whether I'm in over my head or not

THANK YOU!!

[G4ME]

might be better in a different forum, but i will give a suggestion, 300 isn't that much for a pair of monitors, but I have a pair of Pi Speakers Studio Series II, they have decent bass but the low end is pushing it for the Eminence drivers, but for moderate listening they are really nice. I also have the previous version, the ones with a piezo tweeter and i can only imagine that the Vifas they replaced them with make the top end much much better.

[lunchmoney]

thanks

which forum do you think would yield more responses?

[richie00boy]

Ask a moderator to move this topic to the Loudspeakers forum

Do you only want a single speaker? It's not clear from your oroginal post if you want a pair. I think you need to be looking at a 10 inch drive unit if you only want one speaker. I guess the Eminence range is the place to start looking. Don't be concerned about power handling figures, they are largely nonsense and irrelevant.

[pinkmouse]

No need to ask

[Magnetar]

These are already built -- $369.00 Pair



- 2-way Bass reflex cabinet manufactured with a rugged, high-quality Poly-Resin material.
- 12" High Output, Long Throw Woofer with treated cone and high temperature voice coil (3" VC diameter ->58.8 oz magnet!).
- High Efficiency Light Weight 1 1/2" Pure Titanium Wedge Compression Driver with True Formtm 90° x 60° exponential horn tweeter.
- Inputs/Outputs - 1/4" jack Mic-In,RCA Line In/Line-Out, XLR In/OUT
- Bass/Treble Controls
- 260rms/500 Watts Amp Music Power
- Size: 25.0"(h) x 21.5"(W) x 14.2"(D)
- Adjustable Frequency Response: 45~20KHz
- SPL: 95 +/-2 dB
- Weight: 40lbs each
- Strong side carrying handle.
- Steel grill.
- Hard-rubber feet.
- Adjustable bottom pole mount allows for easy tripod mounting.

[lunchmoney]

Thanks guys.

Just one monitor...(read it again )

As for those 12's, they're simply too big. Often there is limited space to put the monitor.

[5th element]

I think for $300 you will be hard pressed to get what you want out of it

You are going to want to build two power amplifiers an active crossover, the loudspeaker cabinet finished with some sort of heavy duty design, the drive units themselves etc. The amplifiers will require a power supply which is likely to cost alot unless you know of where to get bargain stuff.

The speaker posted by Magnetar is a good idea, mass produced stuff can do things cheap, like power supplies amplifiers etc.

This is rather adventurous for a 1st time project and not one I would recommend on a budget. If you wanted to build a passive version of this then I would say its doable but including all those electronics stretches the budget too far. Youd be surprised of all the other things you will include or use that will bump up the price.

Actually your best bet may be to hunt down a cheap and cheerful budget amplifier and use that as the main box of tricks. Most come with all the features you could need and will also have a preamp section already with suitable voltages for an active xover of your own design. Or you could just use PLLXO's, high pass on the left channel, low pass on the right channel then feed the drive units from the suitable output. How much can you get a budget integrated for on clear out in the states? Adding a PLLXO to one should be cheaper then making all your own electronics right? a £50 sale at richersounds would be cheaper over here then if I had to make all my own amps and xovers.

[audiobomber]

Originally posted by lunchmoney
Please kindly help me with:

- recommended components and where to get them
- how-to advice or links to how-to advice
- an assessment of whether I'm in over my head or not

THANK YOU!!

I'm thinking along the same lines as Magnetar. DIY'ing an active speaker is no trivial matter, and probably best left to someone interested in the hobby for its own sake, rather than to fulfill an imminent business need.

I'd recommend a pair of these Berhringers. I've never heard them, but as you stated, you don't need super-fi. They're at your budget for a pair, but you could sell one, or keep it as a spare.

http://www.partsexpress.com/pdf/248-640s.pdf

Good luck,
Dan

[richie00boy]

Well, maybe a little ambitious

$30 18mm plywood
$20 covering enclosure
$10 enlosure handles & tophat
$80 bass-mid
$30 tweeter
$80 bass-mid amp
$50 tweeter amp
$50 input, crossover etc circuitry

$350 total