first DIY speaker project

tomek · « **on:** 23 Nov 2004, 12:02 am »

hi there,

i'm wondering if anyone can recommend a good first DIY speaker project. I've got a nice pair of speakers already myself, so this is more for fun than anything else.

i'm guessing a kit would be the best place to start, although I've got an engineer friend with me on this that would rather start ground up from theory and go nuts.

any ideas?

rosconey · « **Reply #1 on:** 23 Nov 2004, 12:08 am »

i wouldnt start from scratch- you cant equil what a seasoned designer can do on your first attempt imho-

rick craig here(selahaudio)does nice work-he did mine
also dennis murphy-

madisound has a good forum as does parts express-if you want to have a go -

PEB · « **Reply #2 on:** 23 Nov 2004, 12:47 am »

I would characterize your search across a few categories:
expected sonic performance
budget, speaker size, max SPL, usage (2ch vs HT, etc.)
format (MT, 3way, line array, horns, etc.)
cost savings vs labor expended
tool investment (acoustic, electric, woodworking, etc.)

A critical decision is whether you and your friend want to start from ground up and go nuts, or not.
If so, you might end up spending thousands for your first pair of crappy sounding minimonitors! Still, having measurement capability opens your eyes for the first time. (To that end, talk to me about DSP filters and budget measurement/design systems. They can take you far.)

It's kind of like sticking your big toe into the wading pool, then looking up to see the horizon of a vast ocean.

If you are looking for a proven design, first pick the format, then pick your designer.

tomek · « **Reply #3 on:** 23 Nov 2004, 01:21 am »

i quite see your point about being too vague.

i think a kit or detailed already-existing design is the best way to go for me.

since this is my first project, i'm not looking to lose a lot of money.

the speakers we build won't be better than mine, but let's say that i'm going for something that would be better than my friend's paradigm mini monitors. i'd like to go through the trouble of building this thing and have a better sounding speaker than that as a reward.

as for tools, we have access to a drill press, a table saw and a router. my friend works in an astronomy lab building a telescope so we have more metal work gear than woodworking. is a metal enclosure a bad idea, because I think this would be easier for us.

toodles!

mcgsxr · « **Reply #4 on:** 23 Nov 2004, 01:25 am »

Metal enclosures can work, so long as you can appropriately damp the resonance and ringing.

Wood is easier for most to work with, but is far from a requirement.

Christof · « **Reply #5 on:** 23 Nov 2004, 02:30 am »

If this is a 'just for the hell of it' project you might look at Wayne J's Dayton 3 design. It's very cheap and I think you would be hard pressed to find a better sounding DIY design for $150. It's a free design as well so no premium to pay on top of parts cost (though Wayne deserves it).

http://www.speakerbuilder.net

ooheadsoo · « **Reply #6 on:** 23 Nov 2004, 03:15 am »

I'd second one of Dennis Murphy's budget oriented designs. The mb20 or mb27 are pretty inexpensive. I made the mbow1 and am very happy with them. PEB makes some fantastic speakers too according to all the hot press but I think his starting price is a bit higher - and I'm not sure if he still sells kits...PEB, do I have this right? IMO, the cost of Wayne's design is mostly the cabinet...if you can spend a bit more, you might as well use better drivers.

www.murphyblaster.com is Dennis's site.

Your budget is very important here. Designs range from a couple hundred dollars to thousands, depending on where you look.

tomek · « **Reply #7 on:** 23 Nov 2004, 03:09 pm »

Quote from: ooheadsoo

IMO, the cost of Wayne's design is mostly the cabinet...if you can spend a bit more, you might as well use better drivers.

www.murphyblaster.com is Dennis's site.

Your b ...

i took a look at the dennis murphy site. maybe it's a bit over my head right now.

if i substitute better drivers in wayne's design, i'd have to redo the crossover and everything right? there is no easy switching for a higher quality driver?

JoshK · « **Reply #8 on:** 23 Nov 2004, 03:13 pm »

Quote from: tomek

if i substitute better drivers in wayne's design, i'd have to redo the crossover and everything right? there is no easy switching for a higher quality driver?

Yes, most definitely. Every speaker driver has its own characteristics that must be taken into account individually so unfortunately it is not an easy substitution. Better drivers don't mean better sound always, a LOT depends on a well executed design. It is better that you start with something proven if you don't want to be discouraged.

ooheadsoo · « **Reply #9 on:** 24 Nov 2004, 02:26 am »

Yep, you absolutely cannot substitute drivers willy nilly.

Murphy's speakers aren't tough! The mbow1 I built was my first diy speaker! Don't let the fancy diagrams discourage you, it's just a fancy game of connect the dots. You can always pm me either here or on head-fi if you get in a pinch, and Dennis always answers his emails if you have a question for him re: his designs.

JLM · « **Reply #10 on:** 25 Nov 2004, 12:55 pm »

tomek,

Simply/easy options for very nice speakers:

Single driver speakers!

Open baffle is the simpliest of all, just pick a driver with Qts of say 0.4 or higher (higher the better) and put it in a board (bigger the better). You may need a sub depending on your taste, driver, and/or baffle size. Bass output is limited by both driver and baffle size (unless you add bass boost of some kind), so don't bother trying a big driver in a small baffle or vica versa. The open imaging and speed can be very addictive. Note that the dipole dispersion loads bass differently into the room.

Fostex offers very nice extended range drivers. The Fostex FX120 (the cost/quality compromise champ, F120A (quality champ), or FE127E (low price champ) drivers could all work well. Baffles can be made from anything (cut a finished solid core slab style door in half for instance). You can experiment with pieces of plywood. Just make circular cutouts and braces to allow the baffle to tilt back. Adding folding wings is an alternative to the braces and increases the effective size of the baffle without it getting really wide. (A "classic" open baffle is 31 inches tall by 39 inches wide with the driver offset in both directions to minimize baffle step losses.) Project cost should range between $100 and $600 for any of the options mentioned. The amount of effort/tools needed is minimal.

Madisound offers a pre cut panel kit for an efficient rear horn loaded design.

Bob Brines offers the efficient FT-1600 transmission line floorstanders in a variety of options: instructions only, pre cut panels, assembled cabinets ready to sand/finish/mount drivers, or fully assembled.

E. J. Jordan 92S drivers are less efficient, but smaller. Plans only, but are free and include bass reflex, sealed, and transmission line designs.

Common Sense Audio offers a variety of bass reflex cabinet plans for high efficiency Fostex drivers.

james_b · « **Reply #11 on:** 9 Dec 2004, 02:51 am »

Try the Single Driver site for some great ideas and inspiration
http://melhuish.org/audio/

JoshK · « **Reply #12 on:** 9 Dec 2004, 02:54 am »

JLM is right, single driver speaks are a good way to start...no crossover! try fostexspeakers.com for a variety of single driver speakers, prefab and plans.