crazy enclosure for a school project...

[nerd of nerds]

hi! one of my classes in high school is a tech class...

right now i'm in the electronics section and i'm blazing through all the projects (stupid simple stuff that i was doing when i was seven) and need a final project...

some of the stuff deals with capacitors, inductors, speakers, and amps...so i thought that i could do some small active speakers for my final project using some pioneer 4" buyout drivers...seeing as i have about 24 left after killing a few in the name of science

i don't just want a box...i want some crazy enclosures...i have access to a ton of fun tools...lathe, mill, lazer engraver (maybe cutter?) cnc mill, cnc lathe, plus various stuff at home...the only problem is i wasn't able to get into the cnc stuff in the class so i dont' think they'll let me use it

sooooo...can i have some links to some oddly shapen speakers? i'm not afraid to put a lot of work into em because i plan on keeping em once i'm done...


ideas? some spheres sound fun...or cones...

 

[joe carrow]

hi! one of my classes in high school is a tech class...

right now i'm in the electronics section and i'm blazing through all the projects (stupid simple stuff that i was doing when i was seven) and need a final project...

some of the stuff deals with capacitors, inductors, speakers, and amps...so i thought that i could do some small active speakers for my final project using some pioneer 4" buyout drivers...seeing as i have about 24 left after killing a few in the name of science

i don't just want a box...i want some crazy enclosures...i have access to a ton of fun tools...lathe, mill, lazer engraver (maybe cutter?) cnc mill, cnc lathe, plus various stuff at home...the only problem is i wasn't able to get into the cnc stuff in the class so i dont' think they'll let me use it

sooooo...can i have some links to some oddly shapen speakers? i'm not afraid to put a lot of work into em because i plan on keeping em once i'm done...


ideas? some spheres sound fun...or cones...

If you can get them to CNC machine a bunch of plywood, a back-loaded horn sounds like an awesome way to go with a single fostex driver. Those 4" drivers are fun, but they need help on the top and the bottom. By the time you get woofers, tweeters, and crossovers- well.. that's enough money to buy better drivers. IMO, their best use is in a line array as midrange.

Search the forum, if people here know about them, they're probably already linked. Otherwise, I'd look into a trapezoid shape. This shape can help tame resonances- both internal and box.

 

[Cal Weldon]

How about you build a copy of the Nautilus? Now that would be something.

Cal

Edit: Link on next reply

 

[Cal Weldon]

This seems to work:

http://www.futurebytes.ch/images/news/bw_nautilus_large.jpg

 

[Cal Weldon]

no post here, keep going

 

[nerd of nerds]

well...

i also have some 5" aluminum mcm 55-1870 woofers on hand...i've heard those do pretty well on their own...could use help in the higher freqs...but those would DEFINETLY look better (and sound better) than the pioneers...

i guess i could upgrade...


there is a problem with the cnc thingy tho...its smaaaaaalll so i wouldn't be able to do anything very large...

i'm wanting to stay single driver for simplicity....

cal weldon: those are very pretty speakers...but a bit out of my construction abilities


any other ideas? i'm thinking of painting em silver to match the aluminum...i might just copy some speakers i say and go for a snow man shape but instead of a tweeter just have a port...paint em silver...that'd be pretty

P.S. i'm thinking bookshelf speakers, no floorstanders

 

[Stocker]

Dipole, but good luck explaining why you may think it's better to a bunch of high schoolers...


...without pretty phase and output graphs!

 

[nerd of nerds]

yeah...

Dipole, but good luck explaining why you may think it's better to a bunch of high schoolers...


...without pretty phase and output graphs!

i can't stand the knowledge level of most of my peers...and for that matter...most consumers!

watts...i hate that word soooooo much...i also hate car audio, its the biggest joke in the world in my opinion..."5000watts!!!" ugh...

then we come to lcd tvs... ...i feel the deepest hatred towards best buy when i see those things...in short: i hate everything


but i do like the idea of a dipole....that could simplify the enclosure a little bit...and i have some piezo tweeters lying around that could have the horn removed and all the tweaks applied...

i COULD do an MMt dipole and make use of 8 of those things...then just leave the horn on the piezo and call it good...if it werent too efficient...

but efficiency is going to be another big thing when building the amp...i don't really want to go too nuts with that...its just going to be a super simple lm386 or something of that sort...i could even biamp it...

oh the possibilites...

 

[Cal Weldon]

Re: well...

i also have some 5" aluminum mcm 55-1870 woofers on hand...i've heard those do pretty well on their own...could use help in the higher freqs...but those would DEFINETLY look better (and sound better) than the pioneers...

NoN,

I have four of each of those drivers and I must say, I don't consider them in the same ballpark. Use the MCM units. The pioneers as mentioned earlier are great for line arrays or maybe a centre channel.

No to the Nautilus? I thought you said you have all those woodworking tools available to you.

Cal

 

[nerd of nerds]

i think i will...

i think i'll go with the mcm woofers...i reall like em and i've build several beginner projectes with em... plus they might get SOME kind of bass...little it may be...

i think what i'll do for the enclosure is, if i can use the cnc machine, just cut several pieces shaped like an 8 with the top part being smaller...then just make the inside an egg-like shape...

good ieda bad idea?

 

[purplepeople]

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

Oh heck, just look here: http://www.exoticaudio.org/index.html

ensen.

 

[nerd of nerds]

AH HA!

An externally hosted image should be here but it was not working when we last tested it.

that is the one i want to base my design on!

i think i'll make 3 enclosures, 2 for speakers and 1 for the amp...

for the amp, i'll just replace the tweeter with volume control and the woofer with some kind of a VU meter...

but i'm going to simplify the design and just make if an 8 shape with a smaller top...egg shaped interior...


that is unless there are any other suggestions?

 

[Stocker]

Here is a suggestion for you:

If you get "some" bass out of the 5" drivers... and you have a lot of them...

Isobarik. If you have enough, set up a pair of pairs per driver to get efficiency back, layout permitting. Tweeter on top, 'bass' units on bottom, like this, from the side

*
))
))

Is that understandable?

A jigsaw or router would be the ticket to get an enclosure size that is reasonable for bass extension in your speaker modelling program.

I love that one with the red suit, with driver for a face! Too much work though, eh?

As for your peers' knowledge / experience levels, blame
The public school system
The parents
The legislators
...all for the past 3 generations (at least)

 

[nerd of nerds]

Here is a suggestion for you:

If you get "some" bass out of the 5" drivers... and you have a lot of them...

Isobarik. If you have enough, set up a pair of pairs per driver to get efficiency back, layout permitting. Tweeter on top, 'bass' units on bottom, like this, from the side

*
))
))

Is that understandable?

A jigsaw or router would be the ticket to get an enclosure size that is reasonable for bass extension in your speaker modelling program.

I love that one with the red suit, with driver for a face! Too much work though, eh?

As for your peers' knowledge / experience levels, blame
The public school system
The parents
The legislators
...all for the past 3 generations (at least)

meh, i'm just gonna go with one driver per speaker...i only have 2 on hand and if i ordered today i wouldn't get em in time...

check on the single driver website for a project using these drivers...aparantly it got ok bass for a 5 inch woofer...but it might be power hunry so that brings me to what type of (simple & cheap) amp to build....

 

[Greg B]

The 55-1870 do have good bass for teeny little speakers. An added plus is that the wide bandwidth will allow a simple first order crossover that actually works. IE, try a 1mh choke and a 4uF cap on the tweeter.

They do well in very small boxes. So, in this case, there isn't much point to isobarik IMO.

GB

 

[nerd of nerds]

The 55-1870 do have good bass for teeny little speakers. An added plus is that the wide bandwidth will allow a simple first order crossover that actually works. IE, try a 1mh choke and a 4uF cap on the tweeter.

They do well in very small boxes. So, in this case, there isn't much point to isobarik IMO.

GB

silly me, i've never designed an xover...hehe...ummmm...can i just use caps from radio shack? or is there some special type that i need to get? i know that i can wind my own inductors, thats no problem...

do you think that the piezo tweeter will work well with the mcm woofer? or should i *sigh* get another tweeter for it? i'm just trying to use stuff that i have on hand...

should i go for sealed or ported enclosure?

 

[nerd of nerds]

or maybe...

or maybe i could do some small t-lines with em? like the translam t-line in the full range reference thread...hmmmmmm....

 

[Greg B]

silly me, i've never designed an xover...hehe...ummmm...can i just use caps from radio shack? or is there some special type that i need to get? i know that i can wind my own inductors, thats no problem...

Lucky for you that you are using a driver that works well with a simple xover. Xover design is one of the most difficult challenges speaker building.

Anyway, I've used the driver before, and can assure you that a 1mH choke lowpass is fine. Do not use textbook values. It's bigger than you would think to compensate for baffle losses. I'm assuming you will make a low diffraction enclosure similar to that space snowman pic. Of course winding your own coils is fine.

Ideally, you should use film caps, at least mylar and preferably polypropylene, but nonpolar electrolytic from the shack will do in a pinch.

Which piezo do you have? It might not be my first choice, but it should work. The ones I made used the linaeum planar things ratshack used to sell. Ask again for crossover help when you have your parts decided on.

Yeah, actually it might do fine in a TL. Download the mathcad sheets at www.quarter-wave.com after reading through the site, and Dave's www.t-linespeakers.org too.

 

[Greg B]

should i go for sealed or ported enclosure?

Oh, ported. Try 8l tuned to 50hz, smallish port. Sounds stupid, but that's what I would do.

G

 

[thomas997]

silly me, i've never designed an xover...hehe...ummmm...can i just use caps from radio shack? or is there some special type that i need to get? i know that i can wind my own inductors, thats no problem...

Your probably going to want polypropylene caps, which will be much larger than electrolytics and will cost more as well..

If you dont want to go for that, you will need bipolar electrolytics at the very least. You can do this simply with two electrolytics in series (I think its neg to neg, or pos to pos, maybe it doesnt matter).

If you go active crossover, you can use a LM4780 chip amp (if allowed?) or similar per enclosure. Then the components needed will be very small, nano and pico farads.