fullaranger as midrange, and plastic enclosures

[lufbramatt]

hi guys,
A couple of questions here, to get some background info for my current uni project.
The main focus of the project is the application of polymer technology into loudspeaker enclosure design, due to the excellent internal damping characteristics if the right material is used. An issue that has been raised by a tutor is how do people perceive the value of a loudspeaker? lots of people may think that for thier wad of money they want the biggest, heaviest beast of a speaker they can get . . . would this affect any of you guys?
To my mind the benefits include greater freedom of form due to the moulding methods that can be applied to the plastic, enabling more acceptable forms to be made- making them appeal more to women and interior designers lighter weight to aid practicality, possible sound quality benefits due to the properties of the material, and lower cost due to the construction methods.
I would dearly like to break free from the "rectangular box" of traditional loudspeakers, without the boutique pricetag of speakers such as the £4500+ vivid B1's and wilson beneschs of this wourld. Any comments on this area would be much apprieciated.


Secondly, although the enclosure is the main focus of the project, the electronics and drivers also have to be top notch. I have been thinking along the lines of using a full range driver as a midrange, crossed to a small tweeter such as a vifa xt19 at the top and an 8" woofer at the bottom. How would something like a fostex fe168 integrate with this and say a 8" paper woofer from vifa or scanspeak?
I have also been looking at the css wr125 and fr125, but the low efficiency has put me off.
Would using drivers with a large overlap in frequency range be best crossed over with a simple first order xo or do ppl think it would be best to go for a higher order xo? obviously i will be testing both iterively, but would like to have a good starting point.

Any comments most appreiciated

[Cal Weldon]

My first comment is that plastic has a tendancy to "cheapen" the sytem. Regardless of the sonic qualities, you "aint gonna sell me no plastic speakers", 'less they're $19.99 a pair or less. People want wood or a more exotic material.

Second, we want them heavy. If it aint heavy, it aint worth ****. Beside you only want a light speaker of you plan you move them a lot.

Third, the WAF. She don't like no plastic speakers neither. If you want to please the "interior decorator" make them from something shiny and pretty. Not too shiny mind you or they might clash.

Fourth, if you are using a nice full range, why not use a larger woofer. Unless you are constrained by size, why not consider at least a 10 if not 12. Makes better use of the mids ability and reaches further down.

Finally the XO: If you have compatible drivers then by all means use a 6dB. If the integration is seemless, I can't think of a better way of doing it. Basically, the less compatible the drivers, the steeper the slope to prevent unwanted overlap.

Sorry to dampen your spirits, but remember plastic has been around for a bit and if it were suited for enclosures, something other than the $19.95 and a few others would be made of it. (PA equipment excepted, as moulded is more popular than ever)

That's not to say you can't re-invent the wheel but you'll have to work awfully hard at convincing some persons of the benefits.

(profanity, poor grammar, bad spelling and awful sentence structure yours at no extra cost)

Cal

[lufbramatt]

thanks, I appreciate any feedback

Thats exactly what i was worried about with the idea, although who says a plastic speaker has to be cheap and crappy? If i made a brochure saying it was made of an "advanced laminated polymer" or "layered composite technology" then would people be more receptive to the idea?

And i can make them as shiny as you want, just need to get out the spraygun and laquer

keep em coming guys . . . .


oh and can i point you in this direction polymer guitar link

[Tweeker]

Blend some graphite in that plastic and allude to carbon fibre in your literature.

[johnnyx]

Yes...Wilson benesch use carbon fibre, but they aren't 19.99. A composite could be good, if the price could be kept low.
Look Here

[lufbramatt]

yeah, i heard the wilson benesch range at the bristol show last year, and really like the clear, upfront sound. The engineering in them is very nice, much better than the mdf box you get with most speakers.

[audiobomber]

Just don't make 'em too cute, like these:

http://www.podspeakers.net/

[sdclc126]

You can always finish the speakers in wood veneer or paint or a zillion other things that will make them more aesthetically pleasing in the home, then the "plastic" becomes less of an issue.

If the material is acoustically inert then it's good for loudspeaker enclosures. If it's expensive or difficult to work with then it's less desirable for DIY. With plastic I guess you have to pour it into a mold (so I guess you need to go to a specialty fabricator?) and then you're stuck with the results - with wood it's easier to correct errors.

But as DIYers we love to experiemnt - so go for it and let us know what you come up with!

[AJinFLA]

Dr. Geddes Summa design uses a molded enclosure. Very advanced design. Just because you intend to use plastic doesn't mean it couldn't be a nice thick robust enclosure. I say go for it
Just to get a grasp of the scale of it, that a 15" (38cm) woofer!
It's no minipod .
http://www.gedlee.com/Summa.htm


Cheers,

AJ

[AJinFLA]

Plastic could make some rather unique shapes




Cheers,

AJ