what speaker designs are actually worth building?

[demogorgon]

Hi!

for quite some time now i'v been thinking of uppgrading my speakers.

I'm currently using a pair of bookshelf speakers, ported design. cheap 6'5 sammi drivers and a pair of semi cheap seas tweeters.
not really good, but considering what they cost..

now, i have a extra pair of those sammi's lying around, and i would like to take advantage of them.

so i imagine a D'Appolito design, perhaps transmission line?
at the very least floorstanding.
there are plenty of designs around on the web, but which ones are actually worth building, and can be used with my speakers?

Iv been thinking of perhaps building the SEAS thor and just use my own speakers in them..

buying new speakers are noe an option, cant afford anything new for theese speakers than the MDF really, the crossover will be acvtive BTW...

hope you will help me out here..

regards
marius

[richie00boy]

Thiele-Small parameters would get the ball rolling

[tiroth]

Using your own drivers means you flat out cannot use anyone else's design unless you have an almost exact match. Trying to replicate Thor using different drivers is going to be an exercise in frustration unless you really know what you are doing, and it's still going to take a lot of time testing and tweaking. In my opinion, this effort isn't worth it unless you expect stellar results.

Personally, I think that unless you have a really suboptimal design you aren't going to get a night and day improvement simply by changing the alignment or crossover. In my experience, it's better to do something right than take a halfway stab at things--you end up spending half the money, and you get less than half the results.

There are some very interesting designs out there for cheap speakers -- maybe one of them would end up in your budget. "Doing it right" doesn't necessarily mean "Expensive"--it just means you have to pick a driver/design that someone has found to be a good deal. Preferably a project that is well documented and has been reproduced by others.

[demogorgon]

richie00boy: would you care to deffine?

Tiroth: So what i'm left with is making a design of my own, making a pair of boxes that fit my drivers.. well, ok, but how?

i dont have a clue of even where to begin really, i guess i need to download some king of tool where i feed driver data into, and wanted end parameters of the completed loudspeaker.

what more for the design process would i need?

If i have to design from the ground up, i would like to make speakers with a smooth, laid back, deep and wide soundstage, if possible.
I'm tierd of "up-in-your-face" stressing agressive sound without deep bass and air.

now, designing out from subjective wanted goals may not be a good idea?

well anyways, if anyone is wondering, the data on the sammi's can be seen here:
http://www.mamut.com/dynabel/subdet183.htm

the datacheet for the seas can be downloaded here.
http://www.mamut.com/homepages/Norwa...ff_-_h0831.pdf

i really appreciate all your help.

-Marius

[richie00boy]

Resonance frequency, Fs
Total Q of resonance, Qts
Volume of air having same compliance as suspension, Vas

Tell us those for your driver and we can get started with modelling different responses. It would be a good idea to verify the parameters yourself by measuring them.

Nothing wrong with designing with subjective wanted goals in mind

[tiroth]

All the TS parameters can be found on the linked pages.

You should also tell us the current design (box size, port size if ported, and a schematic of the crossover).

[demogorgon]

the current design of my speakers are 2way bass reflex at about 16 liters, the x-over network i'm not really certain about, i'l have to get back to you on that one, but i belive the drivers are crossed at 3khz.

[GM]

Greets!

I did a couple of dual driver ML-TL tower designs, one a ~T/S max flat where Vb = Vas, Fb = Fs and another at the lower practical limit of ~28 Hz, but you'll have to input the specs into MathCad if you want to view the various FR, etc., plots. MJK has a demo link at his site (http://www.quarter-wave.com/) that you can use, but you can't save anything except by copy/pasting into WORD doc or similar.

Anyway, if/when you're interested/set up to input them, send me an email.

GM

[demogorgon]

GM, i thank you for the offer, but you lost me on the thread i fear..

i'l check out the site, and down the demo you suggest.
and then we can take it from there?

thanks for all your help!

-Marius

[GM]

Greets!

That's fine.

GM