# Enclosure Design Question



## mattsipes (Feb 24, 2011)

This is probably super basic for you guys but i'm finding a lot of conflicting info out there. What should I use to get the volume of an enclosure based on the Fs, Qts and Vas? The online calculators give me wildly different results and i usually end up doing it by hand from the Weems book. Any other suggestions?


----------



## Jungle Jack (Jul 28, 2009)

Hello,
This Thread seems more applicable to the DIY Forum and I think you will get the best answers here. If you would rather it be back where you had it, I would be glad to move it back.
Cheers,
JJ


----------



## hgoed (Mar 22, 2010)

The most basic questions are the ones most difficult to answer. You didn't really state what you're trying to build, but I'm guessing it's a sealed sub. If that's correct, I think your question revolves around what Q to shoot for, which would give you very different volume calculations. People can give some advice given a particular driver, room, and type of sound you're trying to achieve, but just be aware that there is no real correct answer.


----------



## hgoed (Mar 22, 2010)

Two minutes later and I already regret my post...basically what I was trying to say is that, with a sealed sub, you can't really go wrong. You just may not be going the way you prefer, and at some point it becomes reasonable to consider other box designs, which may or may not be better (hence the DIY addiction). Otherwise, probably the best and easiest option is to use .707 and be done with it.


----------



## mattsipes (Feb 24, 2011)

Well i'm trying build a box for a tiny full range driver. 2" with a Fs of 155, Qts of .36 and Vas of .01 ft. If I do the calculations by hand using the Thiele method I end up with a ported box of about 8.5 cubic inches. which is too small to get the driver into! any advice is much appreciated-


----------



## Mike P. (Apr 6, 2007)

What is the make and model number of the driver? Can you post the T/S parameters for it?


----------



## mattsipes (Feb 24, 2011)

its a Tang band w2-852sh. i don't know what the T/S parameters are.


----------



## GranteedEV (Aug 8, 2010)

mattsipes said:


> Well i'm trying build a box for a tiny full range driver. 2" with a Fs of 155, Qts of .36 and Vas of .01 ft. If I do the calculations by hand using the Thiele method I end up with a ported box of about 8.5 cubic inches. which is too small to get the driver into! any advice is much appreciated-


Small drivers like this are meant to be used sealed where q = .5 and crossed over at 2 to 3X their FS.


----------



## mattsipes (Feb 24, 2011)

Granteed- do you mean to choke down the drivers to 300-400 Hz and then use a sub for bass? i don't understand changing the Q. isn't it a fixed value of the driver?


----------



## hgoed (Mar 22, 2010)

Well, I was way off. Anyway, I agree with going sealed. No point in using a ported box as you you're going to need something else for the low end anyway.


----------



## GranteedEV (Aug 8, 2010)

mattsipes said:


> Granteed- do you mean to choke down the drivers to 300-400 Hz and then use a sub for bass? i don't understand changing the Q. isn't it a fixed value of the driver?


 No 2" driver will work decently enough below ~400hz... most will barely sound acceptable below 1khz. Even nearfield it's just too much demand on a 2" driver. This particular driver is best crossed IMO at 700hz or higher... it's really a large format tweeter.

So yes, "Choke it down", and then use a midwoofer. The Exodus Anarchy is a good choice. You'll need to implement electrical filters as 2nd order acoustic rolloff won't protect the tang band 2" driver, and you'll also want to roll off the midwoofer at the top of its passband.

You will of course need a crossover and that's where things will start to get very complex... a crossover makes sure multiple drivers are working in their best frequency region, their output is summing together properly for the and in the right order, and also to compensate for the baffle step to make sure your midrange and bass are tonally balanced and not anemic. A miniDSP + a sure 50x4 amp is probably your best bet. You'll want measurement gear for best results.


----------

