Can anyone explain the reason why some subs like big boxes and some like smaller boxes.

I put my 12" BB in a 4cu box with 72.5sqi of port tuned to about 46-47hz and bottomed out like crazy, only got 143db from that.
Then I put a MA15" in the same box and went up 4db to 147 while playing the same frequency, 49hz.

[img]graemlins/beer.gif[/img]

 

more cone area is my only idea..

 

it all hasta do with teile/small peramiters

 

Which parameters???

I thought it has to do with something with the suspension. I guess it make sense that a stiffer subs would be able to control itself better in a big box than a sub with softer suspension. Anyone else wanna comment on that.

 

T/S parameters to an extent, yes... Resonant freq. and Qts will give you a good indication of a subs ability to control cone movement. A sub with a low Fs and Qts will likely have a "looser" suspension, where a sub with higher values will likely have stiffer suspension, and therefore better suited to larger enclosures, or even infinite baffle. But 4ft^3 seems huge for a single 12 to me for ported... A lot of subs I've worked with are usually looking for maybe a little over half of that, but I'm assuming you're into SPL, so usually bigger is better... In a box that big though I'd imagine the group delay would be horrible, and with that much internal volume there would definitely be less "spring" or back pressure from the port to help control cone movement. Throwing ther 15 in there probably solved your problem because it is able to sweep much more volume than the 12 to make use of all that air. That, and it's T/S parameters are probably a lot different... My $.02.

[ March 23, 2005, 04:02 PM: Message edited by: Ex-Maxx ]

 

^^ mostly agreed... I would try to re build thta 4 cu ft box... take away some of that box volume by using a larger port around 100sq in and make it quite a bit longer ..check your PM