[Matt__P]

Hello, I recently picked up a new pair of 12" JBL 2142H Coaxial really cheap on Craigslist and I know nothing about determining box size or port diameter /length for them
http://www.jblpro.com/pages/pub/components/2142.pdf

I've tried to model some ported enclosures in win isd but they keep coming out enormous...like 12 cu ft
Jbl is recommending 3 cu. ft. but they don't say what that's tuned at. These are for my brothers college house and he wont have a sub so I'd like to get some bass out of these if possible.

thanks for any help you can give me

matt

[JoshK]

I haven't played around with box modeling software much, other than that spreadsheet one.  However, usually these hi-eff pro audio drivers DO require huge boxes to obtain adequate bass.  Its known as Hoffman's iron law.  What are you trying to tune to? 12cuft is probably right if you are shooting for 20's or low 30's.  You can relax this a bit because of typical room gain and the fact that most rock music usually only has content done into the 40's. 

[JoshK]

I took a look at the datasheet.  This driver has an Fs of 72hz.  That tells me that this driver really doesn't want to be a bass driver.  It'd be happier being tuned to ~80hz (guessing) and using a sub below.

[Matt__P]

Thanks Josh , thats what I was afraid of . I kinda figured they were more of a PA speaker. Hopefully they're still worth the $100 i paid for 'em.
Anyone else have a box suggestion?
thanks,
Matt