View Full Version : JBL gt1200 enclosure

04-19-2010, 05:23 PM
JBL's website says for a vented enclosure to go with 1.8ft3 internal volume with port tuned to 30hz (14in long, 4in diameter). For a general daily driver, does that tuning sound about right?

04-19-2010, 06:58 PM
Should be fine, but I'd personally use more port area.

04-19-2010, 08:57 PM
think im better off sticking with a cylindrical port or going slotted? if you were to go bigger, how much bigger would you say?

04-19-2010, 09:18 PM
You can do a 4" port if you use an actual aeroport and not just some PVC or something like that. I'd do 6" if you were to use a non-flared circular port. The only problem is that the port ends up being 38" long if making a 2ft^3 box. I prefer slot ports myself though, much easier to tune low.

04-19-2010, 09:40 PM
so if i did a slot port, should i be shooting for the same volume as the 14x4diam cylinder, assuming i stick with the 1.8ft3 as per jbl?

04-19-2010, 09:46 PM
I'd go with 2ft^3 tuned in the low 30's(30-32hz). The thing with ports is the size of the opening itself. The bigger it is, the longer the port needs to be. With the slot port, something in the 10-14in^2 per ft^3 of box volume is pretty standard and a good rule to work by. So in your case, a slot port with an opening between 20-28in^2 will work fine.

04-19-2010, 09:51 PM
awesome, thanks man. really appreciate it.

So if the opening is 20-18in2, how long does it need to be? also does the 2ft3 account for the port size as well or do i need 2ft3 of "box" and then add port size to that?

04-19-2010, 09:54 PM
No problem.