JBL gt1200 enclosure

[chawski]

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?
Thanks!

[RAM_Designs]

Should be fine, but I'd personally use more port area.

[chawski]

think im better off sticking with a cylindrical port or going slotted? if you were to go bigger, how much bigger would you say?

[RAM_Designs]

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.

[chawski]

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?

[RAM_Designs]

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.

[chawski]

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?

[RAM_Designs]

No problem.