I decided to go with 8" sonotube ports. The box is 3.96 cubic feet internal volume and its for a 15.
I was wondering if i would really benefit much from 2 ports or if i should stick with a single port.
I was originally just gonna go with 2 8" ports, but im tuning the box to 40Hz, so it requires just under 37" port lengths. I'm alright with that, but just figured id get the input from the pros whether i would really benefit from both ports or if id be just as well off with a single 8" port.

Im repeating myself now...im tired.

Thanks in advance

I'd suggest doing two 6.5" sonotubes.
Rule of thumb is 12-16sq inches of port per cubic foot of air space.
I like working at the higher end.

From what i understand, the port size is more dependent on the excursion of the sub (to prevent port noise). The sub i am planning on running is a Power Acoustik Mofo-15. Yeah i know, "they arent loud". I'm not after winning competitions here, just tryin to beat my own personal best....which isnt much to beat either.

I checked their site and they suggest a 3.4 cubic foot ported box tuned to 40Hz with a pair of 4" ports. I have tried this and it made a ton of port noise, and sounded kinda crappy. Actually what i found interesting is that when i had plugged one of the ports (bringing the tuning to around 30Hz'ish) it sounded better. I know it only sounded better because it was hitting lower notes, but i have noticed that this thing just doesnt do any higher tones at all. I figured i would go with a pair of 8" ports and tune it to around 40Hz, this way i could still choose to plug a port for daily listening to bring the tuning down low to make it sound better.

Anyone got any other ideas?....other than lighting the sub on fire and buyin a good SPL sub. hehe

use 6" instead or go slot port

__________________
Big box installer (Timmins)
02 GRAND CARAVAN SPORT
I change my mind like i change my underwear lol

new system coming.
-CD7200MKII runing active
-2x RF400-4
-3 set of energy components. 2 front 1 rear
-4x energy 10" subs
-DDSS1 curently have
-Monster cable RCA and wires all over
-2 1/0 to DDSS1 and 4 gauge to each RF amps
-new alternator 160amps
-sound deadning