View Full Version : obsidians box recommendation for 18

07-31-2012, 09:38 PM
I got a 18 obsidian and want build me a ported instead of the sealed I built now at 4cf. Obsidian recommends using a 6in diameter port for the sub. Im going slot port and found an equation to convert it and got basically 1.5in wide based on my box im going to build...little under 5cf. That seems small to me for an 18 but again im running the rated 600wrms to it because I like my dual alpine pdx setup. Obsidian seems to clearly state u should go by their recommendations...1.5in wide should be fine for port if im running rated 600 to it correct? Gona b tuned to bout 30hz...

07-31-2012, 09:45 PM
I would increase enclosure volume and port area.

07-31-2012, 09:54 PM
Waz thinkin the same but im tryna stay at 5cf for volume. Havent built nearly enough enclosures to kno wats a good port area. I want a good all around sound but little more low end if that makes sense. Dnt want a fart box.

07-31-2012, 09:57 PM
I would shoot for 5.5-6ft3 net personally.

07-31-2012, 10:05 PM
Wat about sq in of port? 50? Not really sure how to determine that.

07-31-2012, 10:08 PM
50 in^2 of port would work. Can pick up an 8" sono tube from lowes/HD for like $5 and you can play with tuning too.

07-31-2012, 10:14 PM
Is 50 sq in like universal for all big n mid to high power handling subs? hear it alot... Wats difference if I went with 40 or even 70 sq in? Work wit me...

08-01-2012, 08:07 AM

08-01-2012, 08:10 AM

To be honest if u dnt really know "as i dnt on alot of stuff" its best to just buy a design from someone who does know. Dustin can draw ya one up for a fair price. Rather be right the first time then to have to build the whole thing over..

P.S bring me ur Rott.. I got 3 buddys he can play with... Great pack dogs..

08-01-2012, 10:24 AM
Well I kno how do build n get dimensions just want to kno how a ports sq in is determined...roughly. Guess its just sound preference.

And yea would bring ”aiden” but he not very sociable when it comes to other other dogs his size...Proly jus walk up on ur dog n put his head over ur dogs...not really tryna see sum rotts fight. Roun ppl hes cool..but will watch u.