Now I have my 3 18's in a ported wall and thinking of trying a bandpass wall. I seen a few guys setup on YouTube with DP 15's in a 4th order and it looks pretty impressive but I know they aren't recommended to be in a sealed box. Thinking of going with just a 2 to 1 ratio and giving the 18's around 6 or 7 cubes sealed and as much as possible ported. Really want a low end monster that moves a lot of air for a daily setup that can play all music. Was told around 2 cubes sealed is about good for 18's just leery of going through this and it not working out. Planned on facing them all forward in a triangle but the loading wall is what confuses me because I don't understand how you tune the opening (port). Thanks

Anyone? Trying to figure out if I should try a BP or just make a bigger ported box

I don't think many people have experience with BP's.

I would say experiment with one. Make one and see how it performs, and adjust from there.

Kef

If I were you, I would definitely seek the advise of either iamamp3pimp or 80inches for some assistance on Bandpass designs. Both guys are pretty well versed from what I have seen in the design/implementation of bandpass enclosures.

From talking with gmonk I picked up that the 2:1 ported to sealed is a good starting point. 20-25in^2/cube of port tuned to low 40s to low 50s is good for all around ground pounding.

this might be a better approach-

how much NET volume do you have for your wall right now?

What's the loudest you've scored on a meter?

You might be using too many subs..

Sorry guys wasn't getting many replies so haven't checked here. But yea I've been talking to gmonk and he's helped.

My current wall is about 14.5 cubes tuned to 36 and i know it is small but they are powered by two 40.1's so they are getting a good amount of power. And the loudest I scored was a 150.0 on music sealed up. Like you said and a few others suggested was to just use two subs in my wall but if I'm doin this bandpass and have alot of room then I definitely want to run three.

Probably going with about 7 cubes sealed. Inner dimensions 38.5 wide x 30.5 tall x 12 deep = 14091/1728 = 8.15-.75 (subs) = 7.4 then with some internal bracing down to 7. Ported with be inner dimensions of 38.5 wide x 30.5 tall x 33.5 deep = 39337.375/1728= 22.76. Then my port will be 13 wide x 30.5 = 396.5" port area x 10 deep = 2.29 cubic feet. 22.76-2.29 = 20.47 ported airspace and according to 12 volt my tuning would be around 45hz.