Box Design for 2 18" BTL's in a Avalanche....last page

[tejcurrent]

There is no way to correctly state how much port area you need without knowing the box size. It sounds like the box you have in mind would work, 11ft net with 150sq should be good.

I've used Fi's recommendations for every box I've built and had great success. 5-8ft, 12-16sqin of port per foot.

[cnate777]

mxman sorry that I didnt get back to you.......we should hook up so you can see whats goin on.......

[bkolfo4]

There is no way to correctly state how much port area you need without knowing the box size.

Man that gets old. . .

Port size is determined by air velocity, which is determined by the woofer, how much power you give the woofer, and tuning frequency. . .

Using box size is a great estimate, but you do not have to know it to figure out how much port area you need.

Brian

[tejcurrent]

Maybe I phrased that wrong, you are right, but in the case of the op it is a good rule of thumb.

For daily use you can't just throw the same amount of port in a huge box as you would a small box. It would not be a good idea to overpower a sub with 250sq of port in a 10ft box for daily use, no matter what a calculator says, specially if the setup is not tuned correctly.

[tristan560]

12-16 is a good rule of thumb to follow for those who havent been in the game for long, or who dont know better. its all about trial and area, what works for your car. Most of us have changed enclosure numerous times trying many different ideas to see what we can get the most output out of.

Get dirty...waste money on tons of wood...and have some damn fun. Its what this hobbys all about aint it?

[dt64bulldog]

20x45x30 dimensions

12.25x12.25x21 port dimensions

31 hz

150in^2 port

[cnate777]

Well, some things have changed since I last posted.....I went and bought a 2007 Chevy Avalanche........and I am in the process of getting 2 more BTL's for a total of 4 18's.......I need some help figuring out a box design that is going to work........as far as dimensions go I have 21 in in height 48 in wide and 67 in in length........Let me know what you guys think

[cnate777]

ok how about any ideas on 2 18's

[Siete_Cinqo]

the most I think you can get away with doing is 4 15's. You run out of room in the Avy's real fast. And even then you're going to have to get real creative with the rest of the install. I have an 07 Avy as well and I did 4 12's. It worked out great for me. Just enough room to keep it all in the bed. Batt's, amp's and all.

2 18's is going to be much easier then anything else, IMO.

[cnate777]

Yeah I am heading toward the 2 18's the more and more I think about it....I am thinking about a slot port both the subs and the port firing into the truck........

I am thinking about the box being 21.75 inches high by 48 inches wide by 30 inches deep........for the port I am thinking 20.25 inches high by 7.5 inches wide by 12 inches deep and then with the subs and the bracing I am thinking about 1.5 cubes of displacement for a port frequency of 31.30.....what does everyone else think......let me know....thanks