18xl bandpass help

[windowtinter]

doing a 18"xl in a cut through f150 looking to do a nasty bandpass since he should have the room but im not well versed on bandpass design so i was hoping for some pointers as to front and rear volume and overall port size per cube and tuning front and rear,due to the fact it is four stiff spiders and will see somewhere around 3000-3500 im guessin that a 6th order will be ideal.looking for a decent passband tuned fairly low as his daily box now is at 33hz tuning. thanks in advance for any suggestions or help.

[dwright27]

I'm on my phone right now but I'll giv you a response when I get home

[jmitch]

sorry to thread jack but i been lookin for the same answer too. yo dwright could u help me out with the same thing also.

[dwright27]

in a 6th order, your front chamber should be tuned high. Usually around your loudest note, the rear should be tuned low, but not as low as most people think.

as far as box size, ive heard you can get away with 1.25 front - 1.5 rear sub size dependent. you can also use a 2:1 ratio, as well. the lower tuned rear should have less square inches. and he front port should have a decent ammount of port area. id say twice - 3 times as much.

now, being as its a blowthrough, you can do a standard ported box, and where the cut comes into the cab, will act as a port. id tune around 35 on the rear, and about 10 hz above whatever the truck peaks at on the front. this will determine the passband/bandwith.

im still; trying to learn a few things about 6th orders and modeling them, but this is my insight so far from talking with singer and a few other people.

here is a link to some series tuned design insight.

http://www.diysubwoofers.org/bnd/6thord4.htm

and another short read.

http://www.diysubwoofers.org/bnd/6thorder.htm

and here is a little calculator. i havent used it but might try it sometime. Team bassick may be able to help you with bandpass designs as well, and Ray over at audio innovations. i would PM s-saudio

http://www.mh-audio.nl/Bandpass.asp

Edited August 25, 2010 by dwright27

[windowtinter]

thanks dwright so with a 18"xl i should be in the vacinity of 5cubes rear tuned around 30-35hz 70-80sq.in port and 10cube front with 180-210sq in. port at around 55-60hz?or does it need to be a little smaller boxe size due to the amount of power?(should be around 3000-3500watts rise dependent of course)thanks for the help and to any one else who may offer input.

[matt402]

thanks dwright so with a 18"xl i should be in the vacinity of 5cubes rear tuned around 30-35hz 70-80sq.in port and 10cube front with 180-210sq in. port at around 55-60hz?or does it need to be a little smaller boxe size due to the amount of power?(should be around 3000-3500watts rise dependent of course)thanks for the help and to any one else who may offer input.

rear chamber should be ~1/2 that size & a bit smaller on front chamber IMO.

personally id stick w/ a 4th order ...

im going to do a 4th order for my 2 XL 18s when i get sum $,

if i finish my box b4 u ill let u know how it sounds .

[windowtinter]

so now im talkin say 3cube rear bout 50sq in.port at 33hz and 8.5cube front tuned around 55hz. 140sq. in. port

[matt402]

that sounds better =].