currently have 2 18" bl's off a kx2500.1 @ 1 ohm. birthsheet states ~3kw @ 2 ohms. here is my post copied from ca.com

"currently they are sitting in 11.5 cubes or so tuned to about 35hz. output is pretty good but still not quite where i want it to be. seems like with my ammount of power they should be louder, especially for 2 18's. the only thing i can think of is box volume being on the small side. i was told by the FI guys that 5.5-6 cubes would be fine with my power, but im having doubts now.

im thinking of sacrificing my rear seats and build the box to take up the whole cargo area but still be at/under the window line. this would give me a chit load more room to work with not to mention also having room to mount my amps more favorable and add batteries. and also i would be able to get a huge ass port as well, compared to my 168" sq port that i have now.

is this worth it, or am i chasing ghosts trying to get these things louder?"

the thread is here if you want to take a look at it. i have pictures on the third page post #43 if your interested to see how it looks.

hopefully the FI guys can chime in as you guys know these subs probably like the back of your hand.

edit: chit lol. didnt mention im looking at basically 16-20 cubes for the set.

Edited September 3, 200718 yr by George

bump...

Without looking at things too deeply on my part, if there is still excursion to be had and you are not running into BL or Cms based power compression, then going larger will gain you more efficiency and more output. Being that you are using a bass-reflex enclosure, there is likely still some excursion available, particularly as you approach your tuning frequency. I can't say so for sure without having looked at this more closely, though. Give me time in that respect, if you're unaware of how to do so yourself.

Without looking at things too deeply on my part, if there is still excursion to be had and you are not running into BL or Cms based power compression, then going larger will gain you more efficiency and more output. Being that you are using a bass-reflex enclosure, there is likely still some excursion available, particularly as you approach your tuning frequency. I can't say so for sure without having looked at this more closely, though. Give me time in that respect, if you're unaware of how to do so yourself.

well for the most part i know what it should do in theory. im more so wondering if the bl will do better in a 7-8 cube box versus the 5.5 or so its in now.

i was told that this sub was more designed to use motorforce and not excursion to get loud (much like the mt's) and therefor e do great in smaller boxes. thats what confused me.

You will gain if you have a larger enclosure if you are still within the limits of the sub. Looks like going from 5.5 up to 8 cuft per sub will net you 1.2-2 dB in the 35-50 range. If that is a worthwhile difference, then cool. Not night and day. But have you noticed the subs softening up much from new? There is a decent amount of suspension to break in. Most people seem to think that they get louder as they soften up...

You will gain if you have a larger enclosure if you are still within the limits of the sub. Looks like going from 5.5 up to 8 cuft per sub will net you 1.2-2 dB in the 35-50 range. If that is a worthwhile difference, then cool. Not night and day. But have you noticed the subs softening up much from new? There is a decent amount of suspension to break in. Most people seem to think that they get louder as they soften up...

well the definatly need some more breaking in thats for sure. they have loosed up some though.

do these things like particularly bigger boxes with 1.5kw? or would they do better in a smaller box?