2 lvl5 15's , 4k in a grand cherokee just not hitting the numbers

[Bluebrindle]

Right i have got 2 lvl5 15's in a grand cherokee off about 4k between them.

I am just not hitting what i think it should be. To the ear it is hard, does hairtricks and people are noticibly impressed. The uk importer of these dc's has 2 lvl4's off 3k, hits 148.9 db drag, he heard mine and said that is a 150 car.

with lvl4's in here off about 2k it was just 142 peak.

I have only tested in a format i think only the uk has which is called propper droppers

the term lab is on the passenger headrest and you are allowed windows and doors open.

for me i hit my peak with both front windows open, it is noticibly louder and moves a lot of air with the front windows open so on db drag i think it would be even worse, i am getting about 2 or 3 db less iirc with car sealed but term lab on headrest.

i am doing very near to my peak score on music too, about .4 db off i think.

heres my scores

Peak= 146.8dB @ 37hz

40hz= 146.1dB

33hz= 145.0dB

25hz= 141.6dB

20hz= 137.3dB

as an example theres a guy with 1 15 mayhem off 3k hitting about 1 db more and about 4 more at 20hz

his box is tuned to 24 hz, mine is 32 but his peaks about the same freq as mine.

my box was designed by someone over here, it certainly moves lots of air and sounds good to me.

made from birch, big flared ports, glassed inside with matting and 45's on corners, 45 on bottom of port. m16 rod through box, its 2 chambers not a common chamber. subs up port up, no room for port back.

car is fully deadened all over, theres still a lot of flex with the rear window coming open by maybe a quarter inch. i tried pressing down on this during testing but made no difference.

I have heard cars which hit higher scores but they dont sound anywhere near as loud or hairtrick etc.

Is the jeep just a bad car for this? people over here say because its a big car its harder to hit high scores (most good scores are from smaller cars to be fair)

sorry for the long post but where am i going wrong?

[itssteve]

well the box is tuned really low to put up a really high score i would also have to wonder what your voltage looks like and what kind of jeep that you have

[J00bles]

if the vehicle is a boxy styled older model, try tuning higher in the box. the early model suvs tend to like higher frequencies best

[redbaron80]

more power = bigger numbers

[Bluebrindle]

Its an 04 jeep grand cherokee

the voltage is high 12's when booming and maybe low 13's on one of these propper droppers burps.

i,m using a soundstream xxx6500 at .7 ohm, its meant to do just over 4k at 13.5v so i,m basing the power i have stated on that.

I have 2 sundown 3000's about to go in so that may gain a bit i,m hoping. but still i was shocked at the high scores from 1 mayhem off 3k, the guy even admits mine sounds way louder to the ear and we are both confused.

[loganberry]

im at right around the same power as you, same subs, and i did a 148 in a box tuned to 29hz, re did the box to 35hz and its much louder now, idk numbers yet, but try re tuning it

[mhart]

we seem to have the same problem, tuned to low to hit numbers, but it kills on the streets.

[Bunker]

More power your just teasing those subs. Tune higher or find out where your car peaks at then add a removable port. Ground pound daily and fart machine on comp days.

[BulletInjection]

Yeah I haven't tuned my system much but I only hit a 141.9 on music in my 01 jeep 6" off the pillar legal

[loudmofo]

its tuned to low and the ss 6500 only does like 3000w at .5 on 12v its to power hungrey to do well its not a good amp to run on 12v