dbjunior

what type of vehicle is it going in 8cu is a large box. the q likes the larger boxes and is more of a sealed box sub the bl18 will do fine with 8cu ported. what size was your old sub and what type of box was it in

if using 6 cu before displacment id use a 15 not an 18 get the ble big box lots of port and tune to like 32hz 6 cu with 84sq in of port tune to 32hz will have about 4.4cu after displacment better for a 15 than 18

the jl is a very power hungry amp your better off with the 1500zx and 2 q15's will be louder off that power depending on enclosure. what vehicle do you have and why cant the alt be upgraded

13v is not a good thing if running a 16v battery you should see 17.xx V

what did you use to make this and how did you get it on

get the havoc its a little better than the Q on lows and will handle the power fine.the gain is to match the rca outputs of the headunit. gains normaly range from 8v-200mv 8v being very little gain if you have a headunit with 5v preouts you would turn the gain slightly to match the 5v to achieve full power if you want less output from your amp turn the gain down. if your headunit has 2v preout you would need more gain to achieve full power. if you turn the gain higher than your preout voltage the max output will be acheived at lower volume but if you pass that volume you will send a clipped signal than will produce distortion and heat that can blow a sub or speaker

http://www.woofersetc.com/index.cfm?fuseac...Product_ID=6097 more than enough power and will be great for comps later i have the txa6004 wich is the same thing just a 4 channel i use it to power comps and an q18 it works great plus its only 129

will have enough power for the sub and when you are ready to upgrade you can use it to power a nice set of speakers http://www.woofersetc.com/index.cfm?fuseac...Product_ID=4197

4 12 will handle the 6kw just as the 4 15's you planned on for the wall its not that much over there rated power handling so if the box is made right it should have no problem. if you are at all concerned just get 4 lvl4xl's then you would be giving them rated power

if you have the room why not do 4 lvl4 12's crx box. box shouldnt be much bigger than the two 15's

they can swap the basket to a 12 but you would only be able to get the new soft parts idk how much it would cost though id reccomend selling itand buying a new one so you get the new magnet to

unless you plan on running more power i wouldnt bother switching sub a direct swap with a btl will get you a little morein the lowerend but less around 40hz if you retune the box you will get more output at 40hz but lose the lowerend the q18 really needs a bigger box and more port area if you swap out to a bl and add 2 more areo's same length you will notice a difference in output but still lose a little lowend

if you are gonna do sealed id get 2 q's if you go ported with the power you have id do a single loaded bl

any local audio shop doesnt matter what they sell should be able to build a box for you just tell them exactly what you want and they should give you a price. or you could ask fisher or pound that sound but shipping might cost a bit

have a box built 37wx37lx28h double baffle on top lots of bracing subs up port back have a port 35.5wx8hx22l. find a local audio shop they should be able to build one for you or one of the guys on here can build one for you. first before getting an amp you will need electrical upgrades like a huge alternator 250amp or bigger an upgraded battery under hood and probably a large second bat located near amp. you will also need the big 3 done in 1/0 and have 2 runs of 1/0 to the back. the look into a 4kw rms amp like the rockford t40001bd or hifonics cyclops or goliath dont buy there lower end stuff though. a saz-3000d would be a good starter amp then bump up to two later if you need more

that means you have plenty of power at the battery but you need to do the same at the amp to see if you are getting voltage dropping from a bad ground or to small of power wire or something like that

im note sure of the note but its pretty steady bass try beastyboys intergalactic

nightshade upgrades to nightfall and eventually there will be the pitchblack

just need some 8's in the kicks dayton makes a nice 8 that works great for midbass the qt210-4 $60 each and they take 150wrms 9.5mm xmax good to cross from 60-250hz

if you go larger tune lower like 28hz middle 30hz and the smaller 32hz personally i recommend the large low tuned box

budget goals and available space to use plus power if you already have the amp

so whats the peak 145@ 40 or so hz

is it possible that you have a water problem on passanger side causing issues like the crossover getting wet and blowing

only if its a small install if you do anything of good size you will still need to run new wire from the alt to the battery stock cant be that big 4gauge possibly 6gauge if you dont replace them you will burn them up with high current draw and then you wont be able to start the car

low 140's is nice mid to high 140's would be sick considering it will also be a lowend beast good luck stopping all the rattles