Bass Cabinet for cheap subs

[mitchbowman]

hey guys, new to the forum and stuff so i dont know my way around yet

just wondering what you would think about making a un-powered sub box for 2 cheapy JBL GT4-15 i have laying around just for now just to get some low end at gigs ?

I do abit of dj work and currently run 2 jbl mrx515's on a crown xti2002 amb but there is no low end in sight.

any thoughts ?

[CapFive]

Ok man I'm glad you asked this because I know my Car audio!

first things you need to think about are how you are going to power it, these subs are built to be plugged up to amplifiers that run off 12v systems, and the sub woofer is 4 ohms, which means most 240v amplifier setup's won't really want to play nice with it, you can't just plug it up because it could put to much load on the amplifier and either one will give out. You are lucky in this case because it looks like you have a pretty high end amp!

With saying this, are you looking to add these subs to the system? or are you going to be replacing them? you only have 2 channels and your current speakers are 8ohm and the subs are 4ohm, so you will have to think about how you will wire it up, you will certainly get more power out of the subs but you could risk blowing them because the amp is way overpowered for the subs (800w per channel with your subs being 250w rms) so you could just be wasting your time with this setup.

BUT! The difference between car audio subs and home audio/PA subs is that they're engineered with different goals in mind.

if you are thinking that this subs pumps hard in the car, it probably won't give you the same result outside the car, the reason it sounds so good is simply because of the pressure the car makes, it is like being inside the box, once you take that into an open area, you will loose all the impact.

I personally think that the subs you are using now will probably give a better result, but unless you go get a professional sub box made which will cost more than buying a new set of PA's, you probably won't get a great result.

Just my 2c

[mitchbowman]

hey thanks for the interest but since then ive realized they wouldn't really be suited for the application anyway so i sold them in a cheap car box i whipped up and bought myself a pair of VFM 18" woofers, a behringer epx4000 amp and a dbx driverack pa to get the ball rolling

now ive just got to decide on what box to make for them to keep the size on the low side. i wanted to make 2 boxes similar to the cubo 18 but sixe is a bit of an issue