i got my l7 15 put in my truck. it pounds pretty hard but its not hitting like it should i think my box is to small and the amp isnt putting out 1500w i think its putting out 750 cuz its at 2 ohms. how hard should a single 15" l7 hit if its in a good box and is getting 1500watts of power?

 

that should be right at 4 ohms you would be getting the most out of the sub, aka 1500.

should have a box built to specs for the sub since it is the 15, and what amp is it. most don't push out the true wattage it says it does. and depends on the voltage of you truck

 

Its a crunch audio 1500.1 I think it might be a monoblock. I plan n upgrading to a better amp

 

that amp will never put out the "true" 1500 it claims. no offense but power acoustik, crunch, boss, an so forth of the high power super low cost amps are not what they claim.


kenwood, jl, alpine, kicker, mb quart, sundown audio, stetsom, Aq, and so forth are better amps that will put out close to, more than, or exactly, what they claim.


if you are running a 2 ohm load, buy something from the first 4 i listed if you want quality, durability and nice looking. one ohm, cheap clean power would be the AQ and mb quart. sundown and stetsom will run you more money but be power horses

 

I used to have 2 15" L7's wired to one ohm with an MA-Audio 4400W RMS amp using 0-gauge wire. They hit like no other system I had ever heard before!! You couldn't sit in there for more than a minute running at 75% volume unless you wanted a killer headache!!!

 

I think you may have thought backwards there, as it would have put out the 1500 watts at 1 ohm, not 4.

Aside from that whether or not an amp putting out 1500 watts blows an 80 amp fuse or 200 amp fuse depends entirely on its design. A lot of subwoofer amps these days use designs that are lower voltage, higher current designs. The power supplies don't step the voltage up very far, but the design allows for a ton of current flow. On the other hand a lot of old school amps had power supplies that stepped the voltage up much higher and didn't require near as much current to produce the same power output.

Regardless it takes power to make power. Making sure your power supply to the amp(s) (i.e. batteries, alternator, wire, grounds) is up to par is far more important than worrying about whether or not the fusing is too high, or whether or not the amp puts out the true amount of power it's rated at. As long as it's running as good as it possibly can and it's making you happy then you shouldn't worry about it.

 

Thanks for the help guys I plan on getting a better amp I know it should be a lot louder thn it is know. Don't get me wrong its hits hard but not like it should. Im thinking about getting another L7 and building a nice box for it cuz my prefab box isn't getting the job done.

 

You know, the box has WAY more to do with the output and sound of the sub than the amp does. Build or have built an optimum enclosure for the sub, then if after that's done it's still not enough (and it likely won't be since it's never enough in this hobby, LOL) add another sub and change it up on the power. The box is cheaper and has more impact on the overall performance of the sub than the amp ever will.

I could rattle the little hell out of my house with a cheap 15" sub and a 100watt plate amp. Loud enough that it was hard to stand in certain areas of the room. The sub was rated for and could easily have taken another 400watts of power but it didn't need it. The enclosure was very large, a little bigger than my side by side refrigerator and built to be VERY efficient. Used some junk a friend had lying around to prove a point to him, the enclosure is everything. Obviously that's a little trickier in a car due to the down right Hulkish size of the enclosure, but the same principals apply. Build the proper enclosure for the sub and the goals of the system and it'll shine on that amp.

 

Well the box I have now is pretty small like a little bigger then the sub. How big of a box should I build and what will I need to build it?

 

If you don't have the tools and experience for building enclosures I would recommend finding someone who does or ordering a custom built enclosure from Argent Audio, Fisher Customs, Pound That Sound, Audibel Customs, Handcrafted Car Audio, or one of many other's who can build an enclosure to spec for you. The reason I recommend that is because a ported enclosure for a sub that size with that kind of power handling ability needs to be built very strong and sturdy, plus it needs to be properly designed.

Kicker recommends between 3 and 6 cuft of enclosure volume for the L7 15" sub. That's a decent playground in size to play with. I would personally cut it down the middle at 4.5cuft tuned to ~34hz with about 90sqin of port area. That would yield an efficient low end monster. It should still maintain good response on the upper end of the bass spectrum, yet take your breath away when the music dropped bottom, and easily handle the 1500 watt Crunch amp @ 2 ohms without worry of mechanical failure as long as the SSF (sub sonic filter) was set properly.