I have a JL 12w7 and a JL 12w3 V2 subs. What is the best amp to power those two? i was thinking of getting 1001bd rockford 1 ch 1000w or the 34230 Eclipse 2 Ch 1100w but i like to know what your guys opinion first. thanks

 

There's two important things when considering an amp for a sub:

1. Finding the "sweet" spot of power
2. Matching up the ohms.

Your amp should have certain power ratings of which it is stable at a certam ohm load.

For example, the 1001bd amp you mentioned has the following stats:
500W @ 4ohms
1000W @ 2ohms

If your speaker is 4ohm, you'd be pushing 500W to the speaker. If you have two, and you wire them in series the ohms would split in half, and you'd be pushing 1000W to both speakers. If you had a DVC (dual voice coil) sub where each coil was 4ohms you could wire each coil in series which would give the speaker a total load of 2 ohms and you'd be pushing 1000W total to the one speaker. Additionally, you can bridge, or wire in parallel, speakers which doubles the ohms (ie. two 4ohm speakers bridged become an 8ohm load).

The second thing you want to match is power. If the speaker is rated at 500W to 1000W max, then finding an amp that does about 750W will be about right for that speaker. It's best to be around the middle area.

 

thanks for the advice I'm still new to sounds and theres few things i don't understand like ohms and ch1 ch2. Could you fill me in. Sorry if this was a dumb question because I'm a dumb person who doesn't know alot about audio stuff.

 

I went from knowning nothing to understanding enough to install my own system in about a month and a half. Here's the book i read:
amazon.com link . I've seen a lot of people recommend it. It goes over the basics of everything that can go into your car, and gives practical advice on how to choose parts. It also talks about installation and various other topics like sub building. It's more of an overview than an exact step-by-step type book. I'd highly recommend it.

The channels of an amp are how many outputs it has. For example. Let's say i wanted to power all 4 interior speakers with thier own power channel, i'd need a 4 channel amp. If i needed to save some money i'd run front and back left off of the same channel and the same for the right side. I'd need a 2 channel amp. The subwoofer only requires one channel. To make things more confusing you can bridge channels. So say i buy a 2 channel amp. (if it is supported by the amp) i can configure it to run in bridged mode which outputs 1.5 times the power of the individual channels.

 

thank you so much for clearing that up but im still confuse on the ohm part

 

Manufacturer's websites can be good. Here's the product page for that woofer:
jlaudio.com They actually give you a recommended power chart . That's pretty cool. Here's the official data sheet .

Anways, it says your sub's coil is 3ohms. This would have to be the first 3 ohm sub i've ever seen. :P

Anyways, basically it's like this. The ohms of a coil are how much load the speakers put on the amplifier. The greater the resistance, the less power is pulled through. Once you know how many drivers you're going to be using you can do the math to find out what power it'd be putting out. On the data spec sheet i see they recommended thier own 1000/1 amp, which probably means that at 3ohms it'd be drawing about 750W (this is an assumption).

By the way, have you been to Mobile Car Audio? I've been there a few times and it seems like they're all rather knowledgable. Plus, if you're not into install it yourself, they only char $85 and it includes all the wiring (which can easily cost almost that much anyways).

 

As far as I know, parrallel wiring (two wires to one input) cuts the impedance (ohms) in half. To raise the impedeance 2-fold, series wiring is necessary. Series wiring hooks two speakers to one channel (run the positive on one speaker and the negative on the other to the amp channel, then connect the unused positive and negative speaker terminals together... voila!)

As far as amps go..... stick with RF (Ive had good results with every Fosgate amp ive owned)

Look here (good prices/cheap shipping/reliable site) The Zeb

 

scoobsport98 -- Thanks for the correction. You're right. I don't know why i reversed those in my head. Parallel does reduce the resistance while series boosted it. It was a long day. :P

Reference

 

thanks guys for the info:banana: i'll just go with the JL amp. I have another question how do you bridge channels and could you give a better explaination on how to parallel wiring?

 

Bridging two channels together involves hooking up one wire (pos/neg) to the two channels you'd like to bridge. For instance, if you have two adjacent channels on an amp (pos, neg, pos, neg from left to right), the most common method to bridge them is to hook up the speaker wire to the positive terminal on the left channel and the negative terminal on the right (or whichever are on the outside). Most amps say specifically how to bridge channels right on them, but this is the only way I've seen. Parallel wiring is just hooking up two speaker wires to one channel; two wires in each terminal. Both bridging and parallel wiring cuts the impedance in half, so combining the two methods is how you blow channels, unless your amp is 1ohm stable. If you do this, it will work temporarily, but not for long. Oh, also, both of these methods alone change the signal from stereo to mono, which is not desireable unless you are running subwoofers, or if you simply dont have enough channels to run all of your speakers and must run them parallel. Heres a pic for you visual learners

 

SWEEEET!! thanks a bunch. I had two kenwood subs and the acoustick amp 2ch and i was about to parallel both subs and bridge it but i remember my friend doing that and his fuse got burnt. so I decided not to do it.

 

Have you considered Xtant amps? They match very well with JL subs and many feel (including me) that they offer much better sound quality than RFs of recent years. Are you looking at running both the W3 and W7 subs at the same time? That would be an interesting setup.....although I'm not sure how efficient it is. The W7 takes a ton of space and power. Also, the W7 is a dual 3ohm sub while the W6 comes in dual 2, 4, and 6ohm configurations.

If you have a high end sub (which the W7 is considered) it deserves a comparable amp. You can match a very good amp that puts out power at the upper limits or even slightly over whats recommended for the sub and still be safe. This will allow you to run the amp at more efficient levels which will provide better sound quality (less distortion). Most amps tend to draw way too much current when operating at their limit.

 

if you've got the money, you should consider a jl 1000/1 amp...it'll give you flexibility in terms of resistance load (ohm).

 

Yeah, mono amps are awesome for subs. On top of being stable at low impedances, the "class D" circuitry (sp?) doesnt draw much from your battery and genererally require smaller fuse ratings.

PS, RF makes these one channel wonders also (it seems that people stay loyal to whichever brand has worked well for them. Personally, I've seen lots of, too many in fact, blown amps between my friends and I, but not one of them was Fosgate)

 

If you are trying to run both those subs at the same time, you NEED to have separate amps to do it. The W7 wants like 800-1000 rms i think. The w3v2 wants 200. Those speakers should not be run off the same amp. The power draw would be all off and would run your amp hot, and either blow the small one from too much power or blow the big one from too little power. Yes speakers can be blown from too little power.