[trojan]

i need to power 4 subs. 2 of them are 300 RMS and 600 peak. and then 2 smaller ones that im not sure on the watts but i know is less then the other two. is there any way to get a resister or something like that. ive seem some bass control knob. will this work in my situation.

 

[sixfofalcon]

The power (watts) rating on the subs is there so you don't overpower them with an amp that supplies too much wattage. It's not really important that they all have the same rating. More important info would be the impedance (ohms) of the subs. Most subs are 4 ohms, but some other common impedances are 2, 6, or 8ohms. There are even some that have "weird" ratings like 3 ohms. Tell us what the impedances of each of the subs are, and we can tell you how to wire them up to an appropriate amp. It's usually on the back of the sub, but you may have to search the model number on the internet to get the specs.

 

[trojan]

the smaller subs are 6 ohms im not sure about the bigger ones because they are general brand (electra, yes i kno there not that good). i wanted to take the smaller ones, they are 6 inch subs. and im gonig to make a box to go in between the front seats. and i wanted to buy an amp to do all 4 subs but i dont want to blow the little ones. they are good quality. another thought i had but dont know if its possible is to take a high-pass crossover to the front speakers and a low-pass to the subs in between the seats. im thankful any help thx.

look at the bottom couple, i think i will get one of these. run the signal from both front speaks into the crossover and then to my 2 lil 6 inchers...will this work?
crossovers

 

[sixfofalcon]

I would tend to assume that most generic (or cheap) subs would be 4 or 8-ohm. However, you don't want to risk your amp on an assumption. If you have a multimeter you can read the impedance with that.

If you wire the two 6-ohm subs in parallel (+ to +, - to -) the amp will see a single 3-ohm load. If the other subs are 4 ohms each, and you parallel wired them, the amp would see a 2-ohm load. In this case, a good 2 channel amp would power all four of them nicely. Run the left channel + and - to one of the 6-ohm subs. Then connect the + of that sub to the + of the other 6-ohm sub, and the - to -. Use the right channel of the amp to power the other two subs, wired in the same way.

As far as the crossovers go, you won't want those Cerwin Vega units. They are for running a midrange and tweeter, not full range and subs. Passive crossovers are cheap, and you should probably cut out anything below 100hz or so on the front and rear speakers. Let the subs handle everything from 150hz or so, on down. These numbers are flexible... some people make the divide around 200hz or so. Most amps will have a low-pass crossover so you can cut out the high frequencies to the subs. Then all you'll need is some "bass blockers" for the front and rear speakers. Bass Blockers at Crutchfield

How much are you looking to spend on an amp?