120w rms 8 0hm subwoofer, which amp?

toneee · Post by **toneee** » Tue Feb 21, 2006 7:07 pm

Ive recently bouth a 10\" kicker impulse subwoofer which has an impendence of 8ohms and an rms power rating of 120w, as i cant find an amp which gives a figure for wattage at 8ohms i need some help figuring out what sort of power this sub will need. can anyone help?

flash22 · Post by **flash22** » Tue Feb 21, 2006 7:33 pm

whats your budget on the amp ?????? most of the amps under £400 wont do 8 ohm and theres only a hand full then most mono block amp make ther peak power at 1-2 ohm and multi channel amp make there peak power at 4 ohm. Theres a couple of options tho 1. take/send the sub back and get a 4 ohm one 2.buy another sub the same as that on and wire the pair of subs in parallel to 4 ohm there a good wiring guide here..... http://www.phoenixgold.com/2004/wiringtutorial.html

out of intrest how much did you pay for the sub ?? there are a lot better subs out there than the kicker imo for the money

Is the sub single or dual vioce coil ?? and do you have the part number for the sub???

toneee · Post by **toneee** » Wed Feb 22, 2006 7:44 pm

flash22 to the rescue once more. cheers mate. The sub only cost me 20 odd quid unused, hence why i ended up with it, got it from someone who had 4 then changed theire minds about their system. wishing id got 2 now so i could wire them parralel, because i cant seem to find any more! Its a kicker impulse 10\" Item number is I108 Im asuming its single voice coil as i cant find anything saying otherwise. Would it not be possible to over power it slightly from a 4ohm amp, as it is just causing double the resistance? Ive only got my basic GCSE physics knowledge on this one!
thanks again
Tony

flash22 · Post by **flash22** » Wed Feb 22, 2006 8:22 pm

most amps will go to 5 ohm when pushed but your more than likely kill the amp over powering it to run the sub at 8 ohm. I would chalk this one up to experiance this time. shame your so far away as i have a 12\" kenwood sub sitting here in its box brand new unused you could have cheap aswell as a new jbl 75.4 amp (i was on a budget for my system at the time but i never fitted them due to needing my boot space) i have just ordered some alpine stuff for the car so there no longer needed

toneee · Post by **toneee** » Wed Feb 22, 2006 11:34 pm

My google search found me this:
\"All amplifiers can handle a higher resistance (load), but they will produce less output. Most quality amplifiers can also handle a lower resistance.\"
Is there anyway of calculating how much the resistance will effect the output. say if i were to run the sub from an amp supplying 200w at 4ohms what this would be at 8ohms??

flash22 · Post by **flash22** » Fri Feb 24, 2006 6:46 pm

in theory yes it would work but in the real world you more than likely kill an amp trying due to the nature of the way thay are made. In theory you could put an resistor in parralle but again its just theory