# 4ohm amp into a 8ohm cab?

Discussion in 'Amps and Cabs [BG]' started by tat2d_13, Feb 22, 2004.

1. ### tat2d_13

Feb 4, 2004
Minnesota USA
I have a GK800rb and Im barrowing a buddies ampeg bse115(200 watts @ 8ohms) and being its not mine I just thought Id ask so I dont smoke it but Im wondering if Id be pushing the cab to hard if I ran the 300watt 4ohm output into the cab?Thanks!(and yes I did a search)

2. ### DWBassThe Funkfather

The cab will not get the full 300 watts! The amp (all amps) will push less wattage as the ohmage goes up. It'll probably only push 200+/-watts into the cab (at full volume).

3. ### Saetia

Mar 27, 2003
Wisconsin
As I take it, and have heard (I may be wrong though so take it with a grain of salt) a head will produce 2/3 the watts at 8 ohm then it will at the rated 4 ohm load. Just for instance, my old trust Peavey Session bass head that I have lying around put's out 200 watts @ 4 ohm, and 130 watts @ 8 ohm, both specs are listed on the head, if you take 130 and devide by 200 you get .65 which is basically 2/3 (.66666666 irrational number or 66%). Using the math that I just gave I just reversed the formula and took 300 x .66 (66%) and It came out to 198 watts you would be feeding the cab (once again a third is an irrational number when speaking in 10's and 100's so the further you extend the repeating decimal the closer you will come to the actual output), again this is if in all cases a head will put out 2/3 the rated 4 ohm load at 8 ohms. So in a long drawn out explanation as DWBass said it will put out roughly 200 watts at 8 ohms. I hope I helped
peace
-Ben

4. ### tat2d_13

Feb 4, 2004
Minnesota USA
Makes sense.Thanks Ben