how to determine ohm load?

5 dual 4 ohm subs in parallel would come out to a 0.4 ohm load on your amp, most amps are not stable at less than 2 ohm with the exceptions of corse.if you think of the number voice coils instead of the number of subs the problems become easier. if you have 4-4ohm voice coils in series you would have a 16 ohm load, just add the impedences together. if you take those same 4-4ohm voice coils and put them in parallel you would end up with a 1 ohm load, easy way to figure is the impedence over the number of voice coils.in your situation with 5 dual 4ohm voice coils you would have a total of 10-4ohm voice coils. by putting the impedence of the voice coils over the number of voice coils you will get 0.4 ohms with would be the impedence if you ran all of the voice coils in parallel.everything gets a little more complicated when you start using series and parallel together but the same rules apply except the circuits become like a single voice coil with the lower or higher impedence. if you ran 4-4ohm voice coils in a parallel-series you would take the first two voice voils and put the impedence over the number of voice coils, which will become 2ohms this then would be treated as if it where a single voice coil in your thinking instead of the two in parallel.if confused i can try to elaborate more.Quad L Handyman services

i havent decided if your up really late or really early but no problemQuad L Handyman services

well welcome to the 12volt forumQuad L Handyman services

Thank You