Re: Audio question - running 8 speakers off a 2 channel amp
 

three 8 ohm loads would be
(8 x 8) / ( 8 + 8) = 64/16 = 4

then take that load and parallel it to the other 8 ohm

(4 x 8) / (4 + 8) =32/12 = 2.66666667 is the load for 3 8 ohm loads

Re: Audio question - running 8 speakers off a 2 channel amp
 

So, how do you do that? To keep it simple say you want to hook up 3 4 ohm subs to a mono channel amp. How do you calculate the ohm load?

Re: Audio question - running 8 speakers off a 2 channel amp
 

Whoops you beat me to it! Thank you. It drives me crazy when I can't figure this kind of stuff out!

Re: Audio question - running 8 speakers off a 2 channel amp
 

just because that worked this time I would always use the formula because, that worked out right that time and some times it will work out easy but usuallly it is wrong if you just divide.

Re: Audio question - running 8 speakers off a 2 channel amp
 

Right. Thanks for the help.

So in my example 3 4 ohm speakers on a mono amp would be:

(4x4)/(4+4) = 16/8 = 2

(2x4)/(2+4) = 8/6 = 1.33 ohms total?

Re: Audio question - running 8 speakers off a 2 channel amp
 

I guess going to school for degrees in mechanical engineering, electrical engineering and acoustical engineering finally paid off.

Re: Audio question - running 8 speakers off a 2 channel amp
 

It sure did! So are my above formulas right? 1.33 ohms for 3 4 ohm speakers wired in parallel?

Re: Audio question - running 8 speakers off a 2 channel amp
 

Also, is there a way to figure out power(wattage) that an amp poduces between the 2 and 4 ohms? In other words, if an amp is rated at 720 watts RMS at 4 ohms and 960 watts RMS at 2 ohms how do you figure out what power it would have at 2.67 ohms?

Re: Audio question - running 8 speakers off a 2 channel amp
 

Ya but what is the formula for shear :drink: :drink:

Re: Audio question - running 8 speakers off a 2 channel amp
 

depends on what kind of shear you are talking about, shear strength, shear force, horizontal shear vertical shear, they are all different actual forumlas.