Originally posted by bob_vdi
I posted this in Troys message.
I'm not sure if it is safe for his receiver (4ohm at 250 w or 8ohm at 150w).
Total Ohms was 4.67 as drawn.
First, I think you got the math wrong.
Three 4 ohm shakers in parallel = 1/(1/4 + 1/4 + 1/4 ) ohms
That results in a load of 1.33 ohms.
Putting that in series with one 4 ohm shaker results in 5.33 ohms load.
Putting that combination in parallel with another like combination is
1/(1/5.33 + 1/5.33) ohms.
Doing the math, your wiring diagram results in a resistance of 2.665 ohms to the amplifier.
I doubt that is any good for the amplifier.
Compounding the problem, as I said in an earlier post, the wiring you illustrated does not equally shake each "shaker"
Most of the power is delivered to the two shakers you have in series with the others. The remaining power is shared by those in parallel.
So, not only will it result in a load that is bad for your amplifier
, but equal distribution of power is not even close
. In my opinion, the power should be distributed equally to all the shakers. Not 1/4 of the power to two
(those in series with the others) , and 1/12th of the power to the others
(those in your diagram wired in parallel).
I might suggest that you use the PE suggested drawing and present an 8 ohm load to the amplifier (don't get hung up on trying to get a 4 ohm load)