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Vintage threads from the first ten years

Connecting external cab; Impedances.

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7/17/2000 12:33 AM
JC	Connecting external cab; Impedances. If I connect a 16 ohm cab in parallel to the 8 ohm internal speaker of a combo, am I doing something really wrong to the 8 ohm OP transformer of my amp? I remember I read better to go high in impedance load than low... Thank you. JC

7/17/2000 12:44 AM
Casey4s	If you connect 16 and 8 ohm in parallel it is going to yeild about 3.2 ohms. (If my math serves me correctly) Casey4s

7/17/2000 12:52 AM
JC	Really? That little? Oh my God. I must re-read that math about resistances in parallel and series. Thanks. JC

7/17/2000 12:57 AM
Les	wrong answer... formula is 1/(1/x+1/y) in this case: 1/(1/16+1/8)= 5.3333 ohms... Les

7/17/2000 1:09 AM
JC	Les, Casey4s, The fact is that in any case, I'm under the desired 8 ohm. I shouldn't have forgot those formulas... Thanks again. JC

7/17/2000 1:31 AM

If you still want to do that wire a 16 ohms resistor in parallel to the speaker cabs so (16 parallel to 16 parallel to 8) will make 4 ohms. Then set your amp to 4 ohms if that's possible. (If it isnt possible dont do it!)
But this will not be very efficient and it may not sound very good. Also the resistor will get very hot. BTW, you should determine
the power rating of that 16 ohms resistor according to your amp's power rating.

Kurt

7/17/2000 2:21 AM
Casey4s	Thanx for the Math lesson Les Casey4s

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