Re-coning ?

[MickyMcD]

but besides that, why would impedance affect efficiency? wouldnt dual 2s for example be as efficient as any other impedance?

speaking of coils, what makes dual 1s diff from duals 2s in that it would change efficiency?

Every amplifier class (A, B, A/B, C, D, G, H), apart from Class TD (Lab.Gruppen and their amazing amplifiers!) and valve amplifiers, run more effeciently at a higher impedance. You may not think so as you get more power from an amplifier at a lower impedance, but power is not effeciency. An amplifier running at 1 ohm runs far hotter than one running at 8 ohm, and draws significant amounts of power to generate output. This heats up the transistors in the output stage, and impedes the amplifier's ability to function. That is why you will NEVER see any sort of professional speaker or speaker array lower than 2 ohm.

Also, with class A, B, A/B and G-H amps, they have what is called '1/3 power.' At '1/3 power', the amplifier is creating exactly the same amount of heat in watts as it does output power. You will reach '1/3 power' faster with a low impedance load than you will a high impedance load.

So yes, you will alter effeciency through resistive loading.

Cheers,

Mick

[dleccord]

yeah the amp efficiency i understand.

its not really clear on the subs' efficiency though. i've never thought about the efficiency being change due to the physical structure of different impedance in coils. the only efficiency ive ever noticed was the size of the driver.

[dwright27]

is that so? then maybe more companies should make dual .25s so that people could run their amps at 1/8 an ohm to maximize efficiency.

1/8 of an ohm, wow!!!!!!

dude effeicency would be so low on any amp at that ohm, i dont think you could put it in a percentage.

[MickyMcD]

yeah the amp efficiency i understand.

its not really clear on the subs' efficiency though. i've never thought about the efficiency being change due to the physical structure of different impedance in coils. the only efficiency ive ever noticed was the size of the driver.

This scenario will not have too much of an impact on overall woofer effeciency in terms of db/w/m. Yes, the change of impedance and coil weight, moving mass etc will modify the Thiele-Small parameters of the driver, but not enough to be of any concern.

But yes, every little thing you do to a driver will affect overall effeciency, as you are changing the Theile-Small parameters, and thus how the driver functions. Effeciency is not purely based on size.

dwright27, I'm not sure. Could be useful. If you get hungry, you could just whack a pork roast on the heatsink and she'll be right as rain.

Cheers,

Mick

[Guest MegaloManiac]

or buy that amp with magic pixie dust, i hear Stetsom has some