does impedance affect an amps efficiency?

[Lil Poot 5,000+ posts]

so i want to get the most out of my memphis 4k. lets just say that at volume 30, while wired for 1 ohm, its throwing 4kw exactly. if i rewire to a half an ohm, and lets say that at volume 25 i'm now getting exactly 4kw, will the amp still be pulling the same amount of current as it did to produce that power at 1 ohm?

basically, i want to wire for a half ohm daily... i know the amps not going to like me going balls to the walls like that, but if the efficiency is always constant, i can theoretically just back it off a few notches for the same result and wear and tear on the amp, right?

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[Buck 5,000+ posts]

I believe the lower the load you put on your amp, the less efficient it runs.

 

[Lil Poot 5,000+ posts]

if thats the case i may just stick with 1 ohm. i'm getting ready to order 4 sundown sa-15s but i'm using the same amp/electrical. i think 1 ohm will get the job done.

 

[KRYPTO 10+ year member]

yes the lower your ohms the higher the THD and also more power draw.

Even if your HU is playing at 25 with a .5ohm load on amp, the amp is still going to be drawing the power until it receives the signal through RCA's

I could be wrong.

 

[emilimo701 10+ year member]

I believe the lower the load you put on your amp, the less efficient it runs.

correct; efficiency of any particular amp is rarely constant

 

[helotaxi 5,000+ posts]

yes the lower your ohms the higher the THD and also more power draw.

This is true.

Even if your HU is playing at 25 with a .5ohm load on amp, the amp is still going to be drawing the power until it receives the signal through RCA's

No idea what you're trying to say here.

Here's the deal. Every time you increase current through the power supply and the output stage, you increase the voltage drop across the switching devices. This creates losses due to heat which are the definition of a drop in efficiency. This was really apparent in many of the amps that did the same power regardless of impedance. At higher impedances they were fairly efficient, but drop the load and the current consumption for the same power output would go through the roof.

 

[SpeedEuphoria 10+ year member]

yup the higher the ohm load the more efficient and clean the signal is