higher impedance easier on electric system?

[neo_styles 10+ year member]

Lol, yet another engineer on here!

Makes sense.. but by lower impedance you mean lower impedance being 4 ohm compared to 2 ohm, right?

I wouldn't go so far as to say I'm an engineer. I work in an engineering department and do have to understand enough electrical/electronic theory to do my job, but I am FAR removed from the design category.

And think the other way around on impedance. The lower the number, the lower the impedance. That's why some amplifiers might be rated for 25Wx2 channels at 4 ohms, but are somehow able to crank out close to 1K at 1ohm bridged. The amplifier is more easily able to apply its power switching to take a low signal and produce a comparably large amount of power in output.

 

[AxT4430 10+ year member]

Basic Electrical Engineering. One of the first classes we take for my line of work.
As for impedance levels and efficiency, it's not overly complicated. Just think of what "impedance" means. Just like "resistance" is the ability to resist voltage, impedance is the ability to resist the flow of current. So at lower impedances, the system is easier able to accept changes in current.

I was thinking you were explaining the concept of car systems being able to handle 4ohm vs 1ohm because the "higher impedance" @4ohm would resist more current and be able to fluctuate the different signals being presented by the headunit to the amp..

 

[neo_styles 10+ year member]

I was thinking you were explaining the concept of car systems being able to handle 4ohm vs 1ohm because the "higher impedance" @4ohm would resisiting more current and be able to fluctuate the different signals being presented by the headunit to the amp..

No but I guess I did cover that aspect as a segue. Running your amplifiers at a higher impedance allows your car's electrical system to not be taken over because it constantly needs to be feeding load to your sound system. So, overall, the whole system (the car) is more efficient because it can better prioritize all loads instead of having to cater to the sound system specifically. In other words, the amplifier will get the power it needs without having to place such a heavy burden on the entire system. Savvy?

 

[av83 10+ year member]

[quote name='AxT4430']@neo_styles; @pro\-rabbit; @ciaonzo; @keep_hope_alive; @Spooney; @av83;

Just listing people I think could explain past common dogmatic beliefs.. Thanks for any replies![/QUOTE]

I'm not on the same level as these guys, but thanks for thinking highly enough of me to lump me in, lol.

 

[keep_hope_alive Premium Member]

Why are higher impedance's usually more effiecient with lower THD ratings?

Efficiency drops as impedance load is reduced (same output power level) due to increases in current...

the load current at 4 ohms is much lower than at 1 ohm. as you pass more current through the output stage you generate more heat.

heat = lost energy.

it really does depend on the amplifiers in question as each is designed differently and has a different efficiency peak.

but in general, running an amp at it's lowest impedance rating is the least efficient method since output current is at maximum.

 

[neo_styles 10+ year member]

the load current at 4 ohms is much lower than at 1 ohm. as you pass more current through the output stage you generate more heat. heat = lost energy.

it really does depend on the amplifiers in question as each is designed differently and has a different efficiency peak.

but in general, running an amp at it's lowest impedance rating is the least efficient method since output current is at maximum.

Keep in mind he's talking about net efficiency of the system in this example. More heat is generated due to the higher current carry, but you're also talking about significantly higher amounts of current at each impedance stage relative to the one before it. So while a system can be 80-85 percent efficient at 8 ohms, it might drop down to 50-60 percent efficiency at 1 ohm, but the overall amount of current being passed is still larger.

 

[ciaonzo 5,000+ posts]

I'm not on the same level as these guys, but thanks for thinking highly enough of me to lump me in, lol.

Same here. I wish I knew enough about amplifiers to build or fix them.
What I do know is that I love the sound of a very hot amplifier, lol. Probably a high bias thing. My dead head runs hot, my amps run hot... I keep my drivers cool, though.

Anyway...

 

[Spooney 10+ year member]

I appreciate having my name thrown into the hat but I can't provide a more detailed explanation than Keep Hope Alive already has.