higher impedance easier on electric system?

[crashprime 10+ year member]

I am doing an install in an older (90s) truck and I am guessing it doesn't have the greatest electric at the moment. I don't have a great grasp on how to minimize strain. I hear things like efficiency thrown around, but there isn't a real substantial way to measure it and plan accordingly.

One piece of information I've come across is that an amplifier will be more efficient at 4ohms than it will be at a lower impedance.

So I guess the question comes down to this. What will cause more stress on an electrical system:

an amplifier rated/running at 600w @ 4ohm (capable of like 1500w @ 1ohm)

an amplifier rated/running at 600w @ 1ohm

given that it's the same company, same line, similar design.

I know that I will get more watt/$ shooting for 1ohm, but I am also trying to be nice to my stock electric.

Any advice here to clear this up?

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[hispls 5,000+ posts]

I am doing an install in an older (90s) truck and I am guessing it doesn't have the greatest electric at the moment. I don't have a great grasp on how to minimize strain. I hear things like efficiency thrown around, but there isn't a real substantial way to measure it and plan accordingly.
One piece of information I've come across is that an amplifier will be more efficient at 4ohms than it will be at a lower impedance.

So I guess the question comes down to this. What will cause more stress on an electrical system:

an amplifier rated/running at 600w @ 4ohm (capable of like 1500w @ 1ohm)

an amplifier rated/running at 600w @ 1ohm

given that it's the same company, same line, similar design.

I know that I will get more watt/$ shooting for 1ohm, but I am also trying to be nice to my stock electric.

Any advice here to clear this up?

"2000w" amp run at 4 ohms hands down. Not only much more efficient, but much much easier on the components in the amp. 1 ohm loads are really stressful on semiconductors. WAAY more than most people know.

Also most "80% efficiency" ratings on amps are at 4 ohms fully driven. Lower impedence and lower percentage of max output and you won't see anywhere near that. Really most of them don't even count the inefficiency in the power supply, so 80% real world is typically NOT going to happen real-world.... at least with very few amps.

 

[Chriszle 10+ year member]

It would be nice to know what your stock system is. Running an amp at 4 ohms will be more efficient, but if your running 600 watts, it should not be too much of a strain for most stock electrical systems.

 

[crashprime 10+ year member]

It's a 1994 Chevrolet C2500 454ci, and I believe that means it has a 105a(80a idle) alternator, and I just installed a brand new 124aH (20hr discharge) Champion brand battery. I know switching to an Optima deep cycle would be a good idea, but when I replaced the battery a few weeks ago, I needed to make sure it started, not which battery would work best for bumping subs I didn't have yet lol. I plan on doing a simple 4 gauge run to the amp. I took a look at the wiring under the hood and most of it looks pretty close to 4 gauge, so I was going to hold off on the big 3 until I get everything up and running.

There is actually quite a bit of room under the hood for a 2nd battery should I decide to go that route, but again, why mess with that if I am planning a pretty small install if I don't have to.

I just was struggling with the idea that an amp that can do 1500w @ 1ohm (but running only 600w @ 4ohm) might actually cause more of a voltage drop than an amp doing 600w @ 1ohm. It seems that I was right to assume the 4ohm route would be overall easier on my gear and the truck.

 

[TheUnderFighter 10+ year member]

4 ohm would be easier.... but 600w is very miniscule. Your truck should be fine with 600w @ 1 ohm. If it's not, you've probably done something wrong.

On the other hand though.... if you get an amp that does 600w @ 4 ohms, you will have plenty of room to upgrade later on that amp.

 

[fasfocus00 5,000+ posts]

can you guys explain to me how you are all coming to the conclusion that 600 watts a 4Ω is less strain on the vehicles electrical than 600 watts at 1Ω.

 

[trumpet 5,000+ posts]

I just was struggling with the idea that an amp that can do 1500w @ 1ohm (but running only 600w @ 4ohm) might actually cause more of a voltage drop than an amp doing 600w @ 1ohm. It seems that I was right to assume the 4ohm route would be overall easier on my gear and the truck.

Watts = volts x amps. In this most basic equation, 1,500W requires ~104 amps at 14.4V. 600W requires ~42 amps at 14.4V. If you look at it this way, it's pretty easy to see the difference in current requirements. It goes up in the car because our amplifiers aren't 100% efficient. However, in the real world playing music that 1,500W system is going to play fine on a lot of stock alternators.

 

[trumpet 5,000+ posts]

double post

 

[TheUnderFighter 10+ year member]

can you guys explain to me how you are all coming to the conclusion that 600 watts a 4Ω is less strain on the vehicles electrical than 600 watts at 1Ω.

Amplifiers are more efficient at higher ohm loads.

 

[fasfocus00 5,000+ posts]

Amplifiers are more efficient at higher ohm loads.

i understand the more efficient parts but you also have more resistance at 4Ω than at 1Ω.

 

[tc300 10+ year member]

Amplifiers are more efficient at higher ohm loads.

And run alot cooler on those hot scorching days!! Haha

 

---------- Post added at 01:34 PM ---------- Previous post was at 01:33 PM ----------

 

i understand the more efficient parts but you also have more resistance at 4Ω than at 1Ω.

I'm pretty sure it's about efficiency not resistance....

 

[stephens30228 10+ year member]

So if I could run two AQ1200's @ 1 or 2 @ 2, it would be recommended to run the 2 @ 2, to achieve say 2000watts whereas I was pushing my alt hard with about 1400 @ 1 before?

 

[cyn 10+ year member]

the 600watts on stock should be fine, do the big 3 upgrade... if the battery you have is an AGM stay with it and stay away from yellow tops... get one of the die hard platinum series.

 

[_dontaskwhy 10+ year member]

the 600watts on stock should be fine, do the big 3 upgrade... if the battery you have is an AGM stay with it and stay away from yellow tops... get one of the die hard platinum series.

i thought yellow tops were good for audio systems??

 

[cyn 10+ year member]

i thought yellow tops were good for audio systems??

A lot of people have been having issues with the Yellow Tops lately, I have a brand new one that rests at 12.1, I need to bring it in, this is the second one in a year.

I plan on upgrading to something better upfront with a 120ah+ for the rear.