amp starving?

[lubetek 10+ year member]

Morning everyone,

So if your lights dim when the bass hits does that actually make the amp less efficient? will the amp actually put out less power than its rated for because there is not enough juice hitting the amp when the bass hits?

I know I need a new battery, and to do the big 3. I also need to look into a HO alt.

I was just wondering if i'm losing power to my sub everytime the lights dim.

I guess another question I have is if I do all the things to improve the electrical of the car and the lights stop dimming will I hear an increase from the sub and amp?

Thanks!

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[GCAdidas13 10+ year member]

When your lights dim, it is a telltale sign that the voltage in your car is decreased. If the voltage of the car is decreased, the performance of your car audio components is also decreased.

It's the equivalent of playing your subs loudly with the car off vs. playing your subs loudly with the car on and at about 2000RPM.

Of the three you listed, the best (and most expensive) option is purchasing a HO alternator. I'm actually going to be putting in a money order today to participate in the Irragi Alternator Group Buy. Take a look, and if you have the money now or anytime before Feb 15th maybe you could get one.

But to answer your final question, the answer is probably. You will probably see an increase from the sub and amp if they are seeing 14.4v even when the amps are drawing maximum current. It depends on how bad it is right now.

Brian

 

[lubetek 10+ year member]

good info thanks. well its not too bad unless I really crank it up and if I set the gain higher. Right now i turned the gain down some to keep it from drawing too much and the lights barely dim now.

 

[AcidicDreams 10+ year member]

good info thanks. well its not too bad unless I really crank it up and if I set the gain higher. Right now i turned the gain down some to keep it from drawing too much and the lights barely dim now.

Do the bat and the big 3!

 

[helotaxi 5,000+ posts]

Alot depends on the amp as far as power decrease with a voltage drop. An amp with a tightly regulated power supply won't have much of a change at all in output, but an unregulated or loosely regulated supply the difference could be huge.

All car audio amps use a switching power supply to get the desired rail voltage from the 12V input. The voltage can either be a rough multiple of the 12V input in the case of an unregulated amp or be controlled by varying the duty cycle of the switching supply in the case of a tightly regulated amp. The unregulated amp will draw less current with lower voltage and the regulated amp will draw significantly more.

Another reason that you might have dimming problems when you turn up the gain is that you are turning it up to the point of clipping the amp. An amp draws a ton more current at clipping than it normally does and the distortion maynot be audible, especially with subs.

Any way you look at it, you will probably want to do something about your electrical system. The long term solution is to get an alternator big enough to comfortably supply the regular current demands of your system. The first step though is to do the big 3 and see where that gets you. Replace your battery only if it is old.