Back in the day power caps were all the rage on audio install. I understand the concept about making sure an amplifier has a good constant power supply etc. But then I seem to remember them being widely regarded as a waste of time.

Anyone know anymore as in good or bad?

I used to have one cost £20 looked cool did nothing tho :-/

That's it isn't it. I had one in an Astra many moons ago, no idea if it actually needed it or if it did anything.

Measure the car voltage with an analog voltmeter while playing a song at your normally maximum volume. If the voltage drops under 13V along with bass peaks, you may need a capacitor.

You'll get better results if you upgrade "the big 3" rather than mess about with power caps.

The big 3 incase anybody was wondering is the earth and power cabled feeding you altenator, battery and the ground to the chassis.

Measure the car voltage with an analog voltmeter while playing a song at your normally maximum volume. If the voltage drops under 13V along with bass peaks, you may need a capacitor.

 

nope, not at all.

 

The only time a "power cap" might be useful in car audio is when smoothing of current is required. Not to help with voltage drop.

 

If you suffer from voltage drop there are a number of options.

 

1. Are you using the correct sized power cable? Too small cable from the battery to amps can cause drop as the current cant get through the cable.

 

2. Battery. If you are getting voltage drop you are draining more current than your alternator can produce so and uprated battery will help as you will have more stored energy to help the alternator.

 

3. Upgrading tb3. This is a term used for upgrading the cables attached to the battery under the bonnet. These include earth cables (battery, engine, alternator) and upgrading alternator positive

 

4. Adding a second or more batteries. If you are running big power then adding multiple batteries increaces your stored energy which you can use.

 

5. Upgrading the alternator. This gives you a larger buffer before your batteries are being used.

 

6. Something people have just started looking into (and I have just fitted) is using Supercaps or ultra caps. I have a bank of 6 3000 farad super caps wired in series to give me 500 farad of energy and a max charge voltage of 16.6v. I gained over 1v when running a full tilt which also meant my amp could put out more power to my sub.

I wrote may need. What I meant (and as you correctly point out), voltage drop is a necessary, but not sufficient condition for concluding that one needs a power cap.