Aftermarket stereo headunit dims

[subru92svx]

I have a aftermarket stereo in my SVX which consists of alpine deck, front alpine component speakers, rear alpine 6x9's, alpine MRD-m1001 amplifier, custom box with two 12" alpine type R subwoofers, Rockford Fosgate 4 gauge amp kit, and 1 farad Rockford Fosgate digital capacitor. I also have a new alternator and a Optima red top battery. The problem that I'm having is when my subwoofers hit hard my alpine headunit dims a little. I bought the 1 farad Rockford Fosgate digital capacitior and installed it after being told by a few people that would fix my problem, but it still dims. I talked to a few stereo shops and after I told them I had already installed a capacitor they were kind of at a loss for what might be causing it. The only other thing I could think of was maybe running a thicker power wire to the deck it self. I was just curious if anyone on here might of had the same problem or have an idea how to fix it?

[Earthworm]

You're stuck with that dimming. 1000W will drain that cap pretty quick. I have almost the same system.

[SubaSteevo]

Originally Posted by Earthworm

You're stuck with that dimming. 1000W will drain that cap pretty quick. I have almost the same system.

+1

I have an 860w amp and I still get some dimming with a 2 farad capacitor.

[subru92svx]

Thanks for the replies. I guess I won't try and mess around with it anymore then.

[Trevor]

Originally Posted by subru92svx

Thanks for the replies. I guess I won't try and mess around with it anymore then.

N.B. It is important that the capacitor is connected to the amplifier with short and adequate cross section conductors and connectors.

[ItsPeteReally]

Let's plug some numbers in.

The energy stored in a capacitor is ½Cv², which, for a one Farad capacitor at 12 volts will be 72 joules.

If your amplifier really does consume 1000 watts, or 1000 joules per second, then, in the best of all possible worlds, the capacitor will keep it going for a whole 72 milliseconds. That’s just about long enough to stop the display flickering on waveform peaks.

The current demand at 1000 watts will be 1000/12 amps, or just a little over 83 amps. So, unless you’ve wired it all up with a similar gauge of wire as used between the car battery and the starter motor, some dimming is going to be inevitable.

[Trevor]

Originally Posted by ItsPeteReally

Let's plug some numbers in.

If your amplifier really does consume 1000 watts,.

[Tim]

A capacitor is more of a bandaid for a broken bone. Your best bet is to upgrade the "big three" wiring and if its still that bad you may want to consider a 2nd battery.

I've found that the amount of power it holds easily discharges way faster than it can recharge so it often doesn't pay to invest in a capacitor.

[Earthworm]

Originally Posted by ItsPeteReally

If your amplifier really does consume 1000 watts

If his amp has similar specs to my Apline M1005 then it's rated at 1000W continuous with a peak of 1800W. Mine came with a sheet showing it was verified at 1072W continuous.

[Trevor]

Originally Posted by Earthworm

If his amp has similar specs to my Apline M1005 then it's rated at 1000W continuous with a peak of 1800W. Mine came with a sheet showing it was verified at 1072W continuous.

You should be aware that manufacturers use various devious methods of measurement in specifying amplifier power output, in order to impress. e.g. music power, peak power, all not a true RMS figure. In order to deliver a true 1072 watts continuously, the unit would draw in excess of 89 amps at 12 volts.

[Earthworm]

I, too, hate when manufacturers quote their power output in PMPO as opposed to RMS. Alpine used to do this but has since switched over. Here's the specs page for my amp:

http://www.alpine-usa.com/en/product...odel=MRD-M1005

Originally Posted by Trevor

You should be aware that manufacturers use various devious methods of measurement in specifying amplifier power output, in order to impress. e.g. music power, peak power, all not a true RMS figure. In order to deliver a true 1072 watts continuously, the unit would draw in excess of 89 amps at 12 volts.

[Trevor]

Originally Posted by Earthworm

I, too, hate when manufacturers quote their power output in PMPO as opposed to RMS. Alpine used to do this but has since switched over. Here's the specs page for my amp:

http://www.alpine-usa.com/en/product...odel=MRD-M1005

Even so they tend to exaggerate by specifying they supply as 14.4 volts into 2 ohms, but one must accept that they must get the best from the figures, in view of what the competition will no doubt put forward. Therefore you can accept them as being fairly honest.

The figures which really annoy, are those which are so often applied in regard to loud speakers.