Is a capacitor required for low power amp install?

texan_176 · 02-13-2008, 10:54 PM

I might put in a relatively low power amp (4x45 watts RMS) but was wondering about the capacitor. Generally speaking 1 farad is required for each 1000 watts. I'm not even half way to 1000 watts.

Capacitor cost is about $75-100....I'd like to save money if I can.

DenverMR2 · 02-13-2008, 11:57 PM

No it isn't required but you could put one in. Though it would be better to put in a new battery and upgrade your alt first.

texan_176 · 02-14-2008, 01:18 AM

For that low of a wattage?

The headunit puts out 22 watts of RMS so this is basically like running 2 head units at once....power wise if I ran the amp. The alternator should be able to handle that much don't you think?

LoverofMR2s · 02-14-2008, 08:34 PM

From Basic Car Audio Electronics website:

Quote:

Originally Posted by BCAE

Current demand and flow:
If you have an alternator that can produce 120 amps of current (max) and the the total current demand from the electrical accessories (including the battery) is only 20 amps, the alternator will only produce the necessary current (20 amps) to maintain the target voltage (which is determined by the alternator's internal voltage regulator). Remember that the alternator monitors the electrical system's voltage. If the voltage starts to fall below the target voltage (approximately 13.8 volts depending on the alternator's design), the alternator produces more current to keep the voltage up. When the demand for current is low, the full current capacity of the alternator is not used/produced (a 120 amp alternator does not continuously produce 120 amps unless there is a sufficient current draw).

I'd mainly upgrade your grounds from the alt to the chassis as well as the tedious task of running a new fused positive line directly from the alt to the battery (I'd suggest a 4 gauge wire), as well as a new ground from the battery to the chassis..... That'd be the "Big three upgrade" which is what I'd do first before a new battery, alt and if I got one for free a capacitor...

DenverMR2 · 02-20-2008, 01:11 AM

Yeah it should be able to handle it and you shouldn't really need to upgrade until you surpass 750 or so

02-13-2008, 10:54 PM	#1 (permalink)
texan_176 91 NA Hardtop Join Date: Jun 2006 Location: Houston TX Posts: 163 Thanks: 2 Thanked 2 Times in 2 Posts iTrader Rating: (4/100% )	Is a capacitor required for low power amp install? I might put in a relatively low power amp (4x45 watts RMS) but was wondering about the capacitor. Generally speaking 1 farad is required for each 1000 watts. I'm not even half way to 1000 watts. Capacitor cost is about $75-100....I'd like to save money if I can.

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02-13-2008, 11:57 PM	#2 (permalink)
DenverMR2 Mr. Physics Join Date: Aug 2006 Location: Denver, CO Posts: 332 Thanks: 16 Thanked 22 Times in 22 Posts iTrader Rating: (0/0% )	No it isn't required but you could put one in. Though it would be better to put in a new battery and upgrade your alt first.

02-14-2008, 01:18 AM	#3 (permalink)
texan_176 91 NA Hardtop Join Date: Jun 2006 Location: Houston TX Posts: 163 Thanks: 2 Thanked 2 Times in 2 Posts iTrader Rating: (4/100% )	For that low of a wattage? The headunit puts out 22 watts of RMS so this is basically like running 2 head units at once....power wise if I ran the amp. The alternator should be able to handle that much don't you think?

02-20-2008, 01:11 AM	#5 (permalink)
DenverMR2 Mr. Physics Join Date: Aug 2006 Location: Denver, CO Posts: 332 Thanks: 16 Thanked 22 Times in 22 Posts iTrader Rating: (0/0% )	Yeah it should be able to handle it and you shouldn't really need to upgrade until you surpass 750 or so