Voltage problem

[c_james_s 10+ year member]

Hey, I'm having problems getting the 14.4 volts I need to my sub amp. I'm currently getting about 12.6-13 or so depending on how hard the bass hitts. I've got a jbl 600.1 sub amp, 4 gauge power wire, and a 1F cap. I've got the power wire from battery going through a fuse to the cap and than to the amp. the cap and amp are both grounded separately and are solid. I have not upgraded the battery yet nor the alternator, the biggest alternator I could find for my car was 15 amps larger for $300, not worth it to me. any suggestions?

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[Loud3 10+ year member]

What kind of car? How long is the run? How clean are your grounds?

 

[c_james_s 10+ year member]

What kind of car? How long is the run? How clean are your grounds?

my cars a scion xa and I can't have more than 15 feet. I scuffed up the paint where my grounds are but its not 100% clean, will that make that big of a difference? my alt is 85 amps

 

[loopkiller 10+ year member]

If you are staying above 12.5v on heavy bass notes, then that is about all you can expect without a major alt upgrade. Even a big batt is only going to keep you in that same range.

 

[jrwalte 10+ year member]

If you are staying above 12.5v on heavy bass notes, then that is about all you can expect without a major alt upgrade. Even a big batt is only going to keep you in that same range.

Not entirely true. More or bigger batteries will help your voltage say higher, above the battery's resting voltage. Batteries float at the voltage your alt is able to put out (depending on its load/amperage output). If you have enough reserve capacity in that 'floating' range from your batteries then your voltage will not drop as much or as drastically. Now on a long bass note the voltage will still drop, but with more reserve capacity it will drop slower and less.

 

[c_james_s 10+ year member]

thanks for the responses. you guys think its the alternator. if my alternator is rated at 85 amps and the only one bigger I could find was 100 amps for $300 is that going to help?

 

[Enellz 10+ year member]

It isn't worth it. It's just 15 amps. That's a little to nothing. Good but not enough to purchase, you know? I say get some bigger batterie, and call it a day.

 

[c_james_s 10+ year member]

It isn't worth it. It's just 15 amps. That's a little to nothing. Good but not enough to purchase, you know? I say get some bigger batterie, and call it a day.

sounds good, thanks. would getting a bigger amp help or am I maxed out on this electrical system? I'm trying to get around 600 rms too my sub.

 

[king ranch 5,000+ posts]

sounds good, thanks. would getting a bigger amp help or am I maxed out on this electrical system? I'm trying to get around 600 rms too my sub.

loose the cap, and do the big 3 i bet u will pick up a half volt or more from the big 3, and make sure your ground spots are clean of paint and down to the bare metal also test where u have the grounds at you might have your grounds at a bad place and causing voltage loss. and if needed throw a battery in the back or a bigger one upfront but only 600rms thats nothing really

 

[Enellz 10+ year member]

sounds good, thanks. would getting a bigger amp help or am I maxed out on this electrical system? I'm trying to get around 600 rms too my sub.

LOL, thats it? There in no way in hell you will need an alternator for just 600rms. For that much I would just get in optima YT upfront and call it a day. Also ditch the cap, it just adds more strain onto your battery.

 

[c_james_s 10+ year member]

LOL, thats it? There in no way in hell you will need an alternator for just 600rms. For that much I would just get in optima YT upfront and call it a day. Also ditch the cap, it just adds more strain onto your battery.

thanks. I've always been told that a cap helps not the other way around. I'm not doubting you but I would like to understand why.....if you have the time?