What amp should i choose?

[1991 Blue danger ranger]

im putting together a sound system for my ranger (1991 supercab) at the moment and I'm having a hard time finding out what kind of an amp i need. ive decided to go for a completely new set of factory sized speakers in each of their locations, plus a 10 inch sub which i will be building a box for so it can sit on a jump seat in the rear of the vehicle. i chose Kicker 51KSC6504 for the front doors and Kicker 51KSC6804 for the rear, and a Kenwood Excelon KFC-XW1041 10" subwoofer. i understand i need a 5 channel amp for what i am trying to achieve, and that it needs to have a 4 ohm internal resistance as this is what both sets of speakers have as well as the sub. also, I'm sure this would draw on the alternator like nobody's business, can i put in a high output one or use a set of capacitors to hold charge for the system when it begins to draw heavily? Thanks!

 

[SenorNoob]

I've never heard of a 5 channel amp, outside of some OEM systems. I'd use a 4 for speakers, and a single for the sub.

 

[lil_Blue_Ford]

How big of an amp do you plan on getting? I’m at nearly 1,000w on my sub amp feeding a pair of Rockford Fosgate 12” P2 subs (amp is a bridged 2-channel then Y-d out to the subs), plus a RF 4-channel amp to feed some RF speakers, that one kicks out something like 150 watts per channel. It’s fed from the stock alternator (believe it’s a 120amp). I ran 1/0 welding cable into the cab then split to 4 gauge to feed the amps. Ground is run the same way, straight from the battery terminals. I also paralleled in a 4 gauge welding cable from the alternator output to the battery with the stock alternator wiring, so I have access to every amp the alternator will put out. It’s unnecessary, originally everything was running off some hacked together 4gauge left by a previous owner. Never had any problems other than the previous owners hack job.

Oh, and capacitors are a hindrance. They take a bit to charge, and once they’re drained, it’s just another draw on the electrical system during long bass lines or heavy use. Also they’re a potential safety problem. You short out the terminals on a charged capacitor and very bad things happen. Better off buying a bigger alternator, but the stock one is adequate for anything reasonable. I usually never turn the volume above a 10, most of the time I’m at 6 or 7.

One of these days I’m going to have to get out my amp meter and take some measurements…

 

[1991 Blue danger ranger]

How big of an amp do you plan on getting? I’m at nearly 1,000w on my sub amp feeding a pair of Rockford Fosgate 12” P2 subs (amp is a bridged 2-channel then Y-d out to the subs), plus a RF 4-channel amp to feed some RF speakers, that one kicks out something like 150 watts per channel. It’s fed from the stock alternator (believe it’s a 120amp). I ran 1/0 welding cable into the cab then split to 4 gauge to feed the amps. Ground is run the same way, straight from the battery terminals. I also paralleled in a 4 gauge welding cable from the alternator output to the battery with the stock alternator wiring, so I have access to every amp the alternator will put out. It’s unnecessary, originally everything was running off some hacked together 4gauge left by a previous owner. Never had any problems other than the previous owners hack job.

Oh, and capacitors are a hindrance. They take a bit to charge, and once they’re drained, it’s just another draw on the electrical system during long bass lines or heavy use. Also they’re a potential safety problem. You short out the terminals on a charged capacitor and very bad things happen. Better off buying a bigger alternator, but the stock one is adequate for anything reasonable. I usually never turn the volume above a 10, most of the time I’m at 6 or 7.

One of these days I’m going to have to get out my amp meter and take some measurements…

thanks for the advice on the capacitor, good to hear and happy to not spend any more money lol. right now I'm looking at 1600 watt amp, i figure if i just go for an overpowered one i can upgrade other things in the future if i want to, and the one I'm looking at isn't too expensive either ( Kenwood KAC-D8105). its 4 ohm output for 4 channels at 75 watts (kicker speakers are 4 ohm @50 watt so matches pretty well) and then 1x 4 ohm @300 watts for the sub. also changed the sub to a Kicker 45L7R102 after some advice from a coworker. I'm pretty confident this will all work but again just here to confirm. thanks again!

 

[lil_Blue_Ford]

So, one thing I should bring up, since I have a tendency to work in real numbers (or as close as I can get with electrical). When I say that my big amp is pushing close to 1,000 watts, that’s the RMS watt number for the amp. Amp manufacturers for a long time have pushed out inflated amp numbers, the peak numbers, and that’s what gets slapped on the outside really big. To get those numbers, the manufacturer often will supercool it while pushing like 16 volts into it and stuff like that. RMS wattage is what the amp can be expected to put out in a normal application. I’m guessing RMS for that amp is the lower numbers you listed there, because 1 @ 300w and 4 @ 75w (300w total) is only 600 watts, not 1,600 watts.

Personally, my preference settled on Rockford Fosgate. They had a real reputation for downrating their stuff big time back in the day. Their amps came with a “birth sheet” that showed that exact amp on a test stand simulating normal vehicle power. I had (until it got stolen) what was sold as an 800 watt RMS amp. The birth sheet showed in normal real world conditions it was pumping out 915 watts.

Back in the day, Sony had a reputation for melting down, Kicker had delaminating problems with subs and speakers (they’ve fixed that problem since to my understanding), RF downrated their stuff, Kenwood was decent but they didn’t produce anything serious, Alpine was pretty solid and on par with RF, JVC was like a budget Kenwood. There really wasn’t much else to choose from. I don’t know if Sony ever resolved their problems.

Anyway, what you’re looking at can be run just fine on 4-gauge with a stock alternator. My preference has been to run welding cable because it’s a fine strand solid copper conductor, flexible and what I use to build battery cables (or if I need to replace/extend a cable on one of my welders). I run power and ground off the battery, eliminates ground problems. Whether you use welding cable (you can buy it from a welding supplier or from like a farm store like Tractor Supply), or just buy wire for an amp; I’d still recommend running the ground back to the battery?

 

[1991 Blue danger ranger]

So, one thing I should bring up, since I have a tendency to work in real numbers (or as close as I can get with electrical). When I say that my big amp is pushing close to 1,000 watts, that’s the RMS watt number for the amp. Amp manufacturers for a long time have pushed out inflated amp numbers, the peak numbers, and that’s what gets slapped on the outside really big. To get those numbers, the manufacturer often will supercool it while pushing like 16 volts into it and stuff like that. RMS wattage is what the amp can be expected to put out in a normal application. I’m guessing RMS for that amp is the lower numbers you listed there, because 1 @ 300w and 4 @ 75w (300w total) is only 600 watts, not 1,600 watts.

Personally, my preference settled on Rockford Fosgate. They had a real reputation for downrating their stuff big time back in the day. Their amps came with a “birth sheet” that showed that exact amp on a test stand simulating normal vehicle power. I had (until it got stolen) what was sold as an 800 watt RMS amp. The birth sheet showed in normal real world conditions it was pumping out 915 watts.

Back in the day, Sony had a reputation for melting down, Kicker had delaminating problems with subs and speakers (they’ve fixed that problem since to my understanding), RF downrated their stuff, Kenwood was decent but they didn’t produce anything serious, Alpine was pretty solid and on par with RF, JVC was like a budget Kenwood. There really wasn’t much else to choose from. I don’t know if Sony ever resolved their problems.

Anyway, what you’re looking at can be run just fine on 4-gauge with a stock alternator. My preference has been to run welding cable because it’s a fine strand solid copper conductor, flexible and what I use to build battery cables (or if I need to replace/extend a cable on one of my welders). I run power and ground off the battery, eliminates ground problems. Whether you use welding cable (you can buy it from a welding supplier or from like a farm store like Tractor Supply), or just buy wire for an amp; I’d still recommend running the ground back to the battery?

Do you attach your ground directly to the battery or just the frame/body really close to it? Also good to know about the amp, it’s got a few modes so I think it can do more than 600, doesn’t really matter since I’m using it at that though lol. Also good to know about the 4 gauge wire and alternator. Thank you so much! Very glad to get advice from someone who actually knows about this stuff.

 

[Broosedamoose]

If you're looking for a decent amp for the money, the PowerBass ASA3 1100.5 amp. I'm running it in my truck powering JBL Stadium 5.25" components up front and 5x7" in the rear with a DVC Alpine Type-R subwoofer. Not a lot of people know about PowerBass but they are actually pretty decent. Won't win you any awards but won't cost you a paycheck either. The SQ is very good and it has a very high ceiling. The only other amp I can speak for that I have is the one in my Explorer and that is the Alpine Status but now you're getting into a lot more money! I also say skip the capacitor.

 

[Broosedamoose]

Do you attach your ground directly to the battery or just the frame/body really close to it? Also good to know about the amp, it’s got a few modes so I think it can do more than 600, doesn’t really matter since I’m using it at that though lol. Also good to know about the 4 gauge wire and alternator. Thank you so much! Very glad to get advice from someone who actually knows about this stuff.

I run mine back to the battery!

 

[superj]

i always ran rockford too. their amps were always under rated. i ran 4 series1 12 inch subs in my 85 f150 extended cab and 4 series1 12 subs in the trunk of my 65 mustang. i cannot remember which amps i had but the amps ran the subs and i had a high powered eq for the mids and highs so i could tune them to sound how i wanted.

man, those 12s would sure se car alarms off at the mall though. put on some 2 live crew or beastie boys and turn the volume up and every car alarm would go off on the first deep bass hit.

you could park in front of 7-11 and shake the shelves too, if you were bored. but the side effects were you could not look in the mirrors since they were also shaking that bad.

my friend, brian, always said he had a hard time breathing when the volume was up and the bass was hard and fast

 

[lil_Blue_Ford]

Do you attach your ground directly to the battery or just the frame/body really close to it? Also good to know about the amp, it’s got a few modes so I think it can do more than 600, doesn’t really matter since I’m using it at that though lol. Also good to know about the 4 gauge wire and alternator. Thank you so much! Very glad to get advice from someone who actually knows about this stuff.

Power gets a fuse within 18” of the battery ideally, wherever it works best. I take the ground straight back to the battery.

You see, the problem is, factory spec, these trucks have one 10 gauge body ground to the battery and one 4-gauge ”frame” ground that either goes straight to the starter or engine block near the starter, or that ground tags the frame somewhere and then to the block or starter. So if you would run the ground to the frame or if the ground straps that go between the body and frame are in good shape, current can find it’s way through the big ground wire. But it’s still a less than ideal pathway for high-current electrical. If you ground to the body and the ground straps between the body and frame are compromised, you’re trying to feed that power back through the 10g body ground at the battery, along with all the other body grounded electrical in the truck. It can cause some wonky electric issues. Best just to cut all that out along with all the rust and corrosion and less-than-perfect contact points a 30+ year old truck will have for the factory ground system. Since there’s no restriction on the power or ground side, the amp will work at full practical potential.

I’ve also had enough ground issues over the years that I’m a firm believer in using Dielectric grease and NoAlox (an electrically conductive paste electricians use on aluminum wire to prevent corrosion, Home Depot sells it in the electrical section and I’m sure a lot of places that sell breaker panels sell it) on connections, even if they’re copper. I also make myself a little 4-gauge jumper to replace that puny 10g body ground on my trucks.