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Help with amplifier install


RANGermanGuy

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Ok I know this amplifier is way overkill for my situation but it’s what I’ve got. My question is, will I need to upgrade my alternator/battery if I’m only drawing about 400 watts to two front speakers (200 to each one) from that amplifier? My alternator can handle 95 amps. I am wondering if powering the amplifier only using about 400 watts will draw more power than my electrical system can handle. -Thanks
 


Bgunner

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It will be fine in my opinion but if you do notice that the headlights dim when the bass hits it is rectified by using a capacitor. I run a 1000w amp pushing a max of 450w to a single sub and never noticed an issue with my 95A alternator. I did eventually install a capacitor to help save the alternator as I like feeling the base from that 1200W 12" sub.

A capacitor stores a bit of juice so when the amp requires a quick jolt of power it comes from the cap and not directly from the alternator. I run a half ferret cap and it is more than enough for my system. I think I paid around $100 for the cap.

I found that my fire wall had a few rubber plugs in it that I just cut an X in it and fed the wire through and under the driver side rug to behind the seat. Mine being a supercab I ran the wire out from under the back seat plastics for the amp. The RCA jacks I ran under the passenger floor to the rear than over to the amp to help keep the electromagnetic field from interfering with the audio signal.
 
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RonD

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If you have a 95amp alternator that means the Vehicle draws about 40amps with everything on, i.e. engine, fan blower on High, headlights

95amp alternator only produces 95amps when engine RPMs are above 1,800
It produces about 60% of that under 1,000rpms, i.e. at idle
So about 55-60amps at idle
That only gives you about 15amp to spare at idle, unless you shut off blower and headlights, which is not very practical

Audio watts are not the same as electrical watts, but close enough
And audio watt rating is at full volume
40watts in a car will hurt your ears
400watts is actually only twice as loud as 40watts, just FYI
So I doubt you will be running the system anywhere close to 200watts
200watts at 13.5volts is about 15amps
So you should be OK

But you may want to get a 130 or 150amp alternator at some point
People like to brag on the wattage they have, but that's how they sell high watt amps
 

Bgunner

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To know what the amp puts out at realistic listening levels look for the RMS rating for the amp. Example my 1000W amp is rated for 400w RMS unless bridged and at a 2 ohm rating. My 1200W speaker is rated for 550W RMS. My door and rear speakers are a 380W max speaker but the RMS is 80w running off of a 52W per channel head unit that puts out 25w RMS and is deafening in the cab. These are the practical numbers to look at and what you want to match as close as possible.

The max listing for speakers and amps is a 1 shot quick hit of power that is not sustained. If I hooked my amp to my door speakers I'd pop them the first or second time the bass hit at a normal listening level even though they are a 380W speaker for the reasons listed above.


Root mean square

Root mean square or simply RMS watts refers to continuous power handling of a speaker or a subwoofer or how much continuous power an amplifier can output.

As RonD mentioned about 400w being only twice as loud as 40w, decibels are not linear. This means something that is 20db is not half as loud as 40db or even 60db. It has to do with perceived volume levels. I have read a few writeups about it and still don't have a great grasp on it. It is a brain twister wrapped up in in an enigma.
 
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RANGermanGuy

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To know what the amp puts out at realistic listening levels look for the RMS rating for the amp. Example my 1000W amp is rated for 400w RMS unless bridged and at a 2 ohm rating. My 1200W speaker is rated for 550W RMS. My door and rear speakers are a 380W max speaker but the RMS is 80w running off of a 52W per channel head unit that puts out 25w RMS and is deafening in the cab. These are the practical numbers to look at and what you want to match as close as possible.

The max listing for speakers and amps is a 1 shot quick hit of power that is not sustained. If I hooked my amp to my door speakers I'd pop them the first or second time the bass hit at a normal listening level even though they are a 380W speaker for the reasons listed above.


Root mean square

Root mean square or simply RMS watts refers to continuous power handling of a speaker or a subwoofer or how much continuous power an amplifier can output.

As RonD mentioned about 400w being only twice as loud as 40w, decibels are not linear. This means something that is 20db is not half as loud as 40db or even 60db. It has to do with perceived volume levels. I have read a few writeups about it and still don't have a great grasp on it. It is a brain twister wrapped up in in an enigma.
Hey thanks for your help, I am having a better understanding now. I’m pretty new to car audio so it’s nice to have people who know their stuff. Maybe you could answer this question- My head unit is also pretty much putting out the same numbers as yours is but sometimes I feel even when turned all the way up I’m missing out of some sound (even tho it is fairly loud) I feel I can get more out of the speakers. Will using an amp even benefit my two speakers in anyway?
 

RANGermanGuy

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It will be fine in my opinion but if you do notice that the headlights dim when the bass hits it is rectified by using a capacitor. I run a 1000w amp pushing a max of 450w to a single sub and never noticed an issue with my 95A alternator. I did eventually install a capacitor to help save the alternator as I like feeling the base from that 1200W 12" sub.

A capacitor stores a bit of juice so when the amp requires a quick jolt of power it comes from the cap and not directly from the alternator. I run a half ferret cap and it is more than enough for my system. I think I paid around $100 for the cap.

I found that my fire wall had a few rubber plugs in it that I just cut an X in it and fed the wire through and under the driver side rug to behind the seat. Mine being a supercab I ran the wire out from under the back seat plastics for the amp. The RCA jacks I ran under the passenger floor to the rear than over to the amp to help keep the electromagnetic field from interfering with the audio signal.
Awesome! I will probably install without the capacitor but at some point I think I’ll upgrade my alternator so I can possibly install a sub as well. Thanks for the help and knowledge!
 

RANGermanGuy

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If you have a 95amp alternator that means the Vehicle draws about 40amps with everything on, i.e. engine, fan blower on High, headlights

95amp alternator only produces 95amps when engine RPMs are above 1,800
It produces about 60% of that under 1,000rpms, i.e. at idle
So about 55-60amps at idle
That only gives you about 15amp to spare at idle, unless you shut off blower and headlights, which is not very practical

Audio watts are not the same as electrical watts, but close enough
And audio watt rating is at full volume
40watts in a car will hurt your ears
400watts is actually only twice as loud as 40watts, just FYI
So I doubt you will be running the system anywhere close to 200watts
200watts at 13.5volts is about 15amps
So you should be OK

But you may want to get a 130 or 150amp alternator at some point
People like to brag on the wattage they have, but that's how they sell high watt amps
Appreciate your input! I was eventually planning on throwing a sub in there and before I do that I’ll make sure to get a different alternator. For now I don’t think I’d harm anything sticking with my current one, I’m just trying to juice up two little speakers haha. I’ll give it a try and I’ll see if I notice and flickering and I’ll go from that - thanks!
 

RANGermanGuy

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Hey thanks for your help, I am having a better understanding now. I’m pretty new to car audio so it’s nice to have people who know their stuff. Maybe you could answer this question- My head unit is also pretty much putting out the same numbers as yours is but sometimes I feel even when turned all the way up I’m missing out of some sound (even tho it is fairly loud) I feel I can get more out of the speakers. Will using an amp even benefit my two speakers in anyway?
 

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Bgunner

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My credo
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Hey thanks for your help, I am having a better understanding now. I’m pretty new to car audio so it’s nice to have people who know their stuff. Maybe you could answer this question- My head unit is also pretty much putting out the same numbers as yours is but sometimes I feel even when turned all the way up I’m missing out of some sound (even tho it is fairly loud) I feel I can get more out of the speakers. Will using an amp even benefit my two speakers in anyway?
To get missing or reduce over powered tones you would want to install a 7 channel or more equalizer this way you can cut down the over powered tones or raise the missing tones. Most head units only come with a 3 tone equalizer, high, mid and low which miss many of the missing tones at higher volumes.

When you turn the volume up to over 75% it adds in distortion in to the mix and exaggerates missing tones.

If you are running factory speakers then the amp will not help but will surly kill them at some point. What speakers are you running and there RMS? What is the RMS on the amp?
Adding an amp does not boost missing tones but boosts the wattage that it receives from the head unit. This is where the equalizer comes in that is installed between the head unit and the amp.
 
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O No 3.0!

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I wouldn't be hooking that amp to any small speakers. If you do, turn the gain way down & the bass boost off, or you'll blow the speakers. What kind of amp is that? It appears to be 3000 watts rms, not 400.
 

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