# Installing an Amp



## RZA (Sep 24, 2002)

Hi Guys, Im about to install an amp..aprrox 350-400rms.

I know I need to connect it to the battery, and I will be pruchasing an amp kit with 4ga wire and the fuse..but My question is...how do I connect it to the battery. DO i just stick the wire on the positve lead..run it to the amp..and ground the negative lead of the amp to the chasis of the car??

Any help is appreciated.


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## RZA (Sep 24, 2002)

..aww..no one has installed an amp on the forums?? :sigh:


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## crazijoe (Oct 19, 2004)

Howdy ho.
Yes that is the correct way. I would make sure that the fuse is as close as possible to the power souce (i.e. battery). This way if the wire gets chaffed it will blow the fuse.


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## BUDFAN8 (Apr 11, 2007)

you will also need a remote wire so the amp isnt always on and drain your battery. if you vehicle doesnt have a power antenne use the wire for it on the back of the radio, or you could just run another wire to the amp from a always hot source and put a toggle switch inline to turn it off, but if you forgett to turn it off you will run your battery down.


another thing you might need to consider is putting a farred in line if your amp is going to draw too much power from your battery, witch will cause lights to dim and possibly your ECM to not get the voltage it needs.


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## RZA (Sep 24, 2002)

well if the lights start to dim..then I will do that..but I dont think i will need to. I am only running one sub and amp conected through my stock amp. Thanks for the help guys! Now..the fuse that i will connect after the battery...how do i calculate the size of it. The sub is 400rms max and the amp is ...i think is the same..?


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## qldit (Mar 26, 2007)

G'day RZA, I usually use a 25 or 30 amp fuse in those systems with the fuse as close to the battery as possible, and a decent quality fuseholder.
I usually stcick the amp either under one of the front seats or in the boot behind the rear seat.
They really load the vehicle electrical system down.

Cheers, qldit.


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## RZA (Sep 24, 2002)

ok great! i think i got it! i have one last question.

the amp i have (a pioneer) has 2 fuses..both being 30a.

Now..when i stick the fuse in the wiring (from the battery)..does that mean I have to get one 60a fuse?? or can i just use the 80a that comes with the amp install kits? or use a 30? 

does it make a difference how large or small the fuse is? i know it needs to be at minimum the same size as the one on the amp.

thnx again.


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## qldit (Mar 26, 2007)

G'day RZA, no if the fuses are in series, it just gives better protection for the wiring and the amplifier in case of any problem.

So the amperage remains somewhere below 30 Amps, usually there is a 50% at least safety figure, the current that amplifier actually draws is probably only in the area of 15 to 20 amps.

Having extra fuses in that circuit is a better safety idea anyway.

Make sure you use decent connectors and solder the wire (as well as crimp it) in the one you will be using at the + battery terminal otherwise it will quickly corrode inside the terminal you use and give problems. 

I am surprised you have an eighty amp fuse there, is that the one intended for placing at the battery connection?
If so it is for wiring protection so use that one nearest the battery.

Is it a case of a 30 amp fuse being in both the earth and the power leads?

What is the model number if that amp, I will see if I can check the specs on it?

Cheers, qldit.


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## RZA (Sep 24, 2002)

QLDIT, thnx so much for all the help

The amp specs are found here

As you can see in the pic I attached, the amp has 2 green fuses both rated 30a.

As for the 80a fuse I mentioned earlier...it is supplied with the amp install kit (which includes, speaker wires, the power + ground cables, grommet, etc. etc)

Each amp kit comes with a diff fuse. The one I was looking at comes with an 80a fuse and can be used for system up 1400watts. There are kits that come with 50a fuses, 60, 125, etc. 

And yes, that would be the fuse closest to the battery terminal. My question was, since the amp has 2 fuses...does that mean the fuse that I use closest to the battery should be the same amperage as the ones in the amp? Is it ok to go over? 

I also attached a snip from the manual showing how they want me to connect the amp. It had me confused becuase in the diagram it shows that i use two 30a fuses at the battery terminal.


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## qldit (Mar 26, 2007)

G'Day RZA, I can see why that diagram is confusing, if you look at the schematic it only points to one of those wires as being connected to the battery positive terminal, I suspect the other one is the grounding or earthing terminal.
It is quite common to have fuses in both the positive and negative lines to ensure safety for the system.

I suspect you are going to use that amp as a single channel but as you would be aware it has ability for a two channel output with various impedence speakers.

What is the impedence and size of the speaker/s you are going to use and how are you going to arrange the thing? (Single or Dual channel?)
The speaker impedence will show on the speakers as ohms.

You will notice the output wattage is different dependent on the speaker config and their impedences, and there are several different config abilities.
This is because power transfer is greatest when the load impedence matches the amp design perfectly.

The dual channels can be configged as a single channel and increase it's output, but if you do this use extreme care and follow the directions accurately. You only get one chance to get it right.

If you mount the unit in the boot you will probably find the wiring provided with the unit will not reach the engine bay, so the mounting accessory kit has a larger 80 amp fuse to protect the wiring and ensure good current is available.
If you run the heavy current cable from the battery use that heavier fuse at the battery or close to it where you can support it sensibly and neatly.
(I nomally sit that fuse about a foot away from the battery and support and dress it neatly then run that power line through the engine firewall and rout it along the trim beneath the doorway inside trim sensibly, then under the rear seat through to the boot area avoiding sharp protrusions etc.)
Be extra careful drilling through the firewall if you need to, there are often unused places or suitable available places with blank grommets that avoid the need for drilling or you can follow other through harnesses or aircon pass-throughs if you use any of these ensure you suitably seal them to prevent engine fume entry to the cab. 
Check the rear of the firewall for access and suitabilty, it is easy to drill through something unintentially and really cause problems.

You can actually run that heavy positive cable through to the boot and then use a suitably insulated connecting terminal block or inline connector in that area to connect to the positive cable from the unit. (as though that were the battery)
The earthing wire can easily be made anywhere on the vehicle body frame using a clean scraped area and a small bolt and nut.

I suspect that mounting kit is for remote mounting like this, if the unit were mounted under the dash panel it wouldn't neccessarily be needed.

I would suggest that 80 amp fuse (if used) would be perfectly sufficient provided in that installation, I see no reason to use anything larger. 
It's major function is to protect the wiring in case of a short circuit in the wiring routing to the unit and be a low resistance path for the power.

When a short circuit happens with DC, the wiring would burn along its complete path to the earth point where the short circuit is, so that is a very important fuse and that is the reason for having it suitably near the battery.

Where are you figuring on mounting the amp and speaker/s?

There is often room to mount the amp under one of the bucket seats, but make sure there is plenty of room if you do this, rear passenger foot-room and seat movement is a consideration, so it takes a bit of thought.

Usually there is no room to mount them suitably under the dash panel.

The high power speakers usually are limited to mounting on the panel behind the rear seat, but I have mounted them in the front doors on occasions.
This needs a lot of consideration and needs slimline speakers because of the window movement and door mechanisms constraints and they need water protection if that place is used. 
Door mounting is most often not an option with higher power speakers.

Behind the dash panel is usually not an option either so that kind of makes the rear seat panel the only option in most cases and makes the amp mounting there also best. (horizontally on the underside of that panel)

If you have to cut speaker holes to use the rear seat horizontal panel it can be a real ***** cutting the holes, there is not much vertical room to work, the rear windsceen limits jigsaw and filing work from underneath that panel but it is worthwhile because the boot area acts as if it were a speaker enclosure and gives a good sound. I am assuming the vehicle is a sedan.

I assume you are using the AV lines from the radio for the amp input, and with the amp on/off control wire does it include a switch to turn it off, or are you going to have it operating all the time?? 

With the wiring make sure everything is nicely "loomed" or taped and sensibly secured to avoid hic-cups later on.

To do it properly is a pretty decent task!! LOL!!

Cheers, qldit.


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## qldit (Mar 26, 2007)

G'day again RZA, I missed the question about the two 30 amp fuses, if they are the designed fuses for that unit, which it apears to be the case, do not alter that value, they are protection for the amp unit.

Cheers, qldit.


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## RZA (Sep 24, 2002)

qldit said:


> It is quite common to have fuses in both the positive and negative lines to ensure safety for the system.


I don't think I will install two 30a fuses (one in pos and one in neg lines). I will just use the one fuse at the battery terminal. 





qldit said:


> What is the impedence and size of the speaker/s you are going to use and how are you going to arrange the thing? (Single or Dual channel?)
> The speaker impedence will show on the speakers as ohms.


My car (grand am gt1 4 dr sedan) already has a premium monsoon 8 speaker system along with it's own amp which is found in the left side of the trunk. The way it is designed, there are 2 tweaters, 4 door speakers which carry the highs & mids and 2 rear speakers for the lows. These 2 rear speakers are what produce the bass and they do a relativly good job.

Although many people replace all the speakers for aftermarket ones which can support more powerful amps....I dont intend on doing so becuase i am perfectly satisifed with thier capabilities except that i find the system lacking some bass.

For this reason, I purchased an amp to power the subwoofer that I plan on installing. 

I plan on running the system in mono to power only the subwoofer. What I will be doing is splicing some wires before they connect to the monsoon amp and then run those to my speaker line inputs in the pioneer amp.(these will be the wires carrying the rear L+R speaker frequency)

Then..I will connect my mtx sub to the pioneer amp...and my pioneer amp will be running in mono powering only the sub. I will then turn off all lows from all my speakers which will definetly relieve stress from them and have only the sub pumping out my bass. I can do this through the headunit. This way, the stock speakers will play clearer due to less stress and they can do thier job with the highs.

My pioneer amp will be configured for Low Pass Filter which basically means lows only. 


You may ask me, why don't i just remove the stock monsoon amp all together. The answer is, becuase its a Pain In the ### to get the system back working. They way this system was designed was the door chimes, as well as antitheft system are connected to the monsoon amp. The antitheft can be programmed through the headunit. Also the way the speakers are wired....all the speakers run to the monsoon amp and not the way a typical amp connects seperate speaker imput...but they infact are all merged into one singel harness that plugs into one slot on the monsoon amp. Everything from, power, turn on, speakers, door chimes, antitheft, approx 30 wires. I would have to then rewire all the speakers in the car which is definitely a pain if i wanted to remove the stock amp...let alone purchasing more cables etc etc.

My method, I get to keep the stock setup while adding some nice bass.





qldit said:


> (I nomally sit that fuse about a foot away from the battery and support and dress it neatly then run that power line through the engine firewall and rout it along the trim beneath the doorway inside trim sensibly, then under the rear seat through to the boot area avoiding sharp protrusions etc.)
> Be extra careful drilling through the firewall if you need to, there are often unused places or suitable available places with blank grommets that avoid the need for drilling or you can follow other through harnesses or aircon pass-throughs if you use any of these ensure you suitably seal them to prevent engine fume entry to the cab.


I will be doing the same. I plan on running the positive lead and having a fuse about 1 foot away. There is plenty of room in the firewall to insert the positive lead so there is no need for drilling (thank god!!) and I will run the lead under the carpet through the front drivers side...through the back and into the trunk which is wear I will have my amp. As the amp is rather large, that is the best place to install it. 

As for the positive lead under the hood, I will have it run through a plastic tube along with the fuse to help protect it from rain, snow, dirt, etc.
On the inside of the car, I may do the same to help protect the wire.

Once in the trunk, I will splice a cable from the monsoon harness which will be for the remote turn on for my new amp. This way the amp is only on when I start the car. I will then connect the positive lead to the amp...ground the negative lead and have all my speakers connected obviously before I connect the positive lead. I will ensure all cables are neatly gathered with cable ties, tubing, etc and secured properly and away from any sharp edges as you suggested.




qldit said:


> The earthing wire can easily be made anywhere on the vehicle body frame using a clean scraped area and a small bolt and nut.


I will ground it to the chasis somewhere in the trunk.



As for the monsoon harness, I have a pinout diagram that tells me what each wire does so I should be fine. Also, I have checked on a grandam forum and many have gone through the same installation.


Qldit, everytime you respond, the picture in my head on my setup becomes clearer and clearer. You should defintly be a mod for a car audio section. Thanks very much for your help and support and the time you put in your posts.


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## qldit (Mar 26, 2007)

Good Morning RZA, I would advise against removing those 30 Amp fuses at the unit, the probable reasoning behind using a fuse in both the + and - lines at the amplifier most likely deals with possible current paths that can cause damage.

Most of these amplifiers use a high power output stage (usually complimentry) where the high wattage speakers receive very high currents and have potential (if a problem in that speaker circuit occurred) to cause excessive damage to one area or another of that complimentry circuit, because the speaker output is normally taken using a central kind of potential. 
There is also a possible reverse current protection element in case of a mishap with voltage polaity reversal, so the two fuses idea does make sense.

It is also common for those high power speakers to have the speaker voice coil become detached from the rear of the speaker cone and produce odd effects, so I do appreciate their reason for being there.

You sound like you have everything well in hand there, I might suggest having a switch in the power control line and take it from up front for that amp to be able to switch it off, (this is not the main power line) otherwise rear-seat passengers may get kidney damage!!! LOL!!

By the way, check the amp input level, some of those amps have provision to use a "line level" which is considerably less than a speaker level, although you mention that you are going to splice some rear speaker lines to get your mono input, this may affect your existing system adversely, so if you are going to tap into speaker lines at that level for inputs, you may need to use a resistive isolating idea and consider the line input.
This is simply a level reducing attenuating config and will isolate the two systems. 

By the way, an interesting episode happened that I heard about here where a young chap picked up some people at the airport, they apparently quickly shoved their luggage (including a set of golf clubs) in the boot and got in the car to depart, at this time smoke suddenly filled the car and it had to be towed away.
It seems the fellow had installed an amp and was pretty careless, it apparently had no fuse up-front and the wiring wasn't very well insulated, the golf sticks had created a massive short circuit, so these things definitely need a bit of consideration. LOL!!

That is a pretty flash setup you have there. 

I think that vehicle already has a 100 AMP alternator so things should work out O.K.

You certainly have the clues about what you are doing there.

Thankyou for the compliment, I am an irresponsible, lazy, good for nothing, proffesional, retired bum!! (according to my wife) Definitely not mod material!! LOL!!

Cheers, qldit.


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## crazijoe (Oct 19, 2004)

Normally the size of the fuse in the kit will reflect the amperage the kit supplied wiring can handle. You can use a lower rating fuse in it but I would not go higher than what was placed from the factory.
(if this was mentioned in the previous post, sorry, I didn't have time to read through all of them.)


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## RZA (Sep 24, 2002)

qldit said:


> Good Morning RZA, I would advise against removing those 30 Amp fuses at the unit, the probable reasoning behind using a fuse in both the + and - lines at the amplifier most likely deals with possible current paths that can cause damage.


So you suggest I use a fuse in both the grounding wire and the positive lead coming from the battery. I am totally up for doing that as the more protection the better. I just wasn't aware that a fuse was necessary in the grounding wire as..that's just it..you're grounded and that the ground wire doesn't provide power the way a positive lead does being connected to the battery. But then again, I could be wrong...or unless I misunderstood you. 



qldit said:


> You sound like you have everything well in hand there, I might suggest having a switch in the power control line and take it from up front for that amp to be able to switch it off, (this is not the main power line) otherwise rear-seat passengers may get kidney damage!!! LOL!!


LOL!! I defenitly don't intend on having it that loud, but I like that idea. I was actually thinking of incorporating some sort of control for the amp where I can control the low frequency level coming from the subs. But it seems somewhat to complicated for my limited knowledge. 

If I want to incorporate the power control, is it as simple as a circuit breaker? (maybe i used the wrong word here:4-dontkno ) A device that basically switches power on and off in the circuit controlling the power for the amp?




qldit said:


> By the way, check the amp input level, some of those amps have provision to use a "line level" which is considerably less than a speaker level, although you mention that you are going to splice some rear speaker lines to get your mono input,


Well that is what I meant. I have the line level input on my amp so i will tap into and not splice the wires at the harness.

As crazijoe had mentioned, depending on what power your system is, the amp install kit comes with a diff. fuse. It's up to you to purchase the right kit with the right fuse. I have never seen a kit though, that provides two hook ups for two fuses (being one at the positive terminal and one for the grounding lead)

I may double check with the manufacturer if it voids the warrenty if I don't have it setup the way they described.

And..My appologies in advance if I misunderstood/misread any of your posts guys. Kinda responding in a hurry. (im at work):4-thatsba

p.s hoping to install everything this weekend and I will post a few pics of the system


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## BUDFAN8 (Apr 11, 2007)

on most amps ive owned where the main power and ground attach to it there is a place in the center of them to hook another wire (remote). that is the wire you want your on/off switch. or if you dont mind the amp being on all the time your radio is on run a wire from your power antenne wire on the back of your radio, that way when your radio is on your amp is on radio off amp off no switch needed.


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## RZA (Sep 24, 2002)

No, I will defnitely need an on/off switch otherwise, when the car is off, the amp will stay on and empty out the battery into its stomach.:tongue: then we have a problem when i come to start the car in the morning, and find that it wont turn over cuz the amp emptied the battery dry.

hmmz, i think i got it.
thnx ya'll


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## qldit (Mar 26, 2007)

Good Morning RZA, Yes as BUD says, the remote antenna voltage control at the radio is a good place to pickup that control voltage for the amp, but also having a separate on/off switch in line with the amp "control wire" allows the amp to be switched off with your normal system still functioning.

This could be advantageous if you are parked in "lovers lane" playing "Rachmaminoffs 13th variation on a theme by Puccini" and want a bit of extra operational time! LOL!!
(without running the engine) 

Yes, regarding those 30 amp fuses, (and the one in the grounding line) I would be inclined to leave them, although most of that amp wiring could be substantially trimmed.
I am aware you already have other fuses on the Amp.

Cheers, qldit.


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## RZA (Sep 24, 2002)

OK. i Just finished installing everything

Firstly I should say it was an absolute pain in the (insert profanity here) to get the 4g wire through the firewall..

So..3 bandaids later, I have everything hooked up.

I spliced from the monsoon pinouts for the rear L&R speakers and remote on.
I hooked those up to the amp. The amp has speaker inputs so I used those instead of the LOC.

I hooked the sub up in mono mode. And I grounded the cable to a bolt in the trunk and hooked the power up.

Now...everything works... it plays...But it just doesn't hit hard. The back stock speakers seem to bump more than the sub? What am I missing?

The amp is a pioneer GM5200t. At one channel it should dish out more than enouff to power the sub. (380w for the amp and 400w for the sub (max values for each))

The amp kit i used... I have 4g running from the battery to the amp with an 80a inline fuse. To ground the amp the kit had a 9gauge black cable. 
And for the subs and the speaker inputs, i used 14g wire.

I have the amp set to low pass only, makes no differene when i switch it to all frequencies. Any ideas?


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## qldit (Mar 26, 2007)

Good Afternnon RZA, I think a lot of manufacturers purposely sharpen a lot of places in vehicles as a trap for new players! My hands are also battle scarred!

I suspect your speaker input to the amp may be the problem, can you possibly try the amp line inputs. 

Connecting "Y" fashion into operating speaker lines and then making them into a common "Y" again is not a good idea, those speaker lines feed from a complimentry type amplifier and should not be commonly connected unless there is an isolating system. 

If you can pick up a line out from the radio they should already be isolated and can be spliced without problem.

Is there a line-out cabling set in your kit? (they should be shielded wiring)

Cheers, qldit.


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## crazijoe (Oct 19, 2004)

Did you check the gain on the amp? Normally amps will have a control that is recessed (you have to use a small screw driver to adjust it).


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## BUDFAN8 (Apr 11, 2007)

also make sure your wires going to the sub are not crossed. ive seen people put the + with the - and it will work but not be loud.


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## RZA (Sep 24, 2002)

qldit said:


> I suspect your speaker input to the amp may be the problem, can you possibly try the amp line inputs.


I did use the amp line inputs.




> Did you check the gain on the amp? Normally amps will have a control that is recessed (you have to use a small screw driver to adjust it).


That seemed to be it.



> also make sure your wires going to the sub are not crossed. ive seen people put the + with the - and it will work but not be loud.


Will double check on that.


I turned the gain up this morning before going to work. It seemed to be working but I can tell that it is not ground properly becuase it cuts every time i go over a bump in the road.. so I guess that solves it.

I have the sub turned towards the backseat so at times I could feel my seat rumbling with the bass.

Does it matter which way the sub is positioned in terms of sound quality?

After hooking it up to the stock hu... i realised that i want more control over the bass other than just turning it up and down from the HU.

I will install my after market head unit sometime this week.

Question. My aftermarket JVC hu has outputs for the sub... now....i assume i can
1.) hook those outputs to the amp inputs and leave the sub connected to the amp outputs...
2.) then just remove the rear speaker outputs that i had orignally connected from the monsoon harness.. Is this right?


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## qldit (Mar 26, 2007)

Good Morning RZA, it sounds like you are on top of it!

That controlled input to the amp sounds a much better idea.

Make sure the amp volume is lowered when you go to try it with the new config, it is quite easy to pop those large speakers.

The sub should be mounted on a reasonably solid mount.
Preferably facing into the cab.

Low frequency sound is not all that directional or affected by furnishings etc.

High frequency sound is very directional and very critical of furnishings.

Cheers, qldit.


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