Tips For Safe Amplifier Installation

First, be sure that you have turned your radio off and that your ignition key is also off. Never connect or disconnect the power lead, the ground lead, or any speaker leads with the amp turned on, otherwise you may zap it.

Make sure that the first wire you hookup is the ground wire. You might mount your amp to the car at this point. Make it sturdy. You don't want a 15 pound amp to hit you in the back of the head in a collision or have it rolling around in the trunk with all those wires dangling from it.

If you have an amp that uses a 30 amp fuse then you will use a 10 gauge stranded wire for your main power and ground wires. {For a 20 amp fuse, then use a 12 gauge wire. For a 50 amp fuse, use 8 gauge wire.} Be sure that there is a fuse at the battery and another at the amp. Some amps have this second fuse built in. Now is the time to pull the fuse at the battery end of the wire. The size of your wire is the determining factor as to the size of the fuse at the battery. The fuse at the battery will not be installed until all of the other wiring is finished, including the speaker wires. The fuse at the battery will protect your car should your main wire ever get a bad place on it and get welded to the chassis and set your car on fire. The fuse at the amp will protect the amp from extensive damage if you have a problem, like a blown output transistor.

Your ground wire should be only 18 inches or less long. Be sure that you attach your ground wire to the chassis so that the bolt does not cut the wire. Remember, you are trying to get 30 amps or more to flow through this connection. Don't use just a small sheet metal screw that pierces the thin metal of the trunk. This may not be able to handle the current your amp requires. If you are running more than one amp, I recommend that you use a separate ground point for each one. Though not critical, it is the better way to do it. In some installations you may encounter a problem by having two or more amps grounded to the same point.

Be sure to check the connection from your battery negative to chassis ground. Sometimes you will need to beef up the wire size to handle the extra current you will be returning through it from your amp. This connection must be at least as big as the wire that you are using to ground the amp. One size larger would be even better. Remember, your ground is a much more important feed wire than your main hot wire and the most often under rated.

Try not to have any splices in your ground or main hot wire. This will insure that there is no restriction of the flow of current to and from your amp.

The trigger wire on your amp will come from the "electric antenna" wire on your car stereo. This wire can be rather small because it doesn't carry much current. In order to keep it from being too fragile and susceptible to damage, you might consider a 16 or 18 gauge wire.

Be sure to use shielded wire for the sound-carrying wires coming from your radio to the amp. This will help to eliminate ignition noise. This wire will have RCA connectors at each end.

Please see my page with the speaker wiring drawings to be sure that you are not loading your amp with more than 4 ohm load. Some manufacturers say that you can drive a 2 ohm load, but I feel better with nothing more than a 4 ohm load. It is true that you can get more power from your amp with a 2 ohm load, but this is because you are causing your amp to work harder. A four ohm load will leave you with some power "headroom" and will probably let you run longer without a blown output stage or power supply. When running bridged, note that you will be sharing the speaker load between two amp channels and so you will use an 8 ohm load to achieve a 4 ohm load on each output channel. Otherwise, if you use a 4 ohm load while bridged then each amp channel will be driving a 2 ohm load which is a heavy load. Unless you are driving a boatload of speakers with a 1000 watt amp then the best thing to use for speaker wires is 16 gauge lamp cord like you can buy by the foot down at your local Wal-Mart, Radio Shack or hardware store. This has big enough conductors and a little bit extra insulation to protect it from being pinched or getting worn through. There is no need to use monster speaker wire unless you are doing it to look cool. It has been shown that large wire will actually cause you to lose some of your high frequency response.

If you are running a particularly large amp, then you should consider using a booster capacitor or bank of booster caps in your trunk to give you that extra shot of 12 volts when you most need it. This is assuming that you have already sized your main power wire for this huge amp you are driving. (maybe 6 gauge or larger wire). If you are driving a trunk load of amps then this may apply to you also.

It goes without saying that you must not cover your amp. It must be able to circulate air around its heat sink fins in order to cool efficiently. Also, a rule of thumb once your amp is up and running is that you should be able to stand with your hand on any part of your amp all day long and it not get so hot that you would have to remove your hand. It is true that silicon transistors can handle much hotter temperatures than this, but over the long term it will probably shorten the life of your amp. Heat is not your amp's friend.

Now you are ready to set the levels on your amp. This is the part that most people fail to do correctly. I've seen many an amp come into my shop with the gain controls set to max. Try this instead. With the amp and radio off, turn the amp gain controls to minimum. Now go back to your car radio, turn it on and set the radio volume control to about one half to two thirds volume. Assuming that you are not now so loud that it is blowing your speakers out, go back to the amp and set your gain controls on it to the sound level that is about the maximum you would normally listen to. Now run back to your radio and turn the volume down because it is probably real loud right now. You should never have to change the gain setting on your amp from this setting. It will give you the least distortion and will also give you a range of adjustment on you radio volume knob that doesn't cause your amp to reach maximum loudness when you have only turned your radio knob a tenth of a turn. This is a tricky thing to do on a bumpy road.

	First, be sure that you have turned your radio off and that your ignition key is also off. Never connect or disconnect the power lead, the ground lead, or any speaker leads with the amp turned on, otherwise you may zap it.
	Make sure that the first wire you hookup is the ground wire. You might mount your amp to the car at this point. Make it sturdy. You don't want a 15 pound amp to hit you in the back of the head in a collision or have it rolling around in the trunk with all those wires dangling from it.
	If you have an amp that uses a 30 amp fuse then you will use a 10 gauge stranded wire for your main power and ground wires. {For a 20 amp fuse, then use a 12 gauge wire. For a 50 amp fuse, use 8 gauge wire.} Be sure that there is a fuse at the battery and another at the amp. Some amps have this second fuse built in. Now is the time to pull the fuse at the battery end of the wire. The size of your wire is the determining factor as to the size of the fuse at the battery. The fuse at the battery will not be installed until all of the other wiring is finished, including the speaker wires. The fuse at the battery will protect your car should your main wire ever get a bad place on it and get welded to the chassis and set your car on fire. The fuse at the amp will protect the amp from extensive damage if you have a problem, like a blown output transistor.
	Your ground wire should be only 18 inches or less long. Be sure that you attach your ground wire to the chassis so that the bolt does not cut the wire. Remember, you are trying to get 30 amps or more to flow through this connection. Don't use just a small sheet metal screw that pierces the thin metal of the trunk. This may not be able to handle the current your amp requires. If you are running more than one amp, I recommend that you use a separate ground point for each one. Though not critical, it is the better way to do it. In some installations you may encounter a problem by having two or more amps grounded to the same point.
	Be sure to check the connection from your battery negative to chassis ground. Sometimes you will need to beef up the wire size to handle the extra current you will be returning through it from your amp. This connection must be at least as big as the wire that you are using to ground the amp. One size larger would be even better. Remember, your ground is a much more important feed wire than your main hot wire and the most often under rated.
	Try not to have any splices in your ground or main hot wire. This will insure that there is no restriction of the flow of current to and from your amp.
	The trigger wire on your amp will come from the "electric antenna" wire on your car stereo. This wire can be rather small because it doesn't carry much current. In order to keep it from being too fragile and susceptible to damage, you might consider a 16 or 18 gauge wire.
	Be sure to use shielded wire for the sound-carrying wires coming from your radio to the amp. This will help to eliminate ignition noise. This wire will have RCA connectors at each end.
	Please see my page with the speaker wiring drawings to be sure that you are not loading your amp with more than 4 ohm load. Some manufacturers say that you can drive a 2 ohm load, but I feel better with nothing more than a 4 ohm load. It is true that you can get more power from your amp with a 2 ohm load, but this is because you are causing your amp to work harder. A four ohm load will leave you with some power "headroom" and will probably let you run longer without a blown output stage or power supply. When running bridged, note that you will be sharing the speaker load between two amp channels and so you will use an 8 ohm load to achieve a 4 ohm load on each output channel. Otherwise, if you use a 4 ohm load while bridged then each amp channel will be driving a 2 ohm load which is a heavy load. Unless you are driving a boatload of speakers with a 1000 watt amp then the best thing to use for speaker wires is 16 gauge lamp cord like you can buy by the foot down at your local Wal-Mart, Radio Shack or hardware store. This has big enough conductors and a little bit extra insulation to protect it from being pinched or getting worn through. There is no need to use monster speaker wire unless you are doing it to look cool. It has been shown that large wire will actually cause you to lose some of your high frequency response.
	If you are running a particularly large amp, then you should consider using a booster capacitor or bank of booster caps in your trunk to give you that extra shot of 12 volts when you most need it. This is assuming that you have already sized your main power wire for this huge amp you are driving. (maybe 6 gauge or larger wire). If you are driving a trunk load of amps then this may apply to you also.
	It goes without saying that you must not cover your amp. It must be able to circulate air around its heat sink fins in order to cool efficiently. Also, a rule of thumb once your amp is up and running is that you should be able to stand with your hand on any part of your amp all day long and it not get so hot that you would have to remove your hand. It is true that silicon transistors can handle much hotter temperatures than this, but over the long term it will probably shorten the life of your amp. Heat is not your amp's friend.
	Now you are ready to set the levels on your amp. This is the part that most people fail to do correctly. I've seen many an amp come into my shop with the gain controls set to max. Try this instead. With the amp and radio off, turn the amp gain controls to minimum. Now go back to your car radio, turn it on and set the radio volume control to about one half to two thirds volume. Assuming that you are not now so loud that it is blowing your speakers out, go back to the amp and set your gain controls on it to the sound level that is about the maximum you would normally listen to. Now run back to your radio and turn the volume down because it is probably real loud right now. You should never have to change the gain setting on your amp from this setting. It will give you the least distortion and will also give you a range of adjustment on you radio volume knob that doesn't cause your amp to reach maximum loudness when you have only turned your radio knob a tenth of a turn. This is a tricky thing to do on a bumpy road.