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Video: How to install the Alpine KTP-445U Power Pack

Installation and use tips for Alpine's compact car amplifier

Alpine's KTP-445 Power Pack is a car amplifier that fits where other amps can't. It's designed to fit behind the radio in most dashes, and connects in-line between the radio and your factory speaker wiring, so you won't need to run new wire to your speakers from some remote location. In some cars, you may not even need to run power to the battery. It provides a robust 45 watts x 4, and with its simplified installation it's a great choice for an instant upgrade in sound.

Read video transcript

Hey this is JR, training manager here at Crutchfield, and I'm here today to talk to you about the Alpine power pack. It's a compact 4-channel amplifier designed to be small enough to fit into some sort of nook or cranny inside the dash of most cars. Many amplifiers are so large you have to put them under a seat, or in your trunk. The thought here was that you would probably be able to find a place to put it back behind the radio in your dash, and they've also designed it to be fairly easy to install in that location, so we wanted to talk to you today about how we're going to get music into an Alpine power pack, and how we're gonna get it powered up from your battery.

How to connect the power and ground

Let's talk power first. If the fuse that protects the radio, whether it's your factory radio or you've replaced it, is 15 amps or higher, there's actually enough power on that circuit to drive this amplifier. If the fuse is any smaller than that, like say a 10 amp or a 7.5 amp fuse, that's not quite enough power, and you'll need to run a separate power wire to the battery to install one of these amplifiers.

But let's talk about best-case scenario for a second. If that amp, if that fuse is 15 amps or higher, the one that protects your radio, you'll simply be able to tap into the power wire and the ground wire that feed your factory radio, so all the power and ground connections are done right there in the dash behind the radio. If you do have to run a power wire to the battery, that does mean running a wire from the amplifier in the dash, through your firewall to the positive terminal on your battery, and running a separate ground cable to a good grounding spot in your car. If you need any help on that we've got articles about how to install an amplifier, because that's kind of like installing a typical amplifier.

How to make the audio connections

So let's now talk about how to get music into the amplifier. There's a couple ways. It's really designed to be used with any stereo, so if you have an aftermarket radio you'll be able to simply run 4 channels of RCA cables from the outputs of your stereo to the inputs of the amplifier to get the music from your radio into the amplifier. That's called low-level or line-level signal.

If you are planning to use this with a factory radio, what you're going to do is take the speaker wires in the dash that are coming out of the back of the factory radio, and you're going to cut them. Leave yourself enough space on both sides of where you cut, and when you're going to use the speaker level outputs you simply cut the RCA connectors off of the input harness included with the Alpine power pack, revealing two speaker wires, positive and negative, which you'll put in line with your factory speaker wire coming out of the back of the radio.

The output side of the Alpine harness is speaker wire that goes also inline with the wires going from your radio out to all of your speakers, so you'll be able to utilize the factory wiring in your car. You won't need to run new speaker wires out to all of your speakers. Again, the idea is to be able to install this in the dash with minimal wiring, to put the amplifier in line with the radio and your speakers.

So the Alpine power pack is compatible with aftermarket radios and factory radios. An exception to that rule would be if your factory system has a separate amplifier, sometimes they're located under the seat or behind the glovebox, somewhere else in the car, power packs really aren't compatible with factory amplified systems.

The input harness has a blue wire on it which is used to tell this amplifier when to turn on and when to turn off, and that's important to use when you're using this with an aftermarket radio. In fact, aftermarket radios have a blue wire, so that's what you'll connect this blue wire to. If you're using this with a factory radio, high-level inputs, the amplifier can actually sense the music, meaning it knows to come on when you start playing music, and it knows to turn off when you're not playing music.

Universal fit vs. Alpine-specific

There's also one other variation on this. This is the 445U, Universal. Alpine also makes the 445A. A for Alpine. if you plan to use an Alpine stereo in your dash, you might have an even easier time connecting the 445A model because it includes a harness that will plug directly into the radio, making the speaker-level connection as easy as possible.

So that's the Alpine power pack, the 445A and the 445U compact amplifiers designed to fit in your dash, so you don't have to put them under your seat or in your trunk. In many cars you won't have to run power wire all the way to the battery, making them significantly easier to install than most amplifiers. And if you want some more juice, it's a pretty easy solution. Give us a call, chat with us online, send us an email, we'll be able to help you install one of these in your car to get you even more sound.

  • Jordan

    Posted on 8/19/2023

    I have a question regarding the fuse that you guys are talking about. Am I looking at the fuse in the fuse box or the fuse in the back of my stereo. The fuse in the box for my car is 25amp but the fuse in the back of my aftermarket stereo is a 10amp. Which one am I supposed to look at in terms of whether or not I need to wire the amp to the battery or not.

    Commenter image

    Buck Pomerantz from Crutchfield

    on 8/21/2023

    Jordan, JR's referring to the car's fusebox fuse that's responsible for the radio's power. There may be other devices on the circuit - that's why it's a different value than the one on the radio.
  • Thomas from Yorktown

    Posted on 6/5/2021

    Did I hear you correct? If I'm using the high level inputs, I don't need the remote wire hooked up?

  • James Law from Houston

    Posted on 4/1/2020

    I have a 1997 Ford F-150 using original radio. (Cassette still works no cd) I have been using a Bluetooth adapter the plugs into my power outlet, for use of pandora through my phone. Will using this affect the amp in any way?

    Commenter image

    Alexander H. from Crutchfield

    on 4/3/2020

    James, unless you're noticing some sort of change in quality, you should be fine. Had one of those trucks myself. I miss it!

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