Alpine KTP-445U Amplifier Review

Alpine KTP-445U amplifier is an easy to install device that will not disappoint when it comes to its maximum power. This is a class D bridgeable amp with 4 channels. The amp produces around 30 and 45 RMS depending on the power of your battery and stereo. It is surprising how a small amp can produce not just loud but clear sound as well.

The KTP-445U is capable of intensifying the head unit power output of both factory and aftermarket receivers. As a result, there is a 150 percent power increase above the original power from the built-in amplifier found in the head unit.

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Flexible and Easy to Follow Installation Procedures

The compact size of this amplifier allows it to be installed in small spaces where most amplifiers won’t fit. It only measures 7-7/8 inches in width x 1-1/2 inches in height x 2-9/16 inches in diameter. The flexible wires add to the amps space saving feature.

The package you will receive containing the amp will include everything you need for the installation like the standard harness. Power wirings and other necessary things like the wire ties, mounting screws, and metal brackets are also included. With all these gears installation will not be a problem.

Compact Package with Top of the Line Features and Specs

You can play around with the wirings of the amp to get your desired outcome. For instance, the input RCA connection can be cut off and use on the radio as a bare speaker wire. By doing this, it creates a high-level input option allowing you to tap into the factory setting lines for a signal flow.

Alpine KTP-445U also has a built in high pass filter and high passive crossover. The high pass filter gives you control over the frequencies that flows through full range speakers. While the passive crossover lets you take a single input signal to produce a number of output signals with varying frequency bands.

Alpine KTP-445U Features and Specifications

  • 4 Channel Class D amplifier ideal for all in-dash receivers (factory and aftermarket)
  • Total RMS power output of 180 watts
  • RMS power rating: 45 watts x 4 channels @ 4 Ohms, 45 watts x 4 channels @ 2 Ohms, 90 watts x 2 channels (bridged) @ 4 Ohms
  • Fast and easy installation process
  • Measurement of 7-7/8 inches width, 1-1/2 inches height, 2-9/16 inches diameter
  • Increase output of head unit minus installation of amp it or full-size amp

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Alpine KTP-445U Reviews

An editor rating of 10/10 is due to the Alpine KTP-445U amplifier because it delivers according to audio enthusiasts’ standards. All mentioned features are truly incorporated in this device including its energy efficiency.

One customer was very happy with his purchase because according to him this amp is not something that will piss his neighbors because it’s not too loud. It’s just a small amp that has the ability to double or triple the power output of an existing unit. He claims that his amp has been extremely efficient. What he loves most about this that he can mount it anywhere because of its small size.

A different customer said that he is hands down with this amp because aside from its performance it was also very easy to install. He was very glad that his package came with factory wires and all the other things needed for the installation. Hence, he saved on time and money in setting up the amp.

Things to Improve

A minor setback for this amp is that it does not sound as clean when switched to higher frequencies. This is because the KTP-445U is a class D amp which means that high-frequency production is not that impressive. This is true for all class D amps. To solve this issue it is recommended to use low pass filter with the unit.

Even with this issue, the amp still continues to capture the attention of many audio enthusiasts. Even novice appreciates its design because it doesn’t require a lot during installation and it fits even in a small space. The configurable inputs, signal to noise ratio, dependent filters for rear and front inputs are just a few of the features that you will love with this amp.


Start pumping up your car audio with Alpine KTP-445U amplifier. This device may look small but it will definitely add a punch to your current sound system. With its RMS of 45 watts x 4 channels @ 4 Ohms, you will certainly get an increase power output with your current head unit. No more chaotic moments because this amp will give you clean and loud sounds anytime.

Don’t worry if you have limited space because this compact amplifier can be installed even in a confined place. Overall, you get superb features in one small amp with Alpine KTP-445U.

To find out about other reliable amps, visit top amplifier reviews here.

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