If you’re a musician or you’re the kind of person that can sense any imperfection in a piece of music, you will surely appreciate a device that sounds just right. Fortunately for you, this amplifier has great sound quality, and for such a small device it’s impressive. It’s a class D amplifier, and amongst the benefits of this type of amp is the fantastic size that comes packed with great efficiency.
It also has reduced weight, and unlike other class D amps, the sound quality is a good one. When building something so small it’s impossible to get everything right, but the manufacturers got this amp right, focusing more on the sound and less on other not-so-important aspects.
Other car amps can be annoying because of the noise level, especially the background noise that can be heard when no music is playing. Alpine has done a great job of minimizing the noise of this device in such situations. When you first plug it in you might expect a mediocre performance, but once you get to actually listen to it you will be impressed.
The brand says that in order to create a good listening experience they wanted to create an unbelievably low noise floor.
No low-pass filter
Despite the fact that the device features a high-pass filter, it would have been better if it also came with a low-pass one as well. In an ideal scenario, you would want to make the woofers only project the sounds that you can clearly hear. This is because when you are using an amplifier in your car, the space is limited and some frequencies need to be cut to make the music sound good.
Of course, because it’s such a small device, it would have been a really difficult task to incorporate this feature as well. It would have probably increased the costs considerably.
Main features explained
Class D amplifier
Over the last years, there has been a trend involving class D audio amplifiers, as they have become a hot topic in the audio industry. It’s a modern technology that has seen massive improvements since its appearance on the market a few years ago. However, there are still many companies that produce such amplifiers and they still leave many things to be desired, but the Alpine ktp-445u is, fortunately, a great model.
When discussing car amplifiers you need to know that they are based on a basic class, or type, or design. There are Class A models, and these have the lowest distortion and the best sound possible, but they do come with a lot of power drainage and they are the most expensive. Then there are the Class B amplifiers, and so on.
The closer the letter is to the beginning of the alphabet the more powerful and better the amplifier is. Until recently the class A/B amps were extremely common because they proved to be cost-effective, well-designed, and they didn’t require that much power. They could also give low distortion and high power levels, so they were a good investment.
However, many of these amps turn the electrical power into heat, instead of power to drive the speakers. The class D amplifier is newer, and although not as powerful in some cases, it is a more efficient device. These amps work by chopping up or modulating the audio signal and switching the transistors used in the process in a really quick manner.
As a result, the power efficiency is increased and there isn’t much heat produced in the process. While class A/B amplifiers have a maximum efficiency of 65%, class D amps come with around 90% efficiency. This results in no need for a huge and bulky body.
If you have been purchasing car amplifiers in recent years you might have noticed that there are many models that really don’t rise up to standards. Some brands are no longer selling their own products but they just import and rebrand designs that come from other countries. Many class D amplifiers suffer from this problem, and most of them share the same internal components with mediocre performance while only the exterior design varies a bit from a brand to another.
For business purposes only, over the years, low-end brands that were doing a good independent job have been purchased by large companies with the only purpose of gaining more customers, and not for the quality. The result is a market flooded with products that don’t meet the norm.
In some class D amplifiers, the design and sound quality are really poor. The noise levels can be unacceptable and once you get these amps disassembled you see what they are really made of. Of course, when building devices that are so small you need to cut the corners somewhere and some shortcuts need to be taken.
It’s, however, a fortunate case where these shortcuts don’t involve reducing the performance and sound quality. Fortunately, Alpine knew what to focus on when building the ktp-445u model and they tried to give the best performance without compromising too much on anything.
Relying more and more on their excellent engineering resources, Alpine managed to construct a different device in the form of the ktp-445u model. It’s a fresh and original design and it represents the trademark innovation and quality coming out of this company. Unlike other brands, Alpine doesn’t make use of misleading marketing and it doesn’t show false power ratings or sound quality specifications. Their ratings are honest and represent trustful work.
Features and connectivity
A device like this needs to offer you the possibility to change its settings as you wish. A bunch of comprehensive features will always feel good. You might expect this small amplifier to be a plain one, with no features whatsoever, but it will surprise you. The little machine includes several functions often found on more expensive models.
First of all, you have the high-pass filters that are optional, and you can select the frequencies used in the filter, from 60 to 80, and then to 120Hz. You should be able to cut off bass frequencies that distort the sound in your car. Doing a great job when it comes to design, Alpine made sure that the amp can work well when coupled with aftermarket head units using the RCA inputs or speaker-level inputs.
As a result, even if you have a factory-installed stereo system in your vehicle, the device is still capable of giving you more power and a better sound. It’s a device that you will find easy to install as it comes with included color-coded wiring harnesses. You just need to read the instructions before proceeding to the task.
If you plan on adding an aftermarket amplifier to a factory system make sure that you connect the speaker-level outputs, and also get some small-gauge wires for the speaker as you will need to reach the lengths needed to get to the speaker. Being able to connect to a factory-installed stereo system is a huge plus that this amplifier has.
At the bottom of the amplifier, you can find switches for audio controls in case you want to adjust the speaker level inputs or to change the crossover functions. The amp is capable of providing a signal for all 4 outputs even if you are using a 2-channel input for 4 speakers.
Design and installation
Because this is a class D amplifier, one of the most important aspects is the site it has. It’s a very compact device measuring 7 by 1.5 by 2.5 inches, which is a lot smaller than most comparable amplifiers. As a result, it’s a great amplifier if you are looking to install it under a seat, or any other small space you can think of.
Other such devices are 4 times bigger compared to this one, and amongst the advantages of its small size is the fact that you can place it in unheard spots. Inside the dashboard, for example, is a great way to hide this little thing in today’s vehicles. Besides or behind the current stereo is a good idea, but you need to make sure the wiring is properly isolated.
Years ago amplifiers required plenty of fiddling, or a ton of money to hide them. This usually caused people to abandon such projects and to just stick their amplifiers in plain sight. In case you want to install this on a boat, you won’t have to worry about it being ruined by the waves. Of course, you will still need to protect its circuitry against corrosion and exposure to saltwater and air, as it’s not marine rated.
However, given that it’s so small you can have an easier time protecting it, and you can mount it fast with the help of the included zip ties. You can mount it permanently using the self-tapping screws and included brackets.
Given how lightweight this amplifier is you could stick it to the spot you want using double-sided adhesive tape or Velcro depending on your preferences. Being so efficient and needing little electrical current, this amp will not require a heavy-gauge installation kit. A 12V battery will suffice.