In this article: We'll review Alpine's iLX-W650 head unit with their KTA-450 amplifier and tell you what we think.

Every once in a while, a design comes along that is so smart, it makes you wonder why nobody did it sooner. That’s definitely one of those cases with this receiver and amp combo from Alpine. On its own, the iLX-W650 is a fantastic head unit that packs features and performance into one of the shallowest 2-Din chassis on the market. Adding the four-channel amplifier to the back provides five times the receiver’s rated power and only increases the depth of the unit to five inches, making it nearly the same depth as a traditional 2-Din unit. This combo is simple, compact, and shockingly affordable. So, why did it take all these years for someone to think of this design?

Alpine iLX-W650 KTA-450 front

iLX-W650 Features

Alpine's iLX-W650 is a 7” mechless digital media receiver with a great-looking touchscreen. The receiver features 16 watts RMS x 4 channels of power at 2 or 4 ohm, which is a respectable number, particularly at the price point Alpine has set (this is without the secondary amplifier). It’s Apple CarPlay and Android Auto-ready, so you know that it’ll be easy to go hands-free while having access to your favorite tunes. Check out our Why You Need Apple CarPlay for more details about Apple Car Play! The receiver runs Google Assistant and Siri perfectly. The W650 has an input for a backup camera and is designed to integrate with factory steering wheel controls via an adapter that’s sold separately.

The touchscreen is definitely one of the nicer looking ones we have seen. The icons are big, bold, and don’t require experience in hieroglyphics to interpret. The features you use the most are right there, so you aren’t caught fumbling around through different screens trying to get a weather report, navigation, or switch from tuner to Bluetooth. Multi-touch gestures make it easy to change the volume, skip a track, or zoom in or out on a navigation map. The graphics are not as flashy as some designs on the market, but the layout of the iLX-W650 is instead clean and sophisticated. When it comes to touchscreen head units, simpler is better in so many ways.

Key Features iLX-W650:

  • Mechless 7” capacitive touchscreen receiver
  • 16 watts x 4 channels RMS at 2 or 4 ohm
  • Ultra-shallow mounting depth less than 3”
  • Apple CarPlay and Android Auto ready
  • Rear camera input
  • Rear USB connection

We also did an in-depth review of the iLX-W650 here.

iLX-W650 screen with apps

Connections to the unit are fairly straight-forward, and if you have installed a modern head unit before the install should be pretty easy. If you are putting this receiver in a modern vehicle, make sure to get the correct adapters and harnesses for your vehicle. Steering wheel control adapters from Scosche or Metra work flawlessly. The unit does require a voltage-sensing connection to the parking brake, which prevents users from accessing certain features and settings while the vehicle is in motion. A bypass adapter is available to eliminate that restriction. As with all Android Auto and Apple Carplay units, video playback is not permissible. A USB port on the back of the chassis is essential to making many features function, as the head unit requires both a USB connection and Bluetooth connection to your phone.

KTA-450 Features

It’s pretty incredible how small amps can be today. The KTA-450 is a Class-D amplifier that is designed to bolt right to the back of the iLX-W650 chassis. The amplifier takes the receiver’s adequate power and pumps it up around five times for one of the loudest, clearest sounding receivers out there. Alpine exclusive Dynamic Peak Power provides a burst of extra thump when needed. Even with the amp on the back, the entire package is roughly the same size as a DVD/ NAV double-DIN receiver. This tiny amp packs a serious punch, so don’t underestimate what you can do with it. Alpine rates the power at 50 watts x four channels at 4 ohms RMS, which is the perfect power level to get the crystal clear, deep, and realistic sound you crave. It’s the perfect complement to the iLX-W650.

What this amp isn’t meant to do is power a subwoofer. It’s really designed for door, dash, or deck speakers, not pumping up a sub (by its own at least). A separate but similar package from Alpine includes a monoblock amp for subwoofers, but you’d still need an external amp to power your other speakers properly. Several people who installed the KTA-450 along with the iLX-W650 have noted that most factory speakers sound tremendously better, so you might want to install the package before upgrading your car’s existing speakers. Getting great sound without spending extra is a serious bonus.

Key Features KTA-450:

  • Class-D Amplifier
  • 45 watts x 4 channels RMS at 4 ohms
  • Bridgeable to 100 watts x 2 channels
  • Includes PowerStack mounting bracket
  • Dynamic Peak Power (DPP)

Installing the iLX-W650 & KTA-450

Without the amp installed, the iLX-W650 is less than three inches deep. That means you can get this head unit into almost any vehicle that can take a double-DIN receiver. With the amp attached, overall depth is around five inches total. That’s still less than many double-DIN units and about the same as a NAV unit. The dimensions make it a piece of cake to install in most vehicles, even ones with limited room for upgrades.

Most installers will need to get a couple of wiring harnesses to connect the package with factory controls. First and foremost, an adapter for steering wheel controls is vital. Crutchfield recommends harness adapters from Scosche which are vehicle specific. An amplifier install harness is also necessary to connect the amp to the receiver and speakers, as well as power and ground. The rear-facing USB means you will have to route the cable somewhere so that it is easily accessible. One of the best ways to handle this is to install a USB plug, then route the USB cable to the new plug. This keeps your install nice and clean and prevents wires hanging all over the dash.

Alpine iLX-W650 Wiring Closeup

How the iLX-W650 & KTA-450 Sound Together

Obviously, if you are contemplating purchasing this package, you want to know how it sounds in real life. Although we haven’t had a chance to review the sound of this unit ourselves yet (we’ll keep you updated if we do!), reviews online can be a quagmire of results -some people are never going to be happy with anything, while others are satisfied with mediocrity. It’s really a challenge to determine how a unit will sound based on other people’s experiences though, and everyone’s setup is different. But what you can count on is much more adequate power for your speakers without a separate amplifier install.

KTA-450 on receiver
With that said, powering up the package results in full, rich, lifelike sound. As with any amp install, getting the gain properly set is key. High- and Low-pass filter settings need to be adjusted correctly. Interference needs to be eliminated. All of these things can be addressed simply by using good-quality components and ensuring solid connections. Most of the people who have experienced problems with the Alpine package identified wiring problems as the cause of lackluster sound quality.
The iLX-W650 and KTA-450 package provides enough power to get clear and loud sound even in a Jeep with no top or doors rolling down the road. In fact, the sound quality is surprisingly excellent considering the middle-of-the-road cost of the package. Apple CarPlay and Android Auto function flawlessly and accessing Siri or Google Assistant is fast and simple. A really nice touch on this particular model is the inclusion of physical buttons along the bottom of the screen. Anyone who has used a touchscreen-only head unit will tell you how quickly you can get frustrated dealing with searching through menus to find a simple feature. Physical buttons put those needs right at your fingertips. All-in-all, the Alpine package is easy to install, easy on the wallet, and easy to live with every day.


Car audio enthusiasts looking to upgrade an older unit or replace a weak factory receiver, but don’t want to spend the time and money throwing in an added amplifier are going to love this package. The combo of a high-quality receiver and an efficient Class-D amp makes for a straightforward installation that provides plenty of power. The extensive features of the head unit make it a snap to play music in whatever format you choose, whether it’s Pandora, Spotify, SiriusXM, or tuner. The package really is a one-stop to get everything you would want for an excellent sounding package at a price that’s hard to believe.