Kicker 47KEY2004 Key 4-Channel DSP Smart Amplifier, 4x50W

I really couldn't have believed one item could make such an enormous difference in the sound quality of my 2022 Toyota Camry. I had already changed the four door speakers to Kickers. With the factory deck, there was basically no difference. Once this was added, it sounded close to the quality of my Subaru with a HK premium system less the subwoofer. The auto tuned system works incredibly. It sounds generally so good, I may leave the subwoofer out and reclaim my trunk. It just sounds so great. What a fantastic item. I ended up placing it in my glove box because I couldn't find another good spot for it, but I don't use the glovebox anyway. I did get the wiring harness designed for this and my car off Crutchfield. That was far cleaner as I didn't need to cut the factory harness

This DSP and amp is amazing! It gives a huge new dimension to your music. It's pretty small, and it's light, so it can fit in a lot of locations. It's very powerful. You won't need another more powerful amp on the side as well. I can only turn up my volume about 1/3 of the way before it gets unsafe (90dB) to listen to. The color coded wires are helpful and easy to follow.

What an exceptional little amp. The sound quality is phenomenal, the clarity is fantastic! I combined this with Kicker KS series 6x9 components up front and 6.5 coaxial speakers in the rear of my 2019 F150 XLT. I wish I had done this years ago. Only small crux is I ended up needing to run a remote turn on wire as the auto turn on wasn't functioning properly in my truck. One wire and a lot of rerunning wire and it started up with zero issues. I really hope that Kicker expands the Key technology further in the future. It's now a proven concept that can match the performance of most DSP setups but adds the value of being DIY friendly for those of us who prefer to install our own equipment or cannot afford a full DSP setup and the associated installation and tuning costs and or headaches. I'd love to see Kicker offer a higher watt version of this amp. If and when they do, I'll be seriously considering an upgrade. Not to say that this isn't powerful though, I honestly can't crank it all the way up because it's too loud. I love being able to say that! Also it makes all kinds of music better. It truly doesn't matter what you listen to, you will hear instrumentation and vocals that you have never noticed before while listening to your all time favorite songs.

Compact, high quality sound

This little amp is it. It works, does the job for daily car, and I think its well for daily driver. The amp is small, very compact and it serves the purpose that it can hide almost anywhere. The auto tuning function is actually working and the good thing about it is that you only gotta do it once.

Big improvement over stock in 2025 Ford F150. Very clear at higher volume. With upgraded speakers, the system has vastly improved over the factory non B&O system.

This is a compact amplifier with great sound stage. I installed this in a 2025 Kia K5 GT. The amp cleared up the sound in my door speakers so I can actually hear the words at a decent volume. I also replaced my stock door speakers with a set of Rockford Fosgate speakers. Great buy.

Great added to a 24 Colorado. Plenty of power for my small truck. Added a NVX shallow sub to fill out the bass. Running the kicker as a front stage.

I used this product to augment an old Mercedes’ 1970’s Becker stereo. I like my old stock head unit because it’s stylish, matches the old classic car and was quality back in its day. Today though… it’s poor sound quality. Ancient paper cone speakers, 4inch in front, 5inch in rear. I inserted the kicker key 200.4 into the system to work it’s electronic magic trickery. Once installed, I used the self-tuning system with the supplied microphone. The results are staggering. Somehow my ancient tiny speakers have acceptably good clarity and even acceptable levels of bass. They are all matched in volume, and the sound stage sounds like it’s right between my ears when sat in drivers seat. Superb product for lifting an worn out old stock system into the present day. Impressed with kicker yet again. Have ordered a set of their entry level speakers now as a follow up from these excellent results. Just a word of warning though… in old cars with earthed negative returns on the speakers, you will need to wire both negative and positive from/to the speakers and cannot earth the speaker inputs to ground. Because It’s a class D amp. (Same with any class D amps, not just kicker). Enjoy. There is also just a whisper of white noise from the amp when powered up, but no music playing. This needs to be improved for future models Kicker!

When it arrived it was smaller than I expected which made installing it behind the dash on the passenger side possible (2021 Corolla) I installed this after installing some Focal speakers and the improvement in the sound is great after the auto calibration!

Excellent ampli avec dps et 50watts x4 fonctionne très bien dans mon chevrolet bolt ev 2023.

Sí cambia bastante el sonido, un poco “alto” en los agudos para mi gusto, pero suena mucho mejor que el estéreo original sin él. Bajando los test tones es bien fácil de configurar

Installed this in my 1936 ford coupe. I had to do a little bit of wiring as I was replacing a different AMP. Works good and I have not done the auto configure yet waiting for warmer weather.