Customer Ratings & Reviews

Great

Great amp got it to to get my bass back after changing my speakers in a 05 impala boy did it do the job my jbl gto928 and gto628 scream now, by the way bypass factory amps for best results

Alpine KTP-445?

I just bought this, Maybe I should take it back! My Alpine CDA-105 sounds a little better without the KTP-445 installed. Others may have luck with this little amp but not me. Well i guess it sounds about the same as my CDA-105 hooked up straight to the speakers. It doesn't sound like 45 watts RMS, more like 25W RMS x4!

Alpine KTP-445

First of all, i dont quite hear much of a difference or increase in my sound quality or power. maybe a little, but not much. kind of made me mad that i spent 110 bucks for my CD player not to distort a couple more volume levels. i guess that's why they make 4 channel amps. would not recommend unless you really don't want to put a 4 channel amp together. its kind of hard to fit behind your CD player too with all the wires. but on the other hand. it does sound good!

Great Add...

I have this amp installed in my `90 Jeep Wrangler.. I chose it for two reasons.. 1. - compact size.. 2. - good little boost.. It is hooked to the Alpine CDA - 9886M.. I wanted to make sure I had enough power behind the 6 1/2`s and 6x9`s to sound good and it did the job well.. The amp is so small I have it mounted inside the overhead Tuffy Security console with the deck.. Worked out great because I didn`t want a big amp on the floor of the jeep - Space is limited in a Wrangler and amps don`t like the deep water crossings on the trails... =)

Decent

What I like: It's dummy proof. Plug n play. 1 switch for low/high on the back.
What I don't like: Lots of wires, and still bulky. You need a lot of room to hide it.

What could have been done better: Remote for the switch because you will have to get behind the radio or wherever you mounted this to change from low/high. And some wire loom to make it easier to fish the wire.

Other thoughts: it works well, paired with kenwood components and alpine cde-126bt. Volume cranked to 24 and it screams. Without this the volume would have to be at 26 for the same sound. So it does work, well it's meh/ok. The headunit has decent output as it is so if you have a crap headunit it's worthwhile. It is worth the price.

A Professional View

I've been a mobile electronics installer for nearly 30 years. The KTP-445 is a nice amp, but the buyer should be aware of its purpose. This amp is not designed to run subwoofers. Its primary use is to improve the response and lower distortion of four typical full-range speakers. Used with modern Alpine head units, it is a simple plug-in installation. Just unplug your radio at the back, plug one harness back into the radio and the other into the harness you removed. That's it! The amp is so small, it will fit behind most radios or under the dash. There's a fair amount of harness to make it easier to locate. You aren't going to experience a great deal more of volume. Remember, practically all head units today already output from 18-23 watts per channel, so this amp is only about twice that and you don't add that to the radio's power, you REPLACE it. Doubling power gives you only about 3 decibels more volume, barely detectable to the human ear.

Finally, notice that this amp DOES NOT have RCA inputs. It can be wired to other brand radios, but you need to know what you're doing: Not advisable for the novice.

small and easy install

I love this product because its small enough to hide behind my dash, no wiring kit necessary so that saves time effort and money. only drawback is only 45rms. its not a lot so if you every get better speakers a bigger amp might be necessary however i could hear a difference in the sound quality. Highly recommend.

Good value

For someone with an Alpine head unit that wants a little more volume but does not want to aliens the cash on an amp kit and rca's, not to mention labor out the extra cost of a conventional four channel amp, this thing does pretty well. I had this in my ride and it did a nice job. Not a ton of features, but of the head unit had cross over ability and you have reasonable expectations for this, it is a great convenient low cost option to improve your sound system.

Love It

I was trying to choose which way I wanted to go with my highs in my 1998 Lincoln Navigator. And I choose to go with the KTP-445. At first I was wondering would this be enough power and after I installed it. I felt in love with it.

KTP-445

You might want to get an amp with more power.

fantastic

Highly recommended! Dramatically increases clarity at high and low volumes. Obviously not a competition amp but if you want a simple set up at a great price and quality sound then this is perfect. Currently using amp with stock VW speakers and can't believe the difference.

Great Amp

Very easy install, fit just under the head unit. Complete plug an play wiring. Adds enough power to give the bass some punch and goes top end clarity. I am using this with an Alpine CDA 9886 Head unit and 2 sets of Alpine SPR 13S Component speakers. This makes for a great sounding system for under a $750

Decent upgrade!!

Before i got this, the speakers were running off the HU. Not hardly an increase in volume, which was expected anyways it since only doubled the power.. So just a few decibel gain.. Definitely clearer though, and door speakers are putting out a lot more bass now, which is an improvement, and i have my gain switch set on low. if you don't have a lot of money to spend on a big 4 channel amp, and you have an alpine HU, i would definitely recommend this.. This puts out more power than some 4 channel amps and its half the price!!!!!

Good product, but has it's limits

For what it is, this amp is great. If you want to increase the output of your system with minimal effort (as I did when I bought this) then I highly recommend it. However if you are investing alot in high end speakers, don't cut corners. Buy a Boston acoustic multi-channel amp and some high quality speaker wire and re-wire those speakers! Stock wiring only allows so much power and is always of low quality. If I could do it all over again, this is what I would do.

Easy To Install

The easiest amp you'll ever install!

Adding 45 watts RMS per channel is as easy as plugging in two cables. No amp wiring kits, no running wires, no complicated
adjustments. Just unplug the cable from your Alpine compatible head unit, plug the male harness from the KTP-445 into the head unit and the female harness into your vehicle factory harness adapter. The unit
itself is small enough to fit behind the radio. I used some velcro and a couple of wire ties to keep it from moving around.

The Alpine KTP-445 Head Unit Power Pack gets power, ground, and signal inputs from the existing wiring, amplifies the audio and outputs it through the same wiring.

Best of all, it's priced as low or lower than many 2-channel amps. Any Alpine head unit manufactured since 2005 with a black wiring harness is compatible. So if you are considering adding a 4-channel amp, consider the KTP-445.

It Is Normal for You Not To Hear a Volume Increase

First of all, the reason for having this amp is not to hear a volume increase it is to protect your speakers from the possibility of destruction. Generally the radio's built in amplifier is about 18W RMS. To get a just noticible increase in sound volume to the human ear you have to DOUBLE that amount of power. So 18 x2= 36W RMS. To get the next just noticable increase you have to double the power again (36 x 2= 72W RMS) and so on. Each doubling of power is a 3dB increase. The radio volume should NEVER be turned up past 11 0'clock position because distortion is introduced (Clipping of the sine wave peaks). This clipping results in DC applied to the speaker coil and could easily fry it even for short periods of time. The additional booster amp like this one just allows you a bit of "amplifier headroom" so you will not clip the sine wave and thus protect your speaker investment.