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Alpine KTP-445U 4-channel Power Pack Amplifier
|Price:||$113.90 & FREE Shipping. Details|
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- Compact Class D amplifier for factory and aftermarket receivers
- Universal plug lets you send signal from RCA outputs or speaker-level wiring
- Runs off same power circuit as receiver.
- 45 watts RMS x 4 at 4 ohms (CEA-2006 compliant)
- Dimensions: 7-7/8"W x 1-1/2"H x 2-9/16"D
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- Size (LWH): 9.25 inches, 7.5 inches, 3.25 inches
Top Customer Reviews
First of all you will need 4xRCA outs coming from your head unit. Most (if not all) decent aftermarket stereos include these. There may be two more for the subwoofer.
There are two sides to the unit: the harness that plugs into the left is for your speakers, remote turn on lead, and power. All you have to do here is match up each wire with what comes off the wiring harness you bought for your stereo. Use solder to connect wires.
The harness that plugs into the right side is where the RCAs coming off the head unit plug in to. The RCA harnesses that come with the amplifier are labeled F/R, just make sure you match them up with the RCAs you have running off your head unit to the Alpine harnesses. When you have them connected you should test L/R and F/R on the head unit to make sure they are matched up properly.
You have to buy 2 sets of RCA cables as the amp does not come with them. After you buy your new RCA cables, run them from the back of your head unit, into the RCA adapter harness, then plug that into the right side of the Alpine amp.
8 month update: Still works great and runs cool. It is still in my glove box without issue.
Almost 2016 update: Still works great!
It is NOT a "big power" amp that is going to rattle your windows and piss off the neighbors. Nope. It's a small, Class "D" amp that roughly doubles to triples the power output of your existing head unit. To really take advantage of it you need RCA outputs from the head, although it will work with speaker-level outputs. This means that with a FACTORY head unit you will get much less than this amp can offer.
Let me explain -- an amplifier can only amplify what you feed it! If you feed it trash you get louder trash. Your head unit's amp is only so-so to start with (yes, even the expensive aftermarket ones because they figure if you care you'll use the preamp outputs instead!) so you're inherently limited. As a result if you want good sound quality you need RCA (pre-amp) outputs from whatever you're going to connect this to, and you also need to use decent-quality cables (don't waste your money on things like "monster" cables, but do get ones with 100% foil+braid shielding - you can tell they're reasonable in quality because they've got some thickness to them.)
Now let's talk about the amp itself. It's a Class "D" amp. A Class "D" amp is EXTREMELY efficient because the transistors in it are either "on" or "off." They thus dissipate very little power as heat. That's good. However, the way they work is by switching the power at extremely high speeds (typically at least 10x the maximum 20khz audible sound frequency) and then using a low-pass filter made up of reactive components to smooth the output. Due to the way these amplifiers work energy is reflected back up into the power supply as a natural part of their operation.Read more ›
Most Recent Customer Reviews
Great boost to our factory system, nice punch without blowing the doors off.Published 4 days ago by Jeff Urbanski
Installed this with my alpine 6.5" speakers. Lots of power. Barley turned up bc of the power that's put out. Great amp for your mid and highs.Published 14 days ago by Saltybeagle
I have a Question...will this amp sound better with the low level, RCA's as opposed to cutting those off and going speaker level??? Read morePublished 1 month ago by KBMAN
Good amp, great sound, easy installation. Updated my 2013 F150 horrible oem stereo.Published 1 month ago by Anton
Very pleased so far. Super easy to install, especially since you don't have to run a power cable to the battery. Installed in a Honda Ridgeline glove box and works great. Read morePublished 1 month ago by Rocky_Mtn_High
Truth this amp rocks at half way great buy for oem speakers will need to up grade later to really push amp (buy)Published 1 month ago by maura gordon
Bought to put on an 08 Streetglide. Sounds great. Only giving a 3 since it was a used amp and was not noted on the sale price.Published 1 month ago by Jen
My stereo is twice as loud than before I added this amp,sounds good and clean also,I'm very happy with this product!!!Published 1 month ago by Amazon Customer