Alpine KTP-445U Power Pack

Compact upgrade for any car radio — 45 watts RMS X 4

Item #: 500KTP445U

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137 Reviews

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More power, less hassle

Want a simple way to crank up the power of your receiver? Alpine's "Power Pack" amplifier increases your receiver's power output to 45 watts RMS by 4 channels. That's a big jump up from the 7-20 watts per channel typically put out by a car radio, and plenty of power to drive high-performance speakers or keep up with a big subwoofer amplifier. Best of all, this compact amplifier is so efficient you can often run it off the same circuit that powers your receiver. A universal plug lets you feed a signal via RCA outputs or speaker-level wiring.

You can install this compact amp behind most dashboards, but you'll need 4-channel patch cables to connect your car stereo to the amp's preamp inputs. You can also splice into your speaker wiring to get signal to the KTP-445U.

Installation Note: We recommend running a dedicated constant power wire to the battery for optimal performance from this Alpine amp — we offer an inexpensive wiring kit for this installation. This high-powered amp won't work in systems where an outboard factory amplifier is still active.

Note: Sorry, Crutchfield cannot ship Alpine products to Guam or Puerto Rico.

Product Highlights:

  • compact Class D amplifier for factory and aftermarket receivers
  • universal plug lets you send signal from RCA outputs or speaker-level wiring
  • 4-channel amplifier
  • 45 watts RMS x 4 at 4 ohms (CEA-2006 compliant)
  • built-in high-pass crossover (selectable 60, 80, 120 Hz at 12 dB/octave)
  • selectable gain switch (high/low) and switchable 2- or 4-channel operation
  • fuse: 15A
  • dimensions: 7-7/8"W x 1-1/2"H x 2-9/16"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

Alpine KTP-445U Power Pack Reviews

Average Customer Review:

137 reviews
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Alpine KTP-445U Power Pack

Written By Anonymous, New Franklin, ohio on Monday, November 23, 2015

Crutchfield Customer Review (What's this?)

Nice unit, made a big difference

Pros: Small- easy installation-versital

Cons: None yet

Great solution

Written By Pmen, Outer Banks, NC on Wednesday, November 18, 2015

Crutchfield Customer Review (What's this?)

Part of a three sided attack (door speakers, Subwoofer, amp) to improve upon the crappy Ford / Sony non DSP 700W setup in a late model F150 Screw. The input leads as pointed out many times, are very short. Since I wired them to the speaker line of the Sony amp under the center console, it wasn't that big a deal. Set the amp up as a 4 channel. The amp delivers very clean sound through aftermarket JBL coax's in the rear doors and Focal components in the front. One small complaint is that the Kicker soundstage subwoofer replacement under the back seat will not come on until the volume is up beyond 1/3 which is kind of loud for some. It would be nice if everything worked together, but that's another story. Not much help from Tech support. All in all, very compact and fits well under the center console. Delivers clean, much improved sound, in place of the crummy Sony amp.

Pros: Compact design. Clear quality sound.

Cons: Lame instructions. Leads too short.

Clean sound, substantial improvement

Written By Karen, Tennessee on Monday, November 09, 2015

I originally tried the Clarion XC1410 with the factory head unit in my Tacoma (with all new speakers), but had some issues with functionality and sound quality. The unit was professionally installed here locally. We swapped it out for this Alpine unit, and the improvement in sound quality was substantial. The Alpine produces a much cleaner sound, with good dynamic range and a better sound stage. The Alpine unit has a gain control and crossover, and the S/N ratio is higher, resulting in less high frequency noise. This unit, combined with new Focal and JL Audio speakers, produces excellent sound quality.

Pros: Clean sound, more control capabilities

Alpine KTP-445U Power Pack

Written By Anonymous, Pennsylvania on Tuesday, October 06, 2015

Crutchfield Customer Review (What's this?)

excellent speaker for the price

Pros: could have a little bit more bass

Great little amp for any application

Written By Chris G, Illinois on Sunday, September 20, 2015

I have used 1 of these amps in 2 different vehicles and it has been great in both! I installed one in a 2002 Jeep Wrangler with a Kenwood head unit, along with Alpine Type S speakers. It was a great boost in power to the speakers. I also upgraded the factory sub to a small Kicker 6 3/4" sub and powered with an MTX amp. High pass frequency settings on the KTP-445 work wonders! I also just recently used another KTP-445 in my 2016 Subaru Legacy and installed Focal components. Amazing difference! Speakers were installed first and the factory head unit was obviously not enough to give the speakers what they want. Installed the KTP-445 shortly after (within 4 days) and I am beyond pleased!

Pros: Small, Easy to install for anyone with basic car audio knowledge, Very versatile

Cons: None that I can find yet!

Great little amp for Stratoliner Deluxe

Written By R H, Kansas on Sunday, September 06, 2015

I needed a mini amp to fit inside of a Stratoliner Deluxe fairing. I looked at the Clarion, it is also a four channel but it is not brigeable. I only needed to channels and wanted that extra power. Fits perfectly. Wow, what a difference. The factory motorcycle amps are drastically underpowered for hi way use. If anyone wants to know how to do this upgrade, contact me.

Pros: Small, light, great power and sound.

Cons: I don't really care for having to dust off the RCA leads to use them formspeakers level inputs. It's not a problem, just seems like they could have supplied both inputs.

Nice amp

Written By Josh, Ohio on Thursday, July 02, 2015

Crutchfield Customer Review (What's this?)

I am happy with this amp. I have it installed in my 00 S10 regular cab. It is tucked in behind the radio & A/C controls. It fits in there great with both factory deck and aftermarket radio installed. I tapped into the extra aux/cig lighter port below the dash to power it. Perfect spot and is 15AMP rated. Power is enough for me. Anyone with a small standard cab pickup knows that space is at a premium and this small amp allows me external amp power while taking up no room behind the seats.

Pros: Great size. Bridgeable.

Cons: I wish that there were replacement harness for sale. To use the amps speaker level inputs, you have to cut off the RCA ends (i.e. if using factory radio) If you later wanted to use the amp with aftermarket radio, you would have some issues with not having the rca inputs.

Decent amp

Written By Spicy mchaggis, Norfolk va on Wednesday, July 01, 2015

Crutchfield Customer Review (What's this?)

Nice little amp that you can tuck and hide away, the instructions are simple and install is simple. BTW you don't need a 12v turn on, unless your using the 12v remote turn on output. Goes good with alpine type a.

Pros: Simple install

Cons: Needs longer wires, the output wires should be twisted together to aid in install, a drill will do this for you though.

Great for stock HU

Written By Eric, Illinois on Monday, June 29, 2015

This amp is installed in a 2004 Ford Freestar. I have the stick HU still in placed. With the help of Crutchfield I was able to ID the right wires. Taped into the HU power and ground. Took about 40ish mins to install. Really that was just cutting and stripping the wires. But once installed the sound improvement was very noticeable. I have Focal 5x7's up front. And Alpine 5x7's Type S in back. I say it made them clearer and cleaner. Got this amp from a friend for ($20) so all in all great deal.

In the end its a great buy.

Note* If you are using this with out a sub. As in my case. Remember to take off the HPF.

Pros: Easy install. Good improvements

Alpine Power Pack

Written By Anonymous, Texas on Wednesday, June 17, 2015

Crutchfield Customer Review (What's this?)

Great little amp

Great Upgrade

Written By Dennis, Iowa on Monday, June 15, 2015

Crutchfield Customer Review (What's this?)

Small compact and easy to put in even inside the fairing on my 2008 Road Glide. I could have used some direction on wiring in the power. Had to loosen my gas tank up to run the power wired.

Pros: Great amp with low distortion

Cons: Was a little difficult to wire the power.

Pushes out the sound. Compact

Written By ScotM, California on Sunday, June 14, 2015

Crutchfield Customer Review (What's this?)

Small size makes it easy to stash inside a crowded dashboard.

Sounds great. Bold strong sound with no distortion.Great for upgrading your system without going broke.

Pros: Compact Delivers quality sound

Cons: You still need some knowledge of car wiring. It's not a simple "plug-it-in-and-go device."

great solution to no having to run an amp

Written By steve-0, omaha ne on Monday, June 08, 2015

Crutchfield Customer Review (What's this?)

Pushes the non factory speakers just about to RMS like I wanted. The brand name equals quality and that's what you get. It's compact hides well and isn't fighting for battery space against my dedicated mono amp. Speaking of, it keeps my mids and highs in perfect balance against my two 12' fosgate subs running at 800w rms each. It's a mighty little guy and met my expectations.

Pros: Space power frequently range and distortion specs

Cons: I'll have to get back to you on that. I've really tried to come up with something helpful on cons but so far there isn't any. OK they're not giving them away free?

Great sound system!

Written By TS, USA on Friday, June 05, 2015

Crutchfield Customer Review (What's this?)

We replaced our factory equipment in our 2008 Toyota Tacoma with a JVC receiver, six JBL speakers, and an Alpine amp. It sounds amazing! We had it professionally installed and they said Crutchfield was always so good about including everything that makes their job easier. We even saved money on the installation because everything went together smoothly and was made to fit in our truck. The customer service staff at Crutchfield was VERY good at putting together a system specifically for our truck and took the time to make sure everything would work together to give us the best possible sound at our price point. When it comes time to get the subwoofer, we will be buying it, and any other electronics, from Crutchfield.

Pros: Great sound system!

Cons: none

Does the trick

Written By Craig, Colorado on Friday, May 22, 2015

Crutchfield Customer Review (What's this?)

Easy to install if you have 15 amp fuse radio line. Does what it says it will.

Pros: small, Don't have to connect to battery

Cons: can get hot

Not as good as I was hoping

Written By Manny, San Antonio,Texas on Saturday, April 18, 2015

This amp is so small it will fit anywhere. Had it hid inside my dash next to my speedometer cluster. It gets hot w/o air circulation, never cut off though. I have all my amps set with SMD DD-1 so there is no distortion in my system. Bought this amp for my tweeters up front, have a Fosgate T1000 for my sub(NVX VCW122) and an NVX JAD800.4 for my Alpine Type R 6x9s and Crescendo 6.5s. This amp is probably best for factory stereos and not so much for aftermarket HUs. I have a Pioneer DEH-x8500BH headunit which distorts at vol 61, max vol is 62. I can't turn up this amp past 54 bcuz it distorts even when amp vol is at min, but I am using the speaker wires to hook it up so maybe that could be a reason. Either way it's a nice amp just not for my application.

Pros: it's Alpine, small fits anywhere, no need for running power/ground lines, only uses 15 amps instead of 40 or 50 amps, connects straight to stereo power line with 15 amp or higher fuse at fuse box

Cons: not the best for aftermarket stereos, speaker inputs are very short and don't reach far, amp get hot w/o air circulation, no veriable filters only set filters, no bass boost


Written By Bryan M, Illinois on Thursday, April 16, 2015

Crutchfield Customer Review (What's this?)

I installed this amp to the factory stereo on a 2013 Honda Accord LX. It took a bit of doing as Honda is not generous with the wiring under the dash. It was very tight. I spliced into the existing speaker wires which were only 18 gauge but so far, they seem to handle the power pretty well. As other reviewers have noted, the amp does not come with very long wires on one side so I had to delay the install until the next day so I could pick up some additional wire to expand the connections. I went direct to the battery for my 12V power source as the factory stereo only had a 10 amp fuse and this amp requires at least a 15 amp fuse to allow you to tie into the stereo's hot lead for power. For those of you installing this amp on an Accord, the pass through on the fire wall is hard to find. I said a prayer and stumbled across it. It is behind the brake pedal and a bit to the left. You have to cut some of the sound proofing material to reach the grommet. You can first locate it by sticking your hand behind the sound proofing material until you feel the grommet. Once you find it, you are not home-free. The opening passes through a frame member and exits after a 90 degree turn. You will need a flashlight to shine into the grommet hole and locate the exiting light under the hood down below the brake reservoir. Have fun. Once installed, the difference is huge! I have 6.5 inch Kenwoods in the front and 6.5 inch Kickers in the back. The Kickers take the extra power better!

Pros: Great sound! Compact and relatively easy to install for a novice. Contact Crutchfield for a wiring schematic for your specific vehicle. Makes the job easier.

Cons: Needs longer wiring

Big things do come in small packages

Written By Anonymous, Opelika al on Tuesday, April 14, 2015

Crutchfield Customer Review (What's this?)

Thought I needed new speakers. All I needed was more juice.alpine all the way

Power Pack

Written By Tim, Monroeville OH on Thursday, April 09, 2015

Crutchfield Customer Review (What's this?)

This really improved the sound. Great service. I even called them on Easter with a question and it was answered right away. Thanks to my FORD dealer for telling me to call this company.

Pros: Way better than factory crap they put in it now.

Cons: Takes a little time to do all the wiring but worth it.

Great purchase

Written By JeremyD, Kansas on Monday, April 06, 2015

Crutchfield Customer Review (What's this?)

Was greatly impressed by the quality of such a small package. Fit back up under dash no issues find it a home. Wires all all color coded to match nicely. I didn't use the RCA portions I cut them off to eliminate a ton of extra wiring. If your patient and wire it up it's easy. Like not having to install amp kit.

Pros: Great little amp to power speakers using factory wiring.

Cons: Should have spent the extra money to purchase a alpine head unit so that everything just plugged in instead of all the wire connections. The amp would be cheaper this way but woulda had to spend extra cash to get the alpine head unit i wanted with features I wanted. Lessen learned on my side.

Very impressive.

Written By Mac_will2, Wichita, Kansas on Thursday, April 02, 2015

I purchase this amplifier to increase the mids ,highs, in my head deck and I totally noticed a Enormous impact on how my front and rear speakers perform. With the 2000 watt amplifier in my trunk on my subwoofers, everything just connects together almost like meeting your date for the very first time.

Pros: A smaller unit with a greater impact.

Cons: Nothing.

Works good

Written By GMeyers, Illinois on Sunday, March 29, 2015

Crutchfield Customer Review (What's this?)

Lots of power in a small area

Pros: Compact Strong Power

Good way to go when you don't have $$$$

Written By JT, Georgia on Monday, March 23, 2015

Crutchfield Customer Review (What's this?)

A solid piece of equipment to give you the small boost necessary to make your factory stereo sound less anemic.

Pros: Gives necessary boost to wattage w/o having to replace the entire system

The first and the best

Written By Isaac, Wisconsin on Tuesday, March 10, 2015

The first mini-amp that was worth a darn, in my opinion. This little fella has been used on many installs where we weren't looking for full 4ch amp power. At 45wrms it's a touch overrated, based on the old meter, but it really breathes life into some starving speakers vs 20wrms or so that headunits put out. With the ability to be bridged to a 2ch @ 4O output, too, it's very versatile (keeping a honda factory sub working, ya dig!). Most recently I used it to spank on some 120wrms Morel Tempo Ultras, and it got them moving well. Can't recommend this thing enough. The only, only downfall is that it's not waterproof, so if it goes in a Harley fairing don't blast it with water.

Pros: Small, versatile, powerful, affordable. A no-brainer upgrade to any system where some new speakers aren't being powered to their full potential but you don't want to mess with a fullsize 4ch amp.

Cons: Not waterproof

Great amp

Written By WRX owner, Nevada on Wednesday, January 07, 2015

Crutchfield Customer Review (What's this?)

This amp fit in the dash of my 2004 WRX behind the glove box. Using some weatherstrip foam and zip ties it attaches to a horizontal tube found in the dash of Subaru's. The weatherstrip went between the metal tube and amp it cushions the amp from vibration and helped hold it in place. I find that I often use most of the power this amp provides. In hindsight, I would have bought more efficient speakers in the front doors.

Pros: 3-4 times the power of deck with no hassles locating the amp or powering it. Just what I needed.

Cons: None

Great things to come

Written By super soobie fxt, ny on Sunday, December 28, 2014

I'm doing a tablet install on 2012 forester xt touring and this little gem will be my speaker driver. Looks well built and the wiring harnesses are really plug and play .... I bought the Metra wiring kit and like how the radio power can power this up ... Go me.

Pros: Small . meets the basics for amplifier

Cons: Needs a subwoofer companion

Nice Little Unit but Short on Help

Written By SYates, Orlando, FL on Sunday, December 14, 2014

Crutchfield Customer Review (What's this?)

I bought a 2014 Accord Sport with the understanding it had a basic head unit and low end speakers. I started by upgrading to some Blaupunkt Blue Magic speakers but the head unit is so bad, it could not push any sound through the speakers so I did some research and landed on this little unit.

I will say I had some trouble with the settings. For some reason, I have to turn the gain completely off because otherwise it will cause the amp to kind surge through the speakers and the whole car vibrates. It took me some time to figure that out and is really the only reason I dropped a star on it. I am no stereo expert but I am no novice either so I was surprised at how little information there was available to help me troubleshoot. Thankfully the staff at Crutchfield was patient with my questions.

The speakers sound great and it still gets plenty loud. I will not win any car stereo competitions, but it is so much better than the factory stereo and I am enjoying my music one again!

Pros: Small, compact unit that does a great job for the average install.

Cons: Not a lot of tech support or information. Also, I found the input harness that comes will it a tad short. I had zero clearance with my factory stereo and it was tight work back there and the short harness did me no favors. I got it to work, but not with out some effort.

Great little amp for the price

Written By xJoeMama78, Chandler, AZ on Tuesday, December 09, 2014

Crutchfield Customer Review (What's this?)

I purchased this amp to power a pair of Focal 165VRs in a 2015 Forester. I wanted to keep the system upgrades simple and had heard that the power wire to the factory head unit was sufficient to power this amp. I wasn't looking for the ability to play music at really high volumes, but just wanted to provide the Focals with more than factory head unit power to increase clarity and for it to be audible with all of the windows down and the moonroof open while on the highway.

This amp delivered everything it promised. It is small enough to fit behind the dash and the head unit power and ground were sufficient so I did not need to run a separate power wire. My head unit does not have RCA outputs and I did not want to cut off the female RCA connectors from the Alpine harness so I simply added male RCA connectors to the front speaker outputs from the head unit. I followed the instructions to set the amp into 2 channel mode and connected the appropriate amp speaker outputs to run the speakers bridged. The instructions were clear and it was easy to install, setup, and tune.

Overall the amp sounds great. It is not going to be as clean or loud as a more expensive, high end amp, but for the price it is great. Now volume level 10 on the head unit is louder than it used to be at volume level 30. Volume level 10 is sufficient to hear music on the highway with all of the windows open. The amp distorts at higher volume levels but only after the volume is too loud to be comfortable.

Pros: Small size that can fit behind many dashes or in a glove box. Low enough power requirements that it may be able to be powered by the factory head unit power wire. Sufficient clarity and power for the price and size.

Cons: No high level input harness. High level input is possible but you have to cut off the female RCA connectors. This itself isn't an issue but the instructions don't mention which wire is positive and which is negative, and this could be an issue for someone without experience. Trade-off between value and size. There are amps that provide more power and are cleaner for the same price, but they are all much bigger.

Alpine KTP-445U Power Pack

Written By Cliff, Arizona on Wednesday, December 03, 2014

Crutchfield Customer Review (What's this?)

Compact power pack. Easy to mount under the dash


Written By Anonymous, Bardstown, KY on Monday, November 24, 2014

Crutchfield Customer Review (What's this?)

This little box has some kick. I have it on 2 6x8's and 2 6" I think in my Ram. Oops...blew one of the rears. Looks like I'll have to replace soon because the rattle is nerve wracking. I only have the gain at half or barely past...I guess I need to make sure they can handle it.

Pros: Great power at a decent price. Use with any radio? That's thumbs up!

Cons: Make sure your speakers can handle it.

love it, exactly what I needed, but READ MY CONs

Written By tom, Denver, CO on Monday, November 10, 2014

Crutchfield Customer Review (What's this?)

Great little amp, not too difficult to install, makes a noticeable improvement in the sound quality of my aftermarket speakers. Read my comment in the Cons. I would actually give this amp 5 stars, but I want to draw attention to this error.

Pros: small enough to fit behind dash, just enough power so that i don't have to replace speaker wires

Cons: The diagram explaining the switches in the instruction booklet and the diagram printed on the amp are conflicting... since one was printed in black ink on a white background and one the inverse, it leaves the one on the amp telling you the opposite of the switch selections, meaning if you follow the instructions, you'd have your crossover set up incorrectly and you'd probably think the amp was worthless. Some of these negative reviews make me think that's exactly what happened.

Just what my Harley needed

Written By John, Chesterfield, VA on Friday, October 03, 2014

I put a Kenwood KMR D558BT on my 2011 Harley Street Glide along with Hogtunes 5.25" fairing speakers and Polk Audio DB691 6X9 speakers in the saddlebag lids. I was hoping that the 22W RMS power the Kenwood pushed would be enough to push this setup since I'm not looking for thunderous bass just good clear sound at highway speeds. Well that setup sounded great in my garage but once on the highway I had to pump it up all the way past 30 of 35 on the volume and it sounded very shallow and a little distorted. I saw this amp at the store and I loved the small size for an easy add on under my fairing were space is limited. Setup was easy if you can follow directions. After installation...WOW WHAT A DIFFERENCE!. It really gives the system depth and clarity. At highway speeds it sounds awesome. Now at 30 of 35 volume I can't hear myself scream. I have the gain set at about 11 o'clock so it doesn't clip. You can hear all the notes so clearly. I couldn't be happier. It's doesn't have super bass but that is because I don't have a sub. This is for someone that just wants good, clear, deep sound. Don't knock it because it doesn't do what a larger amp does, it's not supposed to. Get the right size amp for the job you need it to do.

Pros: Small size Easy installation Great sound

Cons: None, it does what I asked of it.

Great factory amp upgrade

Written By schambo, Bergen County, NJ on Monday, September 22, 2014

Crutchfield Customer Review (What's this?)

If you want to keep your factory head unit this is the answer. Doubles the power output and is simple to install. I have been using it for over 8 months with Infinity Reference components and it sounds even better as time goes by. For me it is almost too much volume. It's not going to blow your doors off but will satisfy your needs.

Pros: Good power output. Compact size allows for install in tight locations. Built in selectable crossovers let you adjust for best speaker response. Can double power for 2 channel output.

Cons: None as of right now.

Big bang in tiny package

Written By phaelax, ohio on Wednesday, September 17, 2014

My application was a little different than the average user as the car was a '73 Duster. I did not want to cut into the factory dash to fit an aftermarket radio nor have one hang from under the dash like you commonly see in old cars. This tiny amp easily fits behind the dash. I made a custom harness to use an 1/8" audio jack for the input source which I fit into a pre-existing hole where an old radio knob used to be. Using my iphone for music instead of a head unit, this little amp is enough to power the rear 6x9s loud enough (and without distortion) to actually hear the music over the thundering rumble of the 440 block, which is nice on longer highway trips.

Only thing I wish it had was an external line to control the volume rather than the dials on the amp itself. I'd rather be able to adjust the volume from a knob than on my phone.

Pros: Small size, clean sound

Cons: No remote volume

Super power pack

Written By Bob L, Cranston, RI on Friday, September 12, 2014

Crutchfield Customer Review (What's this?)

Unbelievable compliment to any stereo. I put this in my Harley Road Glide. Had Kenwood stereo with Kicker speakers installed without it at first and when riding I had to crank the stereo. after about 15 minutes, the speakers started to cut out. I thought I had inferior speakers. After talking to awesome tech support, they told me to buy this amp. the radio could not handle being maxed out that long. Once installed, which was super easy, I was blown away with the results. I would not install another radio without this must needed add on. Again, cudos for tech support

Pros: small compact size, fit great in motorcycle fairing. Just enough power for a great price

Cons: Sorry, don't have any

Alpine KTP-445U Power Pack

Written By Joe, Wesley Chapel FL on Friday, September 05, 2014

Crutchfield Customer Review (What's this?)

I installed this in a F-150 Out standing little amp. Easy to wire up and fit right behind my H/U with some zip ties no crazy amp wiring . If you are like me and are looking for great sound quality this power pack will bring out every little sound. Here is a tip the RCA jacks are female and if you get a new H/U like I did the jacks on the back of that are female get some adaptors when you order or just get some RCA wire because the one that come with it are only about 4 inches. I was in the middle of the job I just cut off the RCA and just wired it up to the harness.

Pros: GREAT SOUND QUALITY Small size / easy to hide Wiring was very easy Crutchfield did help

Cons: Setting switches a little tricky RCA to short

Alpine KTP-445U Power Pack

Written By James, Hilton Head Island, SC on Sunday, August 24, 2014

Crutchfield Customer Review (What's this?)

It is an okay amp and does what it promises. You can definitely hear the power boost right away. So that's good and don't mistake me. But it leaves me a little wanting as it quickly reaches max gain without distortion. Then the sounds become tinny and you have to back off. I've had mine about 3 weeks. I want a full 75 RMS and this isn't enough for me. And it doesn't' generate more power at 2 ohms. It's all right if you know you aren't going to want more, but I'm going to be ditching mine and getting a regular 75 watt per channel 4 channel AB amp for about a Franklin more. It is supposed to fit up under behind your head unit or someplace else close, and it does, barely finds enough room there. It attaches easily to the cigarette lighter power and ground in the dash with a tap connector. That's the best part. Also, I've had my two regular AB Alpine V12 amps go out on me recently. So I'm not too high on Alpine right now.

Pros: Ease of connection. Just barely fits behind the head unit.

Cons: Reaches max gain quickly and leaves me wanting for more. It's great if you aren't into the big time.

a little more juice

Written By Stan, michigan on Tuesday, August 12, 2014

Crutchfield Customer Review (What's this?)

I have added aftermarket speakera to my doors and dash and they were sucking the juice right out of my cd player. i hooked this little guy up and and now it sounds better than ever and has power left over.

Pros: compact, works great, good quality manufacturing

Awsume Amp

Written By Mack, LaGrange, IN on Tuesday, July 08, 2014

Crutchfield Customer Review (What's this?)

Totally made my speakers come alive!

Pros: Compact size fit behind my stock head unit!

Cons: none

2011 gmc sierra extended cab

Written By Scott, Ky on Monday, June 30, 2014

Crutchfield Customer Review (What's this?)

Awesome little amp , installed it with factory unit with some alpine 6-1/4.

Pros: Small, compact ,and a lot of power , different crossover points on amp a plus . Truck rocks now , need to add subs. Crutchfield customer service provided all the schematics on the wiring diagram. Overall good amp .

Cons: Definitely not a plug and play , didn't like having to cut into factory wiring harness . If you have any experience in installing radios should be fine , was time consuming and had to lengthen speaker wires after cutting RCA 's off .

That added punch

Written By RMJ, Fredericksburg,VA on Tuesday, June 24, 2014

This amp gives my system that added punch that makes the tunes blast.

Pros: Awesome little amp

Cons: Nothing

Nice little Amp (2nd review)

Written By Juan, on Monday, June 16, 2014

Please read my previous comments of this amplifier for a more in-depth review of this product. After removing the power wire that ran from the amplifier and piggybacked off of the head unit. I decided to run the wire directly to the vehicles battery by simply piggybacking off the 8 gauge wire that ran to the amplifier powering my subs and this amplifier no longer suffers from clipping much better performance with the gaines adjusted at the 1 o'clock position

Pros: Clean sound, better base and super tiny

Cons: Running this Amp to the head units power supply doesn't work if you like it loud (must have its own power wire from the battery) despite what the instructions tell you!

works well

Written By Anonymous, st. peters, mo on Saturday, June 14, 2014

Crutchfield Customer Review (What's this?)

Paired this with a new Kenwood kdc-x598 and my older polk speakers in my fox mustang so that I could even be able to hear my stereo over my loud exhaust at cruise speed, but didn't want to have to mount it back near my sub and amp that I have setup for quick removal on track day. Was easy to wire up, plenty of extra wire in the harness to put it just about anywhere in the dash (and small enough too), used the rca inputs, and it sounds really good even without messing with the gain settings on the amp. I just used some strong velcro to mount it on the floor behind the reciever. Gives enough power to actually get clean mids and highs with the windows down at speed (bass was never a problem).

Pros: Easy install, compact size, good power for a small amp

Nice Boost and stays hidden

Written By Hit the road, Moreno Valley, CA on Friday, June 13, 2014

Crutchfield Customer Review (What's this?)

It was nice to fit inside the dash and gave my speakers some more boost especially the bass.

Pros: Nice and small. More Kick.

Cons: Putting all the wires together.

Great little AMP!

Written By Rob H., Milner, GA on Tuesday, June 03, 2014

Crutchfield Customer Review (What's this?)

Great little AMP sounds great, easy to install and hide, would give it 5 starts however I had issues using my Infinity speakers rated at 3 ohms, amp kept going into protect, worked with the tech team and found that to be my issue so if your speakers are not rated at 4 ohms buy the Universal but great product!

Pros: Easy to install and sounds great!

Cons: Does not work on 2 ohm speakers

Small package big quality

Written By Harley rider, Chickasha, OK on Saturday, May 31, 2014

I installed this in my 2012 Streetglide in less than an hour. Amazing difference. It sets easily on top of stereo inside fairing. I had already upgrade the factory speakers so adding the amp gave me great sound and plenty of power left over if I decide to put speakers in my bags. Highly recommend for bikes

Pros: Small, easy to install, good quality

Cons: None

Alpine KTP-445U

Written By John, Northeast Ohio on Tuesday, May 27, 2014

Crutchfield Customer Review (What's this?)

I purchased this a while back to install in an Impreza. I finally got around to that and I am very satisfied with the improvement in sound volume and clarity. A very compact unit that delivers well for its price point. It is also easy to conceal. I would highly recommend this unit to those looking for a little more power in a package that will not take away from space. Others have complained of the poor instructions. I didn't have any trouble understanding the wiring or switch settings. Everything worked right the first time. If you understand wiring diagrams and color codes, this should be no problem.

Pros: Small, good value, sounds great.

Cons: none

The little amp that could...

Written By MisterMike559, Sanger CA on Saturday, May 03, 2014

Crutchfield Customer Review (What's this?)

You can not go wrong with one of these Alpine amplifiers. Whether, you go with the plug-n-play(KTP-445A) model, or the universal model; like the this one. This is the one to get, if you are not using a Alpine head unit, or a head unit that is not plug-n-play compatible. I started off with the the KTP-445A for my front and rear speakers since I have a Alpne CDE-147BT head unit. Sounded clean; and loud. But I was missing the sound imaging I was looking for. I finally added kick panels with components to tie up the mid, and high's in my system. I used this universal model amplifier to send the power to the kicks, via RCA cables. Wasn't sure if I was able to run both models, but a quick response from Crutchfield, reassured me it was possible. Wow, all I can say. Components in the doors and kick panels are the same Alpine models, but now; the system sounds so much louder. Sound imaging sounds so much more equal now. You can't go wrong with these amps. So compact, and simple to use. Hardest part was finding a place to place these. An with the size that they are, it didn't take long. When picking up this amp, get a 8 gauge amp kit, and some good quality RCA cables. Crutchfield can help you out, if you are not sure which ones to get. Make sure to set gain levels properly. That way you optimize this amplifier, and prevent any noise interference. The internet is your friend, when you don't know how to set amplifier gains.

Pros: Compact Low power consumption Adjustment on crossover points 2-4 channel setup

Cons: Requires a 8 guage amp kit. Con, only if you are not ready to run power wire from battery to cab. Setting gain too high can pickup noise. Setting gain to match head unit signal is vital in making sure you don't any noise.

Powerful little amplifier

Written By White Wolf, Arlington, TX on Monday, April 28, 2014

Crutchfield Customer Review (What's this?)

Small enough to fit in my fairing but powerful enough to hear at 100+mph. I am extremely pleased with this amp.

Pros: Small, powerful, easy to connect.

Cons: Dip switches underneath for settings.

Small amp, just right power

Written By Jason, Portland, OR on Friday, March 28, 2014

Crutchfield Customer Review (What's this?)

Works as it is supposed to. Easy install. Fits in nicely under my glove compartment.

Pros: Small, easy to install.

Cons: None that i encountered.

Big improvement, Small Package!

Written By Russ, AR on Tuesday, March 04, 2014

Crutchfield Customer Review (What's this?)

Bought this along with a Kenwood head unit to replace factory Silverado radio. I listened to the new door speaker I bought on just a head unit then on a small amp so I knew I wanted a bit more power. This little amp really livened up the JL Audio's in the truck! Easy install and sounds awesome! Called Mike at customer service with some concerns about not wiring straight to the battery but with his assurance that my trucks power wire was enough I went with the install as per instructions and have had no problems with clipping or distortion. I have an 18 year old son and he was amazed at the difference this little amp made to balance out the system!

Pros: Very Small, runs off head unit power at full tilt with no problems! Great improvement over running just head unit power, really brightens up good speakers.

Deceiving Little Amp

Written By manooti, east stroudsburg PA on Tuesday, January 21, 2014

Crutchfield Customer Review (What's this?)

Installed this amp with a new hu from Crutchfield. It is powering the stock speakers in a 2006 Passat B6. All I can say is w.o.w. I expected clarity and got both ear bleeding volume and clarity. The amp is tucked in the glove box and still stays cool to the touch. Have no problems with install except the tiny little xover switches under the amp. Had to use a fine flat head.

Next test is how they run components after my stock speakers blow. >:)

Pros: Wires are thick. Thicker than a new head unit from pioneer. Long leads. Stays cool due to class d. Front and rear crossover and gain control. Can be bridged in 2 channel mode for more power. Sounds awesome.

Cons: Amp is nice but not when it needs its own power cable when radio fuse is under 15a. At this price, and then running power cable, might as well pick up a stronger amp. It is good if you know it will work for you. Also have a very slight hiss/hum with no audio. Lower gain, less hum but still there. Will not run power cable and use separate ground as it defeats the purpose of this amp. Crossover controls are too tiny to switch. Need a hobby flat head screw driver or a knife.


Written By BJK, OKC on Saturday, January 18, 2014




Nice little Amp but not if your using component speaker set up

Written By Juan, Chicago Heights on Friday, December 20, 2013

Nice little Amp if you want a cleaner sounding system and can afford an expensive amplifier or simply don't want to bother with installing one.... I installed this Amp in a 2006 impala with a set of Kicker components in the front and Kicker 6x9's in the rear using my RCA 5 Volt preouts from my double din eclipse deck ... Its not much louder than the head units amplifier but it will deliver deeper bass and crisper highs at a lower distortion rate, but if you turn up the volume to high for to long, this little Amp will CLIP!!! At least it does with my set up... I'm gonna try supplying a better fused power wire directly from the battery to see if it solves my problem and if that doesn't work than I'll turn down the gains on the amp... However the gains were adjusted using the method described in the instructions (standard method of adjusting gains)... I hope something works, otherwise I'm taking it out and running a real external amplifier.. To bad too because it sounds very good, I've NEVER had an amplifier clip at non-distorted volume levels, so I'm really hoping that piggybacking off the head units power wire is the problem


Cons: Not Recommended if you like your music loud... This Amp will clip at high volumes

Big sound in a little package

Written By B-RAD, Indianapolis, IN on Friday, November 22, 2013

Crutchfield Customer Review (What's this?)

This is a great solution for some who wants a simple solution to add some kick to your factory installed stereo.

Pros: easy to install, small enough to fit behind your radio in the dash. Great company in Alpine and not alot of money for what you get.


Written By Kevin, Arcadia,WI on Tuesday, November 12, 2013

Crutchfield Customer Review (What's this?)

Excellent and affordable upgrade from factory system. Paired with 4 Infinity Kappa 62.11i speakers and they sound great.

Pros: Crutchfield customer service is the best

Cons: None

Great amp

Written By Butchie, Washington on Tuesday, November 12, 2013

Crutchfield Customer Review (What's this?)

Great little add-on amp. I am playing this in my boat, so power consumption was a concern.....don't want to run down the batteries while at anchor in a remote harbor. My existing Bose161 speakers sound much better and the added base far better than before. I especially like the output control screws for front and rear channels, which allows for setting the initial balance between channels. The plug and play convince is great!

Pros: Good sound, easy connections

Cons: None

Alpine KTP - 4450

Written By Tim K, Sanford, NC on Wednesday, November 06, 2013

Crutchfield Customer Review (What's this?)

I have a 14 year old GMC Sierra Z71 truck and the factory stereo system finally bit the dust. Called Crutchfield for guidence and recommendations for replacing all of the factory equipment. I was a little apprehensive in purchasing this amp because of its size, but truly pleased I purchased it. There is noticeable difference with it and a really great product to be so small. The ol' truck sounds great now and extremely pleased with the performance. It is also very easy to store with its size. If your looking for a boost in your system this little amp does a great job.

Pros: Sounds great, easy to install, compact size

Cons: none

alpine amp

Written By Anonymous, metairie la on Tuesday, October 29, 2013

Crutchfield Customer Review (