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Alpine KTP-445U Power Pack

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

179 Reviews | 56 questions - 120 answers

Overview

Our take on the Alpine KTP-445U Power Pack

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.

Alpine Authorized Online Dealer

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.

Great power and sound from a small package. Install was a bit annoying due to the numerous and bulky wires.

James, Wappingers Falls, NY

What's in the Box:

  • Head Unit Power Pack
  • 15-amp ATM mini-blade fuse (installed)
  • 30" Power/speaker-output harness
  • 5.5" Speaker-level/low-level input harness (Turn-on lead is 40" long)
  • 2 Metal brackets
  • 4 Phillips/Hex-head mounting screws
  • 4 Wire-ties
  • Owner's Manual (English/ French/ Spanish)
  • Limited Warranty card
  • "Thank You" letter

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
Reviews

Alpine KTP-445U Power Pack Reviews

Average Customer Review(s):

(179 Reviews)
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Product Research

Features

Overview: The Alpine KTP-445U Head Unit Power Pack is a power upgrade amplifier that allows you to add higher output and more dynamic response to your aftermarket or factory installed car stereo system (without factory amplifiers). The KTP-445U amplifies your aftermarket or factory head unit's power output, resulting in increased power over the original head unit's built-in amplifier. It's small and compact at only 7.875" (w) x 1.5" (h) x 2.5625" (d) and fits behind the head unit in the dash of most vehicles. The KTP-445U comes equipped with RCA and auto-sensing speaker level inputs.

Notes:
  • Because of its high-powered amplifier design, the Alpine KTP-445U does require that a separate +12V constant power wire is run to the battery with a separate inline 15A fuse in vehicles with lower than a 15A fuse protecting the factory radio. Check out the Accessories tab for wiring kit.
  • This Alpine high-powered amp won't work in systems where an outboard factory amplifier is still active. If used in vehicles with a factory amplifier, the factory amp will need to be completely bypassed (this may result in lost speaker channels, if factory amp has more than 4 channels).
  • The increase in power may result in a louder warning chime in certain vehicles.

45 Watt x 4 Channel Amplifier: The Alpine KTP-445U Head Unit Power Pack employs a 45 watt x 4 channel amplifier. The amplifier offers an unbelievably low noise floor, taking extra care to ensure a clean signal path, with no extraneous interference. The end result is a 1 Watt Signal-to-Noise Ratio of 82dB or better. Uniquely, the amplifier distortion actually decreases at higher frequencies, resulting in a clean and clear signal where your ear is most sensitive to distortion (< 0.03% THD+N @ 1W; 1% THD+N @ rated power).

CEA-2006 Compliant: The specifications given by Alpine for the built-in amplifier comply with the CEA-2006 mobile amplifier power testing and measurement standards from the CEA (Consumer Electronics Association). All manufacturers who comply with the standard can display the CEA-2006 logo on their product.

  • CEA-2006 Power Rating: 45 watts x 4 channels (at 4/2-ohms, 20-20kHz, 1% THD)
  • Bridged: 90 watts x 2 channels (4-ohm minimum impedance)
  • Max Power Output: 90 watts x 4 channels (Peak)

Controls: The Alpine KTP-445U Head Unit Power Pack provides independent controls for the Front & Rear inputs.

  • Front & Rear Gains: The Power Pack provides simple variable gain controls (speaker level: 0.5-10V, low-level: 0.2-4V) for flexibility and a wide variety of system applications.
  • Front & Rear HPF: High-Pass selectable switches for the amplifier's Front & Rear inputs allow frequency filtering for a wide variety of speakers. Choose "Full-Range" or a selectable range (60Hz, 80Hz, 120Hz) to fine-tune your crossover points (-12dB/oct.).
  • Configurable Inputs: On the bottom panel of the Power Pack there are selectable input options to accommodate Speaker-Level (0.5V-10V) or RCA (0.2V-4V) inputs.
  • 4Ch/2Ch Modes: Selectable 2-Channel & 4-Channel options give you the control to determine source inputs, and can eliminate the need for Y-adapters.

Low-Level & Speaker Level Inputs: The Alpine KTP-445U Head Unit Power Pack includes a 5.5" low-level/speaker-level input harness. The harness features a proprietary 10-pin connector on one end that plugs into the KTP-445U and two pair of stereo RCA inputs that connect to your source unit's front & rear RCA outputs using a pair of stereo RCA cables (sold separately). If your source unit is not equipped with RCA outputs and only features speaker-level outputs, then you can cut off the included low-level/speaker-level input harness' RCA connectors (or use the optional Speaker Wire to RCA Adapters) and connect the KTP-445U to your source unit's front & rear speaker outputs.

Note: You will need to connect the amplifier's remote turn-on lead wire (blue/white) to your source unit's remote turn-on lead when connecting the KTP-445U via Low-level (RCA). You do not need to connect the remote turn-on lead wire when connecting the amplifier via speaker-level input, because the speaker-level inputs are auto-sensing.

Power/Speaker Output Harness: The Alpine KTP-445U's power/speaker output harness consists of a 16-pin proprietary connector on one end that plugs into the KTP-445U, and bare wires on the other end to connect to power/ground and your car stereo speakers through your vehicle's factory or aftermarket head unit's wiring harness. (What looks like a fuse holder in-line with the amp's power wire is actually a noise filter.)

Note: The factory radio circuit needs to be a minimum of 15A. If it is not, a separate power and ground will need to be installed for the KTP-445U.

Mounting: The Alpine KTP-445U Head Unit Power Pack includes cable ties to attach the amplifier to your vehicle's frame or chassis. The KTP-445U also includes two mounting brackets and four hex-head screws to fasten the amplifier to a flat surface of your vehicle.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Accessories
Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

Recommend by a crutchfield advisor because my front speakers only run at 30w RMS [ Jeremy  May 18, 2017 ]
Compact and good enough to power speakers [ K  May 17, 2017 ]
I needed a low wattage solution to give my stock head unit a boost. I trust Alpine to deliver a great product. [ Jeffrey  May 09, 2017 ]
Small compact size, reliability, and ample power for my application [ BRIAN S  Mar 31, 2017 ]
love alpine brand [ ARMANDO  Mar 27, 2017 ]
This is going on my motorcycle and I needed an amp with a small compact design with good power ratings. [ Geoffrey  Mar 21, 2017 ]
Got this to add some muscle to car midwoofers without the hassle of drilling through firewall and patching into battery, as will traditional amp. Not sure I ever wired this correctly; never sounded right. Good reviews so probably my error. [ JOSEPH  Mar 14, 2017 ]
Wanted something more powerful than the factory receiver provided. Also didn't want to get into the big hassle and expense of big amplifiers. [ james  Mar 02, 2017 ]
bad ass little amp tied the system together [ KIPPLIN R  Feb 16, 2017 ]
my stereo has no bass and not good in sound. I have little ones that loves music, but I don't want it to loud for them. so I cant hook up my subs. I wanted something smaller that would give me that itch im craving :) [ JOSHUA  Jan 15, 2017 ]
inexpensive way to power after market speakers without changing head unit [ T  Jan 15, 2017 ]
Gift for son [ James  Dec 17, 2016 ]
This is the 2nd one of these for a separate vehicle. Good clean power for a reasonable price. [ W  Dec 17, 2016 ]
I have used these in the past and are great for sound and ease of installation [ Tommy  Nov 15, 2016 ]
Got this for a painless audio improvement in my Nissan Frontier. Originally purchased a Punch amp but later discovered I'm no longer interested in messing around with an amp installation. Keeping it simple. [ Evans  Oct 22, 2016 ]
I compared power pack to amplifier of more watts and the results were very interesting, the power pack won hands down on .....clear sound with better highs and mids....there is no comparison when it comes to alpines sound quality . so the alpine power pack with easy wire hook up and placement area of convenience will shock you ....no pun intended! [ SALVATORE  Oct 21, 2016 ]
smaller size [ Juan  Oct 04, 2016 ]
It seem to fit my needs when I did my research, and the advisor when I asked about easiest amp installs. Chance recomeded this amp. [ Scott  Oct 03, 2016 ]
awesome little amp! [ al  Sep 30, 2016 ]
Saw this in the May/June Newsletter. Called Crutchfield, spoke with Buck, and decided to order this to increase the sound quality in my 2010 Rav4 Buck's Bio: http://www.crutchfield.com/Support/Bio.aspx?bio=140 [ Kevin  Aug 28, 2016 ]
Have better performance and clarity to my car audio system in the simplest and cheapest way. Sound quality [ Gustavo  Aug 26, 2016 ]
suggested by advisor [ doug  Jul 08, 2016 ]
Ease of installation is primary reason I chose the Alpine Power Pack. Also based on advice from Crutchfield, should provide additional power to enhance the sound system [ ERIK  Jun 06, 2016 ]
Everyone's opinion on how it works with Factory stereo [ John  May 17, 2016 ]
Great replacement for factory amp in my 2002 WJ Jeep Grand Cherokee, fit in factory location, used all the factory wires (left front dash disconnected, full-range speakers in the front doors) [ Thomas  May 08, 2016 ]
Compatibility with Alpine receiver, small size, ease of installation. [ Albert  Apr 08, 2016 ]
I'm upgrading the front door speakers in my BRZ with Polk db Component 4 ohms and am using this amp to replace the factory amp that only runs the door speakers and only at 2 ohms. [ William  Mar 09, 2016 ]
its an alpine [ Robert  Mar 02, 2016 ]
Compact, better sound from my aftermarket HU [ Ronnie  Feb 10, 2016 ]
I was looking for a small amplifier to add some umph to my factory. I knew I didn't want a full system upgrade. After looking around, the reviews made this amplifier stand out. [ Marc  Feb 08, 2016 ]
Compact design, great reviews, gain control for each channel. [ Miguel  Jan 18, 2016 ]
Daisy found an amp that would fit my tight space in my 06 toyota tundra. Daisy's Bio: http://www.crutchfield.com/Support/Bio.aspx?bio=86 [ Martin  Jan 06, 2016 ]
This amp is reliable, easy to install, and hides away nicely in the dash. It is a great purchase. [ ERIC  Dec 21, 2015 ]
It's super small and doesn't need a whole lot of power. just hook it up to your head unit or amp's power circuit as long as it has a 15A or higher fuse! 4 channels, low power. Perfect for tweeter and tailgate speaker combo. I wouldn't use it on door speakers though. [ Kevin  Dec 16, 2015 ]

56 questions already asked

If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can check and see if there is anything we can do to help. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer, or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/. Here are a couple numbers that may be helpful. Alpine Customer Support 800-257-4631 Pacific Coast Parts (Alpine Parts Dist) 800-421-5080 Hope this helps. [ Kenny  Jun 19, 2017 ]  Staff
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the settings on the product and see if there may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer, or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/. [ Krissy  May 15, 2017 ]  Staff
Technically, what you have is 2 channels if your components use a driver. The answer is it depends on the requirements of the speakers. Don't expect 320w 6x9's, or 300+w components (at 2 ohms) to not cause the amp to go into protection, especially when summertime comes. Maybe if you have it in the cab or floor area where air conditioning can get to it, it may not be as much of an issue. Chances are your speakers aren't that rating, but it may be better to either use higher ohm speakers or a different amp. [ David Norris  Feb 19, 2017 ]
For additional details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on how everything integrates and what you will need for an installation in your vehicle. [ Kenny  Dec 31, 2016 ]  Staff
Thanks for your question. For information on selecting the best amp for your factory system I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They will be able to help determine the differences between the amp models and help you make the best choice for your system. [ Kenny  Nov 23, 2016 ]  Staff
Thanks for your question. For information on selecting the best amp I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They will be able to help determine the differences between the amp models and help you make the best choice for your system. [ Kenny  Nov 16, 2016 ]  Staff
Really sorry can't help u ,a friend of mine installed it for me but it's great [ ALEX  Sep 19, 2016 ]
It has been a while but I think there is a manual dial on the right side that you can set with a small screwdriver. I mounted mine so I could open my glove box to access the dials. [ MARK R  Sep 18, 2016 ]
The amp in the HU is bypassed completely. You'd still only have 45 watts RMS X 4. This is simply just a small amp. [ Michael  Sep 14, 2016 ]
No. The output of the Alpine amp is 45 watts x 4 at Ohms RMS. The Alpine can receive inputs of either line level or speaker level (which would be your HU's 45 watts x 4), but the Alpine will only put out 45 watts x 4 RMS. If your aftermarket HU already puts out 45 watts to four channels you don't really need this amp. [ Aaron  Sep 14, 2016 ]
Tristin: You will just have the power of the final stage of your alpine amp but I would bet the alpine amp is much cleaner than the 45watts out of the head unit. Best thing to do is if your head unit has pre-amp outputs connect those to the alpine pre-amp inputs this will be the cleanest sound. Otherwise connect your head unit (speaker) outputs to alpine speaker inputs. The cleanest sound and the preferred way to connect is preamps out of head unit to preamp inputs to the alpine amp. Either way it will not be 90 watts. Hope this helped. Regards, Jackie L. [ JACKIE L  Sep 14, 2016 ]
Not sure how hot it gets, but mine sits tucked away in the dash, behind the head unit where it gets no air flow. It has survived two Phoenix summers without cutting out or shutting off even once due to thermal issues [ Joseph  Aug 18, 2016 ]
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your factory system. They will be able to pull up your vehicle and see if this will integrate. If it does not, then they will also be able to discuss other options with you. [ Kenny  Jul 05, 2016 ]  Staff
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the settings on the product and see if there may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: http://community.crutchfield.com. Or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/. [ Krissy  May 24, 2016 ]  Staff
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the settings on the product and see if there may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: http://community.crutchfield.com. Or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/. [ Kenny  May 23, 2016 ]  Staff
If your limited on space to mount a amp the Ktp is a awesome little amp , but if you already have the Mvr I would just use it . Although when mounting the KTP you don't have to run a big power cable ,you can just use the supplied wire with the ktp and wire it to your fuse panel . I have one running 4 alpine 6.5 in a GMC Sierra and think it's a great little amp ,it's compact and sounds great. [ Scott  May 04, 2016 ]
You can go big amp get get better options and maybe a few more watts, but this thing is great because you can hide it easily and it packs alot of power... I love mine.. Its alao easier to install because you can on alot of cars hode it behind the main stereo deck and tap i to all your speaker wires and power wires without havekng to run new wireing.. [ KELVIN  May 04, 2016 ]
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your factory system. They will be able to pull up your vehicle and see if this will integrate. If it does not, then they will also be able to discuss other options with you. [ Kenny  Apr 29, 2016 ]  Staff
For additional details on installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on how everything connects and what you will need for an installation in your vehicle. [ Kenny  Apr 22, 2016 ]  Staff
I definitely recommend using whatever crossovers came packaged with your JBL speakers. They are made to work with the provided midbass & tweeter specifically. You can still use the HPF setting on the Alpine power pack if the JBL midbass drivers are not rated to play the deeper frequencies. I hope that helps! My Bio: http://www.crutchfield.com/Support/Bio.aspx?bio=5 [ Ryan  Mar 04, 2016 ]  Staff
I bought this product and had enough room under my front seat to install it. I had to remove the seat to do so but it worked great! [ JOHN A  Jan 19, 2016 ]
You can mount it in your glove box [ REYNALDO  Jan 17, 2016 ]
Hi Craig, First, I didn't put this in a Jeep Wrangler so I am not sure of the landscape you have, but I did put it in both a 2005 and 2010 Toyota Corolla, which may have a smaller interior than the Wrangler. It's a great little amp and I had multiple mounting choices: 1) behind the dash right under the Pioneer head unit I installed (chose this option), 2) in the console near the shift lever, 3) under/behind the glove compartment. It's small and can easily be held in place with a couple nice sized zip ties. Coupled with the pioneer, it made a huge difference in the Corolla's. I would buy this again. All the best! Kent [ Kent  Jan 16, 2016 ]
Yes I have been pleased with the balance in sound. Mine is paired with an alpine stereo and many people say they are impressed with the sound. I'm not an expert but I selected it based on a recommendation from a crutch field advisor and since it is their expertise, I feel it is based on a broad base of knowledge and I have often been happy I took their advice. I hope you find the best choice for your investment. [ Amy  Jan 05, 2016 ]
yes. it works fine just be sure to adjust the output. [ THOMAS  Dec 22, 2015 ]
Mario, I bought this amp and like it. I do not know if the connectors would be plug and play to your stereo deck. Look at back of this amp and back of your stereo (on-line) and the cables provided to see if you'll be able to plug and play. Hope it helps, Dave [ David  Dec 22, 2015 ]
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your system. They will be able to see if this will integrate. If it does not, then they will also be able to discuss other options with you. [ Kenny  Dec 21, 2015 ]  Staff
It will work with any head unit [ Robert  Dec 21, 2015 ]
The 'U' version of this amp is universal so it will work with any head unit. It can be wired for either line level (via RCA cables) or speaker level inputs. The sister product KTP-445A is the one that has specific coupling with the Alpine head units. [ Richard  Dec 21, 2015 ]
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your system. They will be able to see if this will integrate. If it does not, then they will also be able to discuss other options with you. [ Kenny  Dec 21, 2015 ]  Staff
For details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle. [ Krissy  Nov 13, 2015 ]  Staff
In unbridged mode (4x45W) connections are the same for 2 to 4 ohms. The amp is current limited so power output is the same with either. In bridged mode, (2x90W) this should only be used when driving 4 ohm speakers. [ Richard  Oct 14, 2015 ]
i don't know...however l bought one 1.5 yrs ago for my bike...l upgraded my speakers and needed more output...and got it....even at lowest level my wife says its too loud, lol.... [ William  Oct 12, 2015 ]
For details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle. [ Krissy  Aug 13, 2015 ]  Staff
For details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle. [ Krissy  Jul 10, 2015 ]  Staff
I installed in Honda Pilot using stock speakers (cheap) and no issue with unwanted vibration or rattling. Differetn vehicles, so prob not direct comparison. but still a decent amp for the money. [ Paul  May 22, 2015 ]
I Installed it in a jeep xj so my input would not be much help. Handy unit works well. [ KOLE  May 22, 2015 ]
I put mine in a 2007 GTI with factory speakers and it worked great. You should have preamp outputs but I'm unsure [ ALEX  May 22, 2015 ]
IT doesn't matter what you hook it to. Simply connct the speaker wires. The head unit options are irrelevant [ DAVID  May 22, 2015 ]
Hey James, I personally haven't, but I don't see why you couldn't. The sync shouldn't make a difference because there should still be all the basic wires needed to hook it up. What I would do is get behind your head unit and see what you have to work with. If you can identify all the needed wires you should be good to go. [ JANET C  May 22, 2015 ]
I don't know. [ LEONARD  May 12, 2015 ]
If you look at the specs on the this products page you will have your answer. [ WESLEY  May 12, 2015 ]
It is bridgeable, there are small switches on the back to select HP frequency and 2/4 channels [ Christopher  May 12, 2015 ]
I put mine into my 2007 Chevy Colorado and It was a very easy install. Basically all I had to do was cut and splice the unit in. It is even easier if you have an alpine unit as you can just plug it in. But all I did was cut the wires coming off the stereo and solder them to the input on the amp and then solder on the wires going to the speakers to the output. Then I just found a nice spot in behind the stereo and ziptied it down. It also provides a heck of a lot of power for its size I can really have my bass up more now and get much less distortion at higher volumes. [ JANET C  Apr 13, 2015 ]
No, but I have it in my 1990 Jeep YJ. It will work in any application. I know it's a popular solution for Harley's as well. I've been very happy with this tiny little amp. It's quite impressive considering the small size. [ ERIC  Apr 13, 2015 ]
I forwarded your question to an Advisor and they responded with the following: You would still need the HU harness, while the Power Pack harness will plug in to the radio, the HU Harness plugs in on the other side of the Power Pack If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  Apr 15, 2015 ]  Staff
What kind of problems will i encounter. I purchased a 2014 Chrysler 300 with the alpine amp already installed. [ Craig  Mar 15, 2015 ]
For details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle. [ Krissy  Mar 15, 2015 ]  Staff
yes you can, but don't use anything else on that circuit, including cig lighter! [ David  Dec 22, 2015 ]
This DOES NOT require a direct line to battery. You simply tap off of the wiring from your head unit. I used it inmmy Harley and it absolutely cranks and I i didn't have to get creative at all with the wiring. Cheers, d [ DENNIS M  Jan 26, 2015 ]
It has been my experience after using this, and many other amps, that the output voltage has a minimal effect on sound quality. You just have to turn the gain up a little on the amp. These "Amp" ratings are taken with the head unit at full volume. And if sound quality is you goal, and not just "Loud", you won't notice. Being happy with the overall sound and audio controls of the head unit is much more important. OMHO [ DAVID L  Jan 13, 2015 ]
Mine sounded like junk. I took mine out and trashed it. Good Luck! [ ANTHONY  Jan 12, 2015 ]
Thanks Tyler.. Yes, I believe I had better go to 4V or I will always know I could have had better.. Its not really that much more money anyway.. good money spent.. better amp and etc. too.. [ b  Jan 12, 2015 ]
I personally noticed a difference when going from a 2V head HU to a 4V HU. The difference isn't significant, but is noticeable. [ TYLER L  Jan 12, 2015 ]
You will get a "cleaner" sound out of a head unit with 4V pre-outs. I switched from an older head unit with 2V to a newer one with 4V using this amp and it was a noticeable difference. [ Christopher  Jan 12, 2015 ]
That depends on how much of an audiophile you are. The average everyday person will not notice the difference. I use a 2 volt output right now and have used up to a 7 volt output from an older Eclipse. Really not much of difference in daily use. Your choice in speakers is more important. [ STEPHEN M  Jan 12, 2015 ]
No, the Sound quality is the same. Incoming voltage does not change out going response. This is a great unit. I highly recomend it, due to is versatility and ruggedness. [ ALLEN L  Jan 12, 2015 ]
I can't tell you I haven't installed it yet. [ GEORGE  Jan 12, 2015 ]
Dont need to run to battery run it off your red power from vehicle harness. Dont need large guage it is not that many watts just 45watts front and 45 watts back. [ DAVID G  Jan 12, 2015 ]
to power the amp you dont need to run any wires to the battery. you want to make a 3-way connection with the yellow 12v wires coming from the cars wire harness, the back of the stereo and the one coming from the amp. hope this answers your question [ TIM  Jan 12, 2015 ]
Just solder and heat shrink the connection. It depends on your cars wiring and fuse rating. [ MARK  Jan 12, 2015 ]
Personally I prefer using the controls in the amp, and I'm very picky about sound quality. [ DAVID L  Jan 13, 2015 ]
I've used both, it can help or reduce good sound quality. Be aware if you set your low frequency (for the speakers) like trying to reproduce sub woofer sound quality you run the risk of blowing the output transistors in the power amp! [ RICHARD J  Jan 07, 2015 ]
I left the amp at full frequency since my head unit has enough control and adjustments for me. I've been very happy with this unit as it has been plenty powerful to drive my four speakers - Alpine type R components in front, Infinity Kappa in back (roll bar ~Jeep). The small size is great as I was able to completely hide this and the subwoofer amp in a very out-of-the-way place. [ ALAN  Jan 06, 2015 ]
I'm not sure which is better, since I only used the filter if the head unit. But I have been very impressed with the amp. [ ADAM  Jan 06, 2015 ]
If you referring to "Bridging" two amps together? No. If your asking if it will function as a 2 or 4 channel amp? Yes [ DAVID L  Jan 13, 2015 ]
Yes you can bridge it from 4 channels to 2 channels. Hope you enjoy it, it's a great amp. [ JAMES K  Jan 02, 2015 ]
Yes, it is bridgeable. There is a tiny dip switch on one end that allows you to select 2 channel or 4 channel mode. Also instructions for wiring either mode. [ JOSEPH  Dec 31, 2014 ]
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the settings on the product and see if there may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: http://community.crutchfield.com. Or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/. [ Krissy  Dec 26, 2014 ]  Staff
I forwarded your question to an Advisor and they responded with the following: The PAC OS-5 Factory Integration Adapter has an external chime speaker which you'll need to mount facing downward towards the floor so it's away from you. Since it's built in to this module it won't be affected by your separate amplifier. If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  Dec 23, 2014 ]  Staff
I'm sorry, I wish I knew for sure. I had it professionally installed. I believe it ran off the head unit's power. Hope you get figured out and enjoy it!!! [ JAMES K  Nov 16, 2014 ]
We have two of these, one in each car. I've run both off of the factory head unit wiring. [ MICHAEL  Nov 16, 2014 ]
Yes you can use the head unit power line. That is how it is supposed to wire. [ DANIEL  Nov 15, 2014 ]
I used the same power wires that go into the HU. I believe you can do it either way though. [ John  Nov 15, 2014 ]
HI, You need to run a wire from the battery to the amp. It requires a thicker gauge wire and a inline fuse. When i purchased this i also got a amp wire kit. This is a great amp and no problems with it. [ ALAN  Nov 15, 2014 ]
It depends on the amperage handling of your head unit. If it can meet the specs of the alpine then you can, of course you still would need a fuse in line. If it canonot supply the amperage, then you would have to run a line to your battery with an in line fuse. [ BRIAN  Nov 15, 2014 ]
Brendan, I am fairly certain that you should still be able to use your current Sub set up. You may however need to tweak some of the settings on it after installing the Alpine. Good luck! [ DENNIS M  Nov 03, 2014 ]
I use this amp to power some door speakers up front. I still have my self-powered sub in the back. Just pass the speakers you want thru this amp. Bypass it for your sub. [ JEFFREY  Nov 03, 2014 ]
In a word - yes. [ PATRICK M  Nov 03, 2014 ]
If money is not a problem I would go for a more powerful 4 channel amp. Power is important but the THD is just as important. Be sure and check the (total harmonic distortion) at different power levels. Some amps have good specs. Power wise but they get noisy when the power is increased. Hope this helped. Jackie L [ JACKIE L  Sep 14, 2016 ]
ben this amp is well sutited for smaller speakers. it performs well with 6x9 or smaller in set if 2each. bruce [ DEBORAH  Sep 09, 2014 ]
Thank You for your reply. [ ChadW  Jan 04, 2015 ]
I forwarded your question to an Advisor and they responded with the following: As long as you don't have the premium audio system then it will work, but it is not ideal. Your radio is not equipped with a 15amp fuse. I would recommend going with this option by Clarion. http://www.crutchfield.com/p_020XC1410/Clarion-XC1410.html If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  Sep 03, 2014 ]  Staff
Josh The ktp445 that I purchased, I installed behind a Kenwood exelon on Rockford fosgate speakers. So I can't give a direct answer for this application. I have however used this method to hook a JL 1500 mono amp to a factory head unit and it seems to function just fine. I guess it would depend on the quality of the hi to low pass converter that you use. I would not advise hooking a ktp445 to a factory speaker though. As it probably would not last very long. Over all, on a set of aftermarket speakers, as long as the gains on both converter and amp are set correctly. Should be OK. Give it a go man. [ DERIC  Aug 17, 2014 ]
Yes you can, and no sound compromise, make sure that your vehicle' speakers would hold the power output from the power pack, the little thing is small in size but deliver plenty of power. Goodluck! [ FRANKLIN  Aug 16, 2014 ]
I apologize I can't answer your question mine is still sitting on the bench waiting to be installed. [ GEORGE  Aug 16, 2014 ]
I'm afraid I don't have an answer for this. I wired mine to a radio that had the rca outputs. [ LEONARD  Aug 16, 2014 ]
I was able to use the RCA but I see no reason you could not use line level. I don't believe the sound quality would suffer. I'm very happy with this amp. It fit into the space I had to work with (it's about the size of an average TV remote) and is very adequate driving a pair of Alpine type R components and a pair of Infinity Kappas. [ ALAN  Aug 15, 2014 ]
You can hook up rca jacks to output..not sure how the sound quality would be.. [ MARK E  Aug 15, 2014 ]
I had no RCA units on my stock head unit. I did a pop test to make sure there wasn't an amplifier somewhere in the car that I ididn't see (there wasn't). Next, I ran a separate power line from battery to the Alpine KTP, cut the existing speaker wires from the head unit and wired directly to the Alpine KTP and then from the KTP back to the four speakers in my car. No need for line converters in my application. I ran a separate powered sub. [ MARK  Aug 15, 2014 ]
No need for anything. I cut the factory speaker wires and put this unit in line. Factory worse in and out. Sound is fantastic and no distortion due to ability to set frequency on amp. Would buy it again [ DAVID  Aug 15, 2014 ]
You could do that but I wouldn't reccomend it the signal loss is going to be substantial plus a whole slew more hardware to find a place to tuck away I think you'd be better off getting a small amp with line level input [ DAN  Aug 15, 2014 ]
I strongly urge you to ground the amp to bare metal in the car chassis. Not familiar with the GMOS, but the amp should be the last thing on the way to the speakers themselves. [ JOSEPH  Aug 07, 2014 ]
After the adapter for sure. Rule of thumb is to have all power and grounds, especially grounds, to be common, or from the same source. I use distribution blocks that disperse the power and ground grime one source for all audio related gear. Really helps ward off noise. [ ADAM D  Aug 02, 2014 ]
I have mine wired like any other traditional amplifier. In that sense no other harness needed. I am using a kenwood hu. [ DEREK L  Jul 29, 2014 ]
No...you tap into the power and ground on the existing harness then use either rca or speaker line for input...then hardwire the speaker output...just like any other amp would be... [ KELVIN  Jul 29, 2014 ]
I forwarded your question to an Advisor and they responded with the following: The front and rear outputs have independent high pass filter settings, so you can adjust them independently. If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  Jun 25, 2014 ]  Staff
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: http://community.crutchfield.com. Or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/. [ Jeff  Apr 25, 2014 ]  Staff
I'm running my amp off of same power lead as my HU but only running a pair of tweeters. You have to make sure the wire gauge and fuse can handle the combined power rating of all components. [ PETER J  Apr 26, 2014 ]
It's powered right off of the head unit power feed. So you shouldn't have to run another wire to the battery or add anymore fuses. [ MICHAEL H  Apr 24, 2014 ]
The goal is to have a fuse between the amp and the battery that's 15 amp or better. So the radio fuse in the fuse box is an option if its high enough. [ JEFFREY  Apr 24, 2014 ]
Hi Maurice, This is the detail in the manual. I went with option A a year ago and have not had any problems at all. It works great. Battery Lead (Yellow) There are two options: a. Connect battery lead to OEM radio fused circuit The OEM radio circuit has a fuse to protect your vehicle's electrical system in case of a short circuit. Do not connect the battery lead to the OEM radio circuit if the fuse rating is less than 15A. b. Connect battery lead directly to BATT+ Be sure to add a 15A fuse (sold separately) as close as possible to the battery's ( +) terminal. [ JEFFREY  Apr 24, 2014 ]
My install guy powered the alpine amp directly from the stock radio power line. I have four Polk 65 watt max speakers connected to my alpine amp. It more than doubled the output. He was impressed with the amp, output and it's an Alpine. [ CESAR  Apr 24, 2014 ]
No need to add another fuse. Just plug and play [ DEREK L  Apr 24, 2014 ]
I forwarded your question to an Advisor and they responded with the following: This amplifier is 2-ohm stable and the output would be 45 watts. The amplifier has a regulated output which is why the 2-ohm output isn't greater than the 4-ohm output. It should work just fine with the 2-ohm factory speakers. When used in vehicles with a factory amplifier, the factory amp will need to be bypassed (this may result in lost speaker channels, if factory amp has more than 4 channels). The increase in power may result in a louder warning chime in certain vehicles. If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  Mar 16, 2014 ]  Staff
Thanks for your question. For information on selecting the best amp I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They will be able to help determine the differences between the amp models and help you make the best choice for your system. [ Krissy  Feb 12, 2014 ]  Staff
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your current system. They will be able to pull up your gear and see if this will integrate. If it does not, then they will also be able to discuss other options with you. [ Jeff  Jan 16, 2014 ]  Staff
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the settings on the product and see if there may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: http://community.crutchfield.com. Or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/. [ Jeff  Dec 16, 2013 ]  Staff
If you buy speakers and do not change your head (stereo), you need to power them with a amp. This is good to power 2 front and 2 rear speakers. And is small enough to mount behind your head, instead of a normal size amp which you would mount in the trunk. [ STEVEN  Dec 27, 2013 ]
Short answer is no, this unit is not the best choice for a subwoofer amp. The amp is 45 watts by four channels, or bridgeable to roughly 100 watts by two channels. So you would need either a Dual Voice Coil (DVC) subwoofer, or two subwoofer drivers, to take advantage of both bridged channels. Also, while this is a nice amp, the crossover choices aren't really set up for subwoofer use. For a single subwoofer driver, or for multiple subwoofers wired together, you would be better off with a dedicated mono channel subwoofer amplifier. [ JOSEPH  Dec 18, 2013 ]
It ' San accessory to add s [ DENNIS  Dec 16, 2013 ]
Only if it was a very low RMS sub. It is much better suited to powering aftermarket door/dash speakers. Works great with my 4 x Polk 6 1/2 db series. [ DANIEL  Dec 16, 2013 ]
jerry this unit far exceeded my expectations. had unit installed by pros. works great. b mcintyre [ DEBORAH  Dec 06, 2013 ]
I've installed this in a 2013 gmc sierra [ DEREK L  Dec 05, 2013 ]
Not in a Tundra but in a 2006 Honda Accord LX with an Alpine head unit. It fit nicely behind the dash and packs a big enough punch for my listening. My family can here me inside the house when I pull in and jamming to a good tune! [ JOSHUA  Dec 05, 2013 ]
I have not done one in a Tundra, but I put this in my Harley with polk DB speakers. IT PACKS POWER!!! I was able run it without even bridging it and it cranks two 6.5s with deeper bass and crystal clear mids and highs. I used do custom installs for a living. This amp would've fit any where and made my life a lot easier. It's compact but packs intense power. It would be a great add on to any factory stereo. Feel free to email me with added questions. Cheers, Dennis [ DENNIS M  Dec 05, 2013 ]
Nope. Mine went in VERY tight quarters in a '94 Corvette. I'm DELIGHTED with it! [ ANTHONY  Dec 05, 2013 ]
No. In a Jeep Wrangler. Easy to install [ LEWIS C  Dec 05, 2013 ]
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