Alpine KTP-445U

We apologize

This item has been discontinued

Get FAST answers from customers ASK a Question See questions answers

  • Alpine Universal Power Pack 4-Channel Class D for All In-Dash Receivers
  • Increases the output of any headunit without having to install a full size amplifier and amp install kit
  • The fast and easy solution to higher power aftermarket sound
  • RMS Power Rating:
    • 4 ohms: 45 watts x 4 chan.
    • 2 ohms: 45 watts x 4 chan.
    • 4 ohms: 90 watts x 2 chan. (Bridged)
  • Total RMS power output: 180 watts
  • Independent Front/Rear gain switch is adjustable from high to low
  • Runs off receiver's power circuit
  • High-Pass Filter: selectable 60/80/120 Hz @ 12 dB/octave
  • Fast and simple installation
  • 4 channel operation for four speakers
  • Minimum impedance of 2 ohms
  • Is not compatible with factory amplifiers
  • CEA-2006 compliant amplifier
  • Frequency response: 20-20,000 Hz
  • Fuse Rating: 15A x 1
  • Dimensions: 7-13/16D x 2-9/16"W x 1-1/2"H
  • 1-year warranty

Alpine products are warranted solely by Sonic Electronix, Inc. under the same period and terms as the original Alpine warranty. Sonic Electronix is not an Authorized Alpine Dealer and Alpine requires all merchandise purchased by Sonic Electronix customers to be returned solely to Sonic Electronix. Alpine products are also covered by our Standard Return Policy for returns on exchanges or refunds within 30 days from the date of purchase.


Second Depth
The second depth is used only when the box is slanted or angled. This value is the top measurement and it is measured in inches.
The front-to-rear depth of the item, in inches. If the item is angled or slanted, this value is the bottom measurement.
The height of the item, measured from top to bottom, in inches.
The width of the item from left to right (side-to-side) measured in inches.
Color of handle.

Warranty and Return Policy

Parts Warranty Duration
90 days
Labor Warranty Duration
90 days
Warranty Provider

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
4 Star
3 Star
2 Star
1 Star

Average Attribution Rating

Browse 13 questions and 37 answers
Hide answersShow all answers | Sort by
Why did you choose this?
Sonic Electronix Store
I had limited space in my '14 Wrangler. Thought I would try the amp out to run my Polk 6.5" in the rear and my Polk 6.5 components in the front. It does a great job for such a small package.
Matthew W on May 26, 2016
Amp is a perfect 4 channel amp for my small/medium sized speakers and it can be tucked away in the dash plus it can be powered directly from the head unit and no need to go to the battery!
Fahim A on Oct 21, 2015
Great 4ch amp that can be bridged to 2ch. Low power consumption, small footprint. I've used this amp to power main speakers and also used this amp in other applications to power 2 small subwoofers. Love this amp.
Stephen I on Mar 8, 2016
Best compact amp out there! Easily fits behind most stereos in dash.
Rory O on May 14, 2015
The title says its for aftermarket and factory receivers, descriptions says it's not for factory receivers. Which is it???
zac p on Sep 2, 2015
Best Answer: This amplifier is actually for Alpine headunits. Thanks for bringing that up we'll have our descriptions team fix that.
Reply · Report · Enrique S.Staff on Sep 2, 2015
· Add Answer · I Have This Question Too (4)
If I choose to run the the amp in the "2 channel" mode would that be 90W X 2 instead of 45W X 4?
Jon K on Sep 30, 2014
Best Answer: Hello,

There are two ways to answer this, so please read carefully to get the answer to your specific approach.

1) If you only use, say, Ch 1 & 2 , but do not use Ch 3 & 4 , you will only receive 45wRms per channel.

2) If you Bridge (Ch 1 w/ 2) & (Ch 3 w/ 4) THOSE newly created Two channels will provide 90wRms .
Reply (1) · Report · Customer SStaff on Sep 30, 2014
· Add Answer · I Have This Question Too (3)
Hi there, I am wanting to look at using this for a set of Apline SPR-60C components up front, and SPR-60 coaxials in the rear. since the speakers are rates 110w and this 45w, am I going to be causing damage by underpowering them? Cheers
Ben W on Sep 9, 2014
Best Answer: Hello Ben,

Out of the box and right away, this setup will Not cause any damage. However, obviously DON'T expect a 100w+ experience per speaker. If you push the Amp to Clipping, then THAT will cause damage to Any speaker. Really the only "concern" here - besides clipping, which is on you not the product - is that you are going to spend your budget on a set of speakers that are at their Optimum Quality when being power 75-100% of what they ask for; ~45w RMS will be under 50%. A better 'match' will be the S-Type series, but that - like all things Car Audio - comes down to Your preference.
Reply · Report · Customer SStaff on Sep 9, 2014
· Add Answer · I Have This Question Too (1)
Hey guys, will this product work if I have a line out converter as well? I drive an 09 Chevy Impala with the factory head unit (hence the LoC). The Line Converter is PAC AOEM-GM1416A. Thanks!
A shopper on Feb 2, 2015
Alpine KTP-445U
Alpine KTP-445U
Best Answer: I initially had an AudioControl Lc2i between my factory head unit and the Alpine amp. I ended up taking the Lc2i out and running high level inputs from the head unit to the Alpine. I honestly believe the sound is better without the line converter inbetween.
Reply · Report · Shane B on Feb 3, 2015
· Add Answer · I Have This Question Too (0)
So I have a aftermarket JVC head unit that puts out 22rms x4channel, would this alpine amp just add more rms so would it be 45+22rms to equal 67rmsx4channel ?or would the speakers only get 45rmsx4channel and not include the power of headunit?
Simpson29 on Nov 19, 2014
Best Answer: Hello Andrew,

You ONLY get what the amp Provides. In this case, it will in fact be the 45w RMS x 4.
Reply · Report · Customer SStaff on Nov 22, 2014
· Add Answer · I Have This Question Too (0)
Im thinking about purchasing this but my factory speakers are part of a bose system....what do you suggest??
A shopper on May 29, 2015
Best Answer: Your bose system probably sounds better without this. If you're looking to upgrade get a proper 4 channel amp and upgrade the entire system
Reply · Report · piyush s on May 29, 2015
· Add Answer · I Have This Question Too (0)
Im trying to hook this up, any tips on how to do this?
Dustin D on Dec 29, 2014
Best Answer: If you've never wired up an amp before look on YouTube for a how to video, or take it to a stereo shop and have them do it before you blow something up. It's pretty straight forward. Power, ground, turn-on, and plug the rcas in.
Reply (1) · Report · Alex M on Dec 29, 2014
· Add Answer · I Have This Question Too (0)
Hey I was wondering if on this "Power Pack" or any other, can you control the high-pass filter separately for the front and rear speakers? I like most people have smaller speakers in front than in the back.
dan6777 on Nov 3, 2016
Best Answer: Yes, I believe this and most 4 channel amps have a separate crossover for front and rear channels. The degree (frequency) at which you can set them varies however. Some speakers have a built in crossover as well., be cautious of tweeters as they been an in line crossover to filter out any lower frequencies
Reply · Report · Chad E on Nov 3, 2016
· Add Answer · I Have This Question Too (0)
I have a 2013 GMC Acadia Non Bose Factory Radio, i want to install the KTP-445U amp to add more power to the system. How do I hook up a 12 volt accessory power to this amp. This Acadia does not have this wire. This GMC has the 29-Bit Data Lan wire that powers on the radio. BTW will connect 12 volt constant to radio since it has a 15 amp fuse. Any Thoughts?
KY2112 on Aug 11, 2016
Best Answer: Without knowing the wiring diagram for the vehicle id say find an acc/ign switched fuse at the fuse panel and tap it there since all you need is a trigger wire
Reply · Report · harold k on Aug 11, 2016
· Add Answer · I Have This Question Too (0)
Will this fit Orem Dodge Journey head unit?
A shopper on Mar 29, 2016
Best Answer: I'm not a installer, but I had mine installed behind my Honda Ridgeline head unit.
Reply · Report · brett o on Mar 30, 2016
· Add Answer · I Have This Question Too (0)
can this amp be bridged to 2 channels @ 2 ohms? For 90x 2
A shopper on May 11, 2015
Best Answer: No, it cannot. Bridging the amplifier will obligate the setup to a 4ohm final load and above. Anything less will harm the amp and void the warranty.
Reply · Report · Rick MStaff on May 11, 2015
· Add Answer · I Have This Question Too (0)
If I am using the KTU-445U connected to a head unit that has 2V outputs compared to a unit with 4V outputs does it make any difference in quality of sound? In otherwords can I go with a less expensive HU with 2V outputs and not notice any difference in sound quality because I am going through the KTU?
b m on Jan 10, 2015
Best Answer: Thank you.. Being I am spending a fair hunk on the new system, it sounds as if to keep the monster inside of me at bay I better use a 4V system.. lol..
Reply · Report · b m on Jan 12, 2015
· Add Answer · I Have This Question Too (0)

Searches Related to the Alpine KTP-445U

Product Summary


Model Number






Internal SKU


Internal Product ID


Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: Alpine KTP-445U