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 open the box,
verify contents, 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.
Overview: The Alpine KTP-445U Head Unit Power Pack is an
easy-to-install 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.
Note: 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.
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
- 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
- Max Power Output: 90 watts x 4 channels
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
- 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
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.
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
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.