# Alpine KTP - 445



## shanek (Sep 5, 2008)

I suppose I am just wondering if anyone has been able to try this little guy out? There really is a lack of information for something that was supposed to have been released in March.

For those who are unfamiliar, it is supposedly a micro amp that boosts Alpine HU's from 18rms to 45rms x 4. Plug and play simplicity, but supposedly only retailing for $100. Also read it uses Alpine's PDX technology, so the power should be fairly clean.. 

I have been keenly looking into this item for a few days now, and am unable to find much, if anything, about it.

Thoughts? Experiences? Don't bothers? 

Humbly Grateful,
Shane


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## Daniel` (Jul 26, 2008)

Why even bother?

I mean, 45rms isn't really that much..


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## shanek (Sep 5, 2008)

Well, it's 150% more than 18rms.. 

And it's a good boost for beginners. Small wattage, but it's virtually plug and play.

For instance, I installed 4 Alpine Type-S in my car. They're rated at a mere 50rms. I also just installed a Dayton r12" HO w/ 600rms in 1.5ft^3 @ 28Hz. The sub is awesome, but a bit overwhelming at times. So, instead of buying a 4x50 amp for barely worthwhile speakers, plus wire, distro blocks, rca's, fuses, time, etc.. you can just throw one of these in as a temporary fix. I haven't even deadened my car as of yet, that's my next step. I'd like to do that before dropping $$ on a component set, plus it'll give me more time to continue reading / learning.

I suppose I am trying to say that it is a good thing for people who are beginning to learn their systems, before they want to take huge strides in upgrades, because they don't believe that they know enough to make it worthwhile quite yet. I mean, $100 for 4x45rms CEA-2006 isn't bad, let alone the fact that is cuts out the wiring?

The different between 18 and 45 rms should be quite noticeable, no?


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## What? (Jun 5, 2008)

Alpine says it is a significant improvement over deck power and for $99, I think not bad for cheapskates. Has not shipped yet.


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## sobe_death (Jul 31, 2008)

This thing has shipped now, but it is still incredibly hard to find info on it. My main question is whether or not you can bridge it :devil:

YouTube - Alpine KTP-445 Head Unit Power Pack


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## JayinMI (Oct 18, 2008)

No. It is not bridgeable. It's not even a "real" amp. Of the ones we've installed so far, I could tell no audible difference between radio power and this unit. It really makes very little difference.

Jay


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## diamondjoequimby (Jun 30, 2009)

JayinMI said:


> No. It is not bridgeable. It's not even a "real" amp. Of the ones we've installed so far, I could tell no audible difference between radio power and this unit. It really makes very little difference.
> 
> Jay


I disagree. I think they do make a difference. You get quite a bit more headroom with them vs. the chip amp in the h/u. They are not as nice as even say a MRP-F300 @ 50x4 but you save the cost of wire and time or install cost. By no means are they a SQ amp, but they are a nice option for someone who wants more than a h/u will offer power wise but wants to spend very little.


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## sweater914 (May 28, 2009)

I just installed 2 of these in older vehicles that I own. I didn't want to spend alot of money but wanted more than the stock HU power. The units get the job done and save some space.


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## jooonnn (Jul 26, 2009)

Bought one from crutchfield when it first came out. It's class D and doesn't perform high's to save its life. It might have a small increase in head room, but is NOTHING compared to a real amp, can i stress NOTHING? Save the money and spend $30 more on a MRP-F300 if you are on a budget.


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## placenta (Feb 2, 2008)

my only question is:

is the sound at least cleaner than the bare unmolested head unit? I saw the snR on this thing was like 85db or something. Pretty sure my new alpine head unit is much higher than that. I would prefer cleaner sound to more muddy volume.

I havent opened this package yet, until I see a few more reviews. In case I want to return it.


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## ZAKOH (Nov 26, 2010)

Waste of money IMO. You can't bridge it. You can't move it to a different car without an alpine unit. 45watts is not much.. moreover this is just their spec. It could do worse in real life. After all, how much amps of current can it see given that it is powered by the stock head unit power wire? Those are usually fused at 10-15amps at best.

If you want a cheap amplifier, consider this:

Precision Power PPI S320.4 4-Channel Car Amplifier/Amp (S3204)

or

MB Quart REF4.50 4x50watt RMS amplifier.

MB Quart REF4.50 4 Channel Amplifiers at Onlinecarstereo.com

A car audio web site did a test of the discontinued REF4.80 (the 4x80watt version). That unit provided 4x110watts RMS (but was rated for "only" 4x80). I assume the REF4.50, the 50watt version, is underrated somewhat too. Besides that, the unit had very low noise and high channel separation. The only issue is that REF4.80 is difficult to find right now, but some stores still carry REF4.50 for very low price. Good value IMO.


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## placenta (Feb 2, 2008)

hmm another person mentioned a bench test showing it was putting out even more than specified.. i got about a 50/50 split on opinions on this..


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## kyheng (Jan 31, 2007)

I won't say this Alpine amp are an useless amp at any 1 time.... 
Just the seperate power supply to the amp already better than using HU's speaker outputs that sharing the same power supply for everything, from powering the CD mech, USB support, radio. This may cause some noise sometimes...


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## placenta (Feb 2, 2008)

makes a difference for sure. I'm in the middle of my install. tested a base alpine deck with and without the 445 unit. (Alpine deck 124XM or something)

same song. without 445 the sound would break up at volume 20. then i added the amp inline. same song, volume could then go 23-24 without breaking up.

i never liked Alpine PDX amps tho.. i hate them. The sound is so lifeless. So I heard this 445 is the same design. So I wonder if the bare deck would have a little better sound quality or highs, even if its not as loud.


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## its_bacon12 (Aug 16, 2007)

18w rms to 45w rms will give you +4db or so.

Worth the $100? Probably not. But it's all about preference and subjectivity unless you can measure it.


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## gt.in.it (May 30, 2011)

personally save your money, the amout of gain is minimal and those amp put out a lot of distortion. overall not a good amp


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## placenta (Feb 2, 2008)

it was good to get back into a stereo install. havent done one in a long time.

The first 3 pics show the Alpine mini-amp. About the size of a "brick" on a big Asus laptop. This is an inline amp, which requires no power connection at all. You just put it into your oem adapter and then to the Alpine deck. Simple as that. It is a 45Wrms x 4 amp, which is a nice improvement over the decks 18Wrms x4. This amp design is similar to the Alpine PDX amp design.




























This is the XM/SIRIUS module which was included in the deck box, all as one package. It just plugs into the back of your deck, then you run your antenna.










The next 3 pictures showing the wiring preparation and routing:




























The common spot for the SIRIUS antenna, on the top of the sound bar, hidden under the padding. Fiberglass does not block signal.


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## placenta (Feb 2, 2008)

The next 3 pics show the deck installed. This deck has everything but HD Radio. It has XM/SIRIUS, Pandora, USB, AUX, CD, AM/FM.




























The last pic is the amps jumper i forgot to check into. So I broke the tie wraps and did some testing. The LO setting is a lot better. The HIGH setting has more distortion and stress. (Much like a RCA vs hi level inputs theory)










Thoughts.. it all went well mostly. Only thing I don't love about the METRA install kit is how deep the deck sits into the hole. Also, those 2 visible slot holes above the deck. Those are for an ISO mount solution which I didn't use. Suppose I can't really see them unless I really try.


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## placenta (Feb 2, 2008)

my system still sounds pretty crappy after that amp. im sure my speakers are pretty poor, but that amp doesnt seem very special either. I would guess the head unit with less circutry might just be a slightly cleaner signal. I might bypass the amp and do some more tests. It is in my deepest beliefs over the last 10 years here that any amp that doesnt have a dedicated power source is useless. But I wanted to try it to find out for myself.

That being said, i do want to examine that amp holding place under the steering wheel, maybe i can find something interesting. Although.. this deck only has 1 RCA output anyway, so I would have to get a new deck too.


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## ScaryfatkidGT (Mar 31, 2012)

Mhh I really wanted to get this but I guess not now.

Why do you guys say that 45watts RMS isn't that much? Alpine usually under rates there stuff but I always wanted a 100x4 channel amp but after getting my sub and cutting the lows out of my factory speaks they go almost as loud as I would ever want. An amp would sure help but I was looking at about 45 to 50rms.


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## placenta (Feb 2, 2008)

probably cuz a decent 50x4 amp is about 4X the size of this one.


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## tophatjimmy (Dec 16, 2005)

If you're wanting decent power but still wanting small size, this one fits the bill pretty well. Not plug and play but still....

Rockford Fosgate PBR300X4 Compact 4-channel car amplifier — 75 watts RMS x 4 at Crutchfield.com


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## ZAKOH (Nov 26, 2010)

ScaryfatkidGT said:


> Mhh I really wanted to get this but I guess not now.
> 
> Why do you guys say that 45watts RMS isn't that much? Alpine usually under rates there stuff but I always wanted a 100x4 channel amp but after getting my sub and cutting the lows out of my factory speaks they go almost as loud as I would ever want. An amp would sure help but I was looking at about 45 to 50rms.


This one could well be overrated. This is because people usually run solid wiring to their dedicated amps, so they rarely experience big voltage drops. But this one is using the power and ground wiring of your stereo. The factory stereo wires were not meant to power a capable amplifier.


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## its_bacon12 (Aug 16, 2007)

ZAKOH said:


> This one could well be overrated. This is because people usually run solid wiring to their dedicated amps, so they rarely experience big voltage drops. But this one is using the power and ground wiring of your stereo. The factory stereo wires were not meant to power a capable amplifier.


I doubt it's overrated. Even if it were, 10% over rated would mean it's actual output were 40w rms. No difference in terms of reality from 45w.

It's class D so it runs efficiently, most likely not drawing more than 5-10 amps unless driving sine wave.


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