Just wondering if anyone has tried the Alpine KTP-445 "Power Pack" with their Alpine head units. I purchased one today and just installed it with my CDA-9886. I still have the OEM speakers right now but I plan on upgrading them soon.

I was looking for a little more bass response but my lazy self didn't want to do any wiring or buy a separate amp. Happy to report that the KTP-445 did exactly what I needed it to do with the least amount of hassle... everything was plug and play! I would definitely recommend this to anyone with an Alpine head unit in a similar situation.

I don't work for Alpine... just thought it would be helpful to share this bit of information. Cheers .

Crutchfield: Alpine KTP-445

 

I have installed a few of these in some vehicals.. Its not bad and an easy way to up the power on the deck. Not a big gain but it is noticable. The downside, a few of the cars I had to run seperate power from the ignition harness for the KTP because it would draw so much power it would blow the factory fuse..

 

Is there any way to hack in and bridge this thing? 90x2 would power a nice set of components....

 

Depends on the design of the amp. If the amp uses the typical IC amplifier for car stereos and Alpine just bumped the supply voltage to 18 or 20 volts then no, it's already bridged so you can't bridge it again. But if they used a circuit similar to an out-board amp then it may be bridge-able. If you have a meter you can find out.

Disconnect all power and speaker leads from the amp.
Set your meter to the lowest resistance scale
Measure the resistance between these speaker output terminals:

Left Front + to Right Front -
Left Front - to Right Front +

If one of these measurements is zero ohms then it's easily bridge-able, but I'd be very surprised if that's the case.

If you do find that one of the above pairs of terminals are connected to each other, those terminals are the "common" side of the power supply and power amplifier. That means you need to use the other two terminals as the bridged output. For example, if you find that Left Front + and Right Front - are connected, you should use Left Front - and Right Front + for the bridged output.

If you find it's bridge-able that does not mean the amp can handle being bridged. Bridging requires the amp to supply twice the current as when operated in normal mode and not all amplifiers can do that without overheating or just plain frying.

Last ditch test - If you find that one of these combinations gives zero ohms:
Left Front - to Right Front -
Left Front + to Right Front +
it may still be possible to bridge the amp, but you must reverse the phase of one input channel (left or right, not both) that feeds the amp. Usually the inputs are ground-referenced so you can't just reverse the wires, you need to add an outboard phase reversal device and I don't know if those are available commercially. I've done this in the past with a small op-amp circuit that I built but please do not ask me to build one - no time. You may find something on the Internet as "inverting amp" or "inverting op-amp". You essentially want to use a single source (left or right) and feed it to both the left and right amplifiers, but invert the signal on one input channel. This causes the output of that channel to be 180 degrees out of phase with the other channel. Now when you connect your speaker to these two "out of phase" terminals you end up with twice the voltage going to the speaker.

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I just had the same setup put in my car (9886 head unit + power pack), but I have some aftermarket pioneer speakers in the front. I didn't think much of the pioneer speakers with the stock HU, but after swapping the head unit and adding the power pack they sound dramatically better. I can only turn up my head unit 2/3 of the way before it gets too loud, and listening to it with the top down is no problem. Music is much more crisp and clear, and bass is much less muddy than before. I highly recommend this setup to anyone who wants to save a little money and space.

 

what kind of pioneer speakers did you have installed? i'm looking for a decent set of aftermarket speakers but would prefer not to cut the oem speaker basket.

 

I don't know what they are. I bought the car last year with 17K on it and they were already installed by the previous owner. They guy who installed my head unit and power pack took a peek at them and told me they were Pioneer. I'm going to swap them out for some Boston Acoustics Pro60 SE next week anyway. I am ordering them from Sonic Electronix for $273. I've had Boston Acoustics Pro series in my other cars before and was really impressed with the sound. They should clear the window with the included spacers. Gonna Dynamat the doors at the same time to make them sound better. I'll let you know how they turn out.

 

I had the power pack on my 9886 HU to power my Polk Audio db6501 Components. But i had to take it out cause i lost some bass from my speakers. My speakers sounded way better with just the HU powering it.

 

Did you guys place the power pack in the space behind the radio? Sorry I'm a total newb at audio.

RattleHead: I am thinking of purchasing the same Polks for my S, did you spend a lot of time with the settings to get the bass to sound better with the power pack? I wonder why you had problems? =(

 

The Power Pack wont fit behind the radio...as for the settings, i did everything to find the sound that i wanted but it was just not there so i decided to just take it out.

You won't go wrong with the Polk Audio db6501 they really sound good. The only problem is the OEM mounting screws won't fit.