How to INSTALL AN AMPLIFIER in a Porsche Boxster 986 (Alpine KTA-450)

How to INSTALL AN AMPLIFIER in a Porsche Boxster 986 (Alpine KTA-450)

Here is the latest upgrade for the sound system in my 1998 Porsche Boxster. I replaced the factory Harmon Kardon amp with a 4-channel Alpine KTA-450.

This video shows the detailed process all the way from removing the old amp to installing the new one.

I have other videos on my channel that show how I already upgraded my speakers and head unit if you’d like to see the entire overhaul.

Hope this helps, as I could not find any good videos on installing an amp in a Boxster. Please like the video and subscribe! Some of the components I purchased are linked below:

Alpine Amp:

12-gauge wiring kit:

4-Channel RCA cable (12′):

RCA Barrel connectors (2 pairs):

101 Projects for your Porsche Boxster book:

986 Service Manual:

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I am a Do It Yourself, also known as DIY, mechanic. I am NOT a professional mechanic. I do not have any formal training in the automotive field.

Help Me DIY assumes no liability for anything you choose to do to your car, before, or after watching one of my videos or utilizing the content from this web site.

All DIY repairs or modifications you perform to your car are made at your own risk. Sometimes, even if you’ve done everything the right way, you can destroy or damage one or more things on your car. You must understand this, but by leveraging knowledge and patience, the probability of encountering one or more problems can be reduced.

Also, if for some unfortunate reason, I do give incorrect instructions and something breaks because you followed my instructions, I will NOT reimburse or pay in any way for whatever cost that may be incurred due to following my wrong instructions.

Lastly, please don’t do anything to your car unless you yourself feel comfortable and confident in doing so.



Aaron Nichols says:

Great again, any video on the head unit install?

deep6this deep6this says:

brutalizing the fasteners…there are cheap plastic tools designed to remove those "christmas tree" fasteners.

Hal Carter says:

please , buy some tools

Thad Bolline says:

I might have missed it, but is there a reason that you cannot use the existing (factory) amp's power connections and not have to run an additional line for the new amp's power?

David George says:

Which color combo on the OEM wiring hardness did you hook up the blue and white "remote on" wire to?

DR. Smith says:

Wow! I never heard a car stereo with absolutly no bass ….nice song choice

Louis-Philippe GariƩpy says:

Just wanted to say thanks, I had already upgraded the dash and door speakers and switched to a 2-DIN radio, but this video was truly helpful for the amp!! Now looking into solutions for more bass…


The alpine bracket you used was for mounting the amp to the alpine ilx-w650 headunit their should have Been a second set of smaller brackets. Decent video none the less.

MichaelV says:

I just upgraded to a double din carplay head unit. Figured I might as well change the amp now since all my speakers are upgraded as well. I noticed after the new head unit that theres almost no more mid bass coming from any of my speakers. I'm guessing the speakers just aren't getting enough power which is another reason why I want to replace the amp. Also the rear speakers I installed are only running of the head unit right now so I wanna wire those to the amp as well.

Matt Nicholson says:

If you're replacing 4 ohm speakers with 4 ohm speakers, why do you need to replace the amp?

Natovision says:

I'm very confused by the switches and diagrams. They seem upside down compared to the diagram.

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