Plug and Play amp upgrade to basic system

[Varilux]

If you have the basic system (non-Alpine) and want to boost the power with an amp, there's a way to do so that will take all of about one hour to install...

The amp is the Alpine KTP-445U Power Pack (here's a link to it on Crutchfield Alpine KTP-445U Power Pack), and at $189, it's fairly inexpensive. This is by no means a huge amp, but it will give you 4 channels of 45w (which is more than double what the stock head unit puts out).

Okay, this is a universal amp- so how does it become plug-n-play? Well, the KTP-445U is the amp Alpine puts in its PSS-23WRA system (which also includes upgraded front dash speakers, and a subwoofer at a $1299 price tag). The PSS includes a harness for hooking that amp up to a JL, so all you have to do is order the harness to make it plug-n-play.

Crutchfield doesn't sell the harness separately, but you can purchase it at pacparts.com (which sells replacement parts for the Alpine PSS system). Here are the two harness parts you'll need:
Alpine 820SVV90ZUD-PQKUQV Main Harness ($42.86)
Alpine 820SVV90ZUD-WKUQV T-Harness ($42.86)
(Edit as of 1 September 2020- Apparently PacParts no longer carries these harnesses. My guess is Alpine noticed a number of harnesses were being sold and decided to discontinue them- requiring people to go the much more expensive Alpine PSS upgrade route.)

Unfortunately, the main harness was out of stock (and I'm impatient), so I just ordered the T-Harness and fabricated the main harness. Honestly, although it still only took about 2.5 hours to install from start to finish, almost 2 of those hours were spent building the main harness- so waiting a few extra days for the main harness to ship may have been worth it.

Here's a pic of the T-Harness and the ends of the KTP-455U. Although I had to splice the harness that came with the amp into the T-Harness, assuming you order the main harness all you'll need to do is plug one end into the outlets on the T-Harness and the other end in the KTP amp, and you'll be good to go.

I already have a powered subwoofer installed under my passenger seat, and if you do as well you'll want to grab the signal for the subwoofer before the amp, because the amp has dip switches which allow you several high-pass options for your speakers. You don't want to grab the signal after the amp, because if you elect to use the high-pass, you'll lose some of the signal to your sub. The T-Harness has a sub feed that is used for the Alpine system, and I originally tied into that. The sub worked, but for some reason I could not get much power out of the sub- so I spliced into the wires going to the amp and my sub worked just fine again. [Edit: A day later, I realized the sub feeds from the harness were low-powered, so I cut the ends off some RCA cables, spliced the RCA into the sub feeds from the harness, plugged the RCA ends into my subwoofer, and it worked perfectly. If you get the main harness, I believe it will include the RCA jacks on the sub end- just plug them into your sub of choice.]

One of the advantages of the Alpine KTP-455U's small size is you do not need to run a power cable to the battery- you can literally just tap into the power and ground used for the radio. Per Alpine's instructions, if the circuit that powers your radio is over 15A (the JL's radio circuit is 20A) you just tie right into your harness. Here's a pic with the T-Harness installed in the dash- you can see the blue taps where I've tied into the radio's power supply. Also, since the amp is so small, you can put it behind your glove box (I have mine just laying in the glove box for now until I have all the settings just where I want them).

The red end of the harness plugs right back into your radio just like the factory harness would.

I'm by no means an expert at this stuff, but I have installed a few amps in previous vehicles, and it really does not get easier than this. There's no need to add resistors into the speaker lines (this was the thing that kept me from adding an amp before), you just plug it in and it works.

How does it work? Pretty impressively considering it costs about $270 all in with harnesses! I have the gains set super low, (the minimum position is about 7 o'clock, the dials are at about 9 o'clock), and can turn the radio the whole way up without distortion. Of course, going past about 26 becomes deafening (for me, anyway- my 25 year old seemed to be enjoying it), but it's good clean power that will let me get loud enough to enjoy music even with the doors and top removed. My base system (with the 7" head unit) is very comparable to the premium Alpine system in my coworker's JL at this point. Here's what I've done:

Front speakers upgraded to a premium Kicker used in a Dodge Dart- direct fit) Mopar 77KICK25AB - $44.50 pair
Powered 125w 8" subwoofer installed under passenger seat Sound-Ordnance-B-8PTD - $169
Speaker Bar upgraded with SSV 6.5" pods SSV 6.5" Speaker Pods - $199 (including 6.5" speakers)
Alpine KTP-4 channel x 45w amplifier (described above, with links) - $270

I think that puts me all in at around $685, and I'm completely happy with my sound system at this point. It sounds great during normal driving, and I'll be able to overcome wind noise when my Jeep is in its natural state (doors and rear windows removed).

PS- Thanks to emgeesea for bringing the KTP-445U to my attention, it finished off my system.

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[JRod]

So the only splicing you have to do is into a power wire? Or did you have to splice into any speaker wiring?

 

[Varilux]

So the only splicing you have to do is into a power wire? Or did you have to splice into any speaker wiring?

Had I ordered the main harness, the only splicing I would have needed to do would have been the power and ground connection (you don't even have to hook up the trigger wire, because the amp senses the signal from the speaker lines coming in).

As it was, the main harness was on back order when I ordered (I think they indicated it would take 3-4 days to ship), so I just ordered the T-Harness. In retrospect, I probably should have just been patient- but patience isn't one of my virtues...

With both harnesses, this shouldn't take much more than an hour from start to finish (remove the radio, plug in 6 plugs, hook into power and ground, re-install radio).

 

[Varilux]

PS- I figured out why my original wiring didn't work for the sub. The feeds from the radio are a low signal (i.e., not speaker level), so I should have wired them to RCA plugs and connected to sub that way. In fact, I went back and did that, and there was further improvement.

Also, even if you don't purchase the main harness, there is no splicing into your actual factory wiring (all the splicing would be done on the T-Harness). If I want to return my system to stock all I would have to do is remove the T-Harness.

Having driven around with the amp installed for a couple days now, it is amazing the difference it makes. If you have the base system and want some more power- but have no desire to take it into a shop to have an amp installed- this solution is a no-brainer in my book!

 

[TJJL19]

PS- I figured out why my original wiring didn't work for the sub. The feeds from the radio are a low signal (i.e., not speaker level), so I should have wired them to RCA plugs and connected to sub that way. In fact, I went back and did that, and there was further improvement.

Also, even if you don't purchase the main harness, there is no splicing into your actual factory wiring (all the splicing would be done on the T-Harness). If I want to return my system to stock all I would have to do is remove the T-Harness.

Having driven around with the amp installed for a couple days now, it is amazing the difference it makes. If you have the base system and want some more power- but have no desire to take it into a shop to have an amp installed- this solution is a no-brainer in my book!

First off, I would like to thank you for posting this information. I did look at the PSS-23WRA upgrade,I though the 8 inch sub just wouldn't make it for me, I had a 2015 JKU( which my daughter was hit in ,thank the Lord, she is ok, but the jeep was totaled) that I added the Alpine under the seat 10 inch sub.
I was looking to do an upgrade, without cutting wires, nothing on the market that was cheep. I looked at the options, like the metro,pac and wasn't sure if they were the answer. I though I would search for the PSS-23WRA wire harness, I tried a hundred searches and found nothing,so again thank you for the post.
I was wondering if you could use the wire harness to add a sub and amp too? Do you think I could add a different 4 channel amp?

 

[Varilux]

I was wondering if you could use the wire harness to add a sub and amp too? Do you think I could add a different 4 channel amp?

I would think you should be able to use the T-Harness and Main Harness to install any four channel amp (you'll just need to snip the ends with the Alpine amp connectors). I like having the T-Harness, because it makes anything I do completely reversible- just remove the harness and nothing about the factory wiring has changed. I've been wanting to add a sub for a year, but didn't want to cut into my factory harness (plus I kept reading about the need to install resistors in each channel, and just didn't want to bother with that). These harnesses made the project easy enough to motivate me to go ahead and add some punch.

Also, the T-Harness and Main Harness also feature a four wire feed for a sub- so you should be good to go with whatever sub you want to add.

 

[apayne0528]

Does this upgrade make your system louder overall? For example, I like my music loud so I max my volume out on my factory system. Does this make the volume at, say 25, louder than the 25 would be on my factory system? Also, I would buy the main harness, would I need anything in particular to splice into the ground and power? Any kind of piece to reconnect the wires? I have experience with sound systems some what, I just want to make sure I get it right the first time. Thanks in advance!

 

[Varilux]

Yes, definitely louder! Even with the front and rear gain set to the minimum, at the 25 volume setting I can hear my music just fine even with the doors and windows removed. Setting the gain any higher would probably require better speakers (I have upgraded everything except the knee panel speakers, so they're distortion-free even when amplified).

I start to get a little distortion around 35, but honestly the volume is so high by that point it is pretty much deafening (even my son, who always cranks his music said 25 was plenty enough with the amp installed).

As far as connectors, if you order the main harness as well the only connectors you should need are for the power and ground wires. They're in the one of the pics I posted- the two blue pieces (I don't know what they're called- you run the wire you want to connect into one side, the wire you're connecting to in the other side, then you push down a metal piece and clamp it shut).

 

[apayne0528]

Yes, definitely louder! Even with the front and rear gain set to the minimum, at the 25 volume setting I can hear my music just fine even with the doors and windows removed. Setting the gain any higher would probably require better speakers (I have upgraded everything except the knee panel speakers, so they're distortion-free even when amplified).

I start to get a little distortion around 35, but honestly the volume is so high by that point it is pretty much deafening (even my son, who always cranks his music said 25 was plenty enough with the amp installed).

As far as connectors, if you order the main harness as well the only connectors you should need are for the power and ground wires. They're in the one of the pics I posted- the two blue pieces (I don't know what they're called- you run the wire you want to connect into one side, the wire you're connecting to in the other side, then you push down a metal piece and clamp it shut).

Thanks man! I think I'm going to use the same setup except a 10" slim sub with the RCA low inputs. I can't wait to get my music louder!

 

[TJJL19]

I would think you should be able to use the T-Harness and Main Harness to install any four channel amp (you'll just need to snip the ends with the Alpine amp connectors). I like having the T-Harness, because it makes anything I do completely reversible- just remove the harness and nothing about the factory wiring has changed. I've been wanting to add a sub for a year, but didn't want to cut into my factory harness (plus I kept reading about the need to install resistors in each channel, and just didn't want to bother with that). These harnesses made the project easy enough to motivate me to go ahead and add some punch.

Also, the T-Harness and Main Harness also feature a four wire feed for a sub- so you should be good to go with whatever sub you want to add.

I'm going the easy route,getting the KTP445U and I already ordered the T harness and wire harness.
I was thinking of adding the Alpine S-A60M and the SSV Works JJL-DS10.
When I ordered the harness,I didn't think I would need the RCA jacks and at 42 dollars,I was hoping I didn't. The only RCA I need, is the one that plugs into the wire harness. for the subwoofer amp.
The shipping on the harnesses was 23.00 dollars and I certainly don't want to pay that again.
I watched Quadratec video on the install of the Alpine PSS 23WRA and looked on the internet for that RCA connector with no luck,do you have any suggestion?

 

[kd1yt]

Many thanks Varilux for posting this. I want to do something very similar with a Kicker Key 180.4 amp which is also a 45w x4 amp and about the same size as the Alpine that you used. Wanted to ask - where did you mount your Apine KTP-445U and how did you physically attach it? Thanks!

 

[Varilux]

When I ordered the harness,I didn't think I would need the RCA jacks and at 42 dollars,I was hoping I didn't. The only RCA I need, is the one that plugs into the wire harness. for the subwoofer amp.
The shipping on the harnesses was 23.00 dollars and I certainly don't want to pay that again.
I watched Quadratec video on the install of the Alpine PSS 23WRA and looked on the internet for that RCA connector with no luck,do you have any suggestion?

I would just purchase an RCA cable, cut the wires, and tie them into the main harness (in fact, that's exactly what I did). The main harness will have four wires that run to the sub (indicated with a label "sub out"). Just attach the main harness and then at the other end of the harness splice in the RCA connectors from the cable you cut and you should be good to go (that's basically what I did).
I would think you'll be thumping pretty nicely with that SSV 10" subwoofer! The little 8" SoundOrdinance powered amp I have under the passenger seat is only 125W, and it provides plenty of thump for me. We were out running errands with the doors and windows off yesterday, and even at 80mph we could hear the music just fine. I'm really happy with my audio at this point.

Many thanks Varilux for posting this. I want to do something very similar with a Kicker Key 180.4 amp which is also a 45w x4 amp and about the same size as the Alpine that you used. Wanted to ask - where did you mount your Apine KTP-445U and how did you physically attach it? Thanks!

In the Alpine PSS23-WRA set-up, the 445U is mounted right next to their sub under the passenger seat. I already have a different sub under my passenger seat, so I just have my Alpine sub in my glovebox at the moment (since I knew I'd be fiddling with the gains for a while). Now I realize the gains need to be set pretty close to the minimum level (which still makes the system considerably louder and crisper than before), so I'm going to zip tie it up above the glovebox (to the vent tubing). The advantage of it being so small is you can put it just about anywhere. Some who have installed this amp have put it directly behind the factory radio. However, if you are using the T-Harness, there is no way the amp is going to fit back there (you have to do a bit of shuffling to get the radio back in with just the harness back there... it will definitely fit, you just have to move things around into the proper orientation).

I really like that Kicker amp- I think the feature where it sets all the crossovers and gains will come in handy (the three band equalizer on the stock head unit doesn't provide much ability to tune the system).

Let me know how these installs go- I think you'll both be surprised at how much a small amp improves things!

 

[kd1yt]

Thank Varilux - I haven't dug into my dash yet so was not sure on how much space there might be behind or above the glove compartment, but if I can fit the Key amp up in there that would be ideal. I am replacing my smaller speakers with 2" Fountek full-ranges (with adapter plates, and with crossover capacitors to run them from 400Hz-up) and will be replacing the factory 4" speakers in all locations with Dayton 4" speakers with toroid crossover chokes to run them from 400Hz down. Your revealing that there is adequate power for a small amp without a new dedicated power feed is a huge simplifying factor.

The key not only does EQ, it also has capability for DSP delay to get best sound in the driver's location. The idea of 'smart DSP' integrated into a small affordable amp is absolutely brilliant

Unfortunately I injured my back badly last week so it is going to be a substantial while before I will be scrunching in and around dashboards and such....

 

[TJJL19]

Varilux, when you got your Mopar 77KICK25AB were they in a mopa box? In the picture it looks like there is a plastic piece, that sit on top of the speaker? Is it part of the speaker.

 

[Varilux]

Varilux, when you got your Mopar 77KICK25AB were they in a mopa box? In the picture it looks like there is a plastic piece, that sit on top of the speaker? Is it part of the speaker.

My speakers look like this (they just have a screen instead of the black plastic), but it looks like the screen is on top of a black plastic ring that is just as tall as the plastic shield on the speakers in the link's picture- so the fitment should be exactly the same. IIRC, my speakers came in a Mopar box, and it was plug and play- the connector in the Jeep plugged right into the speakers.

The 77KICKAB speakers are nice- I installed a set of them into the center dash of my '65 Mustang as well (which as luck would have it uses the exact same size speakers).

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