Alpine KTP-445U vs KTP-445A

[Flyview]

Hi everyone!

I'm looking at adding an Alpine KTP-445U or KTP-445A to my system. I have upgraded speakers that can handle 50W RMS and an Alpine UTE-73BT currently outputting 18W RMS per channel. I figured the mini amp can give me a bit more volume and make full use of the speakers all while hiding it in the dash. I would like some input on which model to go with.

KTP-445U
-universal (could use it with other head units in the future)
-has line level (RCA) or speaker level inputs
-has cross over controls
-has gain controls

KTP-445A
-plug and play directly into Alpine head unit in between it and vehicle adapter harness
-no line level inputs?
-no cross over or gain controls

I know this is just an entry level amp but I'm curious what quality differences if any there might be between them. Seeing as the 445A plugs directly into the head unit harness connector, I assume it's getting speaker level input? Could this make a sound quality difference? How is it getting enough power through the head unit's power input alone (10A fuse) when it seems to have a 15A fuse itself? Do I need the gain control? I don't really think I need the crossover control because I believe I can do this through the head unit as well and don't have a sub.

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[metalheadjoe 10+ year member]

Difference between a universal power pack and an Alpine power pack is connections.

 

[gduncanson]

Hi everyone!

I'm looking at adding an Alpine KTP-445U or KTP-445A to my system. I have upgraded speakers that can handle 50W RMS and an Alpine UTE-73BT currently outputting 18W RMS per channel. I figured the mini amp can give me a bit more volume and make full use of the speakers all while hiding it in the dash. I would like some input on which model to go with.

KTP-445U
-universal (could use it with other head units in the future)
-has line level (RCA) or speaker level inputs
-has cross over controls
-has gain controls

KTP-445A
-plug and play directly into Alpine head unit in between it and vehicle adapter harness
-no line level inputs?
-no cross over or gain controls

I know this is just an entry level amp but I'm curious what quality differences if any there might be between them. Seeing as the 445A plugs directly into the head unit harness connector, I assume it's getting speaker level input? Could this make a sound quality difference? How is it getting enough power through the head unit's power in

Hi everyone!

I'm looking at adding an Alpine KTP-445U or KTP-445A to my system. I have upgraded speakers that can handle 50W RMS and an Alpine UTE-73BT currently outputting 18W RMS per channel. I figured the mini amp can give me a bit more volume and make full use of the speakers all while hiding it in the dash. I would like some input on which model to go with.

KTP-445U
-universal (could use it with other head units in the future)
-has line level (RCA) or speaker level inputs
-has cross over controls
-has gain controls

KTP-445A
-plug and play directly into Alpine head unit in between it and vehicle adapter harness
-no line level inputs?
-no cross over or gain controls

I know this is just an entry level amp but I'm curious what quality differences if any there might be between them. Seeing as the 445A plugs directly into the head unit harness connector, I assume it's getting speaker level input? Could this make a sound quality difference? How is it getting enough power through the head unit's power input alone (10A fuse) when it seems to have a 15A fuse itself? Do I need the gain control? I don't really think I need the crossover control because I believe I can do this through the head unit as well and don't have a sub.

Have you gotten your answers?

I have the 73bt and the 445a.
The A doesn't have the controls cuz they're in the radio. I had a 53bt in my Passat and it sounded great. Got a 73bt for my Jetta and it sounds weak. Found a reviewer who tested the 73bt HU and found its really only putting out 5w, not 18w. The Jetta is a lower end car, less sound proofing, road noise, etc so that may explain why.

So in the amp instructions it makes it pretty clear that if the factory battery lead is not rated for 15A, you must run a new wire, the Jetta is a 10A so ran a new 14G wire to the harness that adapts from the alpine to the factory radio connection. It's pretty cool that the entire amp sits inline and no cutting required with the A version.

Good luck.

 

[Flyview]

Have you gotten your answers?

I have the 73bt and the 445a.
The A doesn't have the controls cuz they're in the radio. I had a 53bt in my Passat and it sounded great. Got a 73bt for my Jetta and it sounds weak. Found a reviewer who tested the 73bt HU and found its really only putting out 5w, not 18w. The Jetta is a lower end car, less sound proofing, road noise, etc so that may explain why.

So in the amp instructions it makes it pretty clear that if the factory battery lead is not rated for 15A, you must run a new wire, the Jetta is a 10A so ran a new 14G wire to the harness that adapts from the alpine to the factory radio connection. It's pretty cool that the entire amp sits inline and no cutting required with the A version.

Good luck.

I have not, but you're helping!

Can you link to that power use test for the UTE-73BT? I have a battery monitor in my camper van where I'm running it and I too have only ever seen it pull maybe 20-30W total (about 5-7W per speaker) but was told this isn't a good way to measure it.

Yea, I understand the power pack wants 15A. Does it get that power separately or from its harness that plugs into the head unit? If it gets it through the head unit, would the current flow not be:

---> power source ---> head unit (10A fuse) ---> power pack (15A fuse)

That wouldn't make sense. Maybe it goes the other way around?

---> power source ---> power pack (15A fuse) ---> head unit (10A fuse)

 

[gduncanson]

Here's the link: https://www.audiosciencereview.com/forum/index.php?threads/alpine-ute-73bt-review-head-unit.23327/

power setup: I'm not electrically inclined. For my setup I simply bypassed the factory battery source and connected a new one of a higher rating from the battery. To your earlier point, The 445 is inline, I don't know if the A/U differ in power,; I imagine you could have separate feeds with the U version. The 73bt is downstream from the amp and gets its power through it.

My one week old opinion is that I thought I would be playing the radio in my car at half the volume level after the 445 was added. It is noticeable, but not half. I do think my speakers and car noise are factors too.

 

[Flyview]

Here's the link: https://www.audiosciencereview.com/forum/index.php?threads/alpine-ute-73bt-review-head-unit.23327/

power setup: I'm not electrically inclined. For my setup I simply bypassed the factory battery source and connected a new one of a higher rating from the battery. To your earlier point, The 445 is inline, I don't know if the A/U differ in power,; I imagine you could have separate feeds with the U version. The 73bt is downstream from the amp and gets its power through it.

My one week old opinion is that I thought I would be playing the radio in my car at half the volume level after the 445 was added. It is noticeable, but not half. I do think my speakers and car noise are factors too.

Cool, thanks for the link! It sounds like his power supply set up may have messed up a lot of things, but interesting none the less.

Ah okay, if the headunit is downstream from the amp, that makes sense! I imagined the head unit got power first and sent that over to the power pack, like it does the sound signal.

Now my only other question would be, does it make any difference that the head unit is sending the audio signal to the 445A over speaker level outputs instead of the low level outputs?

 

[gduncanson]

Cool, thanks for the link! It sounds like his power supply set up may have messed up a lot of things, but interesting none the less.

Ah okay, if the headunit is downstream from the amp, that makes sense! I imagined the head unit got power first and sent that over to the power pack, like it does the sound signal.

Now my only other question would be, does it make any difference that the head unit is sending the audio signal to the 445A over speaker level outputs instead of the low level outputs?

It does. I've always heard do rca outs if possible. In my application, the amp slips into the owners manual slot in the glove box. It's a compromise amp.

Your camper may have places to stow a larger amp.

 

[Flyview]

It does. I've always heard do rca outs if possible. In my application, the amp slips into the owners manual slot in the glove box. It's a compromise amp.

Your camper may have places to stow a larger amp.

And you'd see that difference comparing the 445U on line level vs 445A on speaker level?

Yea I could possibly use a real amp, but I'm not looking for too much of an improvement at the moment, and don't want to run more wires. I think I'd be happy with the extra punch from the Alpine 445.

 

[gduncanson]

And you'd see that difference comparing the 445U on line level vs 445A on speaker level?

No, I haven't compared them. speaking generally.

 

[Flyview]

I just wanted to update that I ended up installing the Alpine KTP-445A last summer and it sounds phenomenal. It gets way louder with clearer bass than the headunit alone. The speakers had already been upgraded previously. I don't have a 445U to compare with, so my original question remains unclear.