Help with Electrical Issues - Old Alpine 12" Type R, Alpine MRP-500 Amp

shepard715

CarAudio.com Newbie
Sep 20, 2022
3
0
Hello! Going to start by saying that building computers is more my stride, not car audio, so please bear with me. However, I have a very frustrating issue I'd like to get some input on.

Vehicle: 2014 Toyota Corolla, stock head unit and speakers
Subwoofer: Old (looks like this one ) Alpine 12" type R in a ported enclosure
Amplifier: Alpine MRP-M500 Mono

Stock speakers. Everything is wired into the head unit without an external controller. Everything has worked great for years - the setup has been through 2 different cars. Replaced the inline fuse last winter. After sitting for a few days, sub no longer works. Amp still had power. Checked with multimeter, getting readings through all plugs. Removed the old sub, put in another car, and it works. Putting another sub in this car does not work. I figured maybe something was wrong with the RCA signal - traced it to the wiring harness, ran a 15' RCA cable from my car to a car with a working amp and sub. Worked beautifully. So, RCA signal from the head unit is good, power is good, sub is functional. Possibly an issue with the RCA input on the amp? Today, I went and bought a new amp (Kicker CX 400), knowing that it was a lower power than my Alpine. Installed it - nothing.

EDIT: I grabbed an RCA to 3.5 mm jack pigtail and hooked my phone directly into both the Alpine amp in my car and the working system in another car. No sound from the sub in my car. Worked in the other.

Sorry for the long story - my question is, could it be that the 400 W Kicker just doesn't have enough power for a 15 year old Alpine 12" type R? Everything I've read suggests that it should still work. I very much appreciate any input or suggestions.
 

deez283

Senior VIP Member
10+ year member
Apr 29, 2009
639
221
The new amp wouldn't be too little power. You can power the sub with 1 watt.

Did you try a different RCA cable in this vehicle?
 

shepard715

CarAudio.com Newbie
Sep 20, 2022
3
0
  • Thread Starter Thread Starter
  • #3
Thanks for the reply. I did, I got a long RCA cable and tried it with both my setup and the other vehicle's setup. Nothing in my car, worked great in the other. That's why I was leaning towards an issue with the RCA input on my amp, but with the new amp, still no sound from the subwoofer.
 

shepard715

CarAudio.com Newbie
Sep 20, 2022
3
0
  • Thread Starter Thread Starter
  • #4
The new amp wouldn't be too little power. You can power the sub with 1 watt.

Did you try a different RCA cable in this vehicle?
Thanks for the reply. I did, I got a long RCA cable and tried it with both my setup and the other vehicle's setup. Nothing in my car, worked great in the other. That's why I was leaning towards an issue with the RCA input on my amp, but with the new amp, still no sound from the subwoofer.

EDIT: I just noticed that protection mode is on with the new amp. The old amp didn't have any sort of indicator for that (that I know of). Nothing has changed in wiring - the car just sat for a few days.
 

spokey9

5 time International Booty Bandit Gold Meldalist
Apr 10, 2022
1,677
619
If the car sat maybe you got low voltage to your amp from idle drain
 

Bobbytwonames

Trigger Man!
5,000+ posts
Aug 28, 2018
12,593
-192
What ohm is the sub (DVC4 or DVC2)? Are you possibly wired too low for the new amp?
 

Create an account or login to post

You must be a member in order to post a message

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Latest threads

Latest posts

Latest classifieds