Help - More Amp issues

A

ABETRMAN

Member
Location
Washington
Car
2004 FX35 RWD
Name
Johnny
So, resolved the previous issue (///8482) by getting a new amp. Turns out the old amp may be what's having the problem. Anyway, so now I have a new Alpine MRP-M500 hooked up and all seems well with the exception that I am getting no output. I have tried several methods of trouble shooting. As background, I am using the factory sub lines to provide audio signal to the amp.
1. Using a output convertor, hooked up the amp as I had the previous amp(Alpine MRP-F250) before. No output. Was told no need for this due to the fact thefactory sub line is already a low-level out put.

2. Used the speaker level input harness provided with the amp. White wire to the 2(+) wires and Black to the 2(-). Hooked it up - No output

3. Hook the factory sub output lines directly to the aftermarket sub speaker wires. Got sound, not what it was supposed to be, but sound none the less.

This is telling me that something is happening at the amp that is keeping it from pushing the speaker. Any ideas - I am going crazy over here trying to understand what the problem could be. Been without my sub for a couple of weeks now - makes the commute to work just that more exhausting. Help - thanks in advance.
 
ABETRMAN said:
So, resolved the previous issue (///8482) by getting a new amp. Turns out the old amp may be what's having the problem. Anyway, so now I have a new Alpine MRP-M500 hooked up and all seems well with the exception that I am getting no output. .....

....Help - thanks in advance.
Click to expand...

Take a couple photos showing every connection on your installed amp, post them, and note where each wire is going. Someone here will know what's up.
 
I have all of that..8 gauge for the ground and power..plus remote. that's all connected properly. the amp is powering up, however, no audio
 
Did you try this?

Input Gain Adjustment Control:
Set the MRP-M1000/MRP-M500 input gain to
the minimum (4V) position. Using a dynamic CD
as a source, increase the head unit volume until
the output distorts. Then, reduce the volume 1
step (or until the output is no longer distorted).
Now, increase the amplifier gain until the sound
from the speakers becomes distorted. Reduce
the gain slightly so the sound is no longer
distorted to achieve the optimum gain setting.
 
No i haven't. I thought that was only to make the adjustment once you are getting audio. the fact i was not getting anything was what concerned me. i will give that step a try. thanks.
 
if the sub output is low level then you need to feed it into the low level input of the amp, not the speaker level inputs. the low level input of the amp is the rca inputs. if your sure that it's low level then try it connected to the rca inputs
 
thanks turbocad, i tried that type of connection as well. i did the white feed (+) to the inner wire of the rca and the black feed (-) to the outer wire..I am personally not sure if it is low-level already. a member on the org said that is was. he has been very helpful and suggested trying the rca connection. it still didn't work. could be user error on my part but i am alright at doing simple installs. that is why this one is so frustrating. i don't think it is something wrong with the amp, not even two days old yet, but your never know.
 
- Sub levels ARE low level...do not put them to the high level inputs.
- Check the Gain of the amp
- Check to make sure your fader off the head unit is not faded to the rear...for whatever reason Infiniti decided to make it lower the sub volume when you put the fader to the rear speakers. Make sure its to the front or middle of the fader adjustment at the headunit.
- Switch the RCA's from left/right to right/left.

- GOOD LUCK

FXtion's DIY:
///2811

1)Using a output convertor, hooked up the amp as I had the previous amp(Alpine MRP-F250) before. No output. Was told no need for this due to the fact the factory sub line is already a low-level out put.

Yep, you were making a low level input and converting it to a low level input. Only thing it will help you to get an RCA easier...just plug the RCA's in and your set. If no sound, switch the RCA's around, or maybe you have some of the wires mixed up?

2) Used the speaker level input harness provided with the amp. White wire to the 2(+) wires and Black to the 2(-). Hooked it up - No output

Because its a low level line, not a high level line. Wont work, or very low output.

3)Hook the factory sub output lines directly to the aftermarket sub speaker wires. Got sound, not what it was supposed to be, but sound none the less

Wouldn't really work...the sub amp is located in the sub box, so you were feeding it a line with no amplification straight off the head unit. You were probably feeding the sub 2wtts. lol
 
Thanks toy4x. I do have the fader set to the back. I will make the recommended adjustments and see if this thing decides to act right.

---------- Post added at 12:51 PM ---------- Previous post was at 07:57 AM ----------

Is there a minimum amout of power required to get the amp to produce sound? I mean, it is powering up, but could it not be enogh power for the amp to push the sub?

---------- Post added at 01:52 PM ---------- Previous post was at 12:51 PM ----------

Ok, so I ran RCA's directly from the HU (alpine cda-9883) sub output to the amp. Set the power-ic (HU nternal amp) to off. Still no love from the amp. I am pulling out the little bit of hair that I have. Please, if you got any other trouble shooting ideas, please let me know. Don't know how much longer I can go without "my" music. Thanks for your help so far!
 
A couple more ideas:

1. Turn your LP filter all the way up (clockwise) to 250Hz, adjust the fader on your head unit to the center, and play a bass heavy song. The amps internal crossover may be filtering out your music entirely.
2. Reconnect the Bose sub and see if it still works. (to eliminate any problems outside your amp)
3. Go get an 1/8" to RCA adapter from a music store and plug your ipod into the amp. (To verify that the amp is working correctly)

If none of that works...

4. Post this thread on a car audio forum?
 
Tchuck,

tried step 3, still no luck with that. something i did notice is that i am not getting 12v on the amp at the power connection. i am from the remote, but not from the battery. Could this have a negative impact?
 
um yeah

---------- Post added at 05:51 PM ---------- Previous post was at 05:50 PM ----------

there should be 12v from the battery going to the amp and the remote should give you 12v as well. check your ground as well.
 
Check the inline fuse. Although I doubt it would turn on with the fuse popped. Fuse at the battery and the fuse in the amp.
 
Just to verify;
-The power cable should be connected directly to the battery with a single 8AWG cable (as opposed to through the fuse box or any terminals), should have a fuse within 6" of the battery, and should show a constant 12v signal whether or not the ignition is on.
-The ground should be the same gauge cable, should be connected to the closest reasonable grounding location to your amp, and should never show a voltage. One common grounding location is the rear seat belt to frame bolt. Just as a test you can run it to the negative battery terminal but it's not a great idea long term. In fact it's a really really bad idea long term. If it works like that, your original grounding location is the culprit.
-The remote line should be coming from the head unit via the sub harness and should show a 12v signal only when the radio is turned on.

If these are true and it still doesn't work, save the rest of your hair and take it to a pro. :wink: It probably wont cost much to have them troubleshoot it for you.
Good luck.
 
OK, so, I feel like a real dummy now. I got her working again. It appears the wire at the in-line fuse was loose and was not maintaining the power across it. While I feel bad, I must say I learned a lot in this process. Thanks to all of you for trying to help me out. I really do appreciate it.
 
Yeah, what crazy is that I swear I looked at everything regarding that when I removed the fused, but it was just loose which was just enough to cause the power lacking. Now I have to hook my four channel up to see if it is something wrong iwth it or if its was just in safe mode. At least I go a new amp out the deal. Thanks again.
 
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