I'm going friggin crazy!! I think I'm this close to smashing the thing, and my frigging sub into little bits.

I have had THE worst time trying to get my damned JL amp to produce ANY sound. Here is the setup:

1998 Maxima.
Alpine 7894 Head Unit
JL 500/1 amp (bought from guy off ebay, yeah yeah)
Bazooka RX-T1 sub

I am running Monster Cable RCAs to the sub from the head unit pre-out (sub-w).
I have about an 8ga power, 8ga ground and a remote wire to the amp (I didn't install the wiring).
I think about a 12ga speaker wire from the amp (outer +/-, so bridged I guess) to the sub.
The RCAs are on the opposite side of the car from the power.
I have just put in a new 60w fuse (I also have an 80, and I seem to have melted my 40, so I changed that today).

I CANNOT, for the life of me, get the sub to play. I am going nuts. The Alpine HU should be able to pick up the sub, but it isn't.

Originally, I had a Clarion amp (APX 200.2) on there, and the guys who installed it ran a High Level Input Terminal from the rear speakers to the amp (which I guess was providing power to the amp/sub in the first place). I took that off. I wanted to run RCAs for power. I have tried 2 sets of RCAs, with no luck.

Can someone PLEASE offer suggestions as to what I might want to check. I have tried moving my center frequency, my bass boost, all the damn switches, nothing.

If ANYONE with a JL500.1 amp and a sub wants to tell me EXACTLY what settings to put the switches at, that would be wonderful. I am semi-noob to the whole "tuning" of a stereo.

Thanks very much in advance. I'm sure some of you have felt my frustration before.

Mike

 

i have an alpine 7995 headunit, which is similar to your 7894 except the 95 doesnt have speaker outputs. on the 7995, you can disable the subwoofer RCA outputs. maybe your 7894 has the same capability and they're off. just an idea...

 

Naw, went in to the setup function, and have it set to Sub On.

I have never yet had the sub produce power from the head unit - the amp that was running the sub before was getting its power from the rear speakers, and when I ripped off those damn High Level Input Terminal wires, no power whatsoever to my amp from my RCAs it seems (power meaning signal. I get the green light telling me that my amp is on just fine).

HAS ANYONE HAD ANY PROBLEMS WITH THE PRE-OUTS ON THEIR ALPINE UNIT, OR GETTING IT TO CONTROL THE SUB USING RCAs???????????


FUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUCK! (sorry need to vent)

thanks for the input maugs!

Mike

 

you can determine if its your amp or your headunit by dragging a stereo with RCA outputs out to your car and plugging them right into the amp. turn on the car (so the amp turns on) and if you get any sound, your amp is most likely fine and your head is effed. if you get no sound (and you know your stereo is OK), then its probably your amp.

 

In the previous install, the dudes who installed the amp wired the Clarion amp to receive power from the rear speakers (using something on the amp called a High Level INput Terminal). This was wired to the +/- of the two rear speakers. I'm sure that this was how I was receiving power to my amp originally (signal that is), so that the amp was taking the lows, and processing them and throwing them to the Sub, thus I was getting sound from the sub.

Now that i have removed that high level input terminal, and the wiring (took the wires off the speakers, as there was nowhere to plug that in to the JL anyways), I get no signal through my RCAs. I've tried two RCAs, and no luck.

I also ran both the JL and the Clarion on the new setup with everything the way it should be, MINUS the High LEvel INput Terminal, and no luck.

So...

I'm thinking it is one of Two things:

pre-outs on the HU are not putting out sufficient (or any) voltage
or
the RCAs I've got suck and I need new ones.

Just bought a multi-meter, so I'm going to test (at some point tonight, both the HU pre-outs, and the RCAs, so that will narrow it down further.

man am I learning stuff by doing this...

Thanks for all opinions

Mike

 

Yahoooo!!! (sorta)
I found the problem!!

Damn pre-outs from the HU weren't showing a signal. I even have proof.
I used a digital multimeter to test the RCAs at the AMP, no signal.
I tested the MM on a AAA battery, got a 1.57v reading.

I pulled out my dash, and tested two pre-outs, the Sub-W, and the Front pre-out, and NEITHER showed a reading (at 20v on the DC reader).

Positive (and negative, heh heh) proof that my HU is to blame for this problem!

Now I have to get a replacement HU. heh heh.

Mike

 

If you are going to meter the RCA jacks on the back of the Alpine, you need to set the meter to mV or "millivolts". If the meter is set to the 20V range, signal will not register. I have never seen an Alpine lose all of its pre-amp signal. Also, make sure you have it set to AC voltage not DC. While you have your head unit out, try this simple test:
1st- unplug the sub RCA from your radio.
2nd- Get a 1.5V battery and attach/hold a piece of wire on both ends.
3rd- GENTLY touch the wires from the battery to the RCA cable, not the radio. You should hear a thump or pop from the sub if the amp is OK. If you hear nothing, then I suspect the amp. I have seen EARLY versions of the 500/1 to do the same thing.
4th-To make sure the amp is hooked up right, do the following: switch the input sens to low, turn the input gain up 1/2 way, and turn the filter frequency to 65-75.

 

Rich,
I will try this. The only thing is - I tried it on 2 different amps (wiring the sub that is), the same way, and I've had the problem both times. I'm going to try it right now, but I still don't think the HU is putting out enough current to power the signal to the sub properly (or whatever terminology you'd use here, in electrical terms).

bbiaf

Mike