I have connected the LOC to the sub plug wires and to my amp with no success. I called local audio installer and their advice was to install LOC after factory amp into my aftermarket amp. Has anyone ever heard or tried this. I have been searching on these forums with no luck.


please advise

 

What kind of amp is it? Make and model? Web link?

Does it have high level inputs on it? Most amps do, which means you don't need a LOC. In fact, I don't think I've ever seen a car amp that didn't have high level inputs. To be clear, you can go straight off the factory speaker wires into the amp's high level inputs without using a LOC. (And, no, that does not load the wires. They can still be connected to speakers while also going to the amp. The amp will not affect them.)

Do you have a voltmeter? Are you getting 12+ volts to the amp?

Most amps have an on/off control input next to the +12 and GND connections. This signal is normally tied to the head unit's remote antenna control output. It turns the amp off/on when the head unit is turned off/on.

Many amps also have a signal sense circuit that can turn the amp off/on when it senses a signal on the inputs. That way, you can float the on/off signal (ie, you don't have to find the right wire to connect it to) and instead let the amp turn itself off/on when it senses sound coming over the inputs.

But these things may not always work right, so, if you have power and signal to the amp and still nothing coming out, then try connecting the on/off input to +12V. If that doesn't work, try grounding it. One of those will turn the amp on. But keep in mind, if you leave it hooked up that way, the amp will always be on and could run the battery down. So, in that case, you will want to put a manual switch on the on/off input.

Doug

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The amp is an old school Rockford Punch 75. No wire inputs. I had it all hooked up correctly using the wires before the factory amp and there was a faint sound through the new subs using the LOC. Their suggestion was how they usually do that kind of install is after the factory amp into the LOC and then those RCA's to my amp.

 

I found it online, and confirmed it has no high-level inputs That's a first for me!

Your first suggestion should work - connect your factory amp's high-level outputs to the LOC, then connect its low-level outputs to the Punch amp.

I'm thinking you could also take the factory amp's low-level inputs and connect them directly to the Punch. I doubt it would make any difference in sound quality (unless there's a serious level mismatch) but would simplify the hookup a bit.

BTW, the reason you got such a faint sound is because you had doubly low-level signals - the already low-level inputs the factory amp were being further attenuated in the LOC before making it to the Punch, so they were doubly weak.

HTH.

Doug

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ok i appreciate the help for sure... Going to install this evening... Any suggestion where to find 12V on/off in the rear of the truck for a cleaner install?

 

No. I wish I could help with that. But I'm afraid you'll need to pull something from the dash back to the amp.

BTW, I still need to post a couple pics, but I mounted an Alpine amp on the hump below the dash. I built a little console that holds the amp, provides a cubby hole for storage and a cup holder in precisely the right position (as opposed to the stock cup holders which are too close and too far). It's quite the redneck modification - think wooden Harley - but it works great!

My main consideration for mounting it there was so I didn't have to pull wires all over the place. The only wire I had to pull was from the battery for the amp supply. The rest just connect to the radio directly above the console.

Also, I looked at the Punch 75 specs again, and don't see any mention of auto off/on, so you'll very likely need to connect a remote on/off signal.

Will you be connecting the Punch 75's remote bass ****? If so, when you pull that wire, pull another piece of ~22 gauge along with it for the remote. You might could even modify the remote bass **** housing to incorporate the on/off switch. A 3$ mini toggle should do nicely.

Doug

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The old punch amps do have the high level input ability. You use a speaker to male RCA adaptor and just plug into the RCA's.

http://www.rockfordfosgate.com/products/details/rfi2sw

Or just cut an old patch cord. Can't beat free.

If you want the install manual, send me your email in a PM and I'll send a pdf.