Factory Deck Crap?!? with Aftermarket Sub+Amp

[nguyenator]

So I built a custom box under the rear seat and am firing my JL 12W3 upwards. I started to here some popping noises even at medium volume. I thought it was the box. So I made sure it was the perfect 1.125 cf as required. Then thought it was power, so i installed a Monster Cap. Then I thought it was the amp. So bought a new Alpine MRF650 (plenty of power now). Then i thought it was the sub, until i hooked up a friends 10"+box to test and it made the same popping sound. So have concluded its the deck cause i have replaced and changed everything else. Anyone else have this problem? I am putting my head right near the sub so the popping is definitely coming from the sub. Only at a minimum of 25 volume though.

I even tried a couple wiring options, using the Line Input wires on the amp, and buying a Stinger Line Output Converter. Both make the popping noise. Anyone else have this probelm? Cause my next move is replacing the headunit. Something i have been avoiding as a double din hole looks best with a double din dvd player. Thanks for your help!!!

[Chuck]

Originally Posted by nguyenator

I even tried a couple wiring options, using the Line Input wires on the amp, and buying a Stinger Line Output Converter. Both make the popping noise.

I was going to suggest you try this, but you already have. Sure sounds like a HU problem. Where did you tie in to the factory sub output? What type of connection?

[nguyenator]

I used a trick to tie into the factory sub. As the factory sub wire connection is a little too short by just reaching behind the seat, i took off the plastic panel along the floor at the rear drivers side door. Under this panel were a bundle of about 87 wires. I made sure i chose the correct two (green and yellow wires) and tapped in. It worked. To a degree i guess cause the sound quality is crap. I doubt it has to do with the plain wires themselves and still think the deck is the culprit. Agree???

[boobai]

Maybe try adding an active cross-over?

[shovelhd]

You used wire taps (Scotchlocks) to tap into the sub wiring? Bad idea. That's problem #1. Wire it correctly and see if it goes away.

How did you set the gains on the amp? An MRP-650 is too much amp for a single 10W3. Set them correctly and see if it goes away. That may be problem #2.

You have an upfiring woofer. That's a bad idea in a Ridgeline. You are not taking advantage of the floor area, and the driver is firing right into the underside of the seat. The underseat plastic covering is made up of several pieces that snap together. In other words, it's a rattlebox. Try flipping up the seat and see if it goes away.

[hofffam]

If he just tapped into the wiring - isn't the factory sub still playing? Bad bad bad.

[shovelhd]

Originally Posted by hofffam

If he just tapped into the wiring - isn't the factory sub still playing? Bad bad bad.

If he didn't pull the connector from the factory sub, then you nailed it. His factory sub is now blown and could cook his new amp.

[Chuck]

Originally Posted by shovelhd

If he didn't pull the connector from the factory sub, then you nailed it. His factory sub is now blown and could cook his new amp.

I agree that hofffam probably nailed it, but how would this blow the factory sub? Using his "tapped" set of wires to connect to speaker level inputs on an amp or using a LOC seems to me would not affect the factory sub or the new amp, assuming its wired correctly.

[hofffam]

Tapping into the wires without disconnecting the sub could do some weird things. I'd be most worried about the headunit amp. That amp probably expects a 4 ohm load. Adding another circuit (another amp) in parallel changes that from 4 ohms to something else. Not sure what that would be. Normally an amplifier has a high input impedance (~50K ohms) so that would lower the 4 ohm load only slightly. But this seems really uncertain to me. The factory headunit must use a "chip" amplifier and who knows how stable it is.

But having a live woofer on the speaker wire could cause strange behavior in the aftermarket amp.

[shovelhd]

If he had the gains cranked, then that could blow it.