Kicker S12L7 Subwoofer blown voice coil

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Kicker S12L7 Subwoofer blown voice coil

  • I've had my 2004 Kicker S12L7 DVC 4 ohm subwoofer for quite some time now. I bought it refurbished about 3 years ago. It's been a very reliable subwoofer and has gone through several different amplifiers. The first amplifier I had was a Kicker, but that was stolen when my car got broken into. The second amp I had was a Hifonics Brutus, which I shorted out on accident one day when I was working on my system. The amp I currently have is a JL Audio A1800 (currently discontinued, as displayed on the JL Audio website), and I've had it for around a good year now. The amplifier is a monster. It puts out 1000 watts RMS at 2 ohms, and (if I remember correctly) puts out 650-680 watts RMS at 4 ohms. The amplifier is true to it's spec's. The Kicker subwoofer handles 750 watts RMS, and is wired in parallel.

    Over time, I've had to pull the subwoofer out of it's ported box (2.6 cubic feet) many times to solder the wires behind the subwoofer. Since I got the sub refurbished, the wires that attach from the terminals on the subwoofer to the voice coil weren't connected very solid. Every month or so I would have to re-solder the wires to the terminals (the ones that ripped from the terminals, at least), otherwise I would be running with one voice coil. Every now and then I would notice a sudden drop in subwoofer performance, and always knew that one of the wires ripped from the sub's excursions.

    Recently (within the past couple months), I've noticed that the subwoofer hasn't been playing as loud as it used to, even after re-soldering. I checked the rear of the sub to see that all of the wires were connected on the back of the subwoofer, and they were. I used an ohm meter to measure the ohm load, and it came out to around 4-4.5 ohms (measured at the box terminal).

    My conclusion that I've come to is that one of the voice coils is blown. If this has occured, which I'm sure it has, it is possible to repair the voice coil at all? Subs aren't assembled by screws or bolts or nails, so I'm wondering if it would be possible to open up the subwoofer to see what's going on. If this isn't possible, or practical, I just might buy a new kicker.

    My question remains -- Is it possible to repair a subwoofer voice coil?

  • This isn't really my area, but 4-5 ohms at the box terminal would be correct for one of the voice coils disconnected again.

    I think if you blew the voice coil, it would likely be either Infinite or zero impedance, and I don't think that gives you 4-ohms (zero impedance would, though).

    I would pull the sub and measure the resistance on the coils and see if maybe you have a cold-solder joint first.

    Hope This Helps!!!

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • I get 4 ohms since one of the voice coils is blown. Since both voice coils are 4 ohms, wired in parallel, then I should be getting 2 ohms at the box terminal. Unfortunately that isn't the case. I've pull the subwoofer out of the box numerous times and have ran many tests between each and every connection there is. All of the connections are solid. I might consider re-soldering all of the wires, just to be safe. But this subwoofer has just about had it's life, I'd think.

    Thank you for your help.