2002 Tahoe Subwoofer replacement attempt failed, can anyone chime in?

[HeadRusch1]

Hi Forum, first time poster, only owner of a 2002 Tahoe with about 90k on the OD. Subwoofer finally gave up the ghost and fell apart, it would intermittently buzz on and off/rattle so we undid the harness in back so it ran sub-free for a bit, which was painful with the stock stereo.

Today a Blaupunkt 8" 2ohm speaker arrived from Amazon, which was almost a drop-in replacement. Problem is, I can't get it to power on. I tried touching the wires to the stock sub to see if it would rattle or wake up, nothing there.
Nothing driving the Blaupunkt replacement either. I'm a little bit stumped, is there a particular voltage my multimeter should be looking for while the stereo is on sending to the sub, I had expected this to be a simple drop-in replacement.

I've reversed the polarity of the wires just to see if it would run out of phase, but I still get silence at any volume and bass level unfortunately. I know my speaker was bad, did it take the amp with it? Any help/suggestions appreciated.

Thank You

 

[slypher25aussie]

Welcome! Wow that’s really low miles on your Burb! Post some pics when you have a chance.

Is your radio stock? Have you pulled the trim around the sub to see if maybe wires got chewed up or broken?

 

[HeadRusch1]

Crazy, I know. The radio is stock, actually the truck is entirely stock with the exception of tires. I pulled the panel from the rear, exposing the subwoofer box and nothing is chewed up, just the factory sub that fell apart due to decomposition internally. I expected this to be a pretty easy drop in replacement, but no luck on the initial "remove wires, strip wires,connect to new subwoofer" attempt.

Here's a potentially stupid question: Does the speaker for the rear pillar have to be plugged into its harness as well in order for the sub to still get a signal? It was unplugged when I was messing with the subwoofer.

I guess I need to know what voltages I should be seeing from those leads or how to test if the factory amp is outputting correctly, but its just a + and - wire and I'd expect it to do something but clearly something else is amiss.

Thanks for the reply.

 

[slypher25aussie]

Thought of a couple things...

Is your radio the Bose unit? I know there is finicky stuff with regards to the amps in those and getting them to play nice.

Do you still have the original woofer? I can't recall for sure, but when I replaced my sub, I thought I remember maybe there was a resistor soldered to the back of it. Wondering if maybe that has something to do with why your new sub isn't working??

 

[HeadRusch1]

No, it's not the BOSE unit, its the standard double-din Delco branded one (the default factory AM/FM), it has a single CD in dash and a separate cassette that's lower down above the transmission tray. I do still have the original speaker but I don't recall seeing a resistor on there, I'm assuming that would be to bring a 4ohm speaker down to 2ohm? This one from Blaupunkt is supposedly 2ohm and 8" and nearly a drop-in replacement, so I'm a little confused.

 

[Nooj]

Do you have another system you could test the new sub with? I suppose it’s possible they sent you a dud.

If a new sub brought my bass back to life, in my heavily beaten, water leaking, “somebody butchered lots of wiring” suburban- I would certainly think yours would work too.

I’m sure you’ve checked- but double check that the fade isn’t set far forward.

Hope ya figure it out!

Nooj

 

[rockola1971]

You have a multimeter. Ohm out your blaupunkt subwoofer to see if it has continuity (Isolate it from the stereo).
You wont see DC on the speaker wires. Audio is AC and if there was any AC on the speaker wires then your speaker would be making some sound even if it was pops or crackles.
Check your speaker wires. Disconnect your speaker wires from the speaker and the stereo. Check each wire to ground to verify no short to ground. After that check then check for continuity by twisting both wires on the speaker end together (do not do this while hooked up to stereo on the stereo end) and then measure speaker wires on the stereo end for continuity. You should see a low resistance. Probably less than 6 ohms.

Keep in mind when measuring resistance of a speaker your meter is telling you what the speaker's DC RESISTANCE is which is not the same as AC IMPEDANCE(resistance) is. Your speaker resistance spec which I believe you said was 2 ohm is its AC IMPEDANCE not DC RESISTANCE. So you will see a different reading on your meter when checking a speaker.

 

[HeadRusch1]

You have a multimeter. Ohm out your blaupunkt subwoofer to see if it has continuity (Isolate it from the stereo).

Excellent point I hadn't considered.....another one is that this 2ohm speaker is actually a 4ohm speaker according to the packaging......which I only just noticed even though reviews indicate it was 2ohm.

You wont see DC on the speaker wires. Audio is AC and if there was any AC on the speaker wires then your speaker would be making some sound even if it was pops or crackles.

Noted.

Check your speaker wires. Disconnect your speaker wires from the speaker and the stereo. Check each wire to ground to verify no short to ground. After that check then check for continuity by twisting both wires on the speaker end together (do not do this while hooked up to stereo on the stereo end) and then measure speaker wires on the stereo end for continuity. You should see a low resistance. Probably less than 6 ohms.

Noted, Thank You.

Keep in mind when measuring resistance of a speaker your meter is telling you what the speaker's DC RESISTANCE is which is not the same as AC IMPEDANCE(resistance) is. Your speaker resistance spec which I believe you said was 2 ohm is its AC IMPEDANCE not DC RESISTANCE. So you will see a different reading on your meter when checking a speaker.

Thanks for taking the time to lay out the detailed explanation above.

 

[HeadRusch1]

In case anyone finds this thread in the future, here's how the story wrapped up: The speaker blowing took out the amp, got a replacement used amp (because no new ones exist it seems), got a dual-coil Kicker Subwoofer from Crutchfield (4ohm) and wired it down to 2ohm, total cost was in the $75 range. The only modification required was to remove the plastic surround from the speaker but its just held on with sticky foam, then its a drop-in replacement into the stock plastic speaker box. You drill some new holes for the mounting screws and you're done.
Problem solved, and the new Kicker sub is a fairly dramatic improvement in sound quality even using a stock factory amp.

 

[slypher25aussie]

Thanks for following up. Glad it worked out for you!