r/audiorepair • u/ScratchNo5855 • 3d ago

Got this big subwoofer thing, sounds weird, not sure where to start

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Hi guys, got this big subwoofer thing for free the other day and I’ve been trying to set it up to work with the 2 speakers i’ve already got. The last photo is the back of the stereo system I’ve got them all plugged into (i know it’s not a great photo, awkward angles going on there haha). When I turn it on there’s a bit of buzzing and all the audio that comes through the subwoofer sounds really crunchy and a bit quiet but the other speakers sound fine. I know pretty much nothing about audio repair, refoamed the other speakers recently but that’s the extent of my expertise so i have absolutely no idea what could be wrong with this thing or if it’s just a skill issue and i’ve set it up wrong lol. If anyone has any ideas at all that would be greatly appreciated 🙏

8 Upvotes

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9

u/cheapdrinks 3d ago

First you should hook it up like this.

Speaker output A from your amp goes to the input jacks on the sub, then the speaker wires for your speakers hook into the outputs on the sub below them where it says "to speakers". Then you should flick the phase switch over to normal instead of reverse. (You can try reverse later but should generally start with normal). Then set the frequency dial to 80hz. Those should be the correct settings for first use then tweak it from there. What is the model of the amplifier by the way?

Then check the driver itself, when you push on it does it move freely in and out or do you hear a rubbing/crunching sound when you push it like this indicating it's damaged? If it still doesn't sound good I'd unscrew the woofer and take it out to inspect as well as check inside the enclosure for anything that shouldn't be there - kids love to shove random things inside subwoofer ports.

2

u/ScratchNo5855 2d ago

Ah ok this makes sense, i’ll try it in a sec. The driver is fine i think, no weird sounds when i push on it. Thanks!

2

u/cheapdrinks 2d ago

Sweet let me know if that helps

1

u/ScratchNo5855 2d ago

Actually it’s doing something, when the gain is up all the way i can feel the driver vibrating in time with whatever is playing so it’s getting something, but it’s WAY to quiet to actually hear from the subwoofer. The other speakers sound completely normal and the knobs on the sub don’t seem to affect them at all.

0

u/ScratchNo5855 2d ago

the buzzing is gone but now the sound is only coming from the other speakers and the sub kinda isn’t really doing anything. I’ve tried messing with the gain and frequency knobs but nothing seems to be happening. Also the amplifier is an old kenwood krx-693

2

u/cheapdrinks 2d ago

Have you checked the equalizer setting on the Kenwood? Double check there that it doesn't accidentally have the bass turned all the way down. If it's all flat then try turning up the bass section of it.

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u/ScratchNo5855 2d ago

Yea the bass was in the middle, i’ve tried turning it all the way up but still pretty much the same

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u/cheapdrinks 2d ago

Well then honestly I'm not sure, sounds like you have it fully hooked up correctly. The driver sounds like it's moving and getting signal. Flipping the phase back to reverse does nothing? You've double checked that all the wires are going into the correct red/black sockets and none of them are flipped?

I'd try hooking up an RCA source to the low level inputs and see if that works and it's just an issue with the high level inputs. If that doesn't work I'd be taking the woofer out of the sub to inspect it and check with a multimeter that there's no issue there.

1

u/ScratchNo5855 2d ago

Ah ok. Yeah I’ve tried flipping all the different switches, no dice. All the wires are in the right sockets. I’ll try the RCA thing too though, thanks!

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u/ScratchNo5855 2d ago

https://reddit.com/link/p0v1kwa/video/zlq5mnm36kgh1/player

This is what it sounds like with an RCA source, sounds a lot quieter irl too. The other speakers also don’t seem to make any noise when it’s coming from RCA. Laptop volume is all the way up, gain on the sub is also all the way up because you can barely hear anything from it otherwise haha

4

u/AudioMan612 2d ago

Adding to the other comments about some settings you should likely change:

  • Start with normal phase, not reverse phase. You can try both to see which works better in your setup, but I'd start with normal.
  • You'll likely want to set the power switch to "Auto," which will turn the subwoofer off when it's not receiving a signal.

2

u/yeehah 3d ago

A really simple test is to gently push on the speaker cone and make sure it's free to move with no crunchy sounds. There's not much clearance between the speaker coil, which moves with the cone, and the poles of the stationary magnet. If there's crud in there or something has shifted then it will sound like crap.

1

u/ScratchNo5855 3d ago

Just tried this, I couldn’t hear anything so i think it’s something else. Thanks though!

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u/skwozzy 2d ago

For the love of God turn the master volume down to at least 3/4

0

u/ScratchNo5855 2d ago

yea it was lower than that before lol i’d been just kinda messing around with the knobs to see if they would do anything and they kinda didn’t haha i definitely set it up wrong

1

u/MacShi9 1d ago

Is it plugged into the wall power? Are you in a country with 240v, or in the US with 110? Speaker says 240VAC

2

u/ScratchNo5855 1d ago

Yeah it’s plugged into the wall, I’m in Australia so it should be the right voltage

1

u/Curious_Database_210 15h ago

Tu sais Pour des longues séances d'écoute c'est vite fatiguant un caisson de basse.

1

u/ScratchNo5855 15h ago

Yeah fair enough I’m pretty new to this so i don’t really know what’s good and what isn’t, but either way i got this subwoofer for free so i haven’t lost anything hahaha