Sub not working on low volume? Anyone know why?

I have a used subwoofer with an amp that doesn’t really have a brand name. It was working fine for a while, but now it has an annoying issue. Sometimes it won’t make the sub kick at all when the volume on the head unit is low. If I turn the volume up, the sub comes back on. Sometimes, it even stays on when I turn the volume back down.

Other times, only the really heavy bass notes come through while the softer background rumbles don’t. And sometimes it works just fine even at 20% volume on the head unit. It seems like it might be affected by how my car is moving too—fast turns or quick acceleration and braking sometimes cause it to stop or start working again. But it always seems to fix itself by the time I get home, so I can never figure out what’s going on while I’m driving.

Anyone have any ideas on what could be causing this problem? What should I check?

Try checking the connections first. Wiggle the wires going into the amp and see if they move. If they do, tighten them up.

Also, check the ground connection and tighten it if it’s loose.

Bran said:
Try checking the connections first. Wiggle the wires going into the amp and see if they move. If they do, tighten them up.

Also, check the ground connection and tighten it if it’s loose.

I just checked everything and all the connections to the amp (battery/ground, left/right channel, output positive and negative) seem fine. But the connections to the sub are a bit dodgy—I’m using raw 8 gauge wire, and even with the screw terminal all the way tightened, the wire still comes loose pretty easily. This is probably the issue! Thanks!

I’ll fix this by getting proper end caps for the wire, though I’m not sure what to look for exactly. I tried looking inside the terminal, and nothing seems to happen when I screw it on or off. I thought the internal clamp would grab the wire, but it doesn’t: Link to image.

@Bailey
You’re using that terminal cup wrong. The metal binding posts can unscrew almost completely, revealing a hole in the post. You should poke the bare wire through that hole, then screw the top down to clamp it tight. The hole at the end is for a banana connector.

Also, 8 gauge wire is too thick. 12 gauge would work better. What brand and model is the amp?

@Jesse
Ah, I just figured this out after I posted that last comment. I know 8 gauge is probably overkill :sweat_smile:

It’s a 300W RMS woofer, and the amp is rated for 400W RMS. It did burn out the coil of the previous 250W speaker when I cranked it up to 80%, so I think the power rating is accurate, even if it’s not the best quality.

I just want this system to work like it did before—surprised it worked at all with that mistake I made! :smiley:

The new speaker I got is a Helix K 10W, and the store gave me a newer model instead of the one I was expecting. Not sure what the newer model is, but that’s what’s on the invoice.

Here’s the only info I found about the amp: Link to amp.

@Bailey
The amp can handle 400W RMS when bridged. But honestly, 12 gauge is still fine for this setup, so don’t worry about it being too thin.

Do you have a remote wire hooked up, or is the amp set to signal sensing?

Ash said:
Do you have a remote wire hooked up, or is the amp set to signal sensing?

It’s connected via a remote wire. I don’t think the amp has signal sensing mode—it definitely doesn’t have a switch for it.

@Bailey
In that case, it seems like there’s a loose connection somewhere.