One woofer making rattling/crackling sound on low bass

Twodawgzz · 2299

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Offline Twodawgzz

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Just completed build.  Any ideas what may be causing this?  Only one channel, and I believe only one of two woofers.



Offline Thermioniclife

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Reply #1 on: July 05, 2020, 10:17:16 AM
It could be a few things, did you swap amp channels to see if the same woofer cracks and pops? It could be that the speaker is not torqued down evenly, pull the speaker and make sure there is no debris in the mounting recess, then tighten the mounting screws evenly, if the speaker basket becomes warped while installation this can happen. Another thing you can do is gently take your fingers and space them equally around the speaker cone close to the dust cap and gently press in on the cone, if it makes a scratchy sound the voice coil my not be aligned properly in the magnet channel. you must push equally around the dust cover. Sometimes a voice coil can  or dust cover may not be properly glued and can make awful noises. And perhaps something in the cabinet is loose or the cabinet itself.
Thats about all i can offer.

Lee R.


Offline Paul Birkeland

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Reply #2 on: July 05, 2020, 10:17:32 AM
Most often when I have experienced this when doing DIY speaker projects, it is because the cone is hitting something that shouldn't be there (like a piece if wire or random scrap of something), or there is a major air leak around the woofer and what you are hearing is air leaking and not actually the woofer itself.

To debug this, start by using your phone as a signal generator and play a bass tone that really sets it off, even at low volumes, then use your ears to try to precisely locate where the sound is coming from.  Once you've done that, try to determine if there is air leaking there.

If there isn't, then you need to remove the woofer from the cabinet and test it in free air to see if it makes the noise. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Doc B.

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Reply #3 on: July 05, 2020, 11:34:40 AM
All good advice. My inclination would be to pull out the woofer that's making the noise and inspect it.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Twodawgzz

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Reply #4 on: July 05, 2020, 12:42:40 PM
Okay, that was an easy fix.  Thanks all for the rapid responses.  I feel like an idiot for not pulling the suspected woofer before posting.  One soldered lead of the capacitor had become unsoldered.  Working fine now.  Thanks again.

Now onward to the larger problem... the Stereomour that doesn't register any resistances or voltages.



Offline Paul Birkeland

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Reply #5 on: July 05, 2020, 12:59:37 PM


Now onward to the larger problem... the Stereomour meter? that doesn't register any resistances or voltages.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man