Help! Sudden buzz / dead notes in lower frets?? Gibson LPB-1

[slinkp]

I recorded with my favorite bass (1992-ish Gibson LPB-1) a couple weeks ago and it sounded great. Haven't played it since then. Today I took it out of the gig bag and started playing and - what's this?  I can barely play the lower frets, or open strings, especially on the D and A strings. No sustain, all buzz.  The note just goes PLONK, and dies very quickly. It sounds like the string is almost lying flat on some other frets.  It doesn't improve much until about the 7th fret.  Visually it's hard to see what's going on... the action does look very low up there, but I can't spot any curvature of the fingerboard by eye or anything.  Not sure what I should be looking for.

Has anybody experienced something like this?  What could cause it to begin all of a sudden in between last time I played and this time? What should I do to diagnose the problem further?

[Dave W]

Sounds like there may not be enough relief. Have you checked the relief, and if there's none, have you tried slightly loosening the truss rod? With a traditional truss rod, sometimes even a slight change in humidity can cause the neck to move. I could be wrong, but that's what I'd check first.

[Alanko]

Wot Dave says. 

I seem to remember a lot of Geddy Lee basses turn up for sale around this time of year, presumably because they were setup for the winter and are now buzzing like crazy.

[FrankieTbird]

Most likely the truss rod and/or string height need adjustment, as already mentioned, but there's also the possibility that the strings are hitting the neck pickup.  Fret the strings up high on the neck and verify that they're not touching the pickup or anything else they shouldn't be.

[slinkp]

Not hitting the pickup.  Everything is fine from about the 7th fret up.

Thanks for the replies everybody. I'll see if a slight truss rod loosening will help.
It's weird though, I have never experienced this phenomenon in 35 years of playing bass, hence the panic.  This particular bass has given me no trouble in the roughly 10 years I've owned it.  I have touched the truss rod a time or two when I thought the action was creeping a bit higher, but not recently, and this is the first time I've ever experienced the action spontaneously getting lower.   Certainly the weather has changed in the past few weeks, so hopefully that's all it is.

Blame climate change 

[Dave W]

A Gibson truss rod has the most effect from about the nut to the 7th fret, which is why this is my first guess. It doesn't act evenly from end to end like the two-piece rods.

I recently had the same thing happen with a bass I've had for 12 years with no prior issues. I already had it set up with practically no relief. In my case, loosening the rod about 1/8 turn did the trick. It happened right when we got our first warm weather, so I guess it really was climate change. 

[Highlander]

Global warming...?

[slinkp]

Thanks everybody!  It did look like there was basically no relief... It took more like 1/3 turn, but that seems to have done the trick!

I'll check back on it tonight or tomorrow and see if it's settled differently and needs further adjustment.  Last night I felt like it wanted still more relief for the lower frets, AND lower bridge action for the higher frets, but I thought I should give it some time to settle in before adjusting the truss rod any more than I did.

[Dave W]

It doesn't hurt to wait a couple of days before readjusting, although I've found that necks don't often continue to move after the rod is adjusted.

1/3 turn isn't that much, no need to be concerned.

[slinkp]

I did end up doing a bit more relief (about another 1/8 turn) AND lowering the bridge saddles slightly last night; then checked it again this morning and decided I'd overdone it.   So I tightened about 1/4 turn and tweaked the saddles until the action felt nice and low and everything sustains properly with just enough buzz to sound good

Happy again!  Thanks everybody. Next time this happens I won't panic!

[Dave W]

Glad it worked for you.