Most guitars and basses, especially in the lower and middle price ranges have "dead spots", places on the neck that don't sound as well as other places. Sometimes there's a cheaper fix than going out to buy a more expensive axe.
For as few years, I've been the happy owner of a Warwick Corvette Standard, and after several months of adapting from my old Ibanez Blazer bass (P-bass clone), I've grown accustomed to it.
With increased practice level and experience, I started to notice several months ago that three notes didn't sound as well as the others: the Eb/E/F on the G string, especially the E. The sound was significantly weaker than all other notes on the instrument, and the sustain was next to nonexistent, sound level dropping almost immediately after the initial "plong". Annoying.
Of course, I spent some time trying out other basses from shops, and discovered that way the beautiful, and very reasonably-priced, but little-known polish Mayones basses, as well as I tried several variants of Fender Precision and Jazz bass, including the lovely Marcus Miller signature J-bass with it's Rick-like pickguard and pickup ring, and the American Deluxe P-bass.
Alas, although I found myself immediately at ease with the Mayones models, because they feel a lot like the Corvette, all of the fretted ones I tried had a similar dead spot somewhere between the 6th and 9th frets. Strangely enough, a fretless model with a nice ebony fingerboard didn't show the problem, but I'm not yet ready to move to fretless, so it looks like it's a no-go for Mayones at this time.
None of the other brands made much of an impression, and I had my strongest disappointments upon trying a Rickenbacker 4004, hardly mitigated when I could lay my hands on a 4001: as much as I love the sound these basses make in the hands of Chris Squire, I found myself unable to play them, due notably to the heavily lacquered neck on which my left hand wouldn't slide, and the horseshoe pickup that prevented me from using my usual right hand tapping position.
However, the fact that the fretless Mayones didn't exhibit the same dead spot issue as its fretted sistren left me to ponder whether, instead of being mostly a matter of resonance and cutoff frequencies, the issue could not be fret-related. After all, the same notes, played on any other string, didn't have that problem, so it could not be frequency-related, hence not a resonance issue.
So I took the Corvette to Nicolas at DNG, the luthier who already fixed my Blazer and Strat last year, and asked if he could do something about it. Although doubtful at first, Nicolas told me he'd try to look into it. He ended up rectifying all the frets and adjusting the neck, and when he returned the bass to me with a new set of strings, the three dead spots were resurrected. Maybe there's a reason why this small and friendly luthier counts even U2 amongst their customers.
We chatted a little and I learned this was a rather common issue, that has probably been there for as long as I had owned this bass, but one that grows more burdensome as one gets more familiar with one's instrument. At 150 EUR, this is a much cheaper option than dropping an instrument for a new one.
Although, during my marketplace tour, I noticed that the Musicman, except for the rather ugly looks of the Bongo, were definitely axes I should keep my eyes and fingers on: very playable neck, pickups that don't get in the way except on the two-pickup Bongo, and a very extended tone range. There may be a good reason besides endorsement why so many professionals seem to be using the Stingray.