there are multiple factors that contribute to a 'floppy B', and a 34" scale is not as big of an offending item as most believe. first a little dip into the physics ...
between to witness points (in our case a bridge saddle and the nut/fret) a string of a given diameter tightened to a given tension will have a specific pitch. or it could be stated this way: a string of a specific diameter, of a specific length, at a specific pitch, will have a specific tension. OK that's the generic easy part
a simple solution would be to use a different diameter string on that 34" scale bass. something as simple as going from a .120" to a .125" or from a .125" to a .128" diameter string will naturally increase the string tension. but ... this isn't the only thing to be considered in the formula
IME when most people comment about a floppy B, it's usually an acumulation of multiple things colliding together into a massive suckiness. here's several things to consider, and each will impact the B in its own unique way
- set-up: if you're playing basses in a guitar store, I can give you a 95%+ guarantee that they aren't set-up optimally (if they're even halfway set-up at all) why? because a set-up requires the time of a skilled set-up person who must channel what every player prefers their optimal set-up to be. set the action too high and some will complaing it's unplayable. set the action too low and most will complaing the bass buzzes. give it too much relief and many will complain the upper frets are unplayable. too little relief and the bass buzzes when those with a heavy plucking hand strike a note.
beyond the simple feel factor, the set-up will also determine how a bass sounds. pickups set too high and you get volume, but the notes can sound more like square waves. pickups too low will give you more harmonic content, but volume is lost. AND pickups not set right will also make the B sound anywhere from muddy to floppy to nonexistent.
- strings: poor string choice is the norm for most budget basses as manufacturers recognize that one of the things most players do is change the strings when a bass goes home. why spend money on $$ strings that will usually be dead before the bass leaves the store that sold it? the money spent on better strings is pure loss to the bottom line in the eyes of corporate bean counters.
you should also recognize that different methods of winding strings will produce different results in how they sound. I'm not speaking about the material that the string is made of (this does make a difference, but not where I'm going) but instead I'm talking about the physical winding of the string. a string with an exposed core IME is usually going to sound floppy shortly after it's installed. it may be easier to intonate, but it behaves differently than a string with winding all the way down to the ball.
it's also a bad thing to impart a twist to your string when installing it, as this will cause it to behave somewhat differently than a string this is simply pulled taught in a straight line
- neck construction: the physical way that the neck was constructed, and the materials it's made from have a significant impact on how it will feel. a very stiff neck can support low action, which allows you to play with less physical effort, and which will tend to feel less floppy. the trussrod make-up and construction palys a part in how the neck behaves, which impacts how much it will flex, which makes the string to be blamed for a certain feel. so long as they are not so stiff that a trussrod is rendered unusable ... a stiffer neck is always better
- string stretch: here's where people tend to get lost ... they tend to speak of that portion of the string beyond the witness points (brudge saddle and nut/fret) as being included in the length that impacts the tension required for pitch. this is incorrect to do so. what this outside string length can do is impact how much a string will
stretch when played. many, many people speak the phrase string tension when in reality they are describing string stretch.
several factors are at play here - different string materials, diameters, and construction methods stretch at different rates for a given change in tension. more string length available for stretching increases the potential for a string to be stretched. this is exactly what people can experience by those super long headstocks that have 300 meters of added string length available to be stretched in the area between the two witness points. a stretchy string tends to feel floppier that a very stout string. a strout string dampens its fundamental vibrations sooner so notes appear to ring shorter.
sooooo ... all of that to say: it's not the 34" scale that's the sole (biggest) reason for a floppy B since most companies use the same string gauge set for both scales, and because of this the 35" scale will have to have more tension to bring it to the same pitch as its 34" cousin - but that tension difference isn't the only factor in the B string sounding floppy. a floppy B is more the result of poor set-up and string choice than it is scale. I have built 33" scale top loading basses where clients have commented on the bass being the most comfortable 35" scale instrument they've ever played. they justify their comment on the scale by how it sounds. I love their look when they learn they're really playing a 33" scale instrument with a .125" B ... but then I have the right strings with the right set-up combined with solid neck construction of the right materials on my basses. and this is what you get with a custom bass that you usually don't get with guitar store basses
make sense?
all the best,
R