In general, the less friction about the balance point of the trem, the less bass in the tone.
Fender's 6 point trem has a considerable amount of friction, so the tone is generally fatter (more bass)
Fender's 2 point trem has less friction, and less bass.
A Floyd has (usually) the lowest friction, and therefore the least bass.
There are many other factors...the overall resonant frequency of the trem can be altered.
More mass (a heavier block) gives you some of the bass back.
Many Floyd users have fitted larger, more massive blocks, with an increase in overall bass and sustain.
In all cases, it is the ability of the trem to vibrate (generated by the string vibrations) which causes the loss of bass.
If you set any trem so that it will only allow dives (i.e. not floating), then the lone will be fatter.
