The trem cavity itself acts like a resonance chamber. The looser the trem (float), the more the resonance effect of a 'springier', livelier tone.
If you want the trem 'clamped' because you've little use for it as a matter of style or you want an edgier tone, use all 5 springs. If you want a 'floating' trem, use 3. There's more adjustments to the bridge screws to set the gap tight to or off of the body. The tone will generally be more 'acoustic'.
As a rhythm player, or one who prefers the 'latex quack' of the 2 & 4 pup positions, my STRAT has been set up with the 2 & 4 springs out since the day I got it (81), with about a 3mm gap between the trem briege plate and the body. My 5 spring is slung at an angle, from the 5 lug at the bottom end to the 4 lug up top, and the 1 spring is alos angled, goes from the 1 lug at the bottom to the 2 lug at the top. The 3 spring is straight, 3-3.
EDIT: Here's a diagram I found that shows on the right what I tried to describe about my trem spring setup. On the left is the 'usual' 3-spring setup, with the 2 & 4 springs simply left out.
Last edited by wingsdad; June 20th, 2009 at 11:23 AM.
^^
AXES: Fender '81 The STRAT, '12 Standard Tele, '78 Musicmaster Bass, '13 CN-240SCE Thinline; Rickenbacker '82 360-12BWB; Epiphone '05 Casino, '08 John Lennon EJ-160E; Guild '70 D-40NT; Ovation '99 Celebrity CS-257; Yamaha '96 FG411CE-12; Washburn '05 M6SW Mando, '08 Oscar Schmidt OU250Bell Uke; Johnson '96 JR-200-SB Squareneck Reso; Hofner '07 Icon B-Bass; Ibanez '12 AR-325. AMPS: Tech 21 Trademark 10; Peavey ValveKing Royal 8; Fender Acoustonic 90, Passport Mini, Mini Tonemaster; Marshall MS-2 Micro Stack; Behringer BX-108 Thunderbird; Tom Scholz Rockman. PEDALS/FX: Boss ME-50; Yamaha EMP100; Stage DE-1; Samson C-Com 16 L.R. Baggs ParaAcoustic D.I; MXR EQ-10.