Has anybody here got an SPL meter (or similar) that can measure really quiet noises. The noises generated by a PC (fans, HDD...) are the sort of thing I would need to measure. The meters I can find dont seem to go below about 50db, but im pretty sure that there are quite a few fans (in my pc) that are rated at 21db and less! Where might I be able to buy one? Or perhaps borrow over a weekend if I pay for it.... Any ideas please?