A less sensitive thermal sensor would probably solve this problem and make the tonal range more uniform and therefore less distracting. That said, as the fans are rated at no more than 2000rpm, they will never create the kind of tonal annoyances that you’ll encounter from an average case fan.
If you still find the fans too noisy you can attach the supplied resistor cable to lower the voltage and thus slow down the spin rate further. You can use this type of resistor with any fan, but you’d have to buy it separately at a cost of around £3 to £5. A set of rubber grommets are also supplied which can be fitted to the mounting holes in your case before you screw the fan in. These are meant to reduce vibration as the fan spins. However, you may find that the grommets don’t fit all cases since they are quite large. One way to circumvent this problem would be to enlarge the holes in the case, but taking a drill to your PC may be something that many users just aren’t willing to do. There is of course also a set of suitable screws supplied for mounting the fan as well.
On a whole the AcoustiFan is a good idea, but the thermal diode could do with bigger steps in temperature sensitivity as this would reduce the annoying sound you get when fans spin up and then slow down again. The asking price is quite high compared to a normal fan, with the 80mm version costing £14.10, the 92mm £16.45 and the 120mm £19.98 inc VAT. But if you have very noisy fans in your PC, switching to AcoustiFans could make all the difference.
The AcoustiFan is a new approach to lowering the ambient noise of your PC, and it doesn’t cost a fortune. The thermal sensor can cause an annoying tonal range as the RPM changes, but if you prefer a constant spin rate you can just mount the sensor away from fluctuating heat sources. Fitting the supplied resistor will result in near silent operation, as our “Silent Solution” feature showed, and ultimately, that makes it worth the asking price.