Yes. Using a Akasa PWM splitter
http://www.akasa.co.uk/update.php?t...es&type_sub=Fan Cable Adapters&model=AK-CB002
Is available for 2, 3, 4 & 5 fan splits
The master fan is one of your CPU cooler fans plugged into splitter CPU fan socket. Splitter plugs into motherboard CPU fan PWM socket and molex from PSU to power fans. All fans run on the same PWM signal... The PWM signal that is controlling the rpm of the master fan. As long as other fans are similar rpm range they will run at about the same rpm.
I'm running 7 fans in my case this way.
http://www.akasa.co.uk/update.php?t...es&type_sub=Fan Cable Adapters&model=AK-CB002
Is available for 2, 3, 4 & 5 fan splits
The master fan is one of your CPU cooler fans plugged into splitter CPU fan socket. Splitter plugs into motherboard CPU fan PWM socket and molex from PSU to power fans. All fans run on the same PWM signal... The PWM signal that is controlling the rpm of the master fan. As long as other fans are similar rpm range they will run at about the same rpm.

I'm running 7 fans in my case this way.