How do you run a fan at 7V?

[Taz]

Apologies if this is a daft question.

I've seen a few references to lowering the supply voltage to a case/heatsink fan from 12V to 7V. How is this done?

I've just ordered a Panaflo 92mm fan for an XP-90 heatsink. The site I ordered it from gives airflow and noise level specs for both 12V and 7V. The fan is supplied with a 3-wire connector (with tacho). I don't necessarily want to do this with the CPU fan but the case i'm about to order will come with two 120mm fans and I may want to change those to quieter ones and run them at 7V. Hence, I was wondering how to do that.

[CrapshoT]

Have a look here m8
http://www.cpemma.co.uk/7volt.html

[Taz]

Excellent! Cheers, mate.

Taz