Lewis - are these the tyres?
http://www.jaxquickfit.com.au/tyres/...treak/stiletto
Are they fitted with the correct direction of rotation (kinda obvious, but they may have put the apprentice on the job!) - it's printed on teh sidewall, but they look like a uni-directional tyre - if fitted wrongly they can kick up quite a din...
Some of these cheaper tyres can have a real harmonic drum to them - perceivable at some speeds and not others...
I've never used these and can't say I have any first hand experience with them, but if you've just had two fitted, try moving them from the front to the back and see if the noise follows....