K&N's are a performance orientated quality filter that can still perform an air filtering function and the cheapo ones are basically just for looking nice under the bonnet, and don't do much in the way of filtration, which is why they are louder: it's a similar effect to having no filter at all......plus modern cars arn't particularly loud anyway what with all the metering gubbins the air has to flow through.
If you want noise, fit a cheapo filter, or, better, get yourself a proper old non-injection twin carb car and take off the airbox: you'll get all the induction grunt your ears can take!!