SPCR

Would attaching a 80mm to 60mm fan adaptor increase the noise - if all by much?

Theoretically greater airflow over a smaller area should create a higher noise.

My plan is to use a WBK68 (version 1) - remove the fan - add a 80mm - 60mm adaptor and use the panaflo 80mm low speed fan at 5V.

Suggestions, comments?

In theory, yes. But in practice, No.

If we were dealing with much bigger air flow numbers funneling the air down and then pushing it through a heatsink would make more niose. You're basically making a whistle, if you think about it.

But at these airspeeds the flow's too low for the turbulance through the heatsink to make a noise, or at least to make a noise that we could hear. The reduction in fan noise would more than make up for it.

Thats what I wanna hear!! Yeeeeeee!!!