Just how quiet really are the water cooled spindles?

[Jonathan]

The actual cutting noise is definately much greater than the spindle itself.

......and they've a baby

Less noisy than the baby, and unlike the baby it's not tuned to be the most annoying frequency you can hear.

My video may help you. I talked in it at a normal volume to give a reference sound level:
http://www.youtube.com/user/Jonbliss...10/xciLCN2Dz08

[HankMcSpank]

The actual cutting noise is definately much greater than the spindle itself.

But when most of your material is only 1.6mm FR4, that doesn't factor in much (I jog about a lot more than cut!)

Thanks for the link to your video....as mentioned earlier, it's difficult to assess from a youtube video as the mic positioning/sensitivity/AGC circuit can really affect the end result ...but I'd say that only 6,000RPM would be tolerable ...it seems crazy to have a VFD setup in my instance (I guess I could always flog it on to bring the total cost of the machine down). Either that or I can feel an acoustic shroud coming on!

PS Loving your other video...

http://www.youtube.com/user/Jonbliss.../2/k3MG7ww49A8

...if the BBC Radiophonic Workshop lose their Tardis samples, they'll be knocking at your door!