I'm uploading a video as I type this, of my 30 watt "Ebay1" machine engraving some anodized alum parts I'm doing, they're particularly noisy AND fast engraving, the noise even drowns out my talking towards the end- I recorded this because you mentioned no noise and slow engraving...
these are engraved 3 times using the 'fast hatch'--
first 2 passes is a cross hatch ran using .06mm spacing, 1500 speed, 100 power, 30 khz,
3rd 'cleanup' pass is .07 spacing, 2000 speed, 60 power and 70kz...
And you'll notice an anomaly that I just noticed, the cleanup pass, which should be faster than the cross hatch passes, is noticeably slower. There's a reason for this; the START TC/STOP TC etc settings are wrong on the cleanup pass color. I didn't notice until I checked the settings for this post! I changed them after this video, and now the cleanup pass is noticeably FASTER, like it should be. Just something else to think about