Running Marlin? RRF? Klipper?
Have you done an acceleration test? Ringing is almost certain to be acceleration rather than speed.
The way I tune is the following (this assumes you have already calibrated your steps/mm and all the other basic motion calibrations):
Determine maximum volumetric flow rate of hot end:
- Heat up to temperature of the material you are testing
- Extrude 100mm of material at say 4mm/sec - Weigh the extruded amount
- Extrude 100mm of material at 5mm/sec - Weigh the extruded amount
- Keep upping it until the extruded amount drops significantly = skipping.
- Take this figure and put it in to the following equation: t=d/s so time = 100mm/maximum extrusion speed in mm/sec. So, say it's 10mm/sec then it's 100/10 = 10s
- 100mm of 1.75mm filament is 240mm^3. Divide this by the figure above = 24mm^3/sec. This is your maximum extrusion rate.
- At 0.2mm layer height and 0.45mm line width, maximum speed is thus: speed = volumetric flow / (extrusion width x layer height) so speed = 24 / (0.45*0.2) = 266mm/sec
Your figures will be very different to those but the methodology should be the same.
Once you have those figures, take an acceleration test piece and slice it so that you are running at 50% of your maximum speed above and varying the acceleration as you print. Start at 200 mm/sec^2 and go up from there.
Examine your test piece for ringing. Where the ringing gets bad enough to be annoying, that is your maximum acceleration.