woofer excursion at start of lp

Tonearm and cartridge are resonating! You can try fooling with the anti-skating other wise get a subsonic filter so you do not damage speakers!

Try starting the platter with the volume up a little less than at a normal level, and slowly swing the tonearm across the platter. If a hum decreases or increases it could be that you need to relocate the ground wire. Best of luck.

I am also thinking the resonations are being caused by a grounding issue. Try tightening the ground wire on the preamp. Does your turntables speed control also have a ground lug?

Thanks for the responses so far-

As for grounding-everything is tight. I do not have a ground on preamp (Manley Stingray integrated) nor the TT speed control (Origin Live). I use a platter matter (Origin Live) but no clamp, although i have one. It does not appear to help.

I adjusted the anti skate which might have had a small effect, it seems to have lessened, but is still happening. Again, its only on the first half inch or so of the start of the LP, then fades into no excessive excursion. Why would anti skate have an effect?

Thanks again.

You don't mention your turntable....you very likely would eliminate the problem with damping....and would bring better sound to your system as well. Your explanation of the problem indicates an "iffy" match of cartridge to tonearm.