i got a couple of keltiks. unfortunately the spikes are missing. does someone have to sell 10 pieces or knows an alternative with a notch above?

Are they the same as Keilidh / Kaber?

If so, several sets available, the seller is a Linn dealer so can probably let you know if they will fit Keltik:

https://www.ebay.co.uk/itm/Official-Lin ... SwGFZcf-nZ

I have no link with the seller (other than I have purchased from them in the past).

M10 for Keltik

You can buy M10 threaded bolts and grind a point on them. I did this due to a thick pile carpet to raise the speakers up a bit.