Thanks for all the feedback. I believe the thread size is 1/4-20 according to a speaker manufacturer matrix located on Brass and Granite Audio website. I found a number for Klipsch/Mirage Support and they have the spikes but cost is as follows ($18 per set of 4, so $36, plus $16 shipping, plus $2.50 tax for a total of $54.50) Will continue to look at the suggestions in the feedbacks from this posting. For that price I believe I can land some better spikes as it appears the Mirage spikes are not that great (according to the above inputs) Thank you all for your feedback