Stillpoints Ultra SS adapter needed, help...

Here’s a reducer bushing available from Amazon that should work 3/8-16 to 1/4-20 reducing bushing

Davehrab, Thanks I have looked at those. That item would work if it was about 1 1/2" long to reach the outside of the speaker.The problem is that my speakers have a very deep recessed bolt hole.

I replaced the original spikes that came on my Andra II's with Audio Points and even with those, Audio Points provided a 3/8-16 that is 1 1/2"long threaded stem to reach the tightner that is inside the speaker.
I'll try to take a picture and place it on my system page tonight.

I just added the pictures of the spikes on my system page.

Looking at your pictures and being unfamiliar with the Stillpoints. I am curious if the stud can be removed from the Stillpoints? If so the I would remove them and drill and tap the new holes to accept the 3/8" thread you need.
I think and adapters are going to eventual force the 1/4" stud to fail. Just my immediate impression upon looking at the pictures you posted.

Never easy is it (;-)