need ideas to raise speaker stands

If the spikes are adjustable tilt the front of the stands up a fraction of an inch. A minute rise (@ the front of the stands) makes a big difference in the firing angle @ 8-12 feet away.

Material, like Paul suggests, (not the roller blades:-) might work well with his Harbeths as the cabinets are designed to resonate within a certain frequency range (you want them to vibrate as they are tuned this way).

I suspect that this might also be true of the Coincident Triumphs as the ones I tried sounded best on cheap/flimsy stands (not heavy/rigid ones).

You can go to Home Depot and get a couple of concrete "stepping stones". They come in various sizes like 12"x12", 18"x18" or 24"x24". They are about 2 inches thick. You could put some heavy duty cones under them to couple them to the floor if needed. Place your current stands on top of these "risers".

Also, using the existing spikes, you could tilt the stand/speaker back a little by adjusting the spikes to facilitate the bachward lean angle. This accomplishes much the same result as raising the height. It's FREE, so try it!!

I agree with the Granite slabs. The size you need most Tile and Marble dealers throw away. I got two with gold vein for my Silverlines and then set the spikes to where they would rest and drilled small holes for the spikes to seat(not all the way through). They look amazing and added to the low end also, but BluTak is another way to bond them. Now the stands look like a million $$, got a height, little bass to boot.

Well, David, I don't actually use the styrofoam. I have tacky stuff between my speakers and the stands. One pair is on Harbeth wooden stands, though, and I'm thinking of trying the foam on the metal stands under the others.

But, you're on point, of course. Some speakers do better with decoupling. Some, I guess, are better coupled to their stands. It makes no sense to use hard coupling to rigid high mass metal stands with lossy speaker cabinets. But right now, I am listening to a pair of old Harbeth P3's, relatively inert, not lossy, with a couple of napkins between them and the metal stands. They sound wonderful.

Roller blade wheels are great. And cheap.

Longer spikes?