need ideas to raise speaker stands

Well, I disagree with Ken. Roller blade wheels are better than hockey pucks.

There are all sorts of coupling devices, tiptoes? cone-like things. If that's what you want to do.

Go to your friendly neighborhood stone mason and have him cut you some slabs of granite. Ensure the measurements are exactly the same as your monitors' bottom sides. Make sure you specify the thickness which will depend on high you want them raised. You can then put these bases on top of your speaker stands. Use some BLUE TACKS on both sides to secure the bases to the speaker stands and your monitors on top of the stones. This is just another suggestion, I think JDOMBROW's idea is superb.

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.