Should I build plinths or screw spikes into cabinet?

Thanks everyone for the responses.

Jamnesta, I contacted soundocity.com last week, and their cheaper option (non-custom) still added up to about 40% what I paid for the speakers not long ago, so I'm still looking for a cheaper option.

Infection - Are these available in a cryo-treated option? Haha.

bdp24 - I'll do some research on that avenue.  I'm hoping to stay <$100.

I've added spikes into threaded inserts, but I've also ordered DIY roller bearing setups.  The latter will likely end up being used to isolate my components since I'd prefer to reduce the risk of a loudspeaker getting toppled over (baby on the way!), but I plan on tinkering with both.  Thanks again everyone for the feedback!

After getting the speakers up on the spikes I had a quite significant drop in sound quality, particularly in the low-end.  I have suspended hardwood floors, and it turns out I'm suffering the same side-effects from coupling seen by many others.  I should have done more research...

I've got them up on ball bearings in furniture floor cups now (spikes removed), and I am hearing a great improvement.  I'm going to throw some stone tiles between the bearings and the spikes soon, then probably bump up to some vibrapods or feet/isolated spike cups from Herbie's audio labs.

Infection, I wish I would have investigated the Townshend website further instead of just joking about the price of the seismic bars!  They have a great video that explains the benefits of isolation vs. coupling, and I would have initially gone in a very different direction!

Hi BDP, I've done exactly that with each of my components and could not believe the improvement they made.  I'm using marble tiles instead of plywood, it was actually cheaper!  I also have marble tiles under the speakers and above the homemade rollers presently, and every aspect of the sound has been improved over just spikes on the hardwood.  I'm a little unsure about adding the inner tube under the speakers for stability reasons; the system is in a living room and I'm worried someone (or some dog) will knock them over.  

Has anyone tried this with a more traditional floor standing speaker?  I may get 2 more tiles and try sandwiching the tube or rollers between them.  The cabinets are rectangular so I need the tiles to allow placement of the rollers in an equilateral triangle.

Thanks again to everyone for the helpful responses.  

I just put two hardware store sourced jack-posts on top of cinder blocks in my crawlspace directly under the speakers, and wow what an improvement!  The low end has evened out through the lower frequency range where before there were certain bass notes that rang much louder than others.  I believe the level of detail in the mid and upper ranges is up significantly as well.  I read something recently about working to allow your current gear to sound as it was intended before investing money in new equipment.  It has been a fun learning process figuring out cheap DIY methods to get significant improvements out of the equipment I have been listening to for a few years now.  If my system wasn't in a family living space I would move on to acoustic treatments next, but I'll have to stick with creative use of pillows and blankets until we move to somewhere I can get a more dedicated listening area.  I already got shut down for the more "attractive" items by my better half haha.

That's not a bad idea, and I might actually be one of the few North Carolinians who actually has a few hockey pucks laying around...