Similar to Roofmeister, I built my equipment table and amp platform gluing three sheets of 3/4" MDF and trimmed with stained poplar. I'm very satified. Have some pieces remaining and I'll also report back how it works under my REL. The spikes are reasonable from Parts Express. I was going to take the same approach for platforms to support a set of Snell D's that I recently came across.
Down firing sub tweeks
I use a down firing sub on a carpeted surface. Are there any specific tweeks available to better disperse the bass ? For example, would a product like Auralex sub dude make any improvement, or is that just to reduce the bass below the unit? ( Like in an apartment setting). Anyone use a "base" of some type, or is there is there an isolation base surface known to be better than carpet?