A Newport engineer recommended these:
http://www.newport.com/SLM-Series-Compact-Air-Mount-without-Self-Leveling/139799/1033/info.aspx#tab_orderinfo
Very reasonably priced, but certainly not as efficient as the Vibraplane. They do have isolators with terrific vertical and horizontal isolation (1/1.5 Hz respectively), but the load required is just not practical for home audio application.
http://www.newport.com/S-2000-Stabilizer-Pneumatic-Isolators-with-Automa/844255/1033/info.aspx#tab_Overview
http://www.newport.com/SLM-Series-Compact-Air-Mount-without-Self-Leveling/139799/1033/info.aspx#tab_orderinfo
Very reasonably priced, but certainly not as efficient as the Vibraplane. They do have isolators with terrific vertical and horizontal isolation (1/1.5 Hz respectively), but the load required is just not practical for home audio application.
http://www.newport.com/S-2000-Stabilizer-Pneumatic-Isolators-with-Automa/844255/1033/info.aspx#tab_Overview