I bought the Seismic Bars in 2015 when they first came out, I was unhappy with the supplied plinth that Tannoy provided with my speakers that I bought in 2014, the dealer that sold me the Tannoy speakers did not understand how or why the Townshend bars could be better than Tannoy’s own supplied plinth, so I invited him round to my home and we swapped between the two plinths/bars multiple times, he could not understand how much better the sound was, he fed this back to Tannoy, who probably ignored it :-(
A few years later I was given the opportunity to try the Podium version, but I could not detect anything too much different in SQ between the podium ( more expensive ) and the bars ( cheaper) , so I kept the bars and am still very very happy with them :-)
My floorstander speakers are Tannoy Precision 6.4’s and weigh 22kg, so my bars are Size 1, and they sit on a concrete ground floor in my lounge TV room that measures 6m x 6m
My centre speaker - a Precision 6c sits on a strip of black sorbothane, and is only used for 5.1 movies, I thought about using some Size 2 bars under it, but I resisted because the centre speaker sits on top of a fairly substantial sideboard, that houses the amp and oppo player, so I convinced myself that it would not really help all that much !
My Tannoy speakers really punch well above their weight, and for what I paid for them, they sound twice as good as they probably should, all thanks to the Townshend bars.