I have a pair of Revel Ultima Salons and a Gryphon Tabu Century Amp. For music I have been lent a REL Storm III. My room is 6m x 6m x 3m High. The Revels sound great but I need to wind the REL up to the 2 o'clock position (Hi Level) to hear/feel it. The REL has been wired in parallel on the speaker outs of the Gryphon. Do I need a Sub with a bigger driver to match the REVEL?