Hi All SVS Sub Owners / Ron or Tom (SVS), Does anyone know what is the maximum SPL when 2 port plugs are used on a SVS Subwoofer? Example: 25-31PC-Plus Am I still able to play it at Reference Level? My hall size is 24'L x 14'W x 8'H (7.1m (L) x 4.2m (W) x 2.4m (H)), but listening area is on one side that is 13'L x 14'W x 8'H (3.9m (L) x 4.2m (W) x 2.4m (H)). In fact, I don't really play that loud at reference level, most at -10db ~ -15db, but some of the DVD that I played only -20db when I found it really loud at certain section. The reason why I asked this question is that I prefer to have a better feel (REAL Deep Bass) of the LFE from the Sub, 2 port plug used (if I use 25-31+) to achieve and feel of 16hz bass effect (or even lower if I can) but I worried that I might spoilt (bottom out) the Sub when I play it loud, said Reference level (just in case that I need to crack it up to this extend some day). I read the SVS manual stated with 2 port plugged I can acheive 16hz bass playback from the sub but only few db loss at the upper bass but I will like to know what is the maximum volume (SPL) I can play? If 25-31PC-Plus cannot achieve Reference Level when 2 Port Plugged? Can PC-Ultra, PB2-ISD or PB2-Plus can do so when 2 Port plugged and go deep to lower bass? Or the new PB12-ISD can reach 16hz or lower without plugged and play at reference level? But I really don't expect this for a budget SUB but just curious to ask. Million thanks to whoever assist me to clear my doubts. Your sincerely, Lyrad PS. Hi Ron or Tom, actually I sent an email to SVS tech support but I am not sure whether any of your staff has receive it. Anyway I am trying my luck here and hope to get advise from any experts who can help.