My REL strata is now 8 years old and I've noticed recently that it occasionally makes distorted "cracking" noises when playing very bassy scenes as featured in Blade 2, Titan AE and virtually the whole of LOTR! TBH I only noticed this after Prestige Audio recalibrated my Denon AVC A1-D with an spl meter etc after they installed my Sim2 HT300. They did the THX thing and switched all the bass to the sub and I think raised the sub output by 3db. This certainly lead to an increase in bass, but as I said, on very demanding discs, the driver seems to give up! Would an upgrade to, say, a Velodyne CHT 15 be the answer? I'm having to watch LOTR at less than -20db to stop the sub cracking and I've turned the sub channel output back down to "0 db"! thanks for your advice.