Over the years i've been gradually upgrading my subs. Started a few years back with Behringer 1800D and then moved Turbosound IQ series. I have 4x Turbosound IQ18B, 2x IQ15B and IQ15/IQ12 tops to go with that. Been very happy with that setup, but i recently performed at a venue that had the JBL SRX-setup (828sp/835p) and i was blown away.
So Recently bought 2 of these JBL subs and O.M.G what a difference. Without any doubt, ONE of these JBL subs produce more deep wonderful bass at extremely high SPL that 4 of the Turbosound IQ18B's. Maybe even if add the 15's as well.
Also bought the SRX835p's to go with these subs. My Turbosound rig is now living the life as DJ's personal monitors instead, and some will still act as extra fills.
Super troubled and even amazed how naive i've been over the years. I seems that in the end, you really get what you are paying for....
JBL SRX 800 <3