i personally dont think you are going to get any big massive sound from an 8x10 unless your 2 feet away from the cabinet. the 18"s that have the slow muddy reputation is mainly because they used to make the cone so heavy to handle the stress, it was sluggish. nowadays cone materials are stronger and lighter. note- any cabinet with a port or vent has poor transient response compared to a sealed cab. so they automatically dont sound as tight. ( but they are not as loud as a ported cab, so its a tradeoff.) i use evx 180 18 inch speakers in sealed cabs. slow? well we just recorded a record and the producer johnny k (mainly known for producing disturbed) preferred the mids from the 18" over the svt cab. we used the treble from the 10" though. a real "svt" bass rig consists of two 8x10 cabs. look at the old advertising. the guys with one svt cab are half steppin it. 2 svt cabs at a bar gig with 300-600 people is darn respectable. the difference between 1 and two cabs is not twice as loud. it almost seems to be 3 times as loud. im not knocking anyones killer 4x10 rig, but you asked for massive , booming , and defined. if i had to make a new bar rig, it would be 2x18, 2x10, and a jbl horn. and yes it will destroy an svt cab in fidelity and massiveness and tone, and dispersion. side by side the svt sounds kinda like a toy, it dies off sharply below 80 hz. the 2x18 is flat to below 30hz. the 30-63 hz region is where the massiveness comes in, the stuff you feel but dont hear. unfortunatly its expensive to have it made. johnny a. staind.