The only way to tell how close they are in sound would be to hear them in my room. I dont really have a problem with the SuperBam, my system never clipped or overloaded. Besides the boost the Super Duper Bam cuts off the sound lower than 30Hz or 27.. something like that.
The HT3s I heard were in a room that was too small for them and had no rugs, sound soaking devices. lol. There was a nice clarity to the HT3s, midrange was very detailed. Perhaps the Merlins are a tad laid back, very organic & natural. Even the cabinet speaks the music. Sounds weird I know, but it seems the cabinet enhances the sound. An example of a box that hinders the sound would be something like the Tannoys. Great concentric speaker, coherent sound, but you can hear the box in a bad way. Salks are one of the most beautiful speakers Ive ever seen, hands down. I love wood.. hehe, and theyve got em. The HT3s were too much up top for me. Perhaps a tad less in the musical dept. but that might have also been the bass bomb that was going on covering up all the mid action, idk. Songtowers are nice, not nearly as detailed as the Merlins and though Id say the Merlins could have more lower mid detail, the Songtowers had less, and had the transmission line sound when it came to the bass, which isnt as realistic as say the HT3s bass.
Though theres a big price difference. I havent heard any 2 way non transmission line salks yet. Maybe soon.
Love my Merlins!