Merlin VSM-M and Bass

p, it sounds to me like the set ups you have heard the vsms in, have had some sort of bass reinforcement in the upper bass. if anything, the vsm is more linear than the tsm, has higher resolution and much less distortion. because the speaker can go lower it can combine with room nodes the create a false sense of mid bass boost. or...is it you do not like equalizers? :)
bobby

Maybe there is a relation between Bam and bass hump...
Could you explain shortly about frequency response differences between these two options?
Thanks for your inputs

"Maybe there is a relation between Bam and bass hump"

Pojuojuo, it is interesting that you hear a mid-bass hump or boost, must be a room node as Bobby notes. I have never had a mid-bass issue with the VSM-M which I have used for 12 years now, but it took a while in the early days to get the low bass right including dialing in placement, room treatments, isolation devices and matching the right components. I might have welcomed a mid-bass hump in those early years, cause the balance wasn't right but I perservered recognizing the other aspects of their presentation with the encouragement that yes, the speakers do bass.

Until you REALLY get things right, dialed in, it might seem that the speaker doesn't do bass but still.... I never had the hump issue you are experiencing. This is one of their virtues, especially for a 2-way, no humps, no gimmicks. The low bass articulation, control and pitch accuracy of instruments is just unbelievable when it is right. I'm not too sure I have heard well recorded solo piano sound more natural, coherent and resolving top to bottom on any system regardless of what John Atkinson said in his comments in the Stereophile review. ;^).

p, the bam causes no mid bass hump because its boost plateau is actually centered at 35 hz. the vsm response is actually + or - 2.25 db. the tsm is + or - 2.75 and because the qts of the morel woofer, its response is actually boosted by over 1 db in the range up to 180 hz. it is also playing below resonance of 52 so the im distortion is higher and impedance variations considerable because the driver in not kept in linear drive like the scan/bam. i am sure what you are hearing is a room mode. if the vsm's were set up by the 1/4's rule that would probably disappear.
bobby

My VSMs (originally SE, subsequently updated) have seen almost 15 years of use in 6 or 7 different rooms. As some have noted, it may take a bit of work to get satisfying bass balance in any give room. OTOH, the one thing that I've never had to deal with in all these years with my VSMs is a mid-bass bump.

Marty