My girl friend is a genius

I almost got me a pair of the top Merlins... but passed as I am a bass junkie... for whatever reasons.

Recordings play a big part in the sounds actual range depth, and weight. Analog or digi. Naturally so does the amp and all the other audiophile analogies.

I do note a diff in bass from tubes to SS as well. Depending. Speaker design too can make bass sound different. Personally I've found there is little else which produces great bass than great bass drivers. you can tune an enclosure, labyrynth or channel the low end thru a myriad of passages and out a port.... but the sound simply for me, does not replace that which a great large low end driver can generate.

That said, an active sub surpasses a good many floorstanding loudspeakers bass production.

I've found too when introducing another piece into the signal chain you'll get always another perspective on the same recording. thereafter the optician's appraisal... Better, same, or worse?

With all else the same, usually interjecting a different amp will make a greater diff down deep than will a preamp exchange... ordinarily. Fact is, I dig exchanging amps in and out now for various mood oriented musical genres than anything else.... and I'm lately liking hybrid amps a bunch... though these thoughts pertain to the whole of my own system. In a different room, diff speakers, etcv... it could easily be otherwise.

The key is to keep the volume at a level where 'she' can always be heard.

Has she got a sister

I think at lower volumes you end up listening to the music instead of the stereo.

It sounds like you have room treatment when you say you have it on all sides. But what room treatment? Blankets or something along those lines? Or actual acoustic room treatments? Your system profile does not list anything.

I was and might as well still suggest this just in case you don't have it. Bass trap absorption in the bass build up areas like corners. My system and room without bass traps was hard to listen to and higher SPLs. With bass traps, proper ones, my system sounds fantastic at higher SPLs. It is one of the benefits of bass traps I feel is quite significant. I think how a system sounds at low SPLs is a good way to gauge how good it is. But also how it sounds at higher SPLs is a good way to tell how the system sounds.