I think you'd get better answers if you told us your current tubes and associated gear. I recently bought a Rachel and yes, it is much warmer with more Bass than my Monoblocks. I tried some 807 power tubes but found them too warm with my Zu Audio Souls, I went back to my RFT EL-34s that I have always preferred in my Torii and they are a better match...more clarity in the bass and more detail all around. My associated gear is a CSP3 and ZROCK II ...source is a Jolida 100 CD player or streaming from the laptop with a Red Dragonfly DAC in between it and the CSP3.
If I get around to moving my Omega Alinco speakers to try with the Rachael, I think the added warmth with the 807 tubes might be a better match. Mark.
PS...also the gap you use on the bottom of your Omen's will change the sound as will speaker placement. I don't do treatments so others will suggest that.
PSS...one other thing I did when I was having problems with boomy Bass when I added a sub to my primary system was to place the sub on an isolation platform and move the sub farther into the room so the wall wasn't affected as much. The isolation worked so well to tighten and clarify the Bass, I bought two more for the HR-1 speakers. I haven't felt the need to do so in the second system though...where the Rachel and Zu Audio "Souls' reside. The link is the platform and company I bought them from...I recommend both.
https://www.sweetwater.com/store/detail/SubDudeII--auralex-subdude-ii?mrkgcl=28&...