Congratulations. I bet they sound mellow. A cooler mid-range relative to the bass can result in the three-dimensionality that you are hearing. What happens to that effect when you turn the bass down and the treble up with your tone controls?
Tex, this sparked a memory of an old review I wrote up but never posted, where I tried to describe this effect. I think with some speakers, there is a definite point of origin where the sound comes from. It's like stretching a sheet between the speakers and all sound starts and exists from that point forward. I don't know if this can be best described as a flat soundstage, which I don't think is entirely accurate, but more of an "in your face" sound. This is not necessarily an aggressive sound, but a sound field that only moves forward--meaning there is no area behind the speakers filled with sound.
Now, there are speakers that are described as being able to disappear in the room. I had some bookshelf speakers that did this and it really enhanced the spaciousness of the presentation. Looking at my notes, I think I was trying to tie this phenomenon in with a laid back sound signature. I'm not convinced this is the sole reason for it, but I think it certainly is a factor along with crossover design, cabinet shape and size. . .
Well, now I'm stuck again. This is where my written notes bogged down because I could not reason out why the two speakers I was comparing sounded so tonally similar yet had different presentations.