What are the specs of a full range speaker?

"Mdhoover are you saying is that if a speaker requires 6db of amp volume to produce the 20hz, its not near as efficient and accurate as the speaker that can hit the 20hz register at only 1db.
Correct?"
-Bartokfan

I hadn't thought of it in terms of required amplification volume, and cannot comment on that point. All I meant was that some speakers are flat or nearly flat at 20 hertz, whereas others might measure at minus 6 dB at that point. Clearly, if the stated measurements are even correct (see Hififile's post above), then the one that's flat down to 20 Hz has more bass.

I also don't know the precise relationship between loudspeaker efficiency and the associated frequency response curve.

In terms of accuracy, I've READ that frequency response curve flatness is not necessarily indicative of low distortion and/or high accuracy. That certainly matches my limited personal observations, and may be part of what Hififile's post is describing above*.

FOOTNOTE: In my case, the Paradigm Studio 100 V3 speakers seem to have had a very similar dynamic range to that of the Intuitive Design Summits, with the caveat that a killer DAC and better preamp are being used with the Summits. However, despite the perception of similar dynamic range--and therefore presumably similar frequency response curves--the accuracy of the Summits seems far, far superior to that of the Paradigms. (So does the imaging, high end smoothness and detail, and basically everything about them, for that matter. And I really liked the Paradigms--very excellent speakers in their own right.)

Md you lost me. back to the idea of full range, options/tradeoffs.

Mdhoover has a valid point. Your speaker is no good if it can do 20hZ whilst sounding terrible. There are lots of speakers that measure flat from where to where, all the while sounding dull, and lifeless.

Bartokfan, you touched on the same subject in your conversations with your speaker designer. In his designs, you give up some midrange fidelity by going to a bigger driver.

It takes a big speaker to bring all the decibels in full orchestra into play, not to mention the grand sweep of a symphony in full cry.

Muralman, well by going with a 3 way, the single 8inch will bring in the lower hz's that I;m missing with the dual 7's MTMdesign. Fidelity is not the issue, as its the same Seas' drivers. Its that a single 7 acting as the midwoofer in the 3 way (8/7/tweet) will not bring out a full a voice as the MTM/dual 7's. But with the 8 I;'ll get to hear some of the lower octaves that I am missing in my MTM. The bass cellos, cellos, timpini, tubas all have some notes in the 30-40 range that I'd like to hear. It'll be an interresting trade off. I may not like it, and the Tyler 3 ways is a nice chunck of money at $3500. What I;m gaining to hear those rare but precious lower octaves in the 3 ways, may not be worth the sacrifice of losing the fullness of the dual 7's/lower hz's. IOW the 3 way may sound anemic, the lower mid hz's may be a weakened image.
Can I live with that?