What are the specs of a full range speaker?

Another point to consider in all of this is the variable degree of honesty and precision with which different loudspeaker manufacturers report their products' frequency responses.

Even assuming total honesty and/or accuracy of reporting, another question is this: How steep is the low end rolloff? For example, we all know that minus 6 dB at 20 hertz is NOT the same thing as minus 1 dB at 20 hertz.

What a great thread! Very educational.

From "my" point of view and experiences I no longer use the 20 to 20K benchmark for selecting a speaker.

In the late 70's I was 'spec crazy'! I would not consider a speaker for purchase if it did not boast the 20 to 20K spec in it's literature. What I learned was some of the speakers that claimed this did not sound good to me. Some speakers with worse published specs sounded much better.

I now listen for tonality, timbre, image, richness of musical texture (the rosin on the bow sound) and ease of use.

My most memorable example was purchasing McIntosh speakers based on the superb specs in their brochure. After getting them home they were good but not great.

I traded them in on a pair of AR-3a's which did not have the published bass performance but had better, more realistic sound.

Today we are fortunate to have such a great abundance of fine speakers. Also, until we can get speaker manufacturers to conduct speaker tesing in the 'EXACT' same way to include the same test lab, we will never be able to fully use published specs to make our purchase selections.

"LISTEN WELL"

Mdhoover has raised a excellent observation. How steep is the roll off. Though a speaker goes to say 30, how is the graph angle look like from say 40hz down to 30hz? And for those who calim they want the "last little drops" of the music, how is the woofer that voices the 20-30, is a very steep roll from 35 to 20hz? The last hz's are too weak to make a big overall difference anyway, if there is a very steep roll.
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?