A full range speaker?

A speaker has to go flat to 30 hertz with large baffles and large drivers in a full size cabinet to be considered full range and if you can find one made prior to 1965 that is 16 ohms you will definitely hear a full range system unlike anything made today. The baffle should be twice the width of the woofer and three times the height of the woofer to be considered a full size cabinet so for a 15 inch woofer it would be 30 by 45 inches and the cabinet should be 1.5 to 2 times the depth of the driver so for the 15 inch woofer that would be 22.5 to 30 inches deep. When you get a speaker like this with the high quality drivers in it you will know what full range is and the need for a subwoofer will go away completely.

realworldaudio-

The brain makes sense of the fundamentals ONLY when the upper harmonic spectrum is correct. 

If true this would explain a number of things. It would explain whyTownshend Supertweeters improved the sound of instruments far lower in frequency than the Supertweeters output. It would explain why frequencies we cannot even hear as such nevertheless have an effect that can be heard. And it would account for the fact there are three times as many ear cells devoted to detecting these high frequencies than the ones we can hear.   

Maybe not explain, the question of why is always hard to crack, but it does for sure agree with all of these observations.

The bottom octave 20 to 40 Hz is critically important. You can not get the sense of a live performance without it. The breath and feeling of the music disappear. Drums and bass become two dimensional. Synthesized bass just dies. I have never heard a speaker system produce this correctly on it's own not that it is impossible but, it seems to be much easier with subwoofers. It takes more than subwoofers. You have to put them in the right places in a well treated room with additional room control and digital bass management. The subs have to have adequate power and be timed correctly. If not done well you have just mud and a detriment to the rest of the system. This is the most difficult part of the spectrum to get right and a zillion ways to get it wrong which is why there are so many opinions on the subject. A large part of the problem is room acoustics. Even with the best equipment the room can severely F up the bass. Rather, I should say that the room will F it up. +- 10 dB in an octave is not uncommon. The end result is what I call one note bass. There is no one solution to this problem. It helps if the room was designed as a listening room to begin with but most people do not have that option. So, you have to use multiple subs with a lot of power, room control and digital bass management with a two way digital crossover. Those of you who are digital phobic need to get over it. You are just shooting yourself in the foot. 

@douglas_schroeder @millercarbon

I agree with your brief assessment, as well as Miller Carbon's most recent comment, as I think they are parts of the generalized conclusion we can draw that is: We don’t just hear with our ears, we hear with our bodies. Remember Bone Phones? 

I wasn't really aware of that on the upper range, until this post and responses; how else can we explain the effect that truly full range sound reproduction is obvious, and yet inexplicable? I can’t hear much past 12khz anymore, but there must be something I am getting from that range because when I limit a speakers output to that frequency I can't hear it, but I feel there is something wrong.