What are the specs of a full range speaker?

It's useful to think in terms of how our auditory system might have developed. Sensing low frequency vibrations is useful to survival. Sources that make such low frequencies are likely to be harmful. Very high frequencies beyond those used for localization, OTH, are unlikely to be important.

Then consider the mass of the auditory apparatus, an eardrum, three articulated bones with a muscle attached, one of which rocks on a fluid filled structure that houses hair cells along a membrane. Perturbation of these hair cells causes firing of nerve cells, and the firing of those nerve cells leads through higher processing to the perception of sound. Hardly the design for an ultra HF transducer.

Now the argument can be made that beating among higher harmonics can generate combinations tones that are in the audible range, but the harmonics themselves are of much lower levels than the primaries from which they are generated, and any combination tones are at an even lower level.

Disclosure: My doctoral and post doc work was in binaural processing, but most of my pre-retirement career was as a director of a research program then a research center, so I have been out of the technical loop for decades.

I go along with the long-standing notion of 20 to 20 KHz or even 30 to 15 KHz being full range for a speaker system, but I've come to prefer that LF below 80 Hz be handled by a servo-controlled sub. Soundstaging and transparancy are more important to me than absolute frequency range, but I do enjoy that vibration one feels when a big pipe is invoked, whether at an organ recital or in my home.

db

Dave I do not ahve a good grasp of this equation, 3db@45hz vs -3db@90hz. Help me out. Yes thats the ones. Did you use the Thor or Odin measurments? Are they the same?
Gee only to 45hz, the Thors. Well then please ck Tyler's System 2, with the 8 inch. What's that measurement look like? I think Ty has it down at 30hz. So yeah I could notice a difference as "clear as a cloudless day". Those critical 30-45hz's might make my classical take on a new dimension.
Yes?

Dave help me out with this: "Thor, The tranmission line (dual 7 inch) produces 4db of bass lift from 20hz to 110hz, with loss less than 1db of ripple....the -3db point is 45hz with roll off of 12db per octave below 45hz. ....Usable in room bass response extends well into the low 30hz range".
They lost me. I see 20hz, 45hz, and low 30hz. Which hz is this speaker producing?

Bartokfan

The measurement is from the "Thor"...-3db at 45hz would mean bass output (SPL) has dropped by around half at that freq. Most speaker systems are rated at their -3db points although how and where the measurements are taken is often not clearly stated.

The 12db figure...bass will be down in level by 12db at the next octave lower...a lot

Usable in room response means...some amount of sound that they deem "usable" will be output at those freq's. By saying in room, I guess they are saying that you will get some amount of bass help from the room....Maybe not in your huge room?

Dave

Dave, from your explantion + the link I looked at earlier today, I finally get the idea of db level.
"with rolloff of 12db per octave BELOW 45hz" That is not much going on in the 45hz range when the amp is at lower volume, which is how I listen.
I think the "inroom usable bass" has something to do with the open baffel in the back, has a interesting baffel system, and so in a large room there will be less, smaller more. As you explain.
Thanks.