Speaker sensitivity vs SQ

This "signal to noise" ratio thing has implications for the sense of envelopment as well: The further down in level we can still detect the reverberation tails on the recording, the stronger the perception of the recording venue's hall ambience. (This isn't the only thing that matters for "envelopment" to take place, but imo it's one of them.)

Hence why I will harp incessantly w.r.t. acoustics and take with a grain of salt many audiophile claims, especially after seeing listening rooms. Totally laughable when they then make claims about other people's systems not being resolving enough.  But I digress.

Duke, I am not sure your friend has discovered something new, so much as documented what has previously been discovered, but not documented in the real world very much. This paper is a bit of an oldy, but still a goody.  It's from 1992. Okay, it just seems old:  https://pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/Harman_Int%27l/AES-Other_Publications/LS_...    There is a good discussion on driver structure as it relates to heat transfer.  Interesting that relatively old Alnico, which is relatively inexpensive, but still more expensive than ceramic, has great thermal properties.


We audiophiles are to blame (well some of us are). Take one poor measurement to sound correlation (70s/80s and distortion), throw in another weak one (CDs), and as opposed to screaming for better measurements from manufacturers, we let them use it as an excuse to no longer provide measurements as opposed to providing better measurements. If your friend can measure it, then speaker manufacturers can, but they don't because measurements can't possibly tell you how something will sound .....   Oh well, reap what you sew.

Hence why I will harp incessantly w.r.t. acoustics and take with a grain of salt many audiophile claims, especially after seeing listening rooms. Totally laughable when they then make claims about other people's systems not being resolving enough. But I digress.

I'm with you.  What I think I have observed is

a - Self delusion
b - A large variability in the ear brain mechanism being able to filter out room acoustics.

Based on what I know about machine learning, and neural nets, and observations at shows, I believe some listeners can pick out some delicate traits about system despite absolutely terrible rooms.

I personally, cannot.  As studies in learning and acoustics have shown, filtering out noise is energy consuming.  Your brain works harder in an acoustically messy environment and I absolutely feel it.

@erik_squires wrote:

"As studies in learning and acoustics have shown, filtering out noise is energy consuming. Your brain works harder in an acoustically messy environment and I absolutely feel it."

Totally agree.

In home audio, "your brain works harder" = listening fatigue.

[public service announcement] In an acoustically messy environment like the back of a classroom (or even worse the back of a lecture hall), "your brain works harder" = you are straining to use ALL of your CPU power just to understand the individual words, and that takes not only more energy but also more TIME. So by the time you understand one word, the lecturer has already moved on to the next word, and you have neither the spare CPU power nor the TIME to comprehend complex concepts so that you can store them in your long-term memory. This is one of the reasons why the kids in the back of the classroom get tired within fifteen minutes and are by far the ones most likely to flunk. So even if they are shy introverts, tell your kid and grandkids to sit in the front if at all possible! [/p.s.a.]

Duke

Surprised that no one has mentioned “Hoffmann’s Iron Rule” in this discussion.

Josef Anton Hoffman was the “H” in the original KLH company. He was an audio engineer who theorized that you could only have two of the following in speaker design, never all three:

1. Small speaker enclosure
2. High efficiency
3. Accurate bass response

That is, if you want an efficient speaker with accurate bass, you cannot have a small speaker enclosure. 
Likewise, you can have a small speaker enclosure with good efficiency, but bass response and accuracy will be limited. 
My impression is that speaker design is primarily driven by that limitation when addressing SQ and efficiency.

Hoffman's rule applies to passive dynamic drivers in traditional cabinets.

I have found it interesting to see who has worked around some of this at times, including KEF, B&W and even Bose.

Some interesting designs using smaller than optimal cabinets, which fix the bass by EQ are fun to discuss.

Best,

E