Speaker sensitivity vs SQ

@erik_squires wrote: 

" I should point out that we should not attribute thermal compression to what might also be bad acoustics. Very reflective environments will have similar audible results, in at least as similar as you can type about them. A lot of bad / compressed treble complaints I’ve seen on audiogon were addressed with better room treatments. Was it excess reflection, or better treble/bass balance, or did the improvement in sound quality lead to turning down the knob, therefore reducing tweeter power dissipation? Really hard to say unless we are measuring. I sure could not explain in words how to hear a difference. :)" 

Your observation makes total sense to me. 

Dynamic contrast can be viewed as a "signal-to-noise-ratio" thing, and to the extent that undesirable/excess reflections raise the effective in-room "noise floor", they reduce the system's dynamic contrast.  I suspect this may be more common and/or often of greater audible significance than the short-term thermal compression revealed by those tone-burst tests. 

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.)  

The ear/brain system classifies reflections as such based on their spectral content, so imo it makes sense for absorption to be broadband, such that the spectral balance of the reflections is largely preserved (assuming they were spectrally correct to begin with).  If the spectral content of the reflections is skewed too much, they are no longer classified by the ear/brain system as "signal", and so they become "noise". 

Duke

Greg Timbers:

Q: How has the sound of speakers changed over the years? Many yearn for the speakers of the past over those of today… what has changed? Distortion, materials, focus on sound characteristics?

A (by Mr. Timbers): Speakers have generally become smoother, more 3-dimensional and much smaller. This means that they are less dynamic on the whole and rather toy like compared to good stuff from the 60s and 70s. Unlike electronics, miniaturization is not a good thing with loudspeakers. There is no substitute for size and horsepower. Nothing much has changed with the laws of physics in the last 100 years so what it takes to make dynamic life-like sound is unchanged. There have been some advances in magnet materials and a bunch of progress in adhesives but not much else. The cost of a 70s system in today's economy would be considered unaffordable and the system would be deemed unnecessarily huge. The large highly efficient systems of old came at a time when 15 – 30 watts of power was the norm. Today's stuff would choke on those amplifiers. Now that power is cheap, size and efficiency has been thrown out the window because you can always apply more power. Unfortunately, more power does not make up for lack of efficiency. Today's speakers range between 0.1% to maybe 0.5% in efficiency. (On a good day) 60s and 70s stuff was more like 1% to 10%. With most of the losses gong to heat, turning up the power on a small system with small voice coils and poor heat management is definitely not equivalent to a large high efficient speaker.

It is true that the response of many of the old systems was a bit ragged and generally less attention was put in the crossover networks because simplicity generally means higher through-put. However, the big Altec's, JBL's, Klipsch's and Tannoys of the day would still fair well today with a little modernization of the enclosures and crossovers.

Today's multi-channel home theater setups let a bunch of small toy loudspeakers and a sub or two sound pretty big and impressive to the average Joe. I think speakers have mostly become a commodity and small size and price are what counts the most now. The few high-end brands left are struggling for market share in this age of ear buds.

https://positive-feedback.com/interviews/greg-timbers-jbl/

The few high-end brands left are struggling for market share in this age of ear buds.

Thanks great post...

It explain to me why my Tannoy were so good.... 😁

Alas! i own them no more...(2 pairs)

Happily my Mission Cyrus help me to forget them, they are very well embedded in all 3 dimensions, then even if they are not on par in quality with the Tannoy, they sound better than my Tannoy non well embedded ever sounded to my ears...

I will not go further, the word "embeddings" is not very liked, being not understood....

My best to all...

A note: someone not tired to read all day long reviews of costly new electronical design possible "upgrades" said that my "evangelization" of people is too much for his ears.... It is unbeliveable that people are so gullible to throw their money without thinking about the way to use in the better way possible what they already own....




«You can change opinions, you cannot change science»- Harpo Marx

«It is like reverse engineering brother, you can change science and after that opinions change»-Groucho Marx

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.