Indeed and in this earlier post I posed the question why but without any response. History is illuminating because the notion of a physically small speaker being high performance didn't really exist in the hi-fi era before the audiophile/"subjective" phenomenon became mainstream leading to a strong separation of the professional/technical side from the home audio audiophile side. Note that at this time the need for an adequately sized woofer didn't follow from a requirement for deep bass because we were listening to records with rumble filters engaged. It was to cleanly reproduce low frequency percussive sounds.
Here in the UK the BBC designed LS3/5A is probably the most striking example. In the design document it states:
So the professionals that designed the speaker are aware that speakers of this size cannot play loud enough for foreground listening or reproduce the lower octaves but have their uses sitting close in small OB van when you don't want to be cut-off from the environment by headphones. This view of the speaker persisted for a few years until the early 80s when it was adopted by "flat earth" UK audiophiles as having a very high "subjective"/audiophile sound quality when used as main speakers in a room. A significant number of audiophiles genuinely hold the view that the LS3/5A reproduces music in the home with high fidelity. And yet, pretty much nobody involved professionally with high quality sound does. Why? The answer doesn't seem to lie with what is technically required to reproduce high quality sound which is unambiguous and follows from the science/physics but that what people consider to be high quality sound differs. A walk round an audio show listening to people's comments will soon demonstrate this.
Well, I think specs like THD and FR were commercialized & popularized to sell equipment. They do not measure the most important distortions and sound characteristics. Would anybody buy speakers advertised as ONLY 40% loudness overshoot at 5khz, or -30% undershoot at 60hz? Quite good +/-3dB. 0.1% THD on sine wave?? On music transcients, area-under-the-wave-envelope input-output-differences surely approach if not exceed 100%. Never going to see that spec. And in-room response??? Things like the Harmon-Kardon curve "industry standard", Hi-Fi optimized for the average home-use speaker placement c.19??. Who on earth is "average"? 
To put it bluntly, ”professionals that designed xxx" did so to sell so they'd have a paycheck. They are not going to talk about "improving low quallity sound" because we all know marketing trumps quality.
To put it bluntly, ”professionals that designed xxx" did so to sell so they'd have a paycheck. They are not going to talk about "improving low quallity sound" because we all know marketing trumps quality.
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Are you stating that something else is more important than the transfer function (frequency and phase response) and it's deviation from linearity (distortion) to the perceived sound of a speaker? If so, what?
Would anybody buy speakers advertised as ONLY 40% loudness overshoot at 5khz, or -30% undershoot at 60hz? Quite good +/-3dB. 0.1% THD on sine wave?? On music transcients, area-under-the-wave-envelope input-output-differences surely approach if not exceed 100%. Never going to see that spec. And in-room response??? Things like the Harmon-Kardon curve "industry standard", Hi-Fi optimized for the average home-use speaker placement c.19??. Who on earth is "average"?
If this is telling me what I am afraid I don't understand.
How is anechoic infinite-baffle FR relevant to anyone but a designer, i.e. mainly of theoretical interest? THD on steady-state sine wave??
"On music transcients, area-under-the-wave-envelope input-output-differences", surely something this simple has been used? Take a plucked guitar string, compare its CD WAV (audio input) with that of the reproduced equivalent WAV (audio output, wherever in the reproduction chain), superimpose them and tabulate their difference: (area under one wave envelope but not the other)/(area common to both). Identical input=output, this distortion is 0.
(Last millennium in the analogue domain, what-was-his-name did this to sell his amps.)
In reading some of the recent posts, these unless I am reading them incorrectly, suggest evaluating speakers with a very heavy reliance on the "mathematics" if you will. And certainly some of these are quite relevant. Having said that, what was easy to do in days gone by, before the huge consolidation of retail into big box, was to walk into local high end audio stores, see and hear the latest and greatest and bring in your own recordings that you wanted to judge the equipment by. The fine art of A-B-ing. Today yes you can go to audio shows but there's nothing like those instant A-B comparisons IMO with music you know and like. One of the big issues to overcome is sensory adaptation, where you can get used to what you hear and it seems to sound good (unless it is REALLY bad to start with). Sometimes it's just a few bars of a piece back and forth Like was mentioned about Dvorak (I think I had that one) to decide what seemed better, for you.
It informs those with a bit of interest and knowledge what a the speaker will sound like. Prior to the large dumbing down that occurred when the "subjective"/audiophile thing kicked off that would have been pretty much everyone with a hobby interest in home audio. Seems an odd statement to make on a DIY speaker forum though.
This makes little sense to me because the frequency response (magnitude and phase) is the map from the input signal to the output signal. If you know the input signal and the frequency response then you know the output. You don't have to listen or measure.
I have noticed long ago that DIYers are as a generalized group are not at all immune to subjectivism and your typical audiophile snake oil, except maybe they look for snake oil within more technical, engineering aspects of their creations.
Not sure mathematics is the right word. I would suggest engineering knowledge is a better one in the sense of understanding the volume displacement required to create a given level of sound and what is a reasonable cone size and displacement to achieve it in an essentially linear manner. Plus of course understanding what room boom is doing.
Wanting to understand how things work used to be a normal part of a hobby and particularly ones involving DIY. The passive acceptance of audiophile marketing that goes on today is strange given it requires the active rejection of conflicting information without a basis for doing so other than not liking it.
I think snake oil is a bit too strong for what is going on here. It looks more like confusion in first rejecting frequency response as useful and then putting forward an argument for frequency response. Similarly the claims for high sound quality from small 2 way speakers used as mains in a room based on it sounding loud enough and good enough to me. I suspect if pushed many would admit that the 15-18" drivers used by enthusiasts from the other end of spectrum sound a bit more "dynamic". What is missing is a lack of interest in understanding what is going on and how things work in order to tie it all together. It's a hobby after all and if that type of thing isn't interesting then fair enough.
exactly
speed is what HE is all about.
comparing HE big speakers with small inneficient speakers is ridiculous. its like comparing a go kart to a F1 car
now, you have many here who try to convince others and themselves they are equals. borderlines to lying imo.
PA-level high efficiency comes at price in terms of sound quality which is audible levels of resonance. In order to get the required clean SPLs studio speakers tend to be a bit more efficient and have higher power handling than home speakers but significantly less than PA-level HE speakers in order to keep resonances at low levels.
not sure why, but its quite obvious after listening to various low efficient speakers then listenign to horns with a 15". speed is always the first thing that is obvious.
you dont need to struggle to understand, you just need to audition?
I referred to PA-level high efficiency because of the engineering compromises required to achieve those sorts of levels of efficiency. Some speakers that are marketed as high efficiency to attract audiophiles with low power valve amplifiers don't achieve anything close to the efficiencies claimed. Hence the qualification.
Having read...how many you built and measured and actually verified that comb filtering and lobing issues are there and actually are an issue?
Luckilly you found great sounding non expensive 2way, so no issues there 😄
I think you mix up the concepts with the feeling. Speed has nothing to see here. I mean your feeling is not related to a better group delay, better phase.
My 5" 85 dB efficienty that makes 125 hz to 2100 electrical and even more acoustical slope, is subjectivly very "fast", I translate by damped and clean perhaps. It has not audible thermal compression.
If we talk about acurate "speed" between the different drivers, it is coralated to the filters, not the drivers efficienty. So in you mouth I surmise perhaps "speed' means " damped", "dry" !
If you prefer and as far I understand : if your spl is flat in a windows frequency, there it is fast enough and it arrives at your ears at the same constant speed through air around 346m/s at 25°C.
Speed is certainly the wrong word. There is no lack of this attribute in less efficienty driver than the PA.
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