A Broad Discussion of Speakers with Major Audio Luminaries

[Sokel]

For consumers this would correspond to: "the sound quality increases in proportion to the efforts in reading/watching internet/magazine reviews"
For prosumers (aka ASR readers) this corresponds to: "the sound quality increases in proportion to the efforts put into measurement comparison"
In reality, some diy enthusiasts design better speakers than many professionals. And some highly regarded commercial speakers are rooted in diy designs.

On another note, I would ague that the worst sighted bias for tech-savy consumers comes from printed measurements and their (miss-)interpretation.
Correlation between loudspeaker measurements and perceived sound quality may be fairly well understood for frequency-response on- and off-axis.
However, room interaction of certain dispersion patterns (wide/narrow, constant directivity, cardioid) and their effects on sound quality aspects seem less clear.

When it comes to distortion, especially HD can be highly missleading. While ASR members love low THD plots, many also love high THD speakers (e.g. D&D 8C, Kii Three). Maximum SPL with respect to a constant THD limit over frequency basically makes no sense at all. Confusion starts with the combination of all HD orders into one THD value despite the fact that higher HD orders are more audible. A constant limit also ignores the upwards masking effect of the base frequency, which changes with frequency. These aspects comprise narrow-band signals like the sine-sweeps used for testing. More masking will occurr with actual music. Nevertheless, a perceptionally correct (T)HD limit/representation for narrow-band signals would be a good step forward.

Rule of thumb:
When bass stops going "vvvvvv" and starts going "vrrrr" one must start searching for new speakers.

THD (specially higher than H2) down low is absolutely audible no matter how cheap or how expensive a speaker is.

 

[Sal1950]

When bass stops going "vvvvvv" and starts going "vrrrr" one must start searching for new speakers.

Could you maybe vocalize those sounds and submit a recording of them?

 

[Sokel]

Could you maybe vocalize those sounds and submit a recording of them?

I bet you know exactly what I mean and you already recalled it

 

[illusonic]

Rule of thumb:
When bass stops going "vvvvvv" and starts going "vrrrr" one must start searching for new speakers.

THD (specially higher than H2) down low is absolutely audible no matter how cheap or how expensive a speaker is.

Of course THD is audible. But where are the thresholds?
Edit: Plot shows masking thresholds for 50Hz signal at 96dB.

 

[Sokel]

Of course THD is audible. But where are the thresholds?
Edit: Plot shows masking thresholds for 50Hz signal at 96dB.

View attachment 524199

THD consisting of what?

It's one thing some innocent H2 at 5% and it's a whole other thing for a driver reaching its excursion manifesting in hard H3.
Former can be inaudible, the later is as audible as it gets.

 

[illusonic]

THD consisting of what?

It's one thing some innocent H2 at 5% and it's a whole other thing for a driver reaching its excursion manifesting in hard H3.
Former can be inaudible, the later is as audible as it gets.

"innocent" and "hard" is not what I'm looking for. You can check the plots for an innitial idea of potential audibility thresholds.

 

[Floyd Toole]

For consumers this would correspond to: "the sound quality increases in proportion to the efforts in reading/watching internet/magazine reviews"
For prosumers (aka ASR readers) this corresponds to: "the sound quality increases in proportion to the efforts put into measurement comparison"
In reality, some diy enthusiasts design better speakers than many professionals. And some highly regarded commercial speakers are rooted in diy designs.

On another note, I would ague that the worst sighted bias for tech-savy consumers comes from printed measurements and their (miss-)interpretation.
Correlation between loudspeaker measurements and perceived sound quality may be fairly well understood for frequency-response on- and off-axis.
However, room interaction of certain dispersion patterns (wide/narrow, constant directivity, cardioid) and their effects on sound quality aspects seem less clear.

When it comes to distortion, especially HD can be highly missleading. While ASR members love low THD plots, many also love high THD speakers (e.g. D&D 8C, Kii Three). Maximum SPL with respect to a constant THD limit over frequency basically makes no sense at all. Confusion starts with the combination of all HD orders into one THD value despite the fact that higher HD orders are more audible. A constant limit also ignores the upwards masking effect of the base frequency, which changes with frequency. These aspects comprise narrow-band signals like the sine-sweeps used for testing. More masking will occurr with actual music. Nevertheless, a perceptionally correct (T)HD limit/representation for narrow-band signals would be a good step forward.

Yes, indeed.
I discuss distortion in Section 9.7 in the 4th edition - here is a quote:
"The end result of this is that traditional measures of harmonic or intermodulation distortion are flawed. They do not quantify distortion in a way that can, with any reliability, predict a human response to it while listening to music or movies. They do not correlate because they ignore any characteristics of the human listener, itself an outrageously non-linear device. The excessive simplicity of the signals also remains a problem. Music and movies offer an infinite variety of input signals and therefore an infinite variety of distorted outputs. The only meaningful target for conventional distortion metrics is “zero”. Above that somebody, sometime, listening to something, may be aware of distortion, but we cannot define it in advance."
We are fortunate that today's transducers are as linear as they are . . .

 

[illusonic]

Yes, indeed.
I discuss distortion in Section 9.7 in the 4th edition - here is a quote:
"The end result of this is that traditional measures of harmonic or intermodulation distortion are flawed. They do not quantify distortion in a way that can, with any reliability, predict a human response to it while listening to music or movies. They do not correlate because they ignore any characteristics of the human listener, itself an outrageously non-linear device. The excessive simplicity of the signals also remains a problem. Music and movies offer an infinite variety of input signals and therefore an infinite variety of distorted outputs. The only meaningful target for conventional distortion metrics is “zero”. Above that somebody, sometime, listening to something, may be aware of distortion, but we cannot define it in advance."
We are fortunate that today's transducers are as linear as they are . . .

The zero distortion btw. audibility threshold has been reached in electronics. The best speakers may be sufficiently close, but it would still be good to have some perceptionally valid distortion parameters. For harmonic distortion the perceptionally worst case is the actual measurement situation with only a single tone. If the test tone masks all harmonics, we are below audibility threshold. If harmonics peak out of the masking threshold, the distance between threshold and individual harmonics could give a better idea of audibility than the distance to the base tone. Of course harmonics would have to be analyzed independent due to different masking threshold levels. Finally, they may be combined in some way to get a THD value.

One interesting aspect is that harmonics are also masked by lower order harmonics. So k2 will mask k3 to some extend. In that regard, it may make sense to include all lower order harmonics to the calculation of the masking treshold applied to higher order harmonics (e.g. include H1/2 for masking threshold compared to H3). Basically, the "innocent" H2 helps to make H3 less "hard". At the end the combination of harmonics with their relative level will make them more or less audible or obtrusive. In the post MP3 age we should be able to define what is audible THD.

 

[levimax]

Of course THD is audible. But where are the thresholds?
Edit: Plot shows masking thresholds for 50Hz signal at 96dB.

View attachment 524199

How about masking with a 20 Hz or 30 Hz tone taking fletcher-munson perceived loudness into account?

 

[illusonic]

How about masking with a 20 Hz or 30 Hz tone taking fletcher-munson perceived loudness into account?

A good masking model may take this into account. On the other hand most people don't hear anything at 20Hz and will be happy to get 40/60Hz instead.

 

[levimax]

A good masking model may take this into account. On the other hand most people don't hear anything at 20Hz and will be happy to get 40/60Hz instead.

You made my point perfectly. With a 20 Hz input that returns no audible output at 20 Hz and louder perceived 40 Hz and 60 Hz distortion output, no masking it taking place. While some people on some program material on some systems may prefer hearing 40 Hz or 60 Hz tones from a 20 Hz input compared to hearing nothing that is the polar opposite of "Hi-Fi".

 

[illusonic]

You made my point perfectly. With a 20 Hz input that returns no audible output at 20 Hz and louder perceived 40 Hz and 60 Hz distortion output, no masking it taking place. While some people on some program material on some systems may prefer hearing 40 Hz or 60 Hz tones from a 20 Hz input compared to hearing nothing that is the polar opposite of "Hi-Fi".

One can use a "Hifi-Masking-Curve" for guys like yourself (no masking at 20Hz). Others are happy with a more experience-oriented approach and realize that the 20-30Hz region is not overly important for music playback.

 

[levimax]

One can use a "Hifi-Masking-Curve" for guys like yourself (no masking at 20Hz). Others are happy with a more experience-oriented approach and realize that the 20-30Hz region is not overly important for music playback.

That then leads to the question is it better to just roll off @30 Hz or reproduce it with massive distortion? I don't think there are any studies on this. I will grant you that there is little 20 Hz content but there is quite a bit of ~30 Hz content in many recordings and the studies that are out say bass is 30% of the preference score so I am surprized people are so willing to tolerate such poor performance for the last octave.

 

[illusonic]

That then leads to the question is it better to just roll off @30 Hz or reproduce it with massive distortion? I don't think there are any studies on this. I will grant you that there is little 20 Hz content but there is quite a bit of ~30 Hz content in many recordings and the studies that are out say bass is 30% of the preference score so I am surprized people are so willing to tolerate such poor performance for the last octave.

We all have devices that either per algorithm or simply due to speaker limits produce lots of harmonics for which they cannot play the base frequency. Obviously people prefer the hint of bass through virtual bass algos (harmonics generators) over the total absence of this frequency range in their smartphones. And in this case bass means below 300Hz. I see no reason that user preference should be different for other playback systems and even more so for a much lower frequency range.

 

[Juhazi]

Do yoy guys have access to parametric dsp? Or music/sound editing like Audacity?

Test audible effects of missing lows by high-pass filtering. The starting point should be rather capable speakers and music with real low signals. I bet you will be surprised of the difference. More so with action movies.

I have had diy speaker systems with capable bass for the last 15 years, no going back! Just have to measure and manage 20-60Hz room modes!

 

[Thomas_A]

One can always use those LF tones to get a little sick. I lost a bit of my appetite once when listening to a system at a studio in Sweden. Four vented subs with 15 inch woofers in a not too big room. Not everything is audible I certainly felt it.

 

[Floyd Toole]

That then leads to the question is it better to just roll off @30 Hz or reproduce it with massive distortion? I don't think there are any studies on this. I will grant you that there is little 20 Hz content but there is quite a bit of ~30 Hz content in many recordings and the studies that are out say bass is 30% of the preference score so I am surprized people are so willing to tolerate such poor performance for the last octave.

The "studies" you are referring to is the subjective/objective correlation done by Sean Olive, and it pertained only to linear, not non-linear, performance. Bass extension and smoothness are both factors. I suspect that simultaneous upward masking helps us tolerate simple harmonic distortion except for organ pedals and isolated synthesized tones
.

 

[Audionaut]

sometimes it seems reasonable scepticism slides into mere cynicism.

Yes, I agree with you. Sometimes you can sense an attitude that marks the very peak of the pendulum swing, the opposite end of which is represented by audiophiles who always describe everything in very flowery terms and consider measurement data unimportant. I find both of these extreme positions extremely exhausting because their thinking is completely inflexible and lacks fluidity.

I trust my own ears, but I trust measurements even more (especially in the higher Frequencies), which is why I have a calibrated measurement microphone and Equipment at home as well; over time, I’ve learned quite a bit from it in combination with the appropriate Software. Above all, how to measure manure (in german: Wie man Mist misst)

On visual listening: I think that unless you work in the audio industry, you won’t be able to avoid visual listening.

For example, were all the visitors at Axpona blindfolded? Hardly—you look for the product you want to hear and see it automatically.
Does anyone here buy a speaker blind?
Are there any audio stores that offer calibrated blind tests? I haven’t come across any yet.

The only blind test I’ve ever participated in was with an audio magazine, which was interesting, but that doesn’t necessarily reflect the reality of a private consumer buying audio equipment.

That’s why, yes, blind comparisons are certainly good and necessary in audio development and for manufacturers, but as an end consumer, they’re very difficult to implement and would really only be necessary at the time of purchase.

What I’ve noticed here on ASR, though, is that a lot of people order speakers based solely on measurements, which is actually pretty blind and deaf.

 

[IPunchCholla]

What I’ve noticed here on ASR, though, is that a lot of people order speakers based solely on measurements, which is actually pretty blind and deaf.

It might be deaf, but it is not blind at all. I can tell from the measurements and my own tested abilities whether any speaker with spinorama measurements will be good enough for my use case. I have, and I am sure I will in the future as well, buy speakers without hearing them (in some space that has nothing to do with my own use space).

 

[Audionaut]

It might be deaf, but it is not blind at all.

What I meant by that is that the buyer wouldn't have any personal sensory experience with the speaker.
Personally, I wouldn't do it, but if others choose to handle it that way—why not? Good luck