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Why evaluating the sound of a single speaker is essential
- Thread starter Floyd Toole
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One could also reason that spatial quality in not so important in listening to a single speaker?
And what matters in the end is how we use the speakers: in stereo!
Looking at the figure above one could easily disqualify speaker BB in your buying process when only listening in mono.
Depending on other factors (prices, waf, etc) this could then be the wrong decision.
I got into room correction just a few days ago and at first I measured my 2.1 system playing together. I applied the correction curve and measured again. It was not what the prediction in REW was in the 350-700 hertz area. So I did another pass just for that area and added just that peaking filter to my first correction profile. This way the system now measures well as far as frequency response.
Then I read that each speaker needs to be profiled individually and decided that probably that explains why my adjusted FR did not match the REW prediction. To my surprise however, when I measured the speakers separately and profiled both channels separately I got the same 350-700 hertz unevenness with everything else being about the same. Considering this, in my case I did not see how measuring speakers in isolation helps me. Maybe the balance between left and right is better that way? I am just trying to justify the extra hassle.
Then I read that each speaker needs to be profiled individually and decided that probably that explains why my adjusted FR did not match the REW prediction. To my surprise however, when I measured the speakers separately and profiled both channels separately I got the same 350-700 hertz unevenness with everything else being about the same. Considering this, in my case I did not see how measuring speakers in isolation helps me. Maybe the balance between left and right is better that way? I am just trying to justify the extra hassle.
Imo the problem with applying different EQ to each speaker north of maybe 200 Hz (at the highest) is this: Now each speaker has a different first-arrival sound. And the first-arrival sound is what matters most in this region.
Way down in the subwoofer region we don't hear the first-arrival sound separately from the net in-room sound, so EQ is okay down there.
I may not be correct about that 200 Hz figure being the highest you want to go with EQing the two speakers differently but I'm pretty confident that you want the first-arrival sound to be identical from your two speakers over most of the spectrum.
OP
Floyd Toole
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Thanks for the perspective, and thanks for believing in science.
Yes, variety can be the "spice of life" in many ways. For me, I have found the art itself provided plenty of it, and I set out to improve the odds of hearing it as it was created. That cannot be achieved alone, it requires change within an entire industry.
It has taken many years, but now loudspeakers in professional and consumer domains are demonstrably becoming more similar - in fact remarkably so. Slide show 6 on the 4th edition website shows spinoramas of many examples of loudspeakers that are unlikely to result in timbrally corrupted art either during the creative process in recording control rooms or when providing pleasure in homes. Even inexpensive smart loudspeakers and sound bars are demonstrably aspiring to neutral reproduction. From your personal perspective, I guess this is counterproductive.
Equalization cannot alter loudspeaker directivity, so that is one respect in which changing loudspeakers is uniquely distinctive. Otherwise, if directivity is relatively uniform or smoothly changing, equalization based on anechoic measurements can turn a neutral loudspeaker into many alternatives. This is occasionally being done in pro monitor loudspeakers to reduce clutter in the control room while allowing engineers to tailor the sound to suit various actions in the mix process and to estimate how it might sound out in the "real world". The fact that pro monitoring is increasingly being done in a dominant direct sound field makes it easier.
You said about a "distinctive" loudspeaker: "They we’re not neutral, but sitting in the sweet spot with my eyes closed listening to a recording of solo classical guitar," This is an example of chosing the music for the purpose. Solo guitar, or solo almost anything, is demonstrably poor at revealing resonance flaws in loudspeakers. It is what I categorize as "demonstration" program, as opposed to "revealing" program. A lot of "audiophile" music falls into that category - very forgiving of flaws. The topic of program material for evaluations is addressed in all of my books and in a Sean Olive AES paper.
So, as has been found many times in my lifetime of blind comparative loudspeaker testing, starting with the very first one in 1965, people adapt to the loudspeakers they live with, and are happy with them . . . until, they hear something better. Better may not be "perfect" so on it goes in a lifelong iterative process. Now, "perfection" of sound reproduction in small rooms is still not achieved, but it is demonstable that the differences in perceived sound quality are getting smaller. Statistical ties in double-blind listening tests are more common. Bass response corruption by small room resonances remains the weak link.
Would a "perfect" loudspeaker be satisfying for all recordings. No, because recordings are still variable, and old recordings can be hugely variable. But, at least one is hearing what is on the record, and if one's loudspeakers are relatively neutral, tone controls and EQ can bring the result closer to what is preferred.
Separating the art from the technology used to create and reproduce it can be difficult in the absence of trustworthy measurements. Electronics have been neutral for decades because measurement of their performance is simple by comparison to that of loudspeakers radiating in all directions into small reflective rooms. Now, we have a handle on loudspeaker measurements. That's progress.
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Speaking of bass response, and since this thread is about single speaker listening, I've been wanting to ask you something:
It seems to me that the bass region sounds more full in stereo than in mono. So if I let mono comparisons be my guide (which I do for the rest of the spectrum), is there the potential that I will end up with "a bit too much bass" when switching to stereo? Not that "a bit too much bass" is always a bad thing...
OP
Floyd Toole
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This is why we do our best to neutralize the room during multiple loudspeaker comparisons - make it a constant factor so that the differences we hear are attributable to the loudspeakers. Positional substitution does that. With rare exceptions the differences heard among loudspeakers tended to be above the transition frequency, resonances in transducers and enclosures, and directivity problems, which don't exist at low frequencies.
We find problems in loudspeakers in the multiple-loudspeaker evaluations; that's all. Listening for pleasure is a fundamentally different activity, as the room is a real factor in the mix of factors contributing to our perceptions. Prominent resonances can dominate impressions of loudness, and if they are attenuated bass balance will need changing. If playback sound level is altered, bass balance will need changing (the equal loudness contours), program material varies in bass content, so bass balance is an ongoing adjustment for fussy listeners. And so on. Stereo vs mono is not at issue here, because we listen in stereo and that is where bass balance needs to be assessed.
Newman
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Hi Duke, are you talking about the bass post-room-correction? Because if you mean uncorrected bass, the room could be 'playing each speaker' with different nulls and resonances at your listening position.
But I listen in multichannel! Only kidding....although it's true. Unless you mean 'we have two ears'....
MAB
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I agree, and think this is really important. Bass is going to be the largest change between single-speaker vs. multiple-speakers, even post-room-correction unless the room is intrinsically great or many speakers are used.
MattHooper
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Understandable. Use a neutral speaker, and there’s endless variety to be found in the art.
There are many who poo-poo the idea of the circle of confusion ever being broken, and who view the idea of “ hearing at home with the artist heard in the studio” as being a hopeless quest.
On one hand, they have a point. At least with regard to the history of recorded music around the world up until recently, which compromises the vast majority of recorded music, there are so many variables in terms of the monitors and rooms used, and so much unknown about the making of so many recordings, it would seem impossible in most cases to hear or know you are hearing sound as the artists heard it. So lots of audiophiles, including many on ASR, say “ look I could never know what they heard in the studio. All I have is the recorded signal, therefore, my only goal is to reproduce that signal as accurately as possible with this little distortion as possible, to hear what’s on that recording.”
On the other hand, I agree your goal of to some degree breaking the circle of confusion still seems a sensible goal. As you have pointed out, “ things are getting better” in terms of the convergence between audio gear available to consumers, so at least going forward progress seems possible on the circle of confusion. And even if there is still some variation that’s no reason to abandon the idea. As the saying goes: don’t let perfect be the enemy of the good.
So I very much appreciate the direction that you’ve helped audio gear take towards that goal.
To be clear, while I can see how you may draw that conclusion from what I wrote, that’s definitely not my perspective.
Neutral reproduction, as your work points out, tends to be associated with various aspects of good sound quality (e.g. low in audible resonances etc). It’s great that even lower cost gear is improving this way.
In fact, while I do enjoy hearing all sorts of different speaker designs, ultimately my own preferences tends toward to be a neutral sounding loudspeaker or at least a speaker that does not stray too far from neutral. I like a well balanced sound, without anything that distracts me.
One possible part of departure I think is that I personally do not chase or fuss with the idea of “ hearing what the artist intended” or “ hearing the sound that the artist heard in the studio.”
This isn’t because I don’t care at all about what the artist intended. Rather, it’s because I think that the artistic content and message is generally very easy to apprehend, and does not require high-end audio equipment, or strict neutrality. It’s my view that the artistic choices, everything from melody to instrumentation rhythm performance, and production techniques, are salient enough to translate across a wide variety of playback systems.
Everybody understood the change the Beatles had brought in their music and pop music in general, and through their artistic changes. That came through on everything from some 60’s audiophile system to the crappy turntables in a teenagers bedroom, through the transistor radio on the beach, car radio or whatever. The essential artistic aspects of recording are almost incapable in that sense. And I especially think that they tend to swamp lots of the picky details (“ gotta get that frequency response perfectly flat!”) that we audiophiles engage in. (not that there’s anything wrong at all with being an enthusiast who cares about these details).
As a Rush fan, I’ve listened to Rush on many systems I’ve owned since I was a teenager, and Geddy Lee’s bass has always sounded like Geddy Lee’s bass, Neil’s drums like Neil’s drums, Alex’s guitar (and effects) etc. And on every loudspeaker I’ve owned, all the essential studio production choices were easily apprehended.
I find that also the case even when a loudspeaker happens to have a monotonous colouration - eg maybe a bass resonance or treble peak or whatever. Even in the presence of such resonances, in my experience or my view, the sonic information contained in recordings, tend to swamp those playback, colorations in terms of salience. (This is also why I have no trouble switching back-and-forth between playing vinyl records and digital sources on my system. Not that I can’t hear the superiority of digital, but I find the recording quality and recorded content to overwhelm the more subtle differences in those playback mediums)
The reason I DON’T want a monotonous coloration, therefore, simply has to do with whether it bothers me or not (as an audiophile who also pays attention to the sound quality). For me this is where your research has the most personal relevance - the research that relates to preferences, and why low colouration loudspeakers tend to be preferred.
Although I can certainly understand the view “ why not have both?” As it turns out, we have preferences for neutral loudspeakers, which also happens to serve the goal of accuracy and breaking the circle of confusion. So it’s a two-for-one win.
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Floyd Toole
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Thanks for the elaboration. As for the circle of confusion, it will never completely be eliminated, but at least the technical contributions loudspeakers make to what is heard are definitely heading in the same direction for pros and consumers - whether they like it or not. Small rooms are a weak link, and impossible to standardize. Close listening/near-field monitoring avoids much of that problem, while creating a new one, in that most audiophiles do not listen that way.Understandable. Use a neutral speaker, and there’s endless variety to be found in the art.
There are many who poo-poo the idea of the circle of confusion ever being broken, and who view the idea of “ hearing at home with the artist heard in the studio” as being a hopeless quest.
On one hand, they have a point. At least with regard to the history of recorded music around the world up until recently, which compromises the vast majority of recorded music, there are so many variables in terms of the monitors and rooms used, and so much unknown about the making of so many recordings, it would seem impossible in most cases to hear or know you are hearing sound as the artists heard it. So lots of audiophiles, including many on ASR, say “ look I could never know what they heard in the studio. All I have is the recorded signal, therefore, my only goal is to reproduce that signal as accurately as possible with this little distortion as possible, to hear what’s on that recording.”
On the other hand, I agree your goal of to some degree breaking the circle of confusion still seems a sensible goal. As you have pointed out, “ things are getting better” in terms of the convergence between audio gear available to consumers, so at least going forward progress seems possible on the circle of confusion. And even if there is still some variation that’s no reason to abandon the idea. As the saying goes: don’t let perfect be the enemy of the good.
So I very much appreciate the direction that you’ve helped audio gear take towards that goal.
To be clear, while I can see how you may draw that conclusion from what I wrote, that’s definitely not my perspective.
Neutral reproduction, as your work points out, tends to be associated with various aspects of good sound quality (e.g. low in audible resonances etc). It’s great that even lower cost gear is improving this way.
In fact, while I do enjoy hearing all sorts of different speaker designs, ultimately my own preferences tends toward to be a neutral sounding loudspeaker or at least a speaker that does not stray too far from neutral. I like a well balanced sound, without anything that distracts me.
One possible part of departure I think is that I personally do not chase or fuss with the idea of “ hearing what the artist intended” or “ hearing the sound that the artist heard in the studio.”
This isn’t because I don’t care at all about what the artist intended. Rather, it’s because I think that the artistic content and message is generally very easy to apprehend, and does not require high-end audio equipment, or strict neutrality. It’s my view that the artistic choices, everything from melody to instrumentation rhythm performance, and production techniques, are salient enough to translate across a wide variety of playback systems.
Everybody understood the change the Beatles had brought in their music and pop music in general, and through their artistic changes. That came through on everything from some 60’s audiophile system to the crappy turntables in a teenagers bedroom, through the transistor radio on the beach, car radio or whatever. The essential artistic aspects of recording are almost incapable in that sense. And I especially think that they tend to swamp lots of the picky details (“ gotta get that frequency response perfectly flat!”) that we audiophiles engage in. (not that there’s anything wrong at all with being an enthusiast who cares about these details).
As a Rush fan, I’ve listened to Rush on many systems I’ve owned since I was a teenager, and Geddy Lee’s bass has always sounded like Geddy Lee’s bass, Neil’s drums like Neil’s drums, Alex’s guitar (and effects) etc. And on every loudspeaker I’ve owned, all the essential studio production choices were easily apprehended.
I find that also the case even when a loudspeaker happens to have a monotonous colouration - eg maybe a bass resonance or treble peak or whatever. Even in the presence of such resonances, in my experience or my view, the sonic information contained in recordings, tend to swamp those playback, colorations in terms of salience. (This is also why I have no trouble switching back-and-forth between playing vinyl records and digital sources on my system. Not that I can’t hear the superiority of digital, but I find the recording quality and recorded content to overwhelm the more subtle differences in those playback mediums)
The reason I DON’T want a monotonous coloration, therefore, simply has to do with whether it bothers me or not (as an audiophile who also pays attention to the sound quality). For me this is where your research has the most personal relevance - the research that relates to preferences, and why low colouration loudspeakers tend to be preferred.
Although I can certainly understand the view “ why not have both?” As it turns out, we have preferences for neutral loudspeakers, which also happens to serve the goal of accuracy and breaking the circle of confusion. So it’s a two-for-one win.
The non-technical components are much less certain, as both musicians and recording engineers experience hearing loss as an occupational hazard. We will never know what they perceived, even if they heard exactly the same sounds as we do. Also pros get habituated to the loudspeakers they work with. I will never forget discussions after the loudspeaker evaluations done at the NRCC in the mid 80s for the Canadian Broadcasting Corporation to choose new monitors. The listeners were experienced professional recording engineers and producers, and there were comments to the effect that some of them thought that they had never heard better sound in their lives. The loudspeakers they most favored in the blind tests included several consumer products designed by Canadian companies using the NRCC facility to design therir prototypes. They were fundamentally neutral. Good musical art survives much abuse but it is best if it doesn't have to.
Some of the active pro monitors are as good as loudspeakers can be these days, and so are some of the consumer loudspeakers shown in book website Slide show 6. Go online and browse the ever growing collection of spinoramas to be found. There are good products out there, and many good ones that can be made even better with knowledgable EQ based on the anechoic data. But active loudspeakers with built-in DSP and EQ have non-trivial advantages.
@Newman, my beta-testers report that they hear better spatial quality in mono from the configuration that was found to improve spatial quality in stereo.
So apparently "spatial quality preference in mono predicts spatial quality preference in stereo" is true in this case as well. This was of course not a complete investigation into the topic but my beta testers said they were surprised at how much difference there was in mono.
Thank you again for kindling a fire underneath me!
Sidenote: appreciate this very respectful way of conversation as it is an example for how it should be regular with scientists.
Thanks. @Newman started it. He and I had clashed several times and then out of the blue he took the time to send me something helpful in a private message. I started to see that I had been mis-interpreting him all along.
The sharpening stone is not the enemy of the dull knife. Sometimes he is the sharpening stone and I am the dull knife.
The supplemental content page is here. You need to answer a question to "show" that you have the book to access it.
resourcecentre.routledge.com
Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers, Rooms and Headphones
resourcecentre.routledge.com
OT: This reminds me that I need to buy the 4th edition (before anyone asks, I have the first three, but this is a major update). I was not able to pre-order and the paperback has been out of stock every time I have tried. There used to be a discount code for ASR members but it has probably expired.
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Floyd Toole
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Go to: https://www.routledge.com/search?kw=Floyd+toole. They have a Black Friday sale on 25% off. Thanks for being a regular "subscriber". The website has some useful stuff, including some slide shows.
EDIT: I just checked and the paperback is out of stock at the publisher, but I see. that Amazon.com has it at the "regular" price. Bummer. I guess its popular.
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Thanks, that's where I looked first. I'll keep checking, or maybe buy the hardcover, or eprint (though my Kindle is mainly for bedtime READING so's I don't keep my wife awake. Looking forward to a new 4th!
Newman
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Your praise is actually embarrassing! But thank you, Duke. Especially thank you for your none-too-common openness to contradictory information and even more rare willingness to create and conduct blind tests that sometimes challenge your prior understanding. The test you have done here is a credit to the forum and delighted me personally. Well done mate!
Cheers
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