I cannot trust the Harman speaker preference score

[Bjorn]

With a mono test with the speaker placed in the middle, the side wall specular reflections are at a lower level. So this takes the room a bit more of out of the play compared to having speakers closer to side walls with no side wall treatment.

Optimal position for each speaker can makes sense. As a speaker designer you have to tune the low frequency with a certain type of room gain and how a designer does this can vary. Some may tune it with a corner gain of 9 dB in, some with 6 dB, etc. And with a cardioid or a dipole, the best position generally are different compared to a monopole.

Multichannel is a step away from accuracy due to much more comb filtering and lobing. While one cannot hear discrete reflections in the same matter with many channels, everything is sort of a mess. Another approach to achieve spaciousness without this and maintain accuracy is using a high level of lateral later arriving diffuse energy. Something Harman never included in ther researchers to my knowledge but others have and it's often used in the studio world.

Personally I don't fancy multichannel for music and much prefer a late arriving diffuse tail. However, as a speaker designer it would financially be much better to sell more speakers to people.

 

[Bjorn]

View attachment 192053

The walls are slanted, and thus avoid side wall reflections. The energy passes the listener and goes towards the diffusers in the back. This also achieves a higher level of diffuse energy which is psycoacoustical preferable. The quality of the diffusers with avoidance of lobing is important though.

 

[Sean Olive]

I agree that multichannel audio is the superior concept. Here are some issues I have encountered with the implementation of multichannel audio:

1. The music I most want to hear is only available in stereo.

2. My limited experience with upmixing has been that the level of the surround channels has to be correctly set by hand for each recording in order to avoid a potentially distracting (illusion-collapsing) result.

3. Purpose-built center channel speakers are never a timbral match with good left and right speakers.

4. With upmixing or music videos or multichannel music recordings, I have yet to hear a center channel speaker that conveyed the same sense of depth to the center of the soundstage that a good stereo setup could.

5. It seems to me that "bang for the buck" generally favors two-channel, but this may depend on the price range, and surely depends on personal priorities.

And I readily concede that I and my objections may well be in the minority.

Regarding 2
I find the same thing with bass. Adjustments are necessary because of audio circle of confusion issues.

3. There are some excellent center channels that do a good job in terms of timbre match. An alternative is to use an identical speaker as the left/right speaker. Easy to do with bookshelves or inwalls

4. For upmixed stereo the depth of the center could be improved by playing with the center spread. For multichannel recordings there is more potential to achieve depth than stereo

 

[Bjorn]

Three identical speakers. Reminded me what I had that with one speaker behind the acoustical transparent screen. Thought it was going to be the best home theater I ever had. But the center channel ended having up a major dip in the 100-300 Hz area, making it sound like a tiny PC speaker! Ended up selling it and using a phantom center. Just a side not with little relevance!

 

[Newman]

I’m not claiming that mono tests recreate stereo imagery in stereo tests. I’m arguing that a speaker that tests well in mono will test well in stereo. Floyd’s paper shows that spatial ratings in the stereo tests are quite variable and highly dependent on the recording.

If you believe testing a mono speaker in the center of the room is invalid then set it up as a stereo left or right as we can do with our speaker mover. Then the reflections are identical to a left or right speaker in a stereo setup.

As far as how the speaker couples into the room modes the optimal position of the loudspeaker will depend on the acoustical properties and dimensions of the room and the locations of the listener(s). To say that the optimal position is different for every speaker is nonsense, especially for conventional speakers where below the room transition frequency the speaker is close to a monopole and will couple into the room modes much the same way.

As an aside if there were different optimal locations for different speakers I’ve never seen this specified in the loudspeaker setup manual. And wouldn’t they be different for different rooms? And there would no need for room correction and calibration.

A much larger effect/bias is comparing different speakers in different locations of the room. Not only will the reflection patterns be different but there will be differences in bass due to how they couple into the room modes. These positional biases have been well documented in our AES papers and are the reason we invested significant money into an automated speaker mover that places each speaker in the exact position.

Only a single listener in the optimal seat is used in our product benchmarking tests. For group or tour demonstrations we will use multiple seats. We analyze the data separately for each seat and can see how the ratings vary across seat. The consistency in ratings across seats is quite remarkable except when a speaker has a significantly different frequency response on and off axis producing a much different direct sound for listeners in different seats

Sean, it might add context if you know a little more about the views of your conversant Mr Tuga, to wit his past posts:

https://www.audiosciencereview.com/...20hz-20khz-speakers.17392/page-10#post-570142 “Science” in quote marks, Toole is biased, Olive draws conclusions from miniscule samples of listeners.

https://www.audiosciencereview.com/...bjective-preference.11875/page-17#post-349513 The Toole and Olive listening rooms show no evidence of specific listener positions.

https://www.audiosciencereview.com/...ha-p5-speaker-review.15161/page-7#post-531483 “Science” in quote marks again, more limited studies by Olive.

https://www.audiosciencereview.com/...cts-of-room-reflections.13/page-9#post-372602 Toole and Olive sell loudspeakers.

https://www.audiosciencereview.com/...ements-of-the-b-w-nautilus.14105/#post-431252 Toole and Olive have created a bias and prejudice in favour of the Spinorama.

https://www.audiosciencereview.com/...-review-measurements.14310/page-6#post-439999 The Spinorama isn’t enough and the listening tests were ineffective.

https://www.audiosciencereview.com/...es-in-csv-txt-format.16401/page-3#post-586766 The trained listeners in Olive’s tests preferred the B&K curve to the one Olive derived as preferred overall.

https://www.audiosciencereview.com/...-or-an-objectivist.29115/page-37#post-1076571 Only scientists and researchers should use the word “Science” (presumably without the quote marks) because everyone else doesn’t add enough caveats to properly represent what research shows.

https://www.audiosciencereview.com/...r-preference-score.31454/page-21#post-1113635 The shuffler-based experiments are flawed methodology giving unusable results.

https://www.audiosciencereview.com/...er-preference-score.31454/page-8#post-1110532 Sarcastic rebuttal of those who see Olive’s speaker preference score as relevant, taking agreement with the Olive score system as evidence of being blind believers of a God Olive who dictates religious Audio Laws.

cheers

 

[Sean Olive]

With a mono test with the speaker placed in the middle, the side wall specular reflections are at a lower level. So this takes the room a bit more of out of the play compared to having speakers closer to side walls with no side wall treatment.

Optimal position for each speaker can makes sense. As a speaker designer you have to tune the low frequency with a certain type of room gain and how a designer does this can vary. Some may tune it with a corner gain of 9 dB in, some with 6 dB, etc. And with a cardioid or a dipole, the best position generally are different compared to a monopole.

Multichannel is a step away from accuracy due to much more comb filtering and lobing. While one cannot hear discrete reflections in the same matter with many channels, everything is sort of a mess. Another approach to achieve spaciousness without this and maintain accuracy is using a high level of lateral later arriving diffuse energy. Something Harman never included in ther researchers to my knowledge but others have and it's often used in the studio world.

Personally I don't fancy multichannel for music and much prefer a late arriving diffuse tail. However, as a speaker designer it would financially be much better to sell more speakers to people.

Not many home speakers are designed for corner placement or wall placement. If they are that’s how we would test them. This might include soundbars and inwall speakers.
We built a listening room with an inwall speaker mover for that purpose.

Powered Pro monitors often include switches that provide different equalizations for different boundary conditions. We would test those using the appropriate setting for the setup.

I can count on one hand the number of dipole and cardioid speakers Ive tested in my career.

 

[Sean Olive]

Three identical speakers. Reminded me what I had that with one speaker behind the acoustical transparent screen. Thought it was going to be the best home theater I ever had. But the center channel ended having up a major dip in the 100-300 Hz area, making it sound like a tiny PC speaker! Ended up selling it and using a phantom center. Just a side not with little relevance!

View attachment 192055

There is a cure for that problem.

 

[Newman]

The walls are slanted, and thus avoid side wall reflections. The energy passes the listener and goes towards the diffusers in the back. This also achieves a higher level of diffuse energy which is psycoacoustical preferable. The quality of the diffusers with avoidance of lobing is important though.

I clearly showed side wall reflections that are not avoided.

 

[Bjorn]

I clearly showed side wall reflections that are not avoided.

Sorry mate, but your drawing lines are incorrect. Obviosuly one needs to have the right wall angles for this and relate it to the speaker beamwdth. The picture is a general illustration, but you see the general idea below.

 

[Digital_Thor]

And an accurate tonal balance doesn't not seem to be a priority for the majority, since research seems to indicate that most untrained listeners enjoy much exaggerated low- and sub-bass, and up-lifted treble.

And to a trained listener... that extra bass and treble, can sound awful
I have a very smooth bass by the power of multiple subwoofers and a smooth, even response both on and off-axis. The curve falls off smoothly with frequency rising as you move to the listening position, which seems natural, and I have not had people by, that did not think it sounded good.

Some actually complain that they need a bit more "sparkle", which make sense, since those are the ones with more dispersion in their own tweeters, and this can add "openness" because of more reflections. They all like my bass though, because I slowly converted them to multiple subwoofers - it simply works wonders

We are biased though, with our different age, background, hearing, music preference and so on. And I do agree that music can be enjoyed on many different systems, without much loss of total "summed" fidelity.
Maybe speakers should be judged technically by how close they are to neutrality. I think Harman already did this - right?
Then as we have a technical reproduceable reference - people can add by EQ(if possible in the given situation) or simply buy a given deviation from reference, and enjoy - knowing that they like something else. Honesty about feeling different, should not be taboo, because then it often becomes even more pronounced.
I did not build my system to be neutral, to aim for "reference" because it is cool or "better". I did it because it seemed like the best theoretical way to build a loudspeaker in the light of all the experience I could gather from the last 40 years of development.

I chose a waveguide to match the tweeter more easily with the midrange, lower distortion, cross-over point and control dispersion.

Likewise, I use a smaller midrange, so that dispersion smoothly integrated with the tweeter, and because I find smaller midranges better in their upper frequency band - making them sound more detailed and moving the breakup further away from the cross-over point.

My woofers are selected to be able to both play a little midrange, for easier integration with the midrange, as I cross higher, for supporting the smaller midrange. Woofers should also be able to play as most 3 way floor stander, so that they can roll off with a first order around 50-60Hz - making the transition to subwoofers smooth and as an overlap, which again avoids many dips and peaks in the transition from woofers to subwoofers.

Membrane material are chosen, not because they are made of a certain material, but because of how they behave. Paper often seem to have less smooth off-axis behavior in midranges - which is why I finally settled for the SB Textreme, that seem to balance in between hard and soft cones - aiming for a smoother cross over/ dispersion - still keeping details "alive" - not being "soaked up" in the soft cone.

I have a little bit more gain on my subwoofers and my room is only slightly damped in the upper frequencies. But it has slanted walls and is all open and not in any way possible to make symmetrical, and maybe the soft walls and floor, makes for a kind of absorption in the bass, compared to concrete constructions.

No ports in my design - all closed. Simply seems easier and less likely to create that horrible "boxy" sound that way to many speakers suffer from - IMO. Also, because I simply could not care to try a figure out how to design a ported speaker - why should I?
Is this better than so much else? Maybe not. But I use them both for watching youtube, movies and listening to music.

The reason that I mention these details of my system, is to show how many little things that are not taken into account, when tying to create good sound in our homes. And it is a mix of all of them, that create a whole. So even though you for example chose a small speaker, that has a bass/midrange and tweeter, with smooth and well-designed cross-over - then you still need so much more, to even get close to getting the entire music system up and running.

So my point is. I don't think we can make a preference score as such. Unless we really clear up, that the score only dictates an isolated set of details, which again only is a part of the final chain in the entire system - that ultimately make up the total sound that we listen to.

 

[Sean Olive]

There lies the issue, as I see it. Research shows that a single speaker should be listened in order to judge the quality of speakers and as 3D/immersive listening can alter that quality of a the listening experience, research community has left the concept of quantifying individual speaker quality behind.

But here on ASR it is still gospel.

Loudspeaker technology and the science behind it is pretty mature. I am quoting papers that are 37 years old that are still valid today. The science has been peer reviewed and the results replicated in other labs of universities and other loudspeaker manufacturers. It’s no longer a controversial or disputed topic within the industry. If you think it’s controversial you are not well-informed.

The loudspeaker industry has generally accepted the science of what makes a loudspeaker sound good; there are new standards that define what is good and how to measure it, and it’s widely practiced within the industry

If you go to an ASA or AES conference there are almost no papers on what makes a loudspeaker sound good. Most of the attention is to make loudspeakers sound good in smaller form factors, cheaper, play louder, compensate for room modes, or do beam steering arrays to deal with room acoustics or simulate virtual speakers and spaces.

AR, VR, mixed reality, and immersive audio is the focus for applications in the home, the car and mobile.

 

[Bjorn]

I can count on one hand the number of dipole and cardioid speakers Ive tested in my career.

I can only remember seing the Martin Logan speaker. Scored pretty low if I remember correctly.

 

[tuga]

Won't the presence dip that is referred to above sound nice for only some types of listeners? For example, a sound engineer monitoring close to the speakers may prefer the presence dip, but an at-home listener using a more distant listening position may hear it is a lack of spectral energy that distorts the sound reproduction. So what sounds "nice" in one situation will sound "bad" in another situation (at least to an experienced/trained listener).

Yes.
And the fact that some people have different preferences is enough for different "presentations" to be valid. And that is so because many people are still reluctant to use EQ, digital or analogue.

It would seem that a viable approach to solving this problem is to choose a loudspeaker on the simple basis that it is known to be highly accurate at the transduction of the input signal (e.g., very flat, well-extended frequency response, with low distortion and low compression characteristics), and with a well-controlled directivity pattern. It then behooves the listener to adjust their listening room to suit their particular expectations of the sound reproduction quality. This is the classical speaker–room interaction problem, except that the major problems with the loudspeaker have simply been engineered out of the equation, which is what present knowledge and technology seem to be largely capable of achieving.

Would not such an approach help to solve the problem of choosing a loudspeaker from the plethora of products in the marketplace?

I have been doing this forums thing for over 15 years now and, having observed the behaviour of many audiophiles, I am convinced that many find the journey more important than the destination. They have an ideia of what type "presentation" sounds good to them and constantly change gear in a quest for that holy grail.
I don't think that this is a very effective approach or good value-for-money but we must understand that audio is a hobby, and one for mostly geeky-nerdy, somewhat socially-awkward middle-aged chaps with understanding wives and some money to spare...

 

[tuga]

View attachment 192053

A schematic, or schematic diagram, is a representation of the elements of a system using abstract, graphic symbols rather than realistic pictures. A schematic usually omits all details that are not relevant to the key information the schematic is intended to convey, and may include oversimplified elements in order to make this essential meaning easier to grasp.

https://en.wikipedia.org/wiki/Schematic

 

[Sancus]

Looking at it dispassionately, without the embedded marketing streak, it would seem that you have hit the nail on the head. One has to clearly identify what the aim is, and multi-channel audio seems to be largely aimed at providing a different "experience", not a high-fidelity recreation of the sound field as would be heard by a listener in a specific location at the original acoustic event. Much of multi-channel audio seems to be targeted more at creating entertaining "special effects" than high fidelity.

FYI, most multi-channel music is classical, there are 7092 albums listed on hraudio.net and the vast majority of those are 5.1 SACDs with a standard frontal soundstage. That is also how most Atmos albums I've heard so far are mixed as well. There are some more experimental approaches, but they are in the minority.

But experimentation with more than 2 channels is nothing new either. Pink Floyd was writing their songs from scratch to be performed and heard on quadraphonic back in the 70s.

 

[tuga]

It is what you think and it is more than just opinion: it is wrong. You completely misunderstood what Toole is advocating. (You seem to have an anti-researcher bias that leads you too hastily to “passionate disagreement” with them. Not sure why you are so inclined, but you are.)

Toole is 100% in favour of respecting the art of the music in its recording and playback. With no exceptions. You would also know this if you had read his material with an unbiased eye. Strange.

He advocates the use of speakers with smooth, flat and extended FR….because music is art, and should be respected.

He advocates the use of speakers with near-constant or smoothly varying beamwidth and DI….because music is art, and should be respected.

He advocates the use of room treatment that preserves the character of the incident sound….because music is art, and should be respected.

He advocates the limited use of room equalisation to counter the worst effects of small-room playback, particularly in the bass….because music is art, and should be respected.

He advocates the use of multichannel recording and playback technology because it is much better able than 2-channel to capture and replicate …and respect… the artist and the music as art, and more fully experience that art, which artists only put to 2-channel because it was the only widely available alternative in its day, but would always have used multichannel if it was a realistic option, because they would have been easily able to perceive its superior ability to represent the magic and art of the music itself.

And…he advocates the use of tone controls to adjust for many recordings having too much or too little bass or treble, which does not respect the sonic qualities that the music originally had, and failing to have decent tone controls that can make such corrections when necessary is a distortion of the art of the music….because music is art, and should be respected.

That’s where you come in and get it all back to front.

Correct me if I'm wrong but I think he is a proponent of upmixing which messes up stereo for increased "envelopment"/"immersiveness".
I also think that he is as proponent of unsing early reflections too, which also mess up stereo.

Add those to tone control "by ear" and you have 3 elements that will cause a deviation from fidelity. So much for respect.

But I actually agree with him. Because in my view, the goal of a domestic system for reproducing recorded music is to provide listening enjoyment to the end user, and only him, alone, can accurately (pun intended) say what sounds best to him.
Not an engineer nor a scientist, not an objectivist nor an algorithm...

 

[Sean Olive]

I can only remember seing the Martin Logan speaker. Scored pretty low if I remember correctly.

View attachment 192058

Yes it did. It did have a preferred position which was outside the room unplugged

 

[abdo123]

I wonder how many non-audiophile people have heard of Dolby Atmos. Or cared.

Almost everyone i know has an Apple phone with Dolby Atmos capable Apple earphones or headphones with headtracking.

 

[abdo123]

Be that as it may, is the end result of that something that will be taken up by the broad range of music consumers? I doubt it. It's a technology looking for a market, albeit a quite small one, but through its marketing of it, the music industry hopes to sell more music. It would be interesting to know how many listens are via a Dolby Atmos sound system. It seems unlikely that it would be more than 0.5%, if that.

That seems to be quite an inaccurate assessment...

And the bulk of the market will continue to listen in stereo, as they don't really care one iota about the other options, which are simply not on their radar.

I don’t know a single person other than me in my life that has a stereo system.

Statistics back up my statements too. Headphones are not stereo either no matter how delusional you are.

 

[tuga]

I’m not claiming that mono tests recreate stereo imagery in stereo tests. I’m arguing that a speaker that tests well in mono will test well in stereo. Floyd’s paper shows that spatial ratings in the stereo tests are quite variable and highly dependent on the recording.

That alone only makes me more covinced that you took the easy way by choosing mono. You eliminated the variability of stereo ratings but in doing that you're throwing away the baby with the bath water.

If you believe testing a mono speaker in the center of the room is invalid then set it up as a stereo left or right as we can do with our speaker mover. Then the reflections are identical to a left or right speaker in a stereo setup.

I have given 3 reasons for that: possible incorrect positioning of speaker to boundaries, possible incorrect listening axis, possible incorrect postion of listener.
I can see several other problems with listening to a single speaker located left or right.

As far as how the speaker couples into the room modes the optimal position of the loudspeaker will depend on the acoustical properties and dimensions of the room and the locations of the listener(s). To say that the optimal position is different for every speaker is nonsense, especially for conventional speakers where below the room transition frequency the speaker is close to a monopole and will couple into the room modes much the same way.

I have seen photos and schematics of several people performing listening test simultaneously. They can't all be sitting on axis, or in the best acoustical place in the room.

I have performed in-room measurements with both speakers and mic/listener at different locations that I can upload if you wish.
They show that woofer distance to front wall, to side wall, to floor, to ceiling and to listener will affect the response in the bass and sub-bass.
Not taking that into account is a mistake.

As an aside if there were different optimal locations for different speakers I’ve never seen this specified in the loudspeaker setup manual. And wouldn’t they be different for different rooms? And there would no need for room correction and calibration.

The most obvious example would be Danish manufacturer Dali, whose speakers are designed to be positioned with no toe-in. When listened-to on axis they will sound "coloured" (see cursor postion at 45° below):

https://www.stereophile.com/content/dali-rubicon-8-loudspeaker-measurements

Dipoles are designed to make use of the front wall, corner horns must go in corners, on-wall speakers on walls.

A much larger effect/bias is comparing different speakers in different locations of the room. Not only will the reflection patterns be different but there will be differences in bass due to how they couple into the room modes. These positional biases have been well documented in our AES papers and are the reason we invested significant money into an automated speaker mover that places each speaker in the exact position.

Again you're taking the easy way by remove a variable. I understand that this makes the testing more feasible but it also makes it invalid.

Only a single listener in the optimal seat is used in our product benchmarking tests. For group or tour demonstrations we will use multiple seats. We analyze the data separately for each seat and can see how the ratings vary across seat. The consistency in ratings across seats is quite remarkable except when a speaker has a significantly different frequency response on and off axis producing a much different direct sound for listeners in different seats

That deals with my earlier comment regarding people listening off axis.