Is Toole and Olive's Spinorama model incomplete and limited?

[Kvalsvoll]

Below the transition frequency room modes dominate,

It sure looks like this simple model also works in that part of the frequency range, it just does not predict the peaks and dips, which of course it can not do, because the information required is not included.

 

[Duke]

To my knowledge, Harman's Spinorama related double-blind studies have not been reproduced and confirmed by other independent researchers in other listening rooms.

Can the findings be extrapolated to rooms other than Harman's specific listening room?

Is this a typical listening room?

Sean Olive admits that the method is limited to this room and mainly box speakers.

The test conditions in Harman's room are different from the set-up conditions of "typical listening rooms". Whether or not these differences matter is subject to debate. I'm of the (apparently minority) opinion that they do matter.

For one thing, the abnormally-long lateral reflection paths result in the first sidewall reflections arriving significantly later than they would in a normal room. My understanding is that the arrival time and intensity of the first lateral reflections play a role in both perceived sound quality and perceived spatial quality, and the Harman test conditions increase the arrival time and reduce the intensity of these reflections relative to a "typical listening room" situation.

I'm not saying this makes a big difference, but in my opinion it does make a worth-paying-attention-to difference.

 

[Sokel]

The test conditions in Harman's room are different from the set-up conditions of "typical listening rooms". Whether or not these differences matter is subject to debate. I'm of the (apparently minority) opinion that they do matter.

For one thing, the abnormally-long lateral reflection paths result in the first sidewall reflections arriving significantly later than they would in a normal room. My understanding is that the arrival time and intensity of the first lateral reflections play a role in both perceived sound quality and perceived spatial quality, and the Harman test conditions increase the arrival time and reduce the intensity of these reflections relative to a "typical listening room" situation.

I'm not saying this makes a big difference, but in my opinion it does make a worth-paying-attention-to difference.

To my (abnormal) room (33 by 20 feet,12 foot ceiling,approximately and not completely rectangular) everything is smoother on the long side (both have been measured).The downside is that a room like this always has long RT's,can't get it under 500.
I have "big" sound,is not bad but far from ideal.

 

[NTK]

The design of Harman's Multichannel Listening Lab is documented is this white paper.

https://www.harman.com/documents/HarmanWhitePaperMLLListeningLab_0.pdf

 

[Sokel]

The design of Harman's Multichannel Listening Lab is documented is this white paper.

https://www.harman.com/documents/HarmanWhitePaperMLLListeningLab_0.pdf

That's a little smaller but similar to mine,as I just described above (I only do stereo,not multichannel).
Of course still far from the ideal construction that Harman did.

 

[JPA]

...
The room is clearly optimized for box speakers. Dipole speakers and omnipole speakers will not create optimal reflections in this room.
...

I'm curious to know how you think the room has been optimized. It looks like a fairly standard room to me. How would you change it to create optimal reflections from dipoles and/or omnipoles?

 

[Kvalsvoll]

The test conditions in Harman's room are different from the set-up conditions of "typical listening rooms". Whether or not these differences matter is subject to debate.

From the picture it does look different, and it surely does affect sound, and will also favor some speakers over others, compared to how they perform in a more typical listening room. But this needs to be seen in context, they needed to have a room and set-up that worked for comparing lots of speakers, with a shuffler. At least, the chosen solution looks like it was able to present similar conditions for different speakers, but it may also favor speakers with a specific radiation pattern.

The first problem is that the speakers are placed different in relation to boundaries, in a typical room the speakers will be placed closer to both front wall and side walls.

The way the room was treated acoustically is also problematic, judging from the picture. How is the front wall treated, I have not seen any description of that. And in the picture there seems to be some absorbers placed on the side wall, presumably to address first reflections from side walls. If this were to be rebuilt today, we now have better knowledge and would build the room to have surfaces with a combination of broad-band absorption, reflection and diffusion evenly distributed, and a hard floor. This would be much better for comparing speakers with different radiation pattern, and it would also illuminate consequences of defects in radiation pattern better.

 

[kongwee]

I doubt the test room will reflect 99.9% of the real world room.

 

[Frgirard]

It wrote in the conclusion... Easily altered to hemi anechoic to typical domestic room...

What is a typical domestic room? A kitchen, living room, bed room...

 

[Mnyb]

I don't read the preference score as the gospel i remove the decimal pionts and use it as a hint to that the designer has done some due diligence

 

[dominikz]

The test conditions in Harman's room are different from the set-up conditions of "typical listening rooms". Whether or not these differences matter is subject to debate. I'm of the (apparently minority) opinion that they do matter.

For one thing, the abnormally-long lateral reflection paths result in the first sidewall reflections arriving significantly later than they would in a normal room. My understanding is that the arrival time and intensity of the first lateral reflections play a role in both perceived sound quality and perceived spatial quality, and the Harman test conditions increase the arrival time and reduce the intensity of these reflections relative to a "typical listening room" situation.

I'm not saying this makes a big difference, but in my opinion it does make a worth-paying-attention-to difference.

However IMO the main question here is whether or not listening to the same loudspeakers in different listening rooms could change relative preference (and if so - in which cases and how?), not whether room characteristics matter / influence sound reproduction itself (they do).

In other words, can we assume that the same relative loudspeaker preference observed in a specific room is valid for any room? The only article I know on this topic suggests that the room has an insignificant effect on relative loudspeaker preference:

The preferred sound quality of three loudspeakers was rated by listeners within four domestic-sized rooms. Evaluations of binaural recordings/reproductions of the same loudspeaker/room combinations were also made. Both live and binaural measurements showed the room had statistically insignificant effects on listener loudspeaker preferences. In a second binaural experiment each loudspeaker was compared among the rooms. In contrast, the room was the main significant effect on listener preferences, while the loudspeaker was not significant. These contrasts in loudspeaker and room effects indicate that subjective measurements of sound quality are relative measurements strongly biased by the context in which the measured objects are compared.

On the other hand, I can easily imagine cases where preference might be influenced - e.g. a good wide dispersion loudspeaker might be preferred in a room with reflective side walls vs a good narrow dispersion loudspeaker, but this advantage might also be lost in another room where side reflections are absorbed, making the two loudspeakers sound more similar.
What would happen if the wide dispersion loudspeaker has uneven directivity and poor on-axis response and the narrow directivity one had even directivity and flat on-axis - would its wide directivity still give the former a chance in some rooms?

Is there any research showing such effects?

From the picture it does look different, and it surely does affect sound, and will also favor some speakers over others, compared to how they perform in a more typical listening room.

I of course agree that the Harman test room will 'sound different' than most other rooms (since most rooms will sound somewhat different to each other), but can you provide some references to back the claim that this can impact relative loudspeaker preference in listeners under controlled conditions (i.e. some loudspeakers being consistently favored in some rooms)? Thanks!

I doubt the test room will reflect 99.9% of the real world room.

Note that the test room doesn't really need to represent 'real world rooms' if the room is an insignificant factor in listener loudspeaker preferences.

 

[Frgirard]

In the bass frequencies, the room is all. Mode, decay, standing wave.

 

[Geert]

What is a typical domestic room? A kitchen, living room, bed room...

In a wooden or concrete building or a mix of both, speakers distance from the front wall, speakers distance from the side walls, ceiling height, asymmetric setups ... ? Looks very difficult to effectively test how people perceive the sound of different speakers in all these different conditions. And we probably don't need to test all of that as the modal behavior of rooms and boundary effects are well understood.

The only article I know on this topic suggests that the room has an insignificant effect on relative loudspeaker preference

Also Toole's work concludes, above the Schroeder frequency, we are able to "listen through the room" so to speak. Another reason not to test all possible room and speaker location scenarios.

What would happen if the wide dispersion loudspeaker has uneven directivity and poor on-axis response and the narrow directivity one had even directivity and flat on-axis - would its wide directivity still give the former a chance in some rooms? Is there any research showing such effects?

Don't know. Also don't want to give the impression I believe Toole's work is complete. As far as I know Harman is still continuing his research but no longer makes it publicly available.

 

[Sokel]

The design of Harman's Multichannel Listening Lab is documented is this white paper.

https://www.harman.com/documents/HarmanWhitePaperMLLListeningLab_0.pdf

The room in the picture in the first post is what's described above or is it a different one?

 

[DanielT]

The test conditions in Harman's room are different from the set-up conditions of "typical listening rooms". Whether or not these differences matter is subject to debate. I'm of the (apparently minority) opinion that they do matter.

For one thing, the abnormally-long lateral reflection paths result in the first sidewall reflections arriving significantly later than they would in a normal room. My understanding is that the arrival time and intensity of the first lateral reflections play a role in both perceived sound quality and perceived spatial quality, and the Harman test conditions increase the arrival time and reduce the intensity of these reflections relative to a "typical listening room" situation.

I'm not saying this makes a big difference, but in my opinion it does make a worth-paying-attention-to difference.

Furthermore, what is nowadays a typical listening room? Different interior styles. The one, in my opinion really sterilely boring:

Or this one?More cozy, more furniture and colors. A style that, from what I understand, has become more popular in recent years. I can definitely imagine this "new old" kind of interior design style:

Edit:
Perhaps extreme examples, on either side of the decoration scale, but still.

 

[fpitas]

Furthermore, what is nowadays a typical listening room? Different interior styles. The one, in my opinion really sterilely boring:
View attachment 227998

Or this one?More cozy, more furniture and colors. A style that, from what I understand, has become more popular in recent years. I can definitely imagine this "new old" kind of interior design style:
View attachment 227999

Edit:
Perhaps extreme examples, on either side of the decoration scale, but still.

Everybody has their preference, but that top picture is like living in a bar lounge. The bottom one is more like a real home.

 

[Geert]

Everybody has their preference, but that top picture is like living in a bar lounge. The bottom one is more like a real home.

I bought my current set of home speakers second hand from a home just like that. They were as new and the owner was very dissapointed in them ;-)

 

[abdo123]

Everybody has their preference, but that top picture is like living in a bar lounge. The bottom one is more like a real home.

it's contemporary, and it's the current sign of money and wealth.

 

[fpitas]

it's contemporary, and it's the current sign of money and wealth.

Yikes. Suffering for their vanity.

 

[abdo123]

Yikes. Suffering for their vanity.

Well yeah. A couple I'm friends with built a house that is very similar to the 'modern' picture, there were some other people's kids with us and good god it was difficult to stay in the living area.

The reflections were literally uncomfortable and it felt literally like being on a train with all the windows open with 20 people around. So yeah these spaces sound as bad as you think they might.