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Essential AES reading for high fidelity home reproduction

Head_Unit

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Eventually we made a large sonic boom simulator for NASA research
Oh yeah I remember that thing, that was crazy! You should make those segments again and sell them to South American soundoff competitors :D
 

sarumbear

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This is the most important AES paper regarding subwooferolgy.
Fazenda et al.
http://www.aes.org/e-lib/browse.cfm?elib=16324

And free here
http://www.academia.edu/5362839/Perception_Modal_Control
Thank you for posting a link to the free version. It is indeed a most important study. As an acoustician, it proves what I was expecting the results to be, so were the authors, as they ended the paper with this sentence:

These results are generally not surprising, they rather provide the evidence, based on perceptual data, to support the existing good practice in industry.

I liked your rating of this article:), which I regularly recommend. Unfortunately, for most listeners readers, it does not benefit.
I disagree. I think it benefits very much to show members that multiple subwoofer and EQ is not a panacea for good sound. I quoted below the part of the conclusion.

One very clear result is that one single subwoofer positioned in the corner of the room, with no equalization, is not advisable. Simple control steps such as moving the subwoofer toward nodal lines of offending mode shapes or applying magnitude equalization will improve production quality noticeably. Interestingly, perceptual improvements afforded by position control, multiple subwoofers, or magnitude equalization are in general associated with a reduction of decay times for parts of the frequency but may involve a consequent increase in others. This is an interesting result that raises the question of which regions, within the frequency range under study, are more likely to be associated with the largest perceptual improvements when acted upon. This is a topic of current study for the authors. In contrast to modal decay reductions, a significant perceptual improvement resulting from the direct reduction of frequency response variation is not always evident. In conclusion, the results obtained show the benefits afforded by simple modal control methods from a subjective standpoint. It appears that, for high quality critical listening conditions, those systems ensuring a faster decay of low frequency energy are preferred over those attempting a direct “flattening” of the magnitude frequency response.
In other words acoustically treating the room and managing the modes directly using resonators and/or absorbers (which will reduce low frequency reverberation and increase decay times) is better than using multiple subwoofers, positioning them and/or equalising (DSP, etc.).
 
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Newman

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Funny, Toole’s book (3rd edition) addresses Fazenda’s work and questions some of the choices they made setting it up, and most certainly does not think it surpasses multiple subwoofers, positioning them and equalizing.

But, as an acoustician, you think it is incredibly important and instructive… perhaps Toole’s observations in all editions of his book, that acousticians keep recommending inappropriate or outdated or less effective solutions than small rooms and multiple listeners demand, is pertinent here.
 
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sarumbear

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Funny, Toole’s book (3rd edition) addresses Fazenda’s work and questions some of the choices they made setting it up, and most certainly does not think it surpasses multiple subwoofers, positioning them and equalizing.

But you think it is incredibly important and instructive… perhaps Toole’s observations in all editions of his book, that acousticians keep recommending inappropriate or outdated or less effective solutions than small rooms and multiple listeners demand, is pertinent here.
As long as you have similar level of knowledge to the other party I think it is healthy to agree to disagree with them :)
 

Newman

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Sure, sure
 

Flaesh

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I disagree. I think it benefits very much to show members that multiple subwoofer and EQ is not a panacea for good sound. I quoted below the part of the conclusion.
You agree :). People read the article, but in practice they do not use the data from it. EQ is not a panacea for good sound. I'm using DBA (aka CABS).
 

sarumbear

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Tom C

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Would the result change if using dual opposed driver configuration, a la Kef KF92 and KC62?
 

Flaesh

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Article says best result is with SSS
Only more subjective score in this experiment.
Interesting comment about sample A: Results for Sample A lack the statistical evidence to warrant further discussion. However, this result is in itself of extreme importance since it establishes that the selection of tests sample(s), particularly in this type of “realistic” testing, is vital to extract meaningful and reliable results.
Would the result change if using dual opposed driver configuration
I think no. Why?)
I’m afraid I do not know those acronyms.
In the study under discussion, they are explained.
 

Tom C

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Only more subjective score in this experiment.
Interesting comment about sample A: Results for Sample A lack the statistical evidence to warrant further discussion. However, this result is in itself of extreme importance since it establishes that the selection of tests sample(s), particularly in this type of “realistic” testing, is vital to extract meaningful and reliable results.

I think no. Why?)

In the study under discussion, they are explained.
Because of the orientation of the drivers. You will either have them directed toward each other, and a side wall, or directed into the room and the front wall.
 

Flaesh

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Because of the orientation of the drivers.
Sufficiently negligible influence for a wavelength of 3 m or more at a reasonable distance to the listener. Although in a real setup you can measure and listen. It's probably right to talk about it in DBA treads.
 
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Travis

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Per Dr. Toole, a "classic paper" and it's free to members and non-members of AES: J. C. Steinberg and W. B. Snow, “Auditory Perspective – Physical Factors”, Electrical Engineering, 1934 January, pp 12...17



 
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