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In Reply to: The "rigid, blinkered approach" is your prerogitive obviously... posted by Wellfed on March 12, 2007 at 12:34:07:
I think I'd qualify myself more as skeptical, rather than blinkered. I think that it's reasonable to want to see solid evidence before paying big money. No evidence, no money. "It has been reported" is not enough for me to draw my chequebook.The biggest impact on the performance of my system had the new living room with dimensions according to Bonello, the acoustically effective ceiling, the speakers themselves. No intelligent chip is capable of lowering reverberation time, no green CD pen is capable of spreading room modes appropriately, no myrtle block is capable of improving bad speaker dispersion. Get the most important part of the system, i.e. speakers and room, right, then forget about the rest.
As usual, YMMV, my 2 cents, IMHO.
Follow Ups:
Used responsibly I applaud it actually. I also honor the sanctity of a persons will. Again, if used responsibly.As for forgetting about the rest, that's your prerogative. My prerogative is to push the performance envelope as best I'm able. I've found some tweaks to be highly effective in this regard. There is nothing wrong with either approach as ultimately we have only ourselves to please. You're pleased. I'm pleased. There's absolutely nothing not to like there.
If I have the budget, "It has been reported" is enough 'evidence' for me to investigate a given product if I feel sufficiently impressed with the person providing the recommendation. Just yesterday I had a friend contact me regarding his experience with the Acoustic System Resonators. He was wildly enthusiastic over the results he had obtained. Because of my regard for his opinion I would put them on my things to check out list, had I the means. Unfortunately I don't. He described the improvement as being 300-400% which of course is essentially meaningless except to say big. My own experience with some home brewed resonators incorporating Machina Dynamica Brilliant Pebbles have yielded some truly fabulous results as well.
Is there a point to all this? I'm not sure. ;-)
I think Alvin Firpo said it best when he said "You do what you do, I do what I do." Be blessed my friend.
Finally, I of course have to ask, "What are the Bonello dimensions?"
Bonello : A new criterion for the distribution of normal room modes,
JAES 1981, p.597For optimum room dimensions the following conditions should be met:
1. The curve spectral density of modes vs frequency should increase monotonically. Each one-third octave should have more modes than the preceding one.
2. There should be no double modes. At most, double modes only in
one-third-octave bands with densities equal to or greater than 5.
Schroeder : The "Schroeder frequency " revisited, JASA 1996, vol.99,
p.3240The Schroeder frequency fc is the frequency above which the standing waves are so closely spaced that they do not substantially affect the sound. It is dependent on room volume and reverberation time. The larger the room or the shorter the reverberation time, the lower that frequency. A low Schroeder frequency tends to make the frequency response smooth over a wider range.
The Schroeder frequency marks the transition from individual, well
separated resonances to many overlapping normal modes. It is
calculated as follows :fc = 2000 sqrt T/V
T = 60 dB reverberation time in seconds
V = Room volume in m3which has a a consequence that at least three resonances fall within the half-power bandwidth B (B = 2.2/T) of one resonance at frequencies above fc.
I choose to use Bonello rather than any of the other proposed methods (fixed ratio, Golden Ratio, Walker) because it's in line with the concept of the Schroeder frequency: the number of modes per 3rd-octave band rises up to a point where there are that many modes per 3rd-octave band that the individual mode is no longer distinguishable. Thanks to the acoustically effective ceiling our living/listening rooms has a (calculated) reverb time of 0.4 - 0.5 seconds which results in a Schroeder frequency of about 138 Hz.
Were you able to make any meaningful comparisons between your new room and the previous environment?
In this case it was not possible, since the construction of the new room included demolition of the rear wall of the old room. However, the old room was quite bad in all relevant respects, it was/is smaller, non-symmetric in the acoustical sense (left wall bricks, right wall bottom-to-floor windows, all surfaces acoustically hard, the speakers were on the short wall close to the side walls. Room treatment was not possible, that's why I bought those speakers since they were able to address some of the problems.
I trust you are satisfied with the new room. You seem to get involved with some pretty interesting projects. How would you describe the results you've obtained? Sadly, unless I move into new quarters at some point, I'll never have the opportunity to investigate these for myself. I'm still interested in learning about the details however, just in case.
The new room is better in all relevant aspects, reverb time is low such that intelligibility is outstanding, no more smearing, no more room boom. The overall response is much smoother due to the lower Schroeder frequency, so far I could not detect any room modes, and even if, my speakers allow for room correction, so it would be a matter of minutes to get rid of the mode. The speakers themselves provide crystal clear sound, without any stress or strain, even at elevated SPL.The speakers are on the long wall, so no more side wall reflections, thanks to the ceiling no more ceiling reflections, thanks to the good speaker dispersion the floor reflection is not really a problem. Definitely, the time I have spent in reading all those stuff about speaker design, psychoacoustics and room acoustics was well invested.
nt
but beware, except for the turntable, it's all studio gear, including the infamous "Perfect.Period." preamp:-)
...there being more than one way to skin a cat. And thanks for the invite, if I'm ever in your neck of the woods, I will be SURE to look you up.
you will have to hire a boat instead of a car:-) Amsterdam airport is at 6 m below sea level, our place is at -2. And our house doesn't float yet.
...and don't know when the opportunity will present itself again. But if it does, I'll be over to your place with bells on, provided you're still above water that is.
I go to a movie on a say-so, I try a new beer on a say-so, I read a book on a say-so. If I wait for all the "evidence" to mount and for the peer-reviewed journals to print it, the movie will be off the screens, the beer may become nla and the book available only in some cheaply-made paperback. Plus, everyone else will already have experienced them and be uninterested in my desire to discuss.People such as your antagonists seem never to enjoy themselves -- or the learning experience.
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