Now that you had to look up "straw man" you use it back at me. More trollery. Then you bring up "transition region" which in fact indicts your entire claim about "critical distance not existing".
Y'all have a nice day, troll.
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Diffusing 1st reflections of speakers that measure great on and off-axis - instead of absorbing
- Thread starter Music1969
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Now that you had to look up "straw man" you use it back at me. More trollery. Then you bring up "transition region" which in fact indicts your entire claim about "critical distance not existing".
Y'all have a nice day, troll.
There's some bad tempered posting here , we need to maintain a basic level of respect for one another. Unnecessary antagonism is always unhelpful and reflects poorly on all of us.
localhost127
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"your twin". such unprofessional behavior. i have no agenda here and don't know the user you are referring to outside of the fact he/she appears to be versed in the facts of acoustics and physics of indirect sound-fields.
as always when someone cannot directly respond to the subject at hand, deflections and ad hominem attacks ensue.
you haven't provided anything except for deflections from the actual subject matter. NO WHERE has it been presented with measured data that a critical-distance (Dc) exists in a home residential-sized rooms. NOR that a reverberant sound-field develops above the ambient noise floor. for RT60 to be considered accurate and valid, these conditions must be met. otherwise, garbage in = garbage out. an operator must always be smarter than his/her tool!
i don't have an agenda. i'm not a salesman. i don't have users (cheerleaders) replying to others with "my credentials" as if that allows you to speak erroneously about facts of acoustics. please stick to the subject matter and refrain from deflections in an attempt to hide the fact of the erroneous claims made above.
incredible unprofessional and unwarranted behavior. please stick to the subject matter.
Lorenzo74
Senior Member
well said!
always try to reduce effect of first reflections. more dangerous are the vertical one. since our brain might confuse them with the center image.
what I understood is we should have 10-20ms (3-7 meters) free from reflection or at least lower -20dB from first arrival.
any expert in studio recording can confirm or amend this statement?
my Best
L.
Sorry, Thomas, he claims that there is no critical distance in a small room despite measurements that show conclusively that direct to indirect energy goes below one at a distance as presented. He repeats this complaint a few times, then admits to a transition region in *all* rooms. Furthermore, the entire disagreement is actually about the definition of what critical distance is, apparently. After all of this, no engagement on the perceptual vs. the analytic aspects seems to be possible. Unless we are all listening as least mean squares machines, that's actually the most important part of all.
The entire argument from one side is semantic tomfoolery.
The relentless refusal to understand that Txx can be measured as a function of frequency, likewise, is another simple example of refusal to engage, except via insult and denial.
Along with that, there is the endless, very seriously actionable professional disparagement from a person hiding behind a pseudonym, who just joined us in April.
So that's what I see, and how I see it.
The entire argument from one side is semantic tomfoolery.
The relentless refusal to understand that Txx can be measured as a function of frequency, likewise, is another simple example of refusal to engage, except via insult and denial.
Along with that, there is the endless, very seriously actionable professional disparagement from a person hiding behind a pseudonym, who just joined us in April.
So that's what I see, and how I see it.
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To some extent this depends on the listener's preference, but for those who like pinpoint imaging, a very dead room is most often preferred, at any size. Large top and front-lateral reflections are just not good. Some people like LEDE. I don't. That's a preference.
But this is purely a preference issue. Having talked behind the scenes with the OP, who likes pinpoint imaging, I think his question has been resolved.
As an aside, I'm not aware of anyone here who suggests otherwise, despite all of the smoke and mirrors.
localhost127
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if "troll" you mean "contesting erroneous claims regarding acoustic terms and real world physics", then sure.
your behavior is unacceptable and unprofessional. you are now making posts unrelated to the subject (because you are unable to answer or provide any data to substantiate your claims) - and you are loudly proclaiming your ignorance by insinuating that "127.0.0.1" or "localhost" is synonymous to "anonymity".
in IP networking, localhost implies the current computer, and 127.0.0.1 is used as a loopback. that's all. i even have a t-shirt that says "there's no place like 127.0.0.1". how do you link this networking term to that of "trolling"?
People have different opinions and these are complex subjects , it's rare anybody changes their minds based on a random guy on the internet telling them they are wrong .
With this in mind we must try and make room for dissenting voices . The people who you will be informing are the larger readership, keep them in mind rather than letting one's self get into adversarial conflicts .
With this in mind we must try and make room for dissenting voices . The people who you will be informing are the larger readership, keep them in mind rather than letting one's self get into adversarial conflicts .
localhost127
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i think i found the source of your confusion. you think they are conflated? they are separate principles in acoustics 101.
transition region refers to the modal (wave) > specular transition in Small Acoustical Spaces. ie, the physical characteristics and behavior of the indirect sound-field.
transition region also refers to the specular > diffuse (reverberant soundfield) in Large Acoustical Spaces, dictated at minimum by Manfred Schroeders work in this field and his F sub L equation.
critical-distance implies a point within the room where-by the INDIRECT sound-field becomes equal in magnitude to the direct signal, and then "beyond that" where-by you are in the reverberation as the reverberant sound-field can become many times louder than the direct signal. this is a property of Large Acoustical Spaces.
if you care to provide measurement data for your home residential-room where the indirect sound-field is EQUAL or HIGHER in magnitude than the direct-signal from your loudspeaker, please by all means do so.
Nice. I didn't assert that. You're just playing "burn the straw man". So stop.
Amir's already posted evidence. You simply deny it. There's no point in posting more data.
I'm suspending this thread , give time for this situation to pass by.
Thread open , behave yourselves!
Don't make me come back in here
Don't make me come back in here
Lorenzo74
Senior Member
thank you Thomas! Your relentless work is great!Thread open , behave yourselves!
Don't make me come back in here
To everyone here... be gentle and develop this interesting thread.
So...
Who is for diffusing, who’s for absorbing and who is for doing nothing with 1st reflections? But more important: why?
We need your contribution.
best
L.
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Absorb. That is, unless you want that wide, indistinct, miles away sensation. Some people do. As to debates about 30 year old ways of evaluating rooms, well, it all comes down to one thing, for a small room, dead is usually best.
I think probably the direction of the first reflections, as well as the relative distance to the listening position, may be important to consider before deciding whether to consider absorption, diffusion (or scattering, if true diffusion in both direction and phase is not possible), or no intentional treatment.
tuga
Major Contributor
2-channel stereo has limitations regarding width of sweet-spot and envelopment.
In my view, if you care for the latter then having bare walls scattering reflected sound all over the place is not the right way to go about it because it reduces focus and wrecks the recorded ambience cues. You'll be better served by going multi-channel stereo. If your main staple is 2-channel stereo then you have a problem and the only option is to try something like ambisonic or upmixing. I have no experience with multi-channel but perhaps a central channel will even help to deal with the narrow sweet-spot issue...
Ultimately it's a matter of personal choice if you wish to listen to the recording with little room interference or use you room to add some euphonic colouration. A bit like adding harmonic distortion or some other signal correlated distortion.
Not what the artist/producer intended but you're the final arbitrer (actually I am just kidding, I find this "not what the artist/producer intended" argument absurd).
from what I know or think I know ?I disagree with you on the limitations of the 2 channel stereo ..what you describe as sweet spot width and envelope ( LEV end ASW ) it's not euphonic coloration but very well explained phenomena resulting directly from reflections / reverberations.
The spatial impression is explained from two concepts. LEV -Listener envelopment and ASW -Apparent source width LEV describes the feeling of being surrounded by sound. A certain place where the reverberated sound is perceived as coming from all directions with the same level is a place with an optimal LEV rating. The LEV depends on the direction of incidence of the reflections on the listener, the separation between early and late reflections, and the perceived energy level of the reflections. The ASW describes the sensation that the music comes from a source that is larger than the visual width of the real source; the larger the apparent width, the stronger the spatial impression.
tuga
Major Contributor
Correct me if I'm wrong but as far as I know (most) speakers radiate forward towards the listener (direct sound).
The soundwaves reach the listener from the speakers and differences in the recorded channels will produce two illusions:
a) phantom images located on or between the speakers and at the speaker plane or behind it
b) a sense of space resulting from the ambience cues if these were captured in the recording
The combination of these two effects helps you create in your "mind" an impression of the soundscape as captured by the microphones (this is of course only truly valid for real stereo 2-mic, 2-channel recordings).
In addition you have toe-in which is the equivalent of adjusting interpupillary distance with binoculars or a microscope to perfectly overlay the two-images being produced by the speakers.
If one uses room boundaries to reflect the sound/signal transduced by the speakers we are adding distortion (frequency, time/phase) to that sound/signal.
It is that distortion which creates LEV and affects ASW.
For some people what is usually referred to as "soundstage" (envelopment and scene width) is more important than image focus, ambience cues (which nearly only exist in classical music recordings anyway) and perhaps even tonal balance (can the boundaries of our real-world listening rooms really reflect sound above the transition frequency without changing the balance?).
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it's also a question of listening philosophy, as you pointed out earlier.
With the 2 channel stereo anyway we are in the field of illusion . the goal is to have the best possible illusion of a large concert hall .
the best concert halls in the world use lateral refurbishment even though we know that the acoustics of large halls are different from small ones ... some tricks are the same.
tuga
Major Contributor
it's also a question of listening philosophy, as you pointed out earlier.
With the 2 channel stereo anyway we are in the field of illusion . the goal is to have the best possible illusion of a large concert hall .
the best concert halls in the world use lateral refurbishment even though we know that the acoustics of large halls are different from small ones ... some tricks are the same.
I think that this is what the reflection-free zone design gets right, by delaying and attenuating early reflections so that they are not mashed-in with the direct sound. This way you get envelopment but not blurry phantom images and diffuse/masked ambient cues.
