• Welcome to ASR. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Dutch & Dutch 15C Discussion

Oboreal said:
A Non‑Environment Room is a control room where the engineer should hear only the direct sound from the loudspeakers, with virtually no coloration from the room itself. The goal isn’t just to reduce reflections — it’s to make the room disappear as an acoustic factor. As Newell often puts it : the room should not exist acoustically.

The side walls, ceiling, and rear wall are almost entirely absorbent and the target is an extremely low RT60, often below 150 ms across the entire spectrum, including the low end. Absorption depth is substantial, typically 60–100 cm or more and will use menbranes, to target the deep lows. The wall behind the monitors is hard, massive, and reflective.
The loudspeakers are flush‑mounted into this wall to eliminate diffraction, suppress SBIR, maximize time‑domain coherence.

Consequences are that direct sound overwhelmingly dominates, early reflections are virtually nonexistent (desk is the main exception), the diffuse field is extremely weak.
You got an extreme precision, a reduced listening fatigue, and a excellent translation to other systems. It is not a “dead room” in the 1970s sense because you have psycho-acoustics to help your mind to be at ease in the room (reflective floor, diffusion above and back listening point to complete the frontwall.

Newell’s premise is simple : Modern, well‑designed loudspeakers are far more reliable than rooms. So if you want a stable reference, you remove the room from the equation as much as possible. This is the opposite of an RFZ (Reflection‑Free Zone) design, which intentionally preserves a stronger diffuse field.
Click to expand...

Thank you for taking the time to succinctly describe the why and the what and the how of a "non-environment room".
 
Listening to speakers without not even the smallest radiation from the room, is listening in "an anechoic room" or "chambre sourde" (deaf chamber) in french.
I don't konw what's a "no environement room" is ? There are always some room effects, as tiny and well controoled could they be,

Indeed, this concept needs more explanations.
 
Oboreal said:
Careful, i think there are currently some excessive generalizations being made about Floyd Toole’s statements on acoustic treatment.

The way I understand Toole’s point (though I’ve only watched his lectures and haven’t read his book yet) is that if you just put up relatively thin porous acoustic panels—around 10 cm or less—you end up with early reflections that have lost their high frequencies but still contain low‑frequency energy, which can actually make the acoustic problem you were trying to fix even worse. But no serious acoustician work that way for quite a long time now.

The misconception become obvious when i talk about a non environnement design (A concept published by Philip Newell for the AES in 2017 for last edition), and you answer about a Reflexion Free Zone wich is an older concept developped mainly by d'Antonio et Cooper in the Eighties.

A Non‑Environment Room is a control room where the engineer should hear only the direct sound from the loudspeakers, with virtually no coloration from the room itself. The goal isn’t just to reduce reflections — it’s to make the room disappear as an acoustic factor. As Newell often puts it : the room should not exist acoustically.

The side walls, ceiling, and rear wall are almost entirely absorbent and the target is an extremely low RT60, often below 150 ms across the entire spectrum, including the low end. Absorption depth is substantial, typically 60–100 cm or more and will use menbranes, to target the deep lows. The wall behind the monitors is hard, massive, and reflective.
The loudspeakers are flush‑mounted into this wall to eliminate diffraction, suppress SBIR, maximize time‑domain coherence.

Consequences are that direct sound overwhelmingly dominates, early reflections are virtually nonexistent (desk is the main exception), the diffuse field is extremely weak.
You got an extreme precision, a reduced listening fatigue, and a excellent translation to other systems. It is not a “dead room” in the 1970s sense because you have psycho-acoustics to help your mind to be at ease in the room (reflective floor, diffusion above and back listening point to complete the frontwall.

Newell’s premise is simple : Modern, well‑designed loudspeakers are far more reliable than rooms. So if you want a stable reference, you remove the room from the equation as much as possible. This is the opposite of an RFZ (Reflection‑Free Zone) design, which intentionally preserves a stronger diffuse field.

So yes, I agree: having the best loudspeakers you can get is important, and controlled off‑axis directivity, along with good frequency and phase response, definitely makes your life easier. But I don’t see any scenario where you can achieve a flat 150 ms RT from 20 Hz to 20 kHz in a “domestic” room — even with something as impressive as the DD 15C, a large space, and well‑designed geometry and modal distribution. The level of precision that a truly great acoustic design can provide simply isn’t achievable yet through loudspeaker design, DSP, or multisub strategies alone. (Maybe that will change one day with active bass trapping.)

So yes, saying that great speakers with well‑controlled directivity and DSP correction are the most cost‑efficient solution for domestic listening is totally fair. But if you want a genuinely state‑of‑the‑art system — room + speakers — and you have a budget around €100,000, then as far as I know, nothing matches the level of sonic accuracy you get from a properly designed room built around flush‑mounted, top‑tier monitors.
Click to expand...
I'm familiar with nonenvironment rooms. I think you missed my point.

Also it was Tom Hidley who invented the nonenvironment "hemianechoic" room (because the floor is reflective). In early iterations the floor was also absorptive but the overall effect was considered too unnatural.

The issue with past (and current) studio designs is that the psychoacoustic merit is unclear. They are designed towards measurable targets in terms of spatial frequency consistency and so forth, metrology leading the way forward rather than perceptual understanding. The same can be said for loudspeaker designs, and loudspeaker interactions with rooms, particularly in older papers.
 
Oboreal said:
Careful, i think there are currently some excessive generalizations being made about Floyd Toole’s statements on acoustic treatment.

The way I understand Toole’s point (though I’ve only watched his lectures and haven’t read his book yet) is that if you just put up relatively thin porous acoustic panels—around 10 cm or less—you end up with early reflections that have lost their high frequencies but still contain low‑frequency energy, which can actually make the acoustic problem you were trying to fix even worse. But no serious acoustician work that way for quite a long time now.

The misconception become obvious when i talk about a non environnement design (A concept published by Philip Newell for the AES in 2017 for last edition), and you answer about a Reflexion Free Zone wich is an older concept developped mainly by d'Antonio et Cooper in the Eighties.

A Non‑Environment Room is a control room where the engineer should hear only the direct sound from the loudspeakers, with virtually no coloration from the room itself. The goal isn’t just to reduce reflections — it’s to make the room disappear as an acoustic factor. As Newell often puts it : the room should not exist acoustically.

The side walls, ceiling, and rear wall are almost entirely absorbent and the target is an extremely low RT60, often below 150 ms across the entire spectrum, including the low end. Absorption depth is substantial, typically 60–100 cm or more and will use menbranes, to target the deep lows. The wall behind the monitors is hard, massive, and reflective.
The loudspeakers are flush‑mounted into this wall to eliminate diffraction, suppress SBIR, maximize time‑domain coherence.

Consequences are that direct sound overwhelmingly dominates, early reflections are virtually nonexistent (desk is the main exception), the diffuse field is extremely weak.
You got an extreme precision, a reduced listening fatigue, and a excellent translation to other systems. It is not a “dead room” in the 1970s sense because you have psycho-acoustics to help your mind to be at ease in the room (reflective floor, diffusion above and back listening point to complete the frontwall.

Newell’s premise is simple : Modern, well‑designed loudspeakers are far more reliable than rooms. So if you want a stable reference, you remove the room from the equation as much as possible. This is the opposite of an RFZ (Reflection‑Free Zone) design, which intentionally preserves a stronger diffuse field.

So yes, I agree: having the best loudspeakers you can get is important, and controlled off‑axis directivity, along with good frequency and phase response, definitely makes your life easier. But I don’t see any scenario where you can achieve a flat 150 ms RT from 20 Hz to 20 kHz in a “domestic” room — even with something as impressive as the DD 15C, a large space, and well‑designed geometry and modal distribution. The level of precision that a truly great acoustic design can provide simply isn’t achievable yet through loudspeaker design, DSP, or multisub strategies alone. (Maybe that will change one day with active bass trapping.)

So yes, saying that great speakers with well‑controlled directivity and DSP correction are the most cost‑efficient solution for domestic listening is totally fair. But if you want a genuinely state‑of‑the‑art system — room + speakers — and you have a budget around €100,000, then as far as I know, nothing matches the level of sonic accuracy you get from a properly designed room built around flush‑mounted, top‑tier monitors.
Click to expand...

Duke said:
Thank you for taking the time to succinctly describe the why and the what and the how of a "non-environment room".
Click to expand...
"Consequences are that direct sound overwhelmingly dominates, early reflections are virtually nonexistent (desk is the main exception),"
Been in a couple studios and yes all have the console desk right smack dab in the listening area causing who knows what myriad of reflections. Why not place the console against the back wall furthest from the speaker, make adjustments and simply swivel around to listen. You certainly don't need to stare at the speakers to make adjustments. Am I missing something?
CJH
 
CJH said:
"Consequences are that direct sound overwhelmingly dominates, early reflections are virtually nonexistent (desk is the main exception),"
Been in a couple studios and yes all have the console desk right smack dab in the listening area causing who knows what myriad of reflections. Why not place the console against the back wall furthest from the speaker, make adjustments and simply swivel around to listen. You certainly don't need to stare at the speakers to make adjustments. Am I missing something?
CJH
Click to expand...
You need your controls under your fingers to work efficiently, il would be quite a pain in the butt to do constant back and forth between your main work position and listening position

You can always put some absorber on the console if you want, but sound engineers usally listen to different speakers and headphones to make sure the mix really works
 
Hmmm…a non-environment room. $100k. A concept unsupported by much empirical evidence??

Hmmmm…

Sign me up!! I’m an audiophile, after all!
 
  • Like
Reactions: GDK
dfuller said:
It's not atc-like other than the paper diaphragm. The surround is totally different, more like a high output pro driver.
Click to expand...
For me it looks like the SB Audience ROSSO-15W400, but it's most probally an OEM design by one of the OEM builders in Europe tailored to the wishes of the designer/company. The front woofer is also different (probally a midwoofer) than those on the back (probally subwoofers) of the 15C on first sight.
 
I don't know what anyone is talking about anymore.
 
I'm familiar with nonenvironment rooms. I think you missed my point.
Click to expand...

Please don’t do that… Sometimes we just have to accept that we don’t know something — it’s the foundation of critical thinking. You clearly know a lot, and it looks like you’ve looked into it since then, which is great and more than enough. As for me, I’m not an acoustician, and I only know the broad concepts that are useful to my work but i do my best to improve my knowledge day after day.

Also it was Tom Hidley who invented the nonenvironment "hemianechoic" room (because the floor is reflective). In early iterations the floor was also absorptive but the overall effect was considered too unnatural.
Click to expand...

I mainly mentioned Newell because he published for the AES quite recently. So I think it’s hard to argue that this would be bad or outdated science. I think I also partly mentioned some concepts introduced by Northward Acoustics, who went even further than Newell, but I’m not entirely sure.

That said, I have listened to and mastered music i produced in a room built with this type of design, and I can attest to a level of precision I’ve never encountered on any other system, along with excellent translation of the master to other playback systems.

I can’t say whether it’s the best possible approach, but at the very least I can state that an RT60 below 150 ms down to 40 Hz (slightly higher below that) is extremely resolving, comfortable to work in, and reliable when it comes to translation.

That said, since I’m not at the forefront of current research myself, I’d be very interested if you have reliable sources showing that this kind of design—very close to the theoretical ideal—is actually not the most desirable from a perceptual standpoint. But when something measures close to the theoretical ideal and sounds excellent, it seems to me that we should have strong evidence to affirm that it's snakeoil. I'm also curious to know how some folks could pretend have a perfect bass response in a reflective room in the time domain...

"Been in a couple studios and yes all have the console desk right smack dab in the listening area causing who knows what myriad of reflections. Why not place the console against the back wall furthest from the speaker, make adjustments and simply swivel around to listen. You certainly don't need to stare at the speakers to make adjustments. Am I missing something?"

In reality, quite a few mastering engineers have stopped working with desks or mastering consoles for this very reason. Instead, they use a small mobile desk in front of them with just a keyboard and mouse, or a small controller and a large screen between the speakers — sometimes even just a tablet — so they can control all their plugins without any acoustic obstruction. The downside is saying goodbye to the Massive Passive and other analog processors whose character is still not perfectly modeled.

I'll stop with the off-topic stuff here. Sorry for that, maybe we can open a thread on the topic.
 
Last edited:
just curious if the 15c was just being a static display? or it actually on demo at the recent NAMM 2026?

Anyone here heard it and how was the impression comparing to 8C?
 
You must log in or register to reply here.

Similar threads

markstein
Upgrade from Neumann KH310 for home listening?
2 3 4
Replies
64
Views
5K
markstein
markstein
sigbergaudio
Are active speakers the future? (YouTube series)
2 3 4
Replies
75
Views
3K
JohnnyNG
J
N
Hissing from Genelec G Two at short range — should I be worried?
2
Replies
24
Views
2K
bungle
B
zoran-grbic
Found at last: Acoustic Research 150 500R speakers. Feedback?
Replies
2
Views
818
zoran-grbic
zoran-grbic
Jiraya369
Speaker placement help needed (low end struggles)
Replies
12
Views
1K
Jiraya369
Jiraya369
Back
Top Bottom