Are We Over-Optimizing Loudspeakers and Underestimating the Room?

[Audionaut]

Or > From Spinorama to Living Room: How Much Survives?

I’d like to raise a question about system optimization that usually is seen here on ASR as a side issue at other Themes.

We put a lot of emphasis on designing loudspeakers to measure as close to “perfect” as possible: flat on-axis response, smooth directivity, low distortion, well-behaved off-axis curves. That makes sense, and I fully agree that a speaker should be fundamentally well-engineered.

However, in actual listening environments, the final result is heavily shaped by the room and by post-processing: room correction (Dirac, ARC, RoomFit), manual EQ, placement constraints, and acoustic treatment. In many setups, especially in normal living rooms, these factors introduce changes that are far larger than the residual imperfections of a well-designed speaker.

So one question is:
How much of the effort spent on achieving “near-perfect” anechoic performance actually survives in the final in-room result?

Or more provocatively:
Are we optimizing the right variables, or are we overfitting the loudspeaker itself while the dominant errors come from elsewhere?

So maybe the more relevant question is not “How perfect is the speaker in anechoic conditions?”, but:

“How robust is the speaker’s performance under real-world conditions and correction systems?”

Or, to put it another way:
After DSP and room correction, what’s actually left of that perfectly calibrated speaker?

I’m not arguing against good measurements – quite the opposite. But I’m wondering whether we should shift more focus toward system-level optimization instead of treating the loudspeaker as an isolated object.

Curious to hear your thoughts.

 

[sigbergaudio]

From the speaker design perspective we seem to put 99% of the emphasis on the anechoic performance, and expect it to translate perfectly to any room, while as mentioned in the recent thread on listening during speaker development, how the speaker actually performs in a room is a pretty complicated equation.

I personally also think we give automatic room correction systems too much credit in "fixing" both the room and speakers. Competent speakers in a decent room don't really need correction above the transition area (100-300hz), and poor speakers can't be fixed either way. Room correction systems also often "get it wrong" when trying to fix higher frequencies. Many also seem to dial in target curves with room correction systems, while the famed harman curves are not target curves at all. They are the natural in-room result of well behaved speakers.

Finally, acoustic treatment of the room has significant impact on the sound. A good speaker will sound even better in a well treated room, so treatment won't replace the need for a good speaker - but treatment is definitely a cheap way to drastically improve the sound no matter which speaker you have.

 

[90sNintendoKid]

Or > From Spinorama to Living Room: How Much Survives?

I’d like to raise a question about system optimization that usually is seen here on ASR as a side issue at other Themes.

We put a lot of emphasis on designing loudspeakers to measure as close to “perfect” as possible: flat on-axis response, smooth directivity, low distortion, well-behaved off-axis curves. That makes sense, and I fully agree that a speaker should be fundamentally well-engineered.

However, in actual listening environments, the final result is heavily shaped by the room and by post-processing: room correction (Dirac, ARC, RoomFit), manual EQ, placement constraints, and acoustic treatment. In many setups, especially in normal living rooms, these factors introduce changes that are far larger than the residual imperfections of a well-designed speaker.

So one question is:
How much of the effort spent on achieving “near-perfect” anechoic performance actually survives in the final in-room result?

Or more provocatively:
Are we optimizing the right variables, or are we overfitting the loudspeaker itself while the dominant errors come from elsewhere?

So maybe the more relevant question is not “How perfect is the speaker in anechoic conditions?”, but:

“How robust is the speaker’s performance under real-world conditions and correction systems?”

Or, to put it another way:
After DSP and room correction, what’s actually left of that perfectly calibrated speaker?

I’m not arguing against good measurements – quite the opposite. But I’m wondering whether we should shift more focus toward system-level optimization instead of treating the loudspeaker as an isolated object.

Curious to hear your thoughts.

I agree and I think Dirac ART reduced the need for room acoustic treatment.

In my next room, I am going to go for bass traps at the very least to help try and fix room nodes and acoustic panels if and where required.

 

[Torin Krell]

I believe that often DSP room correction is often over emphasized over simple, relatively inexpensive efforts to improve room treatment first.

 

[amirm]

Well designed speakers sound very good to excellent as soon as you turn them on, in almost any room. While you can correct errors above transition frequencies with measurements, this is often made difficult to assess with in-room measurements.

In bass region, how deep and how clean the reproduction is, depends on the speaker. The room will vary the response of course so you need EQ for that.

 

[voodooless]

I believe that often DSP room correction is often over emphasized over simple, relatively inexpensive efforts to improve room treatment first.

I tend to agree, but it makes sense: DSP is not visible. You don’t need to change your room. Any treatment is always invasive to a room, and if you want it hidden, it’s a significant effort in time and money.

So yeah, putting in your speakers and enabling room correction will get you quite far without any additional effort.

Ultimately the best way is a combination of the two, but this simply isn’t a feasible option for many people.

An yes, a good speaker is a good speaker, no matter in what room you put it.

 

[sigbergaudio]

I agree and I think Dirac ART reduced the need for room acoustic treatment.

In my next room, I am going to go for bass traps at the very least to help try and fix room nodes and acoustic panels if and where required.

I'm not super knowledgable about Dirac ART, but doesn't it work mainly in the lower frequencies? In that case it doesn't really replace acoustic treatment, as acoustic treatment realistically won't do much in the lower frequencies anyway.

The sound will definitely improve with acoustic treatement even though you already have Dirac ART or Trinnov or some similar advanced room correction. They do not remove the need for (or effect of) acoustic treatment.

 

[JanRSmit]

From the speaker design perspective we seem to put 99% of the emphasis on the anechoic performance, and expect it to translate perfectly to any room, while as mentioned in the recent thread on listening during speaker development, how the speaker actually performs in a room is a pretty complicated equation.

I personally also think we give automatic room correction systems too much credit in "fixing" both the room and speakers. Competent speakers in a decent room don't really need correction above the transition area (100-300hz), and poor speakers can't be fixed either way. Room correction systems also often "get it wrong" when trying to fix higher frequencies. Many also seem to dial in target curves with room correction systems, while the famed harman curves are not target curves at all. They are the natural in-room result of well behaved speakers.

Finally, acoustic treatment of the room has significant impact on the sound. A good speaker will sound even better in a well treated room, so treatment won't replace the need for a good speaker - but treatment is definitely a cheap way to drastically improve the sound no matter which speaker you have.

In my exercises with Acourate i primarely correct the range below the transition zone. But to find out the 'natural' curve above is a worthy excercise. Once found applying it is simple.
No i do not apply specific acoustic treatment to my living room, i play with positions within given range. As mr Toole said one can listen 'through the room'. I.o.w. do not under value your hearing.
What i find a bonus is that, although there is a best spot to sit and listen, the sound is enyojable on every place in the living room.

 

[sigbergaudio]

In my exercises with Acourate i primarely correct the range below the transition zone. But to find out the 'natural' curve above is a worthy excercise. Once found applying it is simple.

Not sure I understand what you mean here. How do you find the "natural" curve, and how do you apply it? And if you "apply" it, how is it natural?

No i do not apply specific acoustic treatment to my living room, i play with positions within given range. As mr Toole said one can listen 'through the room'. I.o.w. do not under value your hearing.

We do hear through the room to some extent - in the sense we can hear the qualities of a speaker through a normally reflective room, but we don't ignore the room alltogether. A better treated room will sound better.

 

[smygolf]

I'm not super knowledgable about Dirac ART, but doesn't it work mainly in the lower frequencies? In that case it doesn't really replace acoustic treatment, as acoustic treatment realistically won't do much in the lower frequencies anyway.

The sound will definitely improve with acoustic treatement even though you already have Dirac ART or Trinnov or some similar advanced room correction. They do not remove the need for (or effect of) acoustic treatment.

ART will try to reduce the decay between 20hz - 150hz as much as it can.
It can not manage anechoic respons but the gain is substantial.
And then you can use use standard Dirac above 150 if you choose.

 

[sigbergaudio]

ART will try to reduce the decay between 20hz - 150hz as much as it can.
It can not manage anechoic respons but the gain is substantial.
And then you can use use standard Dirac above 150 if you choose.

Right. In this region, acoustic treatment (that is practical to use in normal rooms/homes) are largely ineffective. So it isn't really a replacement for treatment in that sense. The treatment one would apply will affect different frequencies, so you still need that just as much.

 

[AudioJester]

We know what makes a perfect listening environment.

But most of us live in real apartments/houses. So we dial in what we can. Speaker choice, placement, room treatment, bass traps, dsp etc.

A speaker manufacturer can only build the speaker part.

 

[90sNintendoKid]

I'm not super knowledgable about Dirac ART, but doesn't it work mainly in the lower frequencies? In that case it doesn't really replace acoustic treatment, as acoustic treatment realistically won't do much in the lower frequencies anyway.

The sound will definitely improve with acoustic treatement even though you already have Dirac ART or Trinnov or some similar advanced room correction. They do not remove the need for (or effect of) acoustic treatment.

I’ve found if I use speakers with good directivity and calculate a target curve based on nearfield and mlp measurements using Magic Beans, then I can correct above the transition region and I like the results.

 

[Keith_W]

Not sure I understand what you mean here. How do you find the "natural" curve, and how do you apply it? And if you "apply" it, how is it natural?

Uli Bruggemann (author of Acourate) said that the target curve should follow the measurement.

So: do everything that you can to find the minimum-phase response of the loudspeaker and equalize it to flat under quasi-anechoic conditions with the mic at 1m. Then place the mic at the listening position. Apply generous smoothing to the upper frequencies and then use that as the target curve. Alternatively, you can choose to forego MLP EQ of the upper frequencies altogether. The freqs below Schroder can be equalized as you wish.

 

[Chris A]

So one question is:
How much of the effort spent on achieving “near-perfect” anechoic performance actually survives in the final in-room result?

For above the so-called transition frequency, the answer to this depends on the full-range directivity of the loudspeakers, the size/dimensions of the room, and the placement of the loudspeakers near any of the room's boundaries. For something like a full-range MEH, the "anechoic performance" as you call it largely survives intact (for human listeners):

[Note that in my listening room, the above polar directivity plot above the transition frequency largely describes the polar response of the loudspeakers in the front three positions (L, C, R).]

For small loudspeakers that do not control their polars, the anechoic response is very much compromised in room:

Or more provocatively:
Are we optimizing the right variables, or are we overfitting the loudspeaker itself while the dominant errors come from elsewhere?

Clearly, it depends on the loudspeaker design, the room dimensions and placement/size/spectral effectiveness of absorption/diffusion, and placement of loudspeakers and listeners' ears inside said room.

So maybe the more relevant question is not “How perfect is the speaker in anechoic conditions?”, but: “How robust is the speaker’s performance under real-world conditions and correction systems?”

The answer is "it depends"...on the above considerations of room acoustics, loudspeaker acoustic performance, and the array geometry within the room.

Or, to put it another way: After DSP and room correction, what’s actually left of that perfectly calibrated speaker?

In my listening room, first correcting the minimum phase response of the loudspeaker (that which is largely measured in an anechoic chamber) is the major task of "room correction" since (above the transition frequency), one doesn't "correct" the non-minimum-phase reflections in-room, but can only push the polar lobes around.

I’m not arguing against good measurements – quite the opposite. But I’m wondering whether we should shift more focus toward system-level optimization instead of treating the loudspeaker as an isolated object.

Curious to hear your thoughts.

Yes. Loudspeaker and room acoustics response in-room (including the human hearing system and room acoustics) are all part of "the system". Any transfer function nonlinearities in any of the elements that can be corrected--should be corrected.

Chris

 

[JanRSmit]

Not sure I understand what you mean here. How do you find the "natural" curve, and how do you apply it? And if you "apply" it, how is it natural?

It is my choice of words, i ment the response at listening position after removing as much room artefacts as possible. Thr estimated in room response as defined in cta2034 is a good indicator.

 

[Chris A]

One of the interesting insights that one gets from looking at the "system-level view" (as seen in a context diagram) is that all the machinations used by the bass reflex crowd (which, by its own admission must ignore the time domain nonlinearities of bass response around the tuned port resonance frequency) to "reconstruct" the bass response in-room is ignoring the fact that humans are sitting in the listening room, and their hearing systems are responding to the room-loudspeaker array in the same way that microphones arranged on a dummy head records the presentation.

The "reconstruction" attempt for bass reflex response isn't at all what the human hearing system is actually perceiving in-room. So what is the purpose of trying to "reconstruct" bass response?

JMTC.

Chris

 

[Cote Dazur]

From Spinorama to Living Room: How Much Survives?

Very good question.
To me, the "room" is by far the weakest link, so many people have "perfect" system and no where to put them.
For those of us with a dedicated room where we can do what we want as far as speaker placement and seat location, when trying different speakers, we soon discover that the room and where everything is, has a much bigger impact than anything else.
Those with system in a living room, have so little alternative to placement, that a quest for excellence in audio seem like a helpless case to me.
In my world, a claim that a better measuring speaker will fix issues and sound great no matter what in any room makes no sense.

 

[Chris A]

Very good question.
To me, the "room" is by far the weakest link, so many people have "perfect" system and no where to put them.

Here's a place:

Chris

 

[NTK]

Room and loudspeakers are largely independent of each other. Good loudspeakers sound better than bad loudspeakers in any room. To quote Dr. Toole:

.... the predicted room curve is a good match above about 500 Hz, and is corrupted by room interactions at lower frequencies. All of this is discussed in AES papers dating from the mid 1980s, and my books. Obviously all setups and rooms yield different curves at lower frequencies, so individual attention is required for each installation if maximum performance is expected. Listeners have a powerful ability to adapt to, and “listen through” rooms to the extent that, in a given room, they are able to rate and rank the inherent sound quality of loudspeakers in a relative sense – the good ones still win, the bad ones still lose. ...

It is the same principle as music instruments and concert halls. You'll still recognize the quality of a top concert grand, relative to a mediocre piano, in a bad concert hall. You can't compensate for the differences between the top quality instrument and a poor one by moving to a better concert hall. Both the instruments (loudspeakers) and concert hall (listening room) are important.