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How much impact for perceived sound - direct sound and room sound

How much impact for perceived sound - direct sound and room sound

  • 1. The direct sound from the speaker and the room sound is equally important

    Votes: 6 24.0%
  • 2. The direct sound is more important for the perceived sound, compared to the room sound

    Votes: 15 60.0%
  • 3. The room sound is more important for perceived sound, than the direct sound from the speaker

    Votes: 4 16.0%

  • Total voters
    25

Tangband

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My opinion is that the direct sound coming from the speaker , on axis, is the most important for perceived sound quality in many cases .
This because of the precedence effect, that noone of us can ignore. Every delayed room sound coming to the listener is attenuated by the brain as much as 10 dB , compared to the first arriving, direct sound coming from the speaker .
Very different from how a microphone works.


If the direct sound from a speaker is the most important for perceived sound quality - do we really need waveguides for our tweeters ?

Discuss ( as long this thread is not closed ) .
 
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thewas

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Unfortunately I cannot chose any of the options as it depends on the percentage of direct and reflected sounds coming to the listener and thus on directivity, listening distance and room reverberation and size.
 

Bjorn

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Unfortunately I cannot chose any of the options as it depends on the percentage of direct and reflected sounds coming to the listener and thus on directivity, listening distance and room reverberation and size.
Exactly. In some areas, as much as 80% of the sound is reflected energy. Combine that with mediocre or poor off-axis directivity, and which is common, this may contribute more than the direct sound. Despite of the presedence effect.

There isn't an answer that fits everything here. It will depend.
 

audiofooled

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I voted option no. 2 but I agree it will depend on too many variables so it is questionable that this poll can give us useful results. Recently Dr. Toole gave me what I think is a really good answer to a similar topic I was wondering about:

 
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OP
Tangband

Tangband

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I voted option no. 2 but I agree it will depend on too many variables so it is questionable that this poll can give us useful results. Recently Dr. Toole gave me what I think is a really good answer to a similar topic I was wondering about:

Thanks for the information audiofooled.

” So, to answer your question, the direct sound always has perceptual precedence over reflected sounds - that is why it is called the "precedence effect" or "law of the first wavefront". If there is a timbral mismatch between it and the later arriving reflections, the difference, according to double-blind listening tests, is audible and detrimental to the sound quality.”
( Dr F. Toole )
————

Tangbands thoughts:

As some of you already commented, the distance to the sidewalls to the speakers should have a somewhat different effect on different loudspeakers construction principles , and a very damped room should be less dependent on good directivity from the speakers ? ( no need for waveguides in a two way speaker in this case? ) .

… and an undamped normal livingroom should be much more dependent on loudspeakers with good directivity ( using waveguides ) .

We still have the precedence effect where the brain attenuates later arriving sounds , making the need for a waveguide in a damped room somewhat less important ?

As John Atkinsson from stereophile says - ”all measurements tell lies” .

When we see a very smooth off axis curve with good directivity from a speaker - there is a risk that we count the 30 degree off axis curve as important as the on axis response, where in reality, in many rooms the off axis response is much less important and the on axis direct sound from the speaker are dominating the perceived sound quality.
 
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Bjorn

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Acoustic treatment isn't 100% neutral. So a speaker with uniform directivity is always beneficial and where one should start.

A typical speaker with a rather small waveguide and a woofer underneath doesn't exhibit constant directivity in the most important and sensitive area, which is in the 500 hz to 5000 Hz area. That requires a much larger horn or another design.
 

audiofooled

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” So, to answer your question, the direct sound always has perceptual precedence over reflected sounds - that is why it is called the "precedence effect" or "law of the first wavefront". If there is a timbral mismatch between it and the later arriving reflections, the difference, according to double-blind listening tests, is audible and detrimental to the sound quality.”
( Dr F. Toole )
————

As some of you already commented, the distance to the sidewalls to the speakers should have a somewhat different effect on different loudspeakers construction principles , and a very damped room should be less dependent on good directivity from the speakers ? ( no need for waveguides in a two way speaker in this case ) .

… and an undamped normal livingroom should be much more dependent on loudspeakers with good directivity ( using waveguides ) .

We still have the precedence effect where the brain attenuates later arriving sounds , making the need for a waveguide in a damped room somewhat less important ?

As John Atkinsson from stereophile says - all measurements tell lies .

When we see a very smooth off axis curve with good directivity from a speaker - there is a risk that we count the 30 degree off axis curve as important as the on axis response, where in reality, in many rooms the off axis response is much less important and the on axis direct sound from the speaker are dominating the perceived sound quality.

Too me rooms are still important. When designing my DIY tower speakers I had to go to some form of waveguides because of very odd application. "Normal" living room with no acoustic treatment with large window in proximity of the left speaker vs. open space to the right. The only solution was in trying to achieve as flattish DI as possible and it turned out really well.

Take this with a grain of salt because it's only subjective, but in two different rooms (my workshop and my living room), the presentation - soundstage and imaging of the same speakers is so different that it's amazing. While perceived tonality is the same and that's most important, at workshop all the imaging is behind the loudspeakers, reaching great depth, whilst in living room nothing is behind but quite the opposite. Imaging is such that, even though the listening distance is about 4m, stereo effects are within the reach of my hands and on some recordings around my head. It's all due to different setup. At workshop speakers are further out into the room and in the living room they are close to the front wall. So reflections do matter but it really depends on loudspeaker directivity and setup. Also room size, acoustics and what not.
 

ZolaIII

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Direct speakers sound is easier to handle by simply choosing good speakers and eventually EQ-ing them. Unfortunately that can not be said for room influences that may appear and ruin the perception. So for me it's the room.
 

tuga

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If one doesn't have a dedicated listening room then there's a chance that furnishings or even construction of the side walls will be different (i.e. windows and curtains to one side).
As such, one would need a very wide (front wall) room (or a near-field setup) in order for the effect of this asymmetry not to be audible, which is generally not the case in Europe.
If my reasoning is correct then narrow directivity speakers will not only produce sharper phantom images but their frequency response at the listening spot will be less affected. In other words, they will be more accurate.

In a studio or dedicated room one might suggest that off-axis flatness/neutrality might not be as important because early reflection areas will be treated.
 

Trdat

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I have the pleasure of two unique systems at my fingertips, one a horn system with 15 inch(narrower directivity) vs a standard 3 way (wide directivity) and its very hard to compare, my preference is always based on the recording. If the recording is at a live venue with instruments I don't need the extra room sound and the horn system does best. If its a live recording in a club like a boiler room where the sound is quite dead often the 3 way can sound just as good as the horn system. With dry recordings the 3 way can also sound great adding some reverb tail and reflections but its not always black and white, 90's classic house and hard house due to its hard basslines sounds better on the horn system probably because of the 15 inch woofers.

So very difficult to answer the question as there is too many variables when choosing one over the other when it comes to direct vs room sound.

My preference is the horn system but I thought ill illustrate that the 3 way has its benefits but usually loses out.
 

ctrl

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We still have the precedence effect where the brain attenuates later arriving sounds , making the need for a waveguide in a damped room somewhat less important ?
When we see a very smooth off axis curve with good directivity from a speaker - there is a risk that we count the 30 degree off axis curve as important as the on axis response, where in reality, in many rooms the off axis response is much less important and the on axis direct sound from the speaker are dominating the perceived sound quality.
One can always theoretically construct some special cases. If you listen to a loudspeaker in the free field at 30°, only the shape of the 30° frequency response is important. Or the loudspeaker is not aligned to the listener, then the 30° frequency response is responsible for the direct sound. But it makes no sense to discuss such cases.

It seems that you see the precedence effect only in terms of localization.
If the same sound signal arrives at a listener with a time delay from different directions, the listener perceives only the direction of the first arriving sound signal - so this refers only to the localization.

But the brain doesn't "attenuates later arriving sounds" as you said, it only "ignores it" (to some extend) in terms of localization.
The presence of delayed sound alone (e.g. reflected sound) already leads to a timbre change (interference, comb filter effects,...), as well as the direction of the incoming reflection at the listener, since this is influenced by the HRTF - which has an huge impact on timbre.
HRTF for 90°, 0° and 180°:
1680876364617.png
All in all, we manage quite well, our brain expects sound coming from the side to have a different timbre than the same sound coming from the front.
But if the speaker adds additional timbre changes due to a bad speaker radiation, then this is not good - think we all agree on that.

Here is an example of a single loudspeaker measured in the center of the room (as far away as possible from reflecting surfaces), once the reflection-free on-axis frequency response (yellow FR) and once only the reflections without the direct sound (green FR) at 1.8m (70'') distance:
1680879477173.png
Even under these conditions, the sound pressure level of the reflected sound is already dominant or equal in a wide frequency range. Only above 6kHz the direct sound is dominant. Thus, the timbre of a loudspeaker is largely determined by the reflected sound.

Floyd Toole shows in his YouTube presentation (27min) a nice example of what happens when you only pay attention to a flat on-axis frequency response.
1680880238300.png 1680880280977.png 1680880301550.png
The reflected sound significantly influences the timbre of the loudspeaker.


My opinion is that the direct sound coming from the speaker , on axis, is the most important for perceived sound quality in many cases .
This sentence may be true under certain circumstances, but generally speaking, a poorly designed loudspeaker with a flat on-axis FR will sound less good in a normal listening room than a poorly designed LS where the on-axis FR tries to compensate somewhat for the mistakes made in the radiation (don't get me wrong, it will never sound perfect).


If the direct sound from a speaker is the most important for perceived sound quality - do we really need waveguides for our tweeters ?
We don't need speaker with WG, only not bad designed speaker with reasonably uniform radiation and more or less flat on-axis response (with WG or without).
 
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aarons915

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I voted the direct sound is more important but in my experience I would say only slightly or at the least the early reflections can't be ignored. I've had multiple speakers in a small room that were great on axis but were fatiguing to listen to, that can really only be attributed to peaks in the ER curve. The small room surely contributed but I doubt a larger room would make the ER irrelevant.
 

teashea

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For studio use I much prefer nearfield listening - very nearfield. This is to minimize the relative effects of reflected sounds. If one considers the relative loudness of direct sound from a very nearfield monitor, compared to the loudness of the reflected sound, the difference is usually very large. In fact in many situations it is to the point where the reflected sound is less than 5 percent.

For midfield speakers, the room is of quite large importance. This is why I always am skeptical of studios where that use midfield or far midfield monitors. I am not saying that they cannot get good sound, but ...............................
 

teashea

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In have been in studios that have nearfield and midfield/far midfield monitors. In every instance, the engineers only used the nearfield monitors. One of these was a brand new, expensively designed studio with very expensive, very large Dynaudio in-wall monitors. After a couple months, they never used them...........
 

teashea

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I voted the direct sound is more important but in my experience I would say only slightly or at the least the early reflections can't be ignored. I've had multiple speakers in a small room that were great on axis but were fatiguing to listen to, that can really only be attributed to peaks in the ER curve. The small room surely contributed but I doubt a larger room would make the ER irrelevant.
Good point. In small rooms, the reflected sound is much more important than in larger rooms.
 

fpitas

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In have been in studios that have nearfield and midfield/far midfield monitors. In every instance, the engineers only used the nearfield monitors. One of these was a brand new, expensively designed studio with very expensive, very large Dynaudio in-wall monitors. After a couple months, they never used them...........
I was under the impression that mixing used near-field mostly, and mastering used far-field, sometimes large high quality domestic speakers.
 
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