@erik_squires wrote: " For the purposes of this argument, alone, I want to argue that first reflection points don’t matter, ever."
Early lateral reflections contribute to spaciousness and expand the "apparent source width", according to Floyd Toole.
When "presence" is lacking the earliest reflections are the most responsible, according to David Griesinger.
So apparently early sidewall reflections are neither entirely beneficial nor entirely detrimental. They do some things which are desirable, and some which are undesirable.
Earl Geddes is aware of both the benefits and the detriments of early reflections, and here is his thinking on the subject:
"The earlier and the greater in level the first room reflections are, the worse they are. This aspect of sound perception is controversial. Some believe that all reflections are good because they increase the listeners’ feeling of space – they increase the spaciousness of the sound. While it is certainly true that all reflections add to spaciousness, the very early ones (< 10 ms.) do so at the sake of imaging and coloration. There is no contention that reflections > 20 ms are positive and perceived as early reverberation and acoustic spaciousness within the space. In small rooms, the first reflections from an arbitrary source, mainly omni-directional, will never occur later than 10-20 ms (basically this is the definition of a small room), hence the first reflections in small rooms must be thought of as a serious problem that causes coloration and image blurring. These reflections must be considered in the design [of the loudspeakers] and should be also be considered in the room as well."
My own investigation (controlled blind testing, but nothing peer-reviewed) leads me to believe that early reflections are strongly involved in conveying a sense of the playback room’s boundaries being nearby. The weaker the early reflections, the less "small room signature" the playback room superimposes atop the recording venue’s acoustic signature, whether it be real or engineered or both.
I have been involved in several professional recording studio projects, in which the acoustician has designed angles into the sidewalls which geometrically preclude early sidewall reflections at the mix position. This is to facilitate clearly hearing the acoustic signature which is on the recording, without the mixing room’s signature being dominant.
So imo what happens (or doesn’t happen) at the first sidewall reflection points makes a difference. Whether or not this difference "matters", and if to so what extent, is, I suppose, a judgment call.
Erik again: "if you take a dozen panels placed around evenly in a room, I don’t think you could tell that the 1st reflection points do anything more special than the rest."
This would be true in a large room, but not in a small room. In a large room the reflections paths are much longer and there are so many reflections that the reverberant energy is effectively uniform throughout the room, such that WHERE you place acoustic treatment doesn’t matter - the net effect is the same. But in our small home listening rooms, we experience discrete reflections. And the earliest and loudest of those reflections are the ones which have the strongest effects, whether their effects be beneficial or detrimental or both.
Duke
Early lateral reflections contribute to spaciousness and expand the "apparent source width", according to Floyd Toole.
When "presence" is lacking the earliest reflections are the most responsible, according to David Griesinger.
So apparently early sidewall reflections are neither entirely beneficial nor entirely detrimental. They do some things which are desirable, and some which are undesirable.
Earl Geddes is aware of both the benefits and the detriments of early reflections, and here is his thinking on the subject:
"The earlier and the greater in level the first room reflections are, the worse they are. This aspect of sound perception is controversial. Some believe that all reflections are good because they increase the listeners’ feeling of space – they increase the spaciousness of the sound. While it is certainly true that all reflections add to spaciousness, the very early ones (< 10 ms.) do so at the sake of imaging and coloration. There is no contention that reflections > 20 ms are positive and perceived as early reverberation and acoustic spaciousness within the space. In small rooms, the first reflections from an arbitrary source, mainly omni-directional, will never occur later than 10-20 ms (basically this is the definition of a small room), hence the first reflections in small rooms must be thought of as a serious problem that causes coloration and image blurring. These reflections must be considered in the design [of the loudspeakers] and should be also be considered in the room as well."
My own investigation (controlled blind testing, but nothing peer-reviewed) leads me to believe that early reflections are strongly involved in conveying a sense of the playback room’s boundaries being nearby. The weaker the early reflections, the less "small room signature" the playback room superimposes atop the recording venue’s acoustic signature, whether it be real or engineered or both.
I have been involved in several professional recording studio projects, in which the acoustician has designed angles into the sidewalls which geometrically preclude early sidewall reflections at the mix position. This is to facilitate clearly hearing the acoustic signature which is on the recording, without the mixing room’s signature being dominant.
So imo what happens (or doesn’t happen) at the first sidewall reflection points makes a difference. Whether or not this difference "matters", and if to so what extent, is, I suppose, a judgment call.
Erik again: "if you take a dozen panels placed around evenly in a room, I don’t think you could tell that the 1st reflection points do anything more special than the rest."
This would be true in a large room, but not in a small room. In a large room the reflections paths are much longer and there are so many reflections that the reverberant energy is effectively uniform throughout the room, such that WHERE you place acoustic treatment doesn’t matter - the net effect is the same. But in our small home listening rooms, we experience discrete reflections. And the earliest and loudest of those reflections are the ones which have the strongest effects, whether their effects be beneficial or detrimental or both.
Duke