I think I see what you are saying. Honestly I need to recheck my defection of near field.... There's nearfield and there's direct field
I can't say one could measure bass in a room without reflections. But I think nearfield is definitely capable. in a room, regarding bass. Sounds like nearfield extends farther into the sound field for bass than treble if it is a completely omnidirectional source>? And then directivity effects all of it.
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So you want everything to sound like its coming from everywhere at all times and frequencies.
""Direct Sound is the region in which the sound measured can be attributed to the source alone without reflections. Early reflections that reach the listener within 50 ms integrate with the direct sound and can improve speech clarity. However later reflections may have a negative effect on the clarity""""
TBH, this means nothing.
how many db down within 50ms?
just saying no early reflections within 50ms means absolutely nothing as its impossible. how many DB down within 30ms....
is the author confused?
the regular target in studio is -20db within 30ms at the listening position if i recall correctly
wait, it continues:
''However later reflections may have a negative effect on the clarity''
absolutely false
late reflections, more often refered as secondary reflections, are BENEFICIAL. thats why many best room design try to bring back secondary reflections back to the listening position via many methods (angled walls).
thats also why people with bass traps cover their bass traps with reflective material that reflect HF back to the room rather then absorb them.
1st reflection are detrimental
secondary are beneficial
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I guess you can't hear 30Hz outdoors either, according to your logic?
Where do you even get this nonsense from?
Note: this is just a general note to all, not specifically to youknowyou (..it's just easier to reply to his statement here, because his comment does reference a potential problem).
Yes, but in most instances when a phrase like "near-field" is used there is *context - and it usually doesn't take a lot of effort to determine how the poster is referencing that phrase.
Sub/low freq. bass + small room condition from an acoustic perspective means that everything is automatically near-field - so why would we make a distinction about any reasonable distance from the source in a small room context or use a phrase like reverberation field juxtaposed with near-field?
Honestly, it's like arguing about "Fast" bass from the perspective of Hz - which is nonsensical; no one means that "Fast"(er) bass is actually midrange or treble.
*if you strip a comment of context then there is NO point in making a reply because you aren't actually replying at all, and are more likely just derailing the thread.
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That’s not true at all. If it was, bass outdoors or in headphones would be impossible.
I'm pretty sure the idea for most listeners is to have reproduced sound localized from the perspective of the mix itself, NOT the loudspeaker or subwoofer itself (..which is the "source" in this instance).
I at least don't like "hearing" my loudspeaker's location: it destroys the illusion of reproducing the real/(likely)synthesized event.
This got me thinking about me discussion of Direct energy vs Radiation area. I didn't think to use this aspect to try and prove it. With multiple subs for example, you are increasing the amount of paths, from a direct source, to the ear, that are of shorter lengths vs reflection. This has got be to why, if I am right that is, that increasing radiation area increases direct energy to the listener. I think the argument was that with bass in a small room, the modes are too intense for it to matter. I disagree but I am still learning.
Bass traps aren't likely to substantively do anything but suppress (to some extent) room modes (hopefully "peaks" around the listening area if placed well).
You might get some additional broad-coverage (spl) suppression overall, but it's doubtful that the added suppression will be meaningful.
Even most anechoic chambers only eliminate/fully-absorb reflections down to a modest lower freq. limit (often above 80 Hz).
Sure I have. What I have not seen is an actual listening room with woofers within .25 M of the listener's ears. Is that how you listen?
This is in the context of modes, you are still "around" the average spl of the signal.
When we talk of moving the mic. closer and closer to the source/(subwoofer) (particularly for testing *quasi-anechoically), we mean at a distance close enough so that the average spl of direct sound is well above that of reverberant sound. ..again though, IF you are setting your listener/mic near a substantial peak generated by modes for a given bandwidth, THEN the particular distance from the source/(subwoofer) might still not be enough to overcome the the modal peaks. The solution then is either to move the listener/mic or source/(subwoofer) to a lower pressure modal region for the bandwidth of interest, OR get *even closer to the source.
*HiFiCompass's measurements for freq.s below about 300 Hz are measured at little less than an inch (20mm) from the dust-cap. This is so close that at least in his measurement room that the result is quasi-anechoic to at least 20 Hz. This is an extreme example of course, but it does show the relationship with getting closer to the source and having less reveberant sound vs. direct as a result.
The point being that some where in between farthest and nearest is the critical point, the point where room and driver are 50/50 to you ear....
I have specifically noted in my comments that we are talking about domestic rooms. That is, rooms where there are walls, and of dimensions that support room modes at bass frequencies. That means outdoors, headphones, and even large concert halls are not germane to the discussion. Do we need to tighten up the discussion and start talking about Schroeder frequencies and modal zones?
..about 8.5" is very rare, BUT when I recline under normal listening/viewing the driver cabinet-exit (in-phase direct sound) is pretty close to that (..I'd say within 12"):
https://www.diyaudio.com/community/threads/ultimate-open-baffle-gallery.123512/page-197#post-7074980
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