Originally Posted by batpig
Yeah, every extra meter of distance is about a 3dB drop in SPL.
Rather, I think every doubling of the distance reduce the output by half, i.e. 6 dB, so going from 2 m to 4 m removes 6 dB.
For example, I played around with this SPL calculator
and they have a parameter for boundary effects. When you go from "away from walls" to "near a wall" to "in a corner" each step adds 3dB to the calculation.
That site is exactly why I posted the question -- I was wondering what "near a wall" means exactly. I thought that was pretty much frequency-dependent, with low frequencies being easier to boost this way. I'm not sure this applies to tweeters with centimeter-scale wavelengths.
Personally, having never had the fortune to seriously A/B test quality systems playing at those types of levels, I'm not sure how audible that bit of compression would really be in a "real world" scenario.
Me neither. Moreover the topic that lead to this question was basically, are we comfortable listening to movies at reference volume. I said that personally, the highs are the limiting factor, and sounds of crashes, glass breaking, etc. close to reference volume are a bit painful. Some argued that this was probably because my tweeters couldn't go that high without causing harshness due to compression.
I first doubted the compression part, but it looks like it probably happens. Now as far as I can tell, compression is just "in these frequencies, the speaker can't output more" -- it doesn't add unwanted components like harmonic distortion for example. (Compression is indeed a form of distortion, distortion being anything that produces a signal that is not a scaled version of the source signal. Note that we typically make a distinction between distortion and parasitic noise.)
So if compression mostly reduce output in the highs, I can't conceive how this can be perceived as harshness or would actually be less comfortable to listen to than the uncompressed signal. I think the answer to that is that with loud transients, compression can look a lot like clipping, hence the harshness. In any case, somehow the discomfort I get from loud highs doesn't fit this picture -- I think loud highs just hurt my ears. They seem very clear to me; I'd love to compare but I suspect a high-end HT speaker that can play highs cleaner at louder level would just hurt me more
For the typical home setting where you cap out 10-15dB below reference, it's probably a total non issue.
Absolutely! Not changing speakers because of this! Just said it was a good excuse if I ever needed one