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  1. 6 likes
    Kong: Skull Island (Dolby ATMOS) Level - 4 Stars (111.38dB composite) Extension - 5 Stars (1Hz) Dynamics - 5 Stars (28.84dB) Execution - TBD Overall - TBD Notes - This film delivers bass in spades, especially in the shake-and-move-stuff wheelhouse range of 12-25Hz. Clipping analysis shows flat tops in nearly every channel, Center is most egregious, but all the clipping appears to have rounded edges as if some sort of limiting was put in place like Pixels, so not completely objectionable, like Tron:Legacy clipping was. LFE channel clips with sharp corners, but low-pass filtering will smooth them out. Better movie than anticipated, but it almost always seems that way when you expect nothing from a film. Good surround use, good soundtrack. BEQ should make this a structure-endangerer. JSS
  2. 3 likes
    Or, there may not be that much research done on this at all. If the subject has little interest outside audio/hifi - because audio research has always had a tendency to focus on technical properties that may not be very relevant, and less on hearing perception mechanisms. I did a test to find audibility limits for distortion not long ago. Look at these numbers. 440hz: 60dB 2h -34dB 2% 3h -50dB 0.32% 4h -50dB 0.32% 5h -53dB 0.22% 6h -50dB 0.32% 8h -58dB 0.13% 70dB 2h -34dB 2% 3h -50dB 0.32% 4h -54dB 0.2% 5h -65dB 0.056% 6h -64dB 0.063% 8h -72dB 0.025% 80dB 2h -34dB 2% 3h -34dB 2% 4h -43dB 0.71% 5h -65dB 0.056% 6h -72dB 0.025% 8h -76dB 0.016% This data suggests that the presence of a 80dB tone does not reduce hearing threshold when the frequency of the other low-level signal is sufficiently far away in frequency. Because you can see that detection level for higher order harmonics is lower in percentage as the volume increases, and if you plot this data into a frequency response chart, you can see that the detection level remains constant at threshold of hearing around 0dB, with a masking around the fundamental tone. The masking follows the level of the fundamental tone, but far away the detection level remains the same, regardless of fundamental tone loudness. The 80dB fundamental does not reduce hearing threshold, it only masks around the tone. Then we understand 2 things: - Dynamic range is at least 80dB for 80dB sound - Louder means more detail and more revealing to faults in the audio chain So, why did I not test for even louder fundamentals, say up to 120dB? That data could be interesting to have. When I did the test, it was for a different purpose, and 60 to 80dB was sufficient. Louder presents some challenges - more difficult to ensure that the only distortion present is what is being tested for, and listening to tones louder than 80dB up into the midrange is actually so loud it is quite unpleasant.
  3. 3 likes
    That may be true, but that 140dB range does not apply for short time spans, because the ear has a built-in compressor that adjusts sensitivity according to exposed sound pressure level. If a very loud 140dB peak occurs, the sensitivity is immediately reduced, so that sound at very low spl can not be heard until the ears recalibrate, and that takes some time. Purpose of this mechanism can be to protect hearing, and also is the mechanism that actually makes it possible to have such a wide dynamic range. How large is the actual dynamic range, at a given moment, for a given spl exposure? Perhaps someone knows, I am sure there has been lots of research conducted on this. This relationship has attack time, hold delay, depends on peak vs rms level. This has consequences. We see that hearing is not a time-invariant system, because the output (what we hear) depends on what happened before in time.
  4. 2 likes
    Heheh. Yeah, I know what you mean. I believe you when you say it is better. Just poking fun a lil at your post. You're a very smart guy and knowledgeable but it almost seemed like nothing short of perfection wasn't good enough. Do don't that to yourself. You'll never be happy.... but, it sounds like you are so ignore me. Sometimes the constant "improving" can have a detrimental effect on the enjoyment of the HT room. I had to learn to love it even with the warts and all!
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  6. 1 like
    I can't remember who gets credit for that one, but I didn't originate it. That was one clipped mess. It was horrible. JSS
  7. 1 like
    Yes it can play up to 125Hz.I wouldn't run it as high as 150 ideally. It is really intended for below 100Hz as a subwoofer. It depends a bit on the drivers used as well. The 21Ipal drivers are smooth up until around 150Hz but the 21DS115 I expect may be a bit more choppy above 100Hz. Either way if running up that high you would definitely want to EQ down the peak at 215Hz and use a sharp 24dB/octave if not 36 or 48dB low pass for best sound quality and transition to the mains. Don't get me wrong it will melt your face off at 125-150Hz but the response gets real choppy not too far above 150 and it is best to avoid those out of band peaks being audible. Here is the expected response with the 21DS115. This isn't a real measurement set yet. Just a projection so don't take it as absolute. If this is close you would want to use 2 bands of EQ to bring down the 215Hz peak and also the bump near 125. I'll see if I can whip up the same with the 21SW152.
  8. 1 like
  9. 1 like
    So much EDM and DnB is a clipped mess (often intentionally), that I think we are almost conditioned to accept it as a fact of life. Some of my fav bass drum hits in some EDM have lots of flat tops.... You cannot ask more of a sound system than to playback what is on the disc, clipped or not. JSS
  10. 1 like
    I watched Kong at -7dBRef (Reference Level per se for my size room, with -0dB set at 85dBC calibration), and no bad noises, but I expected some flat tops based on the listening experience. Not as bad as the 'lunge for the volume control' as in Tron:Legacy, and DEFINITELY not as bad as Star Trek:Into Deafness.... According to MrEdge's graph, GoTG2 has less of a rolloff than the original. That is a good thing. I do not use an LT boost anymore to watch films, as I get very little room gain in the new room. The Crowsons did get a workout, though. JSS
  11. 1 like
    Dang. That's my favorite bass range for big movie LFE effects. 10-25Hz. I much prefer movies that have this type of weighting to the mix than the overly hot 25-40Hz typical action movie rumble fest. Too bad about all of the clipping though.
  12. 1 like
    http://www.avsforum.com/forum/113-subwoofers-bass-transducers/2763785-ultimate-list-bass-movies-w-frequency-charts.html
  13. 1 like
    Yeah, I got one shipped over by Dave. The VAT was harsh, but it was worth it haha!