Of course I was not referring to RT60 exactly but ...
I wonder what predictive powers the DI etc numbers in the spinorama actually have. There was a discussion about a dB or so, where the tilt begins and things like that.
I also wonder, why the classic's orchestra is so prominent, but foremost why 'illusion' is the word. I never - actually, ever fell into an illusion when listening to a playback. Not even into the feeling of immersion. As that oddball, should I donate my ears to science (after)? I think that expactations regarding the powers of a stereo (surround) system are often pretty much exaggerated. I long for proper frequency response, which is easily achievable today, a smooth reverberant field without hot spots in space and frequency, sufficient dynamic range, lean but extended bass, combined with lowest non-linear distortion and all within reasonable limits and budget. That makes me 'decode' the music, and I'm happy.
With all due respect, maybe you should listen to the music, instead of the equipment. I'm only half-joking. A willing suspension of disbelief, necessary for the illusion, requires will.
I have attended and been a part of orchestra performances in a variety of halls my whole life, and listened to thousands of hours of recorded orchestral music. A neutral system will easily convey the space of the performance space, if the recording possesses it (and that is not assured by any means). If the recording doesn't possess it, and I can't tolerate the music without it, then I ought to buy a digital reverberation device, which is as close as it gets to a plausible facsimile of a reverberant performance space. But that lack of tolerance is, in turn, intolerable to me. Where am I sitting? If I'm on the back row of the orchestra, where the tuba player usually sits, my impression of the overall sound will be very intensely dominated by the trombone section and the tympani, and next in line by the string basses. Those instruments are around me and in my near field. Plus the stage usually sounds quite dry to the musicians in a good hall, because the reverberation heard by the audience is "out there," where the direct sound has had a chance attenuate down to something closer level of some of the reflected sound. On stage, the direct sound is far stronger in proportion to reflections, and stages are either highly reflective to the audience (by using a shell) or they are dead (with curtains that trap reflections). Thus, the back-row musicians only hear a bit of what reflects back to them from the far wall of the auditorium.
If I'm in the audience on Row 10, then I might actually be below the lip of the stage with the back-row musicians out of view. I'll heard the strings dominantly by direct sound, and the winds, brasses, and percussion to a greater extent by reflection from the stage shell or auditorium walls. If I'm on the front row of the mezzanine, I'll hear the whole orchestra in probably the most balanced way. The back row of the mezzanine will be affected by very close direct reflections from behind me. I've sat in all these places, and in all these places, the orchestra sounded like...an orchestra...and Shostakovich sounded like...Shostakovich.
The range of differences I have experienced in person surround the experience I get at home with a good recording, where there is some effects of the performance hall reverberation recorded along with the music. But there is nothing I can do to put me on the front row of the mezzanine, because I can plainly see that I'm on my sofa holding a glass of Scotch and reading silly posts on ASR on my phone while listening. But even so, the orchestra sounds like an orchestra and Shostakovich sounds like Shostakovich. One of the points Dr. Toole makes in his book is that humans are exceptionally good at separating primary sound from reflected sound, no matter in what proportions they are presented.
But I'm extremely sensitive to percussion or high strings that sound crispy (from distortion caused by clipping) and tubas sounding like euphoniums or French horns sound like trombones (from colored frequency response or too much second-order distortion--the kind audiophiles often seem to admire). I can also detect very slight changes in spectral tilt cause by the use of a tone control, even when I don't notice the 72-Hz null in my room that is only 8 or 10 Hz wide. We should think of a broad spectral tilt in the same way as dissimilar levels in a comparison. The correct protocol for comparisons is to match levels accurately, using a capable RMS-reading voltmeter, because even very slight differences in level affect our perceptions and preferences. But if the choices under comparison have subtly different spectral tilts, then that is impossible, because the difference in levels will vary by frequency. Even a couple of tenths of a dB could make a difference. But for music, I can't otherwise hear harmonic distortion less than about 1%, which is good, because very few speakers can do better than that.
Here is my listening room as of a couple of years ago, without equalization:
Notice the dip between 200 and 300 Hz. That's a room effect. Notice the dip at a little above 1 KHz--that's a small dip in the response of the speakers, as noted in the anechoic testing (this is the "listening window" response as reported by Soundstage from testing in the NRCC anechoic chamber):
This listening window is averaged from these on and off-axis measurements:
On axis,15, and 30 degrees off-axis:
45, 60 and 75 degrees off-axis:
That can be fixed by equalization, as Dr. Toole suggests above. And I can also use EQ to do something about that dip in the mid-bass.
I use a Yamaha YDP2006 digital parametric equalizer, because I'm old-school and prefer real devices over software, especially for speaker and room correction that will be applied to all playback. After EQ:
There are still nulls in one channel at 52 and 90 Hz, and in the other channel at 72 Hz, caused by cancellations in the room. And there's a null next to a spike in the upper hundreds. Those nulls under 100 Hz might get help from properly integrated subs, if I would use them, but frankly none of these narrow nulls distract me in the least. I get more of a change from turning my head or reaching over to get my glass, and that much is true even if I'm sitting on the front row of the mezzanine in a concert hall.
If a recording needs a broad spectral adjustment because of the way it is mixed, that's what tone controls are for.
Rick "has to listen to stuff he doesn't get lost in to hear the equipment, which isn't much that is musical" Denney
. The inexperienced listeners were off on their own planet. This experiment needed many more listeners to contribute usefully to a perspective on personal preferences, and the authors admit it.
