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The sadness of wasted bits

Blumlein 88

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You might notice in the K-system it was mentioned Dolby research indicated a lower reference level for small rooms than for large spaces. There is some qualitative difference in the same loudness in smaller spaces vs larger spaces. I don't know what it is, but wonder if in larger spaces reflections of peak sound levels on impulsive sounds is more spread out in time vs in smaller spaces. Anyway, the research and my experience indicate that in a domestic listening space you in fact don't need or even want to duplicate the SPL levels of a live performance in a larger space even those in a "small" jazz club. At an extreme maybe 120 db SPL peaks sound just as powerful at 105 db SPL peaks in your home in some sense. Or at least it seems such very high level sounds can be overwhelming in a way they aren't in the larger space. This actually is a good thing for us at home.
 

Willem

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There is some qualitative difference in the same loudness in smaller spaces vs larger spaces.
I once found some serious acoustics research for just this, with a graph of room size vs the max spl that can be reproduced without issues. Unfortunately I did not keep a copy and I cannot find it anymore. It would explain why we do not play at the same high levels that we hear in a concert hall, even if we have pretty powerful systems. So, to retain a high dynamic range at lower levels we do indeed need to have a quite low background noise. Perhaps this is also why nearfield listening is so realistic.
 

ocinn

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I do really love my large DIY unity/synergy's :D
Speaking of synergy, just did a sidework gig for a warehouse show last weekend with SH96HO flown mains, SM80F flown delays, 2x BC218, 4x BC215 and they never cease to blow me away. Absolutely crystal clear, tactile and unmatched directivity across the dance floor.

Synergy is the the ideal solution when trucking/rigging of delay hangs ends up more economical than fewer hangs of line arrays.

Also re: Hyperion, it’s essentially as dynamic as an SM60 + TH118XL but with DSP and somewhat cardioid bass. Still can’t do the midbass “wind knocked out of you” that I am spoiled with though. But in all fairness, an sm60 and th118xl couldn’t do that either

They are hugely more dynamic than the W371 rig, at least in a vacuum. W371 rigs (and I’d assume 8381 as well) have smoother directivty and obviously far superior room correction and bass control, but are less tactile than the Hyperion.

I really need to demo the 8381. I think it might be the closest we get outside of actually just buying a PA and fixing its flaws with DSP, for consumer use.
 
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AudioSceptic

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16 bit has 2^16 levels, or 65536 (minus one for the sign bit)

24 bit has 2^24 levels, or 16,777,216 (minus 1 for the sign bit)

16777216 / 65536 = 256

---

If a 16bit DAC outputs a maximum of 2 volts at full scale (a common figure), and if the voltage steps were the same, a 24bit DAC should put out about 503 volts at full scale.

They don't.

I was disappointined.
Thanks. DVDdoug has already straightened me out. Your description of those extra 2^8 levels "within" the bottom bit of 16 bits has made me think!
 

MRC01

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... the research and my experience indicate that in a domestic listening space you in fact don't need or even want to duplicate the SPL levels of a live performance in a larger space even those in a "small" jazz club. At an extreme maybe 120 db SPL peaks sound just as powerful at 105 db SPL peaks in your home in some sense. Or at least it seems such very high level sounds can be overwhelming in a way they aren't in the larger space. This actually is a good thing for us at home.
Agreed. I'll add that those live events can be painfully loud, requiring musician's earplugs. And if one's home listening environment is quieter than the live venue, you can still get the full dynamic range of the live event, even if it's a few dB quieter and is no longer painfully loud needing earplugs for listening.
Well, nearly so, anyway, since most recordings use at least some dynamic compression, even good recordings that apply it with a light-handed touch.
 
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CapMan

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Agreed. I'll add that those live events can be painfully loud, requiring musician's earplugs.
Just to take it back to my original post - this was an acoustic jazz trio playing at very sensible levels. No trumpets or saxs No earplugs needed.

To paraphrase the excellent input on this thread - we can only approximate the dynamics of even this modest jazz trio in the home environment for technical reasons I now better understand.

It’s just a good job our music systems can play in tune and in time or we’d be really screwed :)
 

LouB

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Wow ! I know this hobby & a profession for some and the "science" of it is there some where, but you can not reproduce live sound from a club/arena/hall/pub/bar or anywhere else in your house.
Live music is better it's that simple.
 

sigbergaudio

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Wow ! I know this hobby & a profession for some and the "science" of it is there some where, but you can not reproduce live sound from a club/arena/hall/pub/bar or anywhere else in your house.
Live music is better it's that simple.

I guess it's about getting as close as possible to the experience? :)
 
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CapMan

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As I said at the start , this is about dynamics at a specific live event - a piano jazz trio in an acoustic setting….not arenas, concert halls .
 

Blumlein 88

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From earlier in the thread it was mentioned levels can be lower in smaller spaces. Here is a thread with some info about that.

Here is a chart from suggestions by SMPTE. Reference level is sort of an average level and you are expected to have 20 db of headroom above it for peak levels.

1698300843059.png
 

mcdn

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It's a compromise I guess. It's hard to make it perfect for both loud playback on a great hifi system and moderate volume on a crappy car radio while driving 80km/h.
with modern tech we could just provide one full dynamic range recording and let the end system set the dynamic range compression on the fly. Heck, it could compress more when my car is on the freeway and less when it’s stopped at the lights!

but path dependency is a thing so I doubt this will come about for at least a decade, if ever
 

MaxwellsEq

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From earlier in the thread it was mentioned levels can be lower in smaller spaces. Here is a thread with some info about that.

Here is a chart from suggestions by SMPTE. Reference level is sort of an average level and you are expected to have 20 db of headroom above it for peak levels.

View attachment 321260
I used this table and Bob Katz work to calibrate my home listening system. I really recommend doing this. It makes a surprising improvement in sound quality.
 

gnarly

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Speaking of synergy, just did a sidework gig for a warehouse show last weekend with SH96HO flown mains, SM80F flown delays, 2x BC218, 4x BC215 and they never cease to blow me away. Absolutely crystal clear, tactile and unmatched directivity across the dance floor.
Very nice, I would have liked to hear and dance to that. Checks all the right boxes !

Also re: Hyperion, it’s essentially as dynamic as an SM60 + TH118XL but with DSP and somewhat cardioid bass. Still can’t do the midbass “wind knocked out of you” that I am spoiled with though. But in all fairness, an sm60 and th118xl couldn’t do that either
Yep, the SM60 whether on it's on or in an Hyperion/HRE1...kinda defines a smaller live-sound.
No replacement for displacement, anywhere is the spectrum....CD, mid, lows, or sub drivers..huh?
Horn loading, and pattern control horns/guides, are the only substitutes for sheer displacement I know of....
They are hugely more dynamic than the W371 rig, at least in a vacuum. W371 rigs (and I’d assume 8381 as well) have smoother directivty and obviously far superior room correction and bass control, but are less tactile than the Hyperion.

I really need to demo the 8381. I think it might be the closest we get outside of actually just buying a PA and fixing its flaws with DSP, for consumer use.
The Hyperion and 8381 are more kin than not, imo.. The W371 doesn't look to be in the same family.

It's funny how after using a bunch of different PA rigs and/or building a bunch or PA capable DIYs, that you almost don't need to see a spec sheet,
to know what to expect in terms of SPL (across the spectrum even).
Just looking at the CDs, drivers, type subs, ...and their sizes...seems to tell 90% of the "max SPL & dynamics" story.
 

ocinn

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Just looking at the CDs, drivers, type subs, ...and their sizes...seems to tell 90% of the "max SPL & dynamics" story.
Eh… I find the main limitation in most PA systems to be the compression drivers and the classic early onset of distortion which results in a super glaring and abrasive high end. And that varies hugely based on specific CDs and the horn design, ends up being pretty independent of efficiency and wattage rating.

Most “dance” systems (funktion one, void, turbo sound, kv2, etc) fall horribly short of their max spl ratings (rms watts x sensitivity, as well) whereas real pro brands like L’Acoustics, D&B, Meyer, Danley actually hit their targets without causing blood to pour down the jaw from the ear canal of listeners, due to atrocious distortion.

This is further reinforced by the fact that the aforementioned pro brands use DSP amplifiers with very well optimized limiting to keep the drivers out of the danger zone.

The Hyperion and 8381 are more kin than not, imo.. The W371 doesn't look to be in the same family.
the cardioid and subsequent room correction of the w371 is unreal. Probably the main area it is able to beat Hyperion.

8381 should be able to pull off the same. Looking forward to being able to demo them privately. However I generally prefer the Danley approach to constant directivity with using time coherent drivers and a CD horn vs creating your directivify thru an intentional comb filter of drivers like 8381 does.

In live sound it’s basically the same difference as a super tall point source that uses a combiner (Danley J8) and a line array which operates in cancellation.
 

gnarly

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Eh… I find the main limitation in most PA systems to be the compression drivers and the classic early onset of distortion which results in a super glaring and abrasive high end. And that varies hugely based on specific CDs and the horn design, ends up being pretty independent of efficiency and wattage rating.

Didn't mean to ignore the quality of the drivers, particularly the CD, as part of the gut sense of "sizing up" the maximum linear SPL.
And must admit, most all the live sound boxes I have experience with, including my DIYs, have had CD's of known excellence..with generally believable spec sheets..
(My DIY's have all used either BMS or B&C ring coaxs.)

I honestly don't think any driver, CD through sub, can play average SPL at its sensitivity spec raised by it's continuous power rating. I typically knock that down by 3-6dB.
Clean headroom forever!!!! Lol
 

Lopsided

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With the simple 2-mic pole that I used, getting the bass right was tricky. Too close, or if the musicians are near a wall or corner, and the bass is too strong and tubby.
Maybe it has something to do with proximity effect of directional mic? I remember John Eargle mentioned in his Handbook of Recording Engineering that using low-passed omnis to capture low end sub-100hz and mix them back.


IMG_3045.jpeg



IMG_3046.jpeg

Note this was a frontal 3 channel array for surround classical recording.
 

pablolie

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