If this is based on a bad venue, it is known that our perception of secondary source effects changes with level. For example many typical home speakers become difficult to listen to at some level due to diffraction, based partly on how much of it there is.. On the other hand perhaps a spacious presentation depends on such a contribution.
To answer the original question, with a low diffraction/reflection and appropriately room compensated system that can produce club levels (compression diaphragms almost touching the phase plug) cleanly, I don't notice the room acoustics varying. I can hear woofer coils heating, various objects in the room beginning to vibrate sympathetically.
Why would you think that? Did I mislead you?
I answered the question in good faith with what I have experienced in 45 years on the job. Techs in the biz think it's an acoustic phenomenon, I doubt that it is. I think it's more likely due to how we hear rather than something going on in the room.
So no, I don't mind at all.
Chris -- thanks for the info. I asked out of ignorance (no agenda!) and was hoping someone might have measured room response at different levels. My line of thinking was that there are plenty of examples of materials/objects/systems that require a critical threshold before a mode is excited/coupled rather than shunted. There's also modal nonlinearities at high stress/strain but that's more than likely a bit loud.
To what extent any of this is happening at domestic levels, I don't know.
I'm struggling to think of an example of a material which would only vibrate above a certain threshold.
Doesn't that imply a Young's modulus that tends towards infinity under small amounts of force?
For instance, if I put an acoustic guitar in my listening room, I can feel the body of the guitar "singing along" at moderate levels, just by touch. Turn it up, and the guitar body receives larger forces and the vibrations become stronger.
Same for doors, plaster or brick walls, etc.
At low levels, the vibrations aren't detectable by my fingers, but that doesn't mean they aren't there.
Chris
I think people mistake the 'stick-slip' effect for a nonlinear behavior of materials. Needless to say this effect can come into play with not so solid connections between materials. But as I said earlier, given materials move within elastic boundaries, their acoustic behavior will be linear.
Art Noxon wrote an article about room breakup:
Room Breakup, Curse of the Audiophile (2007) | Acoustic Sciences Corporation
A quote from the article:
'At higher volumes, more power is being pumped into the walls than the natural friction of the wall can dissipate and the walls become energized, taking on a sound of their own "wall thunder".'
Room Breakup, Curse of the Audiophile (2007) | Acoustic Sciences Corporation
A quote from the article:
'At higher volumes, more power is being pumped into the walls than the natural friction of the wall can dissipate and the walls become energized, taking on a sound of their own "wall thunder".'
Nick nacks on a shelf dont make noise until they move enough to bounce, this happens at a certain spl and the resonant freq, which is the real pain. Different notes vibrate different things which really makes the vibration stick out. I play the bass and at jam levels in buddies living room every other note vibrates something else, the open g makes the snare sing like during a drum roll. Sweep a sine up to 200hz at increasing spl to see what vibrates when.
Doing some (quick) literature work seems to corroborate with what you're saying. My knowledge comes more from the MEMS/NEMS/optical side of the world, and that's whole different kettle of fish in terms of and size-effect properties and non-linearities, which is why I put so many caveats out there.
I was also thinking about something like a door buzzing above a certain amplitude-frequency, in that above a threshold a system has different modes of coupling, like vibrating enough that the latch itself starts rattling between the two surfaces. Taking your guitar example, hitting the string hard enough that it bottoms out against the fretboard causes a very different sound. Or as CDBD describes.
The ensemble of the interactions between vibrating elements can change with displacement (or excitation frequency). Non-linear was the wrong word, as you aptly described. Thanks for responding! (likewise, markbakk)
Why would you think that? Did I mislead you?
I answered the question in good faith with what I have experienced in 45 years on the job. Techs in the biz think it's an acoustic phenomenon, I doubt that it is. I think it's more likely due to how we hear rather than something going on in the room.
So no, I don't mind at all.
Back a ways I mentioned powering through to a whole different sound and thought maybe it was related to the room reverb timing coming around full circle in effect nullifying the reflections.
But yah.....plain overpowering sounds good to.
It has to be a premium recording and goes from a happy place around 102 db to complete turd going any louder unless you powered through then it cleared up (in my case around 105 db avg @ lp)
I thought it strange that you could go from quite good to unbearable distortion then to even better just by cranking it past what I would have thought was the systems capability.
"Why would you think that? Did I mislead you?
I answered the question in good faith with what I have experienced in 45 years on the job. Techs in the biz think it's an acoustic phenomenon, I doubt that it is. I think it's more likely due to how we hear rather than something going on in the room."
Hi Pano,
Sorry for my very tardy reply!
"I think it's more likely due to how we hear rather than something going on in the room."
I'd agree. The thing which puzzled me for a while was the comment "stupid loud". What is "stupid loud"? 100 dB? 110 dB? I'd be interested in a definition of "stupid loud".
To the point: I haven't found anything in the literature which addresses this scenario. Anyway, I'd tend to agree that, if it's real, it's a psychoacoustic perception.
Since, in my sound reinforcement experience, I haven't observed this, I'll only guess that that's correct. For the moment, I surmise that it's an aspect or extension of the "cocktail party effect", where we are quite adept at ignoring ambient sound and able to "focus" on what we want to hear.
I answered the question in good faith with what I have experienced in 45 years on the job. Techs in the biz think it's an acoustic phenomenon, I doubt that it is. I think it's more likely due to how we hear rather than something going on in the room."
Hi Pano,
Sorry for my very tardy reply!
"I think it's more likely due to how we hear rather than something going on in the room."
I'd agree. The thing which puzzled me for a while was the comment "stupid loud". What is "stupid loud"? 100 dB? 110 dB? I'd be interested in a definition of "stupid loud".
To the point: I haven't found anything in the literature which addresses this scenario. Anyway, I'd tend to agree that, if it's real, it's a psychoacoustic perception.
Since, in my sound reinforcement experience, I haven't observed this, I'll only guess that that's correct. For the moment, I surmise that it's an aspect or extension of the "cocktail party effect", where we are quite adept at ignoring ambient sound and able to "focus" on what we want to hear.
Today, I downloaded the free "NIOSH" sound level meter from the iTunes store. Running on my iphone 6 and at my seated listening position;
Listening to a noisy Alan Holdworth solo (Fred) at my normal volume setting , I'm getting between 65-67 dB(A), with LAeq over maybe a minute ~ 65. The Jazz Groove stream again LAeq ~66 at my normal "enjoyable" listening level.
Running my Kenmore canister vacuum (with power head attached) set on the floor, in between my speakers, back at my listening position I get a steady 72 dB(A)...Room noise floor is about 27 - till the fridge kicks on anyway.
The missing value is the SPL that I feel things are starting to get busy, congested and strained - whatever that threshold is due to. This begs the question, "what level do you typically listen to, SPL wise?". It also will indicate if my personal listening levels are even realistically anywhere near some "room acoustic threshold" I'm supposing.
I mean, if folks can listen @ 90-110 dbA in such 'n such size room with no problem - and I cant come close without ill effect in what I feel is a generous room space, perhaps I need to look elsewhere for the cause of this loudness based congestion I think I perceive.
It'd be great to know what SPL range people are achieving before their system begins to squish into a cacophony. And more of the levels for what's most comfortable for solo listening. Curious how my comfortable SPL is only 65 dB(A) - old age? Yeah, some of what I think I'm hearing at higher SPLs I must attribute to not really liking loud music any more, I assume due to ageing of the ear-brain hearing mechanism. However, I do recall hearing this as a younger man, across various systems I've owned - always sounds better at lower SPLs.
It'd be nice to know the SPL range that would be most comfortable, for most audiophile type people to listen to. That would at least put most in the same spot regarding the Fletcher-Munson effect. Which would be good for a "can you hear this on your system?" given the system being compared to is setup to output the same SPLs.
Listening to a noisy Alan Holdworth solo (Fred) at my normal volume setting , I'm getting between 65-67 dB(A), with LAeq over maybe a minute ~ 65. The Jazz Groove stream again LAeq ~66 at my normal "enjoyable" listening level.
Running my Kenmore canister vacuum (with power head attached) set on the floor, in between my speakers, back at my listening position I get a steady 72 dB(A)...Room noise floor is about 27 - till the fridge kicks on anyway.
The missing value is the SPL that I feel things are starting to get busy, congested and strained - whatever that threshold is due to. This begs the question, "what level do you typically listen to, SPL wise?". It also will indicate if my personal listening levels are even realistically anywhere near some "room acoustic threshold" I'm supposing.
I mean, if folks can listen @ 90-110 dbA in such 'n such size room with no problem - and I cant come close without ill effect in what I feel is a generous room space, perhaps I need to look elsewhere for the cause of this loudness based congestion I think I perceive.
It'd be great to know what SPL range people are achieving before their system begins to squish into a cacophony. And more of the levels for what's most comfortable for solo listening. Curious how my comfortable SPL is only 65 dB(A) - old age? Yeah, some of what I think I'm hearing at higher SPLs I must attribute to not really liking loud music any more, I assume due to ageing of the ear-brain hearing mechanism. However, I do recall hearing this as a younger man, across various systems I've owned - always sounds better at lower SPLs.
It'd be nice to know the SPL range that would be most comfortable, for most audiophile type people to listen to. That would at least put most in the same spot regarding the Fletcher-Munson effect. Which would be good for a "can you hear this on your system?" given the system being compared to is setup to output the same SPLs.
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not that it's an adhered to standard but 75 to 85 db is the target most recording engineers try to package their product at.
and doesn't compression play a part in this?
if your system falls apart at higher listening levels does it have the ability to reproduce dynamics adequately?
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Probably distortion in the audio system itself plays a significant role in the experiences posted above... apart from the psychoacoustic (or rather physiology of the ear-related) limitations we also discussed. The latter remains the most obvious, but do people really recognize distortion from (mainly) speakers? It's likely too that that distortion itself becomes more audible to us when we play our music louder because it reaches thresholds above which such distorted signals are not masked by the original signal anymore. Even the opposite happens: excessive distortion masks low-level signals from the source, thus degrading the listening experience.
Joe, I just checked my noise floor (with fridge running about 12’ away) and was 36db on the same mic/app I measure music levels @ lp with.
My enjoyable preference level is between 95-98db I find that to be where the most dynamics (at least in my system) are to be had. It’s quite clean at these levels with a good recording.
Dave, ‘Stupid loud’ to me is 105db average (@ lp) with peaks to 115db......only one song at a time can be listened to safely and you must build up to it to let your ears get used to it. Anyway not condoning or recommending anyone try it, just explaining my tolerance level.
My new system I’m building is supposed to be good for 120db clean, I don’t want louder but am looking for more headroom as my current system is pretty well maxed out @ 105.
My enjoyable preference level is between 95-98db I find that to be where the most dynamics (at least in my system) are to be had. It’s quite clean at these levels with a good recording.
Dave, ‘Stupid loud’ to me is 105db average (@ lp) with peaks to 115db......only one song at a time can be listened to safely and you must build up to it to let your ears get used to it. Anyway not condoning or recommending anyone try it, just explaining my tolerance level.
My new system I’m building is supposed to be good for 120db clean, I don’t want louder but am looking for more headroom as my current system is pretty well maxed out @ 105.
So let's say a speaker is 100 db efficiency re 1 watt. (Altec made such units and perhaps the Lii F15 is close) Unsure how that translates to 2 speakers in a room at a further distance to the listening position, but 100 is a nice number to work from...
To get toward 120 db, we can add 3, 6db increments at a cost of 4X the amplifier power for each. So 4X4X4 = 64 watts. But realistically the speaker can only handle ~30W, so that limits the continuous SPL to 115 db.
To get toward 65 db, the number 36 is easy down from 100. That's 6, 4X decrements from 1W, which is a really, really small number. So on average, I'm probably listening well within the "first watt" of my 25WPC into 8 Ohms, 0.03% THD amplifier.
I'm reading most music genres have a dynamic range of about 50 db, so if a quiet passage is leveled at 65 db, the louder dynamics go up to 115, which should be within reach of a 100db efficiency speaker with a 30W amplifier.
Is there a tutorial or Article here in DIYAudio where this is all properly worked out? Say, starting with "50" as an ordinary db SPL dynamic range to accommodate, what's the corresponding amplifier requirements across different ordinary speaker efficiencies.
How about given a noise floor of 30 db, with a desire for the soft passages to be twice as loud (+6), 50 db of dynamic range puts the loudest at 86, which is within a 100db SPL capable system. And 1W for some speakers. This is, of course, not for musical realistic SPLs, but rather for enjoyable, non-hearing-damaging levels one could take daily - where you dont have the "stretch" your ears first, like you would muscles before a workout.
Just curious about all this and where one should set an average SPL considering all of the above - then see if at such a level, if the room is muddying up the sound by getting excited and needs treatment. Clearly, I'm not well versed at this. It seems the folks of lore at Altec did understand, with their 100db efficient speakers and 30W amplifiers, allowing a user to set volume level anywhere within a 20 db range above a 45 db fridge-on listening room noise floor. Seems reasonable.
To get toward 120 db, we can add 3, 6db increments at a cost of 4X the amplifier power for each. So 4X4X4 = 64 watts. But realistically the speaker can only handle ~30W, so that limits the continuous SPL to 115 db.
To get toward 65 db, the number 36 is easy down from 100. That's 6, 4X decrements from 1W, which is a really, really small number. So on average, I'm probably listening well within the "first watt" of my 25WPC into 8 Ohms, 0.03% THD amplifier.
I'm reading most music genres have a dynamic range of about 50 db, so if a quiet passage is leveled at 65 db, the louder dynamics go up to 115, which should be within reach of a 100db efficiency speaker with a 30W amplifier.
Is there a tutorial or Article here in DIYAudio where this is all properly worked out? Say, starting with "50" as an ordinary db SPL dynamic range to accommodate, what's the corresponding amplifier requirements across different ordinary speaker efficiencies.
How about given a noise floor of 30 db, with a desire for the soft passages to be twice as loud (+6), 50 db of dynamic range puts the loudest at 86, which is within a 100db SPL capable system. And 1W for some speakers. This is, of course, not for musical realistic SPLs, but rather for enjoyable, non-hearing-damaging levels one could take daily - where you dont have the "stretch" your ears first, like you would muscles before a workout.
Just curious about all this and where one should set an average SPL considering all of the above - then see if at such a level, if the room is muddying up the sound by getting excited and needs treatment. Clearly, I'm not well versed at this. It seems the folks of lore at Altec did understand, with their 100db efficient speakers and 30W amplifiers, allowing a user to set volume level anywhere within a 20 db range above a 45 db fridge-on listening room noise floor. Seems reasonable.
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Actually, having a little trouble wrapping my head around the graphs and charts in the paper "Dynamic Range Across Music Genres..." which can be read at Dynamic Range Across Music Genres and the Perception of Dynamic Compression in Hearing-Impaired Listeners
The Delta dB SPL chart (attached) is saying what? Thanks for any assistance!
The Delta dB SPL chart (attached) is saying what? Thanks for any assistance!
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The vertical scale is dynamic range. Different lines are different genres, and the horizontal scale is frequency.
Rock music is apparently the most compressed across the spectrum, having the smallest dynamic range.
IME, the numbers in the graph are about right. There isn't much music around with a 50dB dynamic range. An orchestra can almost certainly manage that, but the full dynamic swings are never retained in the commercial release.
I'd say the point where things start sounding "messy" due to room acoustics are somewhere above 100dB. My suspicion is that, above certain SPLs, we're no longer able to subconsciously filter out the room reflections.
As an example, I tried my PA system in my living room. Here's a link to it in action, putting out 85dBC-slow at 280': YouTube
It's a capable system - there's no way I'd ever reach full power in my living room without ending up profoundly deaf.
At a fraction of the available power, the sound started to get "messy". If I put my fingers in my ears, the sound was good again (with the expected frequency response differences).
I've measured a speaker in a room putting out some pretty serious SPLs (I was at the far corner of the house, with ear defenders on) and found that speakers are linear in terms of voltage in = sound out, until you're doing something really silly like putting a 70V RMS sine sweep through a 1" compression driver.
The only sensible conclusion I can find is that the effect we're talking about here is to do with our ears and brains, rather than speakers and rooms.
Chris
Listening at 95db, really. My normal level is in the 60-70db. I find my small room 17x11x8( treated), sounds best at low volume. The music floats in the air. The higher the volume the more congested the sound becomes. It's not the equipment (VPI,Meridian,Von Schweikert). Maybe my ears or the sympathetic/resonance walls/floor/ceiling or both make the experience less enjoyable at anything close to 90-100db.
I have a treated room for first reflection points, side walls, and ceiling, a silk rug on the cork floor. My wife is a professional weaver, and made the material for those absorption panels. They have three dimensional square sections(see photo), and work nicely. The panels also have a batting panel on the backside. The house is of typical construction with single layer sheetrock, and a somewhat flexible floor. At higher volumes, that extra energy goes somewhere. I believe the room/walls temporarily store, then release the excess energy, thus mudding/congesting the sound. Pair this with my old ears/hearing, and you probably have the reason I don't listen to the hundreds of 60-70s rock albums at my old college day volumes. I drifted towards acoustic and blues over the decades. Oh, those were the days.....
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