No, it is not that simple...
The impression of loud just doesnt come when you have really good systems, so you always have to choose a balance between good and loud.
I have measured 122dB RMS of "silent music" in the back of a venue once. You couldnt hear yourself scream but the impression was that it was very low almost silent.
Some professionals are very good at using this to their advantage, like hitting a drawmer compressor into distortion to create a massive loudness at 95dBA while others like me really have to fight to get any kind of loudness out of 105dBA.
electroaudio said:
?
this really looks complicated
I have to admit that I don't understand much from what You have said
anyway, I am a classical music lover
no problem of balancing between good and loud, nor compressors nor "silent yet deafening" 122 dB RMS at a philharmonic hall or at an opera house 🙂
how fortunate! 🙂
and perhaps this partly explains why I am satisfied with the target of 100 dB in peaks
reproducing loud amplified music seems to be something REALLY different, not to mention HT's "tank shots and earthquakes" 🙂
best,
graaf
graaf said:
I'm not sure that I agree with you here. I can do this without a large speaker, say 10" max. Its HOW you do it that matters. I'd say that it is true that you cannot do this without using a compression driver and waveguide, but the LF units don't have to be that big. I've found 12" to be about optimal, with a few 10" - 12" subs. This just isn't that big, its not huge. Sure its bigger than most Hi-end mini systems, but thats just my point. Those systems just don't do it for me. One really does need efficiency and fairly high Max SPL capability. Thats the whole point of this thread.
gedlee said:
I was speaking from the perspective of contemporary common hifi speakers available on the hifi/hi-end market
10''-12'' drivers are uncommon
10''-12'' midbass is something very rare and 10''-12'' dedicated woofers generally can be found only in "flagship models" or "superspeakers" 😉
not to mention additonal multiple 10''-12'' subwoofers
only from that somewhat distorted perspective 10''-12'' is something "really big" 🙂
but because that perspective is a perspective of most od diyaudio forum users I wrote just "really big"
best,
graaf
sub response
My personal experience in my primary listening room doesn't support the corner loading as a best scenario. I tried that with my current 12" sonsubs, one in the corner and one elsewhere, as well as a mulitude of other speakers over the years. When corner loaded, I get a huge 32 Hz bloom in several regions of the room, lumpy response thruout, and large suckouts in opposite corners as well as at the primary listening area. Crude mapping using a sound meter for relative intensities indicated greater than 15 dB variation as the norm. This in a slanted ceiling 2 story cathedral great room, ~15,000 ft^3, open on one side to a kitchen area of an additional 4000 ft^3. The room also has large expanse of windows.
After extensive placement and mapping, and having perused the white paper from Harmon Int'l on sub placement, I tried placement ~ 1/2 way along the shorter side walls (main area measures ~30' front to back) roughly 3 feet out from said walls. This has yielded the smoothest response by far, and I reach peaks of 110dB+ on movie LF special effects (Top Gun recently shook the doors and released trinkets from their resting places on shelves).
Other speakers include 4 x 6 1/2" mid woofs in my primary linesources and 2 x 10" woofers in run of the mill Advent 6002 surrounds.
I also must say that my BG linesource dipole setup does indeed produce 1/d fall off in spl rather than 1/d^2 from typical point sources, so they really fill the space with evenly dispersed sound and fewer artifacts of placement. They essentially dissapear sonically.
"Technology: Geometry
The Acoustical Line-Source"
"Now, let's consider the line-source in the sound room. Remember, its characteristics? As you walk toward it, it doesn't appear to get louder. Stand near one line-source speaker and it doesn't drown out its mate. In fact, you get the same type of perspective that you heard in the concert hall, where each instrument is in its proper place regardless of where you are. This is staging. The line-source emulates the staging you heard in the hall. The so called "sweet spot" (the position in your sound room where reproduction is the best) is therefore virtually your entire sound room. No "head-vices" are required to secure your ears to the optimum spot. Get up, move around, and enjoy the full glory of your sound system without penalty. This is the line source.
For the sake of making a complete statement, at the opposite end of the spectrum is the point source. Most other loudspeakers are point sources. Their characteristics are just the opposite of a line source. As you move toward the point source, it gets dramatically louder. When you are near a point source speaker in a stereo system, you will no longer hear the other speaker because of acoustical masking. Also, energy is radiated vertically, which now opens up another bag of worms: the problem of "taming" floor and ceiling reflections.
The only listening position possible to obtain proper staging and spectral balance with point sources is along a line centered between the speakers. You will most likely need a "head vice" to enjoy optimum performance. In contrast, by having no perceptible masking effects, the line-source speaker avoids this problem. Why do designers use point sources? Simply, because it is possible to make a more compact speaker that is inherently cheaper to build. "
http://www.soundlab-speakers.com/tech_geom.htm
John L.
My personal experience in my primary listening room doesn't support the corner loading as a best scenario. I tried that with my current 12" sonsubs, one in the corner and one elsewhere, as well as a mulitude of other speakers over the years. When corner loaded, I get a huge 32 Hz bloom in several regions of the room, lumpy response thruout, and large suckouts in opposite corners as well as at the primary listening area. Crude mapping using a sound meter for relative intensities indicated greater than 15 dB variation as the norm. This in a slanted ceiling 2 story cathedral great room, ~15,000 ft^3, open on one side to a kitchen area of an additional 4000 ft^3. The room also has large expanse of windows.
After extensive placement and mapping, and having perused the white paper from Harmon Int'l on sub placement, I tried placement ~ 1/2 way along the shorter side walls (main area measures ~30' front to back) roughly 3 feet out from said walls. This has yielded the smoothest response by far, and I reach peaks of 110dB+ on movie LF special effects (Top Gun recently shook the doors and released trinkets from their resting places on shelves).
Other speakers include 4 x 6 1/2" mid woofs in my primary linesources and 2 x 10" woofers in run of the mill Advent 6002 surrounds.
I also must say that my BG linesource dipole setup does indeed produce 1/d fall off in spl rather than 1/d^2 from typical point sources, so they really fill the space with evenly dispersed sound and fewer artifacts of placement. They essentially dissapear sonically.
"Technology: Geometry
The Acoustical Line-Source"
"Now, let's consider the line-source in the sound room. Remember, its characteristics? As you walk toward it, it doesn't appear to get louder. Stand near one line-source speaker and it doesn't drown out its mate. In fact, you get the same type of perspective that you heard in the concert hall, where each instrument is in its proper place regardless of where you are. This is staging. The line-source emulates the staging you heard in the hall. The so called "sweet spot" (the position in your sound room where reproduction is the best) is therefore virtually your entire sound room. No "head-vices" are required to secure your ears to the optimum spot. Get up, move around, and enjoy the full glory of your sound system without penalty. This is the line source.
For the sake of making a complete statement, at the opposite end of the spectrum is the point source. Most other loudspeakers are point sources. Their characteristics are just the opposite of a line source. As you move toward the point source, it gets dramatically louder. When you are near a point source speaker in a stereo system, you will no longer hear the other speaker because of acoustical masking. Also, energy is radiated vertically, which now opens up another bag of worms: the problem of "taming" floor and ceiling reflections.
The only listening position possible to obtain proper staging and spectral balance with point sources is along a line centered between the speakers. You will most likely need a "head vice" to enjoy optimum performance. In contrast, by having no perceptible masking effects, the line-source speaker avoids this problem. Why do designers use point sources? Simply, because it is possible to make a more compact speaker that is inherently cheaper to build. "
http://www.soundlab-speakers.com/tech_geom.htm
John L.
gedlee said:
90 dbA 8 hrs
92 dbA 6 hrs
95 dbA 4 hrs
97 dbA 3 hrs
100 dbA 2 hrs
102 dbA 1.5 hrs
105 dbA 1 hr
110 dbA 0.5 hr
115 dbA 0.25 hr or less
Figure 2: OSHA Regulation 1910.95 - Occupational noise exposure
Again, I'll reiterate my point: the levels you set forth are potentially damaging. I like big, dynamic speakers without compression, but misrepresenting realistic and/or safe listening levels doesn't do anybody any favors. If you were to expand your dynamic range requirements, I wouldn't argue that. But the base SPLs are not realistic for most people, rooms, or safety.
If you feel this strongly about it, a formal fellow like yourself might want to pursue it with a AES paper re: SPL requirements and safe levels for a home hifi set. I would enjoy reading a formal treatise on the subject. Until then, it's irresponsible to set forth requirements for speakers, and say that those levels are harmless, when clearly, noise at those levels IS a danger. Hearing loss is progressive, and we're not very good at identifying when it takes place (as in, the listener is not very alert to it), so it's important to watch your levels and keep them reasonable, so you can enjoy music and understand speech when you're 50, 60, 70, etc.
90 dbA 8 hrs
92 dbA 6 hrs
95 dbA 4 hrs
97 dbA 3 hrs
100 dbA 2 hrs
102 dbA 1.5 hrs
105 dbA 1 hr
110 dbA 0.5 hr
115 dbA 0.25 hr or less
Figure 2: OSHA Regulation 1910.95 - Occupational noise exposure
Hello badman
Have you ever worked in a factory where hearing protection was manditory?? These is a big difference between the levels listed in the OSHA standard and music. For most part those levels are continuous. They never go lower ever once the machines are on.
I worked as a die setter in a highspeed metal stamping facillity. We had 100 ton hydraulic presses that ran at 100-200 strokes per minute and were as large and as loud as a locomotive engine. We had 4 of them and sometime all were running at once plus the other more conventional flywheel presses.
If you were an operator you were both up close and 10ft away for hours at a time. Even as a die setter with only one machine running across the room it was hell working in there. I am with you as far as being conservative to be safe but I am not so sure those levels are as meaningful with a source like music that has real dynamic range. They really are very different types of "noise".
Rob🙂
92 dbA 6 hrs
95 dbA 4 hrs
97 dbA 3 hrs
100 dbA 2 hrs
102 dbA 1.5 hrs
105 dbA 1 hr
110 dbA 0.5 hr
115 dbA 0.25 hr or less
Figure 2: OSHA Regulation 1910.95 - Occupational noise exposure
Hello badman
Have you ever worked in a factory where hearing protection was manditory?? These is a big difference between the levels listed in the OSHA standard and music. For most part those levels are continuous. They never go lower ever once the machines are on.
I worked as a die setter in a highspeed metal stamping facillity. We had 100 ton hydraulic presses that ran at 100-200 strokes per minute and were as large and as loud as a locomotive engine. We had 4 of them and sometime all were running at once plus the other more conventional flywheel presses.
If you were an operator you were both up close and 10ft away for hours at a time. Even as a die setter with only one machine running across the room it was hell working in there. I am with you as far as being conservative to be safe but I am not so sure those levels are as meaningful with a source like music that has real dynamic range. They really are very different types of "noise".
Rob🙂
noise levels
Much of what passes for "music" these days is compressed into the last 2 Db's at the upper end of the digital domain on ceedees, so I'm not so sure there IS such a big difference wrt dynamic range between industrial exposure and LOUD rock music.
With HT, I've found the "Wife Tolerance Factor, aka WTF"
tends to limit my exposure above ~100dB to brief momemnts of euphoria, unless I send her out on an extended shopping mission... 😉
John L.
Robh3606 said:
Much of what passes for "music" these days is compressed into the last 2 Db's at the upper end of the digital domain on ceedees, so I'm not so sure there IS such a big difference wrt dynamic range between industrial exposure and LOUD rock music.
With HT, I've found the "Wife Tolerance Factor, aka WTF"
tends to limit my exposure above ~100dB to brief momemnts of euphoria, unless I send her out on an extended shopping mission... 😉 John L.
It seems to me that we are all quibaling about fairly small differences. I got my number off by 5 dB OK. I have listened to 110 dB(c) Slow many times and my ears don't ring and my hearing hasn't changed much since I was a kid (when I did do some damage - either with rock concerts or gun shooting, I don't know). I live with a Hearing Health Care Professional on a daily basis and I take very good care of my hearing, especially around power tools.
BUT 110 dB Music for 1/2 hour is not going to damage your hearing. The OSHA standards are for LONG TERM DAILY exposure. They don't apply to the situation that I am talking about and are much lower than reality for my example as a result.
BUT 110 dB Music for 1/2 hour is not going to damage your hearing. The OSHA standards are for LONG TERM DAILY exposure. They don't apply to the situation that I am talking about and are much lower than reality for my example as a result.
Perspective is interesting. In the 1950's - 60's in North America, 10" and 12" speakers were the norm, and were even common in the new, so-called bookshelf speakers just coming onto the market. (See URL, below.)
Leading designers like Olsen and Klipsch produced very large speaker enclosure designs so that there was reasonable bass response. Some of these things were huge - I know, I have a couple sitting in the room next door
But even average sized speaker enclosures and music consoles were large by today's standards.The reason is PARTLY that larger, higher efficiency speakers were needed because significant amplifier power was very, very expensive compared to cost of efficient speakers. A McIntosh amp/preamp was worth a couple of months' pay! The only affordable way to get reasonable quality electronics was to buy kits from Heath, Lafayette, and Eico
That's not the case nowadays. In fact, it's exactly the opposite situation! Affordable, high performance speakers are almost exclusively a DIY proposition and kits are the way to go, if you can find a kit with high quality specifications.
(Interesting article about the change to smaller acoustic suspension speakers here:
http://history.sandiego.edu/GEN/recording/villchur.html
I always thought the sound of the AR speakers mediocre, but they were a hell of a deal and they certainly could fill small rooms with OK sound and the baby boomer kids were still poor and in cramped quarters in the sixties.....)
Given that decent amplifier power is available at reasonable cost today, it's possible to optimize speaker design and have a good trade off between efficiency and size.
It's also the case that it's even easier these days to produce at reasonable - or even exorbitant - price, mediocre, but live-with-able sounding, eentsy-weentsy, skinny speakers that supposedly fit with modern decorating requirements. Their sound, unfortunately, is nowadays the norm.
I think it's interesting that all these years later a leading researcher like Earl finds the 12" size woofer to be all round about right for most domestic applications requiring high quality sound reproduction.
FrankWW said:
Thats exactly why I am going to offer the ESP line as a kit. The rest of the world simply doesn't care about sound quality and are convinced that small speakers sound as good as big ones. They may never see the light - can't see what your not looking for.
Its also intersting that I came to this size NOT because of output capability or LF response, but because of directivity control. The higher directivity of bigger speakers was considered a bad thing back thing back then.
The widely dispersed belief that small speakers can sound as good as big ones coupled with the mistaken belief that wide directivity is desirable leads to the concept of "smaller is better". I don't buy this and I think that it will become common knowledge that it is false. But, once again, only if you care about sound quality.
Apologies then. I can't get to pick up my (first set ever of) reading glasses until Friday and sometimes I miss the obvious in the blur.graaf said:
It's funny, you know, but I remember using the ARs and little EPIs and the only way I could get them to sound OK for me in the rooms I had was to keep them well away from the walls and listen off axis. If I got the room position and toe-in just right, the EPI's sounded really nice and the sweet spot was fairly large.
Looking back on it, I think what I was doing was diminishing the early reflections.
The downside was the usually very inconvenient location the speakers had in the room 😉
graaf said:
I am sorry if my languageskills arent the best, but i dont understand the mechanisms behind loudness either.
Distortion, rms vs peak, frequencycontent, balance, duration and a lot of other stuff seems to play a role in what the ear uses to measure loudness with, while the actual SPL seems to be useless - counteracted by thresholdshift.
-If somebody do know all the mechanisms please share your knowledge...
"I always thought the sound of the AR speakers mediocre, but they were a hell of a deal and they certainly could fill small rooms with OK sound and the baby boomer kids were still poor and in cramped quarters in the sixties.....)
Given that decent amplifier power is available at reasonable cost today, it's possible to optimize speaker design and have a good trade off between efficiency and size.
It's also the case that it's even easier these days to produce at reasonable - or even exorbitant - price, mediocre, but live-with-able sounding, eentsy-weentsy, skinny speakers that supposedly fit with modern decorating requirements. Their sound, unfortunately, is nowadays the norm.
I think it's interesting that all these years later a leading researcher like Earl finds the 12" size woofer to be all round about right for most domestic applications requiring high quality sound reproduction."
That was my upbringing. My dad had a pair of Bozak Concert grands. Hi-fi, as my dad called them, shops had 3-ways with 12" woofers. Bookshelf speakers were for bedrooms. My first real system was a pair of Infinity 2 ways on top of a pair of original AR1's. I made a 100hz crossover based on info from the Vance Dickenson book so the AR's ran as "subs". Sounded great and I never looked back!
Given that decent amplifier power is available at reasonable cost today, it's possible to optimize speaker design and have a good trade off between efficiency and size.
It's also the case that it's even easier these days to produce at reasonable - or even exorbitant - price, mediocre, but live-with-able sounding, eentsy-weentsy, skinny speakers that supposedly fit with modern decorating requirements. Their sound, unfortunately, is nowadays the norm.
I think it's interesting that all these years later a leading researcher like Earl finds the 12" size woofer to be all round about right for most domestic applications requiring high quality sound reproduction."
That was my upbringing. My dad had a pair of Bozak Concert grands. Hi-fi, as my dad called them, shops had 3-ways with 12" woofers. Bookshelf speakers were for bedrooms. My first real system was a pair of Infinity 2 ways on top of a pair of original AR1's. I made a 100hz crossover based on info from the Vance Dickenson book so the AR's ran as "subs". Sounded great and I never looked back!
gedlee said:
I have found interesting source of information that allows for restarting the discussion
see: http://www.speech.kth.se/music/acviguit4/
aa academic handbook from the Swedish Royal Institute of Technology
I think it is quite credible and authoritative source
as to the content of those parts of the book I refer to:
1) symphony orchestra peaking at 127 dB @1m seem to be an example of "High Level Music". The SPL was calculated from acoustic power measured at 1 m (it was 60W). In comparison bass singer fortissimo is 0.03 W of power and 94 dB SPL at 1 m
2) "inverse square law" practically does not apply in case of domestic listening rooms:
thus even in a really big listening room the critical distance is about 0.8 m
my conclusion: "inverse square law" practically does not apply in case of domestic listening rooms
3) the reverberation field can add more than 6 db to the sound source SPL and the SPL differences from the same sound source between big and small rooms can be >10 dB:
note a difference of 16 dB (sic!) between SPL in a small listening room and concert hall
note that bass singer fortissimo is 86 dB at an auditorium of a philharmonic hall
I wonder if we can apply the same calculation to full orchestra fortissimo?
This would give 119 dB SPL - a result close to results cited by Everest after Fiedler, that is 122 dB SPL full orchestra fortissimo in case of symphonic music with percussion, and 113 dB without percussion
on the other hand the Swedish authors conclude from their own research (the levels are for positions within the orchestra):
I think that we can safely assume that peak levels on the auditorium would be around 120 dB for music with percussion and 110 dB without percussion
thus for symphonic music without percussion to reproduce the peak levels experienced at the auditorium of a philharmonic hall what is needed is about 100 dB @1m from one stereo channel
(about 7 dB is taken on account of reverberant field and 3 dB on account of that the two channels are working)
in case of amplified music especially rock music I would like to restate what I have already written:
noise threshold is very important because human hearing is sensitive to relative SPL
so the lower the ambient noise the less dBs is needed for the same loudness
BTW this was confirmed couple of times in this thread by Salas:
now see also: http://www.chs.ca/info/noise/book3.html
130 dB at a rock concert is something very different from 130 dB in a quiet listening room
as to the Salas calculation that:
in the light of foregoing considerations it seems to be incorrect
to have "110 dB max peak headroom at 3m" we only need about 100 dB "per stereo speaker capability"
+3 dB is from both channels playing and about +7 dB from reverberant field
as to Pan comment that:
I did some measurements with digital peak/RMS level meter and an uncompressed recording of "Mars" from Holst’s "Planets" from Tacet test CD "My Audiophile companion"
the recording starts off with background noise at around -65 dB average/-55 peak, after the pianissimo music starts the levels rise to around -55 dB average/-45 peak
max levels at the fortissimo finale are -12.5 dB average/-0.5 peak
thus the real dynamic range of uncompressed classical music recording is around 70<60 dB, this is max of what We can get from CD
on the other hand and according to the Swedish textbook quoted above:
thus we can assume that the background noise in a quiet listening room can be compared to the concert hall (especially in the presence of the audience in the latter)
this noise standard for " living rooms" is consistent with results my own measurements of background noise in my listening room (well below <40 dB(A) )
this noise level of 30-40 dB in a quiet room and a dynamic range of CD of 60-70 dB above the noise gives us 100 dB SPL representing full dynamic range of uncompressed CD
comments welcome 🙂
best,
graaf
A decent analysis, that is not that far from what I claim, with one exception. Your +7 dB for the reverberant field is a bit high and your calculations are all based on monopole excitation. With my speakers I have almost 9 dB of DI which moves the reverberant distance out almost to the listener and so the reverberant addition would be 3 dB at the most and could even be less. This would push even your numbers up closer to what I was claiming.
And, I think it unfair to add 3 dB for two channels since this would assume that the instruments are playing in BOTH channels. This is a bad assumption - so take away that 3 dB.
My calculations never add (or subtract depending on what you are talking about) for the reverberant field or two channels. This is where we differ. Otherwise we are pretty much in agreement.
And, I think it unfair to add 3 dB for two channels since this would assume that the instruments are playing in BOTH channels. This is a bad assumption - so take away that 3 dB.
My calculations never add (or subtract depending on what you are talking about) for the reverberant field or two channels. This is where we differ. Otherwise we are pretty much in agreement.
Re: Re: SPL targets for speaker design
In a living room you will never get +7dB. About +1.5dB from 1k to 3k for stereo sources is all I have measured in 25-40m2 living rooms.
The inverse square is truncated to -5db per doubling of distance in my example in a domestic environment bcs that is all I have measured. That and the +3dB for stereo, it was calculated in my paradigm.
By any means, if it was an absurd calculation, Dr. Earl Geddes would have protested immediately!😀
graaf said:
In a living room you will never get +7dB. About +1.5dB from 1k to 3k for stereo sources is all I have measured in 25-40m2 living rooms.
The inverse square is truncated to -5db per doubling of distance in my example in a domestic environment bcs that is all I have measured. That and the +3dB for stereo, it was calculated in my paradigm.
By any means, if it was an absurd calculation, Dr. Earl Geddes would have protested immediately!😀
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