Hi, it’s me again, sorry, but there is another subject to ask for experience feedback and to complement others threads.
A mate already post one correlated thread, but it has a different point of view
How LOW should we go... For Music and for Movies ?
The lack of human ear linearity (Loundness) is very well known since long time, and, this lack diminish once you increase the SPL, but it will never get completely flat.
Direct link: https://s26.postimg.org/y8f1n8tll/loundness.png
There are many studies that correlates the low frequencies with people happiness while listening music, there are also some studies that correlate low frequencies with how humans recognize music rhythmic and this is one of the reason why we want to move our body and dance.
There is also many studies trying to understand how our mind/body recognize some aspects of the sound => The Psychoacoustic (like illusionism we can say that it's real, but it's just a smart tricky)
As engineer we always like to discuss about numbers, and we can’t argue against them (thanks David McBean), we also like to discuss about how flat the loudspeakers response is, we search for efficiency, we dream with extremely low frequency reproduction, etc., but probably when we set up a PA system for ordinary people listening it and gives a feedback about how they fill things may change. Power supply can also put some limits, budget, etc. Nothing is ideal.
Phrase from MaxxBas paper:
"We can achieve impressive performance under a tight budget. With psychoacoustic bass enhancement as part of the design process, system designers will be able to maximise the balance of performance and efficiency"
So, what is your “rule of thumb” related to low frequencies to make people happy?
Minimum XX Hz @ XXX dB @ X m ?
If the music don’t have XX Hz at the original track, will you add Bass Synt?
Do you like to set up the Low frequencies X db higher them the other ones?
Is the sentence below the key characteristic to focus on?
A mate already post one correlated thread, but it has a different point of view
How LOW should we go... For Music and for Movies ?
The lack of human ear linearity (Loundness) is very well known since long time, and, this lack diminish once you increase the SPL, but it will never get completely flat.
An externally hosted image should be here but it was not working when we last tested it.
Direct link: https://s26.postimg.org/y8f1n8tll/loundness.png
There are many studies that correlates the low frequencies with people happiness while listening music, there are also some studies that correlate low frequencies with how humans recognize music rhythmic and this is one of the reason why we want to move our body and dance.
There is also many studies trying to understand how our mind/body recognize some aspects of the sound => The Psychoacoustic (like illusionism we can say that it's real, but it's just a smart tricky)
As engineer we always like to discuss about numbers, and we can’t argue against them (thanks David McBean), we also like to discuss about how flat the loudspeakers response is, we search for efficiency, we dream with extremely low frequency reproduction, etc., but probably when we set up a PA system for ordinary people listening it and gives a feedback about how they fill things may change. Power supply can also put some limits, budget, etc. Nothing is ideal.
Phrase from MaxxBas paper:
"We can achieve impressive performance under a tight budget. With psychoacoustic bass enhancement as part of the design process, system designers will be able to maximise the balance of performance and efficiency"
So, what is your “rule of thumb” related to low frequencies to make people happy?
Minimum XX Hz @ XXX dB @ X m ?
If the music don’t have XX Hz at the original track, will you add Bass Synt?
Do you like to set up the Low frequencies X db higher them the other ones?
Is the sentence below the key characteristic to focus on?
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Anywhere between 8db and 12db boost around 28hz, Q between 1 and 2.
Or two EQ points: 23-25hz and 32-35hz that joins together.
Everything else can be flat on a pink noise and sound pretty good, but that boost makes most music/movie more enjoyable, IMO. Except when the fundamental hits right on the spot, then it's too loud, but rarely annoying.
Anything lower is useless and/or difficult to achieve with most speakers.
Anything higher will sound boomy or downright bad.
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Dear Lord
-1) The MaxxBass psychoacoustic bass enhancement adds harmonics giving the impression of missing fundamental frequencies being there, but is not at all the same as the feeling one can get when the fundamentals are as loud as the harmonics would suggest.
2) There is no formula for “fun”, no requirement of high SPL for people to dance, and no guarantee that any two random people will have the same reaction to bass unless they have become accustomed to it.
3) Not unless I want to, and I seldom would want to unless the original recording (or instrument) was exceptionally deficient.
4) As the equal loudness contours suggest, the lower the listening level, the less sensitive the ear is to low frequencies. If listening far below the level the music was intended to be played at, I may choose to engage a “loudness contour”.
5) Amplified dance and R&B music has been chest bass oriented with emphasis on the kick and bass guitar for around 6 decades now, and live drums and dance go back 30 or 40 thousand years. Although Taiko drums go loud and very low with content down into the sub 20 Hz range, most folks have been perfectly happy dancing for millennia with “chesty” drums with fundamentals in the 60 to 160 Hz range.
Cheers,
Art
While a lot of us have been repeating that theory for years, I can't say as I've ever read anything testing how the "psychoacoustic" effect compares to the real bass. Anybody have a link?
The "sensitivity" is the bottom curve. You mean "perceived loudness".
B.
All good points. Everybody should explore what they like for their own "house curve".
I once had a very trick pre-amp with what is called a "four pot" loudness compensation that really could be made to track the Fletcher-Munson world of nested correction. Turns out, it really did prove to be a pretty reliable guide for late-night levels.
While there's no denying "de gustibus non est disputandum", I think the only scientifically interesting question is what curve results in judgments of realism*, not what is fun.
B.
*not sure in what possible senses Brahms' Deutsches Requiem would be "realistic" in my little music room. Heard 100+ voices, orchestra, and pipe organ last night at TSO. Clocked in at 95dB(C) fast.
Yes.
F&M curve (or the latest update in 2003) is ... an average.
What can be found very useful is a grey noise.
Here is what i think to be the only online generator:
Online Grey Noise Generator | Hearing Calibrated
...unfortunately, only 10 bands.
- had a MaxxBass box -- lasted about 3 weeks - IIRC there was ~6dB boost besides the added harmonics - those reminded me of open baffle bass - the system had no bass to begin with and the effect might not make one get up and dance with such a system. Extended/clean bass with some recordings will make the speakers "disappear" and give better feel of room ambiance (if any in the first place)
here's one old plot of a Maxxbass, in-room on a folded horn - you can see it kicked the 2nd and 3rd harmonics up 20dB or so. I listened to it only on a little Karlson enclosure. The box purchased new, crapped out after `3 weeks with no warranty.
the processor also had some LF boost - here's a rough comparison on music
the processor also had some LF boost - here's a rough comparison on music
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I agree with the equal loudness contours. In the 90's I was going all out on a car audio system for SQ. I had 1/3 octave EQs, crossovers, and noise gate. I spent weeks adjusting and tweaking the gains and EQ by ear. Then I took the car to a shop with an RTA. The measurements looked similar to the equal loudness contour. I marked all the adjustments then readjusted for a flat response on the RTA. Looked great on the RTA, but sounded really bad with music. It was unlistenable. We adjusted everything back to where I had it and used the RTA to fine tune from there.
Nowadays I use REW and a calibrated mic to check my work. I adjust by ear first then use REW to find any problems.
Regards,
Matt
Nowadays I use REW and a calibrated mic to check my work. I adjust by ear first then use REW to find any problems.
Regards,
Matt
I use a variety of music from Heavy Metal to Classical, mostly songs or music that I'm very familiar with.
"Sensitivity" is not synonymous for "hearing threshold". So the term "the lower the listening level, the less sensitive the ear is to low frequencies" is absolutely equivalent to "perceived loadness" of low tones.
That's it exactly. It's a common misconception that the "non-linearity" of human hearing would need "correction". It does not. It's not until a known sound is played at a level substantially lower (or higher) than natural that our hearing get's confused.
And even if we apply a "perfect" loudness contour, the result is still just playing tricks to our mind. A well known sound played back at 40 dB SPL but corrected to a perceived loudness like it would have a SPL of 80 dB is not "correct". It just sounds more pleasing. So it is about fun, not realism, because there is no "real" archetype.
At some point I used Audacity to calculate the spectrums of various recorded music. This showed me there is very little content below 40Hz. Perhaps there's not a whole lot of musical content there to begin with. If there was something there, I suspect recording engineers are filtering it out. I'm sure you could find some examples where there's some meat down low, but I don't think it's very common.
I have used a subharmonic synthesizer for a long time now. This can sound good if used in moderation. First, I used a AudioControl PCA, then a DBX Driverack PA, then briefly a Behringer EX1200, then in a Crown XTI 4002, then more recently a DBX 120a. This all spread out over ~20 years now. Older recordings benefit from it more than newer stuff. For instance Dire Straights Sultans of Swing comes to mind. There's not a lot of punch and weight in there to begin with, but a sub synth can add some. Too much, or using it on too high up in frequency can cause things to sound "growl-y". Some older older stuff like Jimi and Led Zeppelin are beyond repair. There's not enough low stuff for a sub-synth to work with.
I find 35Hz sufficient for bass happiness now. My home sub goes down to 25Hz nicely, but I don't think it's necessary. For PA use I don't think it's worth the extra size/power/efficiency tradeoff to do much below 40Hz. Getting the chest slamming ~60Hz right is likely more useful. (Human chests have resonant frequencies typically around 60Hz). Extension down to ~40Hz provides a nice sense of "weight".
I'm currently interested in working towards killing off group delay and phase whackness. With modern DSP this should be do-able (either with FIR, or split-band processing with delays and PEQs), at least in a home environment w/ recorded music where ~50ms of latency is perfectly acceptable. For PA, it likely becomes a problem somewhere around 15ms.
In home room modes are a nuisance and significantly detract from bass happiness. The best I've ever heard my system was outdoors.
I have used a subharmonic synthesizer for a long time now. This can sound good if used in moderation. First, I used a AudioControl PCA, then a DBX Driverack PA, then briefly a Behringer EX1200, then in a Crown XTI 4002, then more recently a DBX 120a. This all spread out over ~20 years now. Older recordings benefit from it more than newer stuff. For instance Dire Straights Sultans of Swing comes to mind. There's not a lot of punch and weight in there to begin with, but a sub synth can add some. Too much, or using it on too high up in frequency can cause things to sound "growl-y". Some older older stuff like Jimi and Led Zeppelin are beyond repair. There's not enough low stuff for a sub-synth to work with.
I find 35Hz sufficient for bass happiness now. My home sub goes down to 25Hz nicely, but I don't think it's necessary. For PA use I don't think it's worth the extra size/power/efficiency tradeoff to do much below 40Hz. Getting the chest slamming ~60Hz right is likely more useful. (Human chests have resonant frequencies typically around 60Hz). Extension down to ~40Hz provides a nice sense of "weight".
I'm currently interested in working towards killing off group delay and phase whackness. With modern DSP this should be do-able (either with FIR, or split-band processing with delays and PEQs), at least in a home environment w/ recorded music where ~50ms of latency is perfectly acceptable. For PA, it likely becomes a problem somewhere around 15ms.
In home room modes are a nuisance and significantly detract from bass happiness. The best I've ever heard my system was outdoors.
Good points.
Even with French organ music or side drums in Mahler, very rare to RTA content below 32 Hz. It is the movie special effects, players that want (and maybe can benefit from) lower.
As anybody who has worked with motional feedback can tell you, reducing "group delay" (a euphemism for awful hang-over) can be very beneficial. While this forum is obsessed with 10th-order boxes to produce eye-pleasing sims, not so much care for sound quality as reflected in other parameters. Ironic, with DSP EQ sure to be near universal soon, freq response is the easy parameter to get where you want it.
I doubt fussing with phase has much benefit and viewed from your ear, kind of geometrically illogical when you think about it. But the other timing issue is time alignment. Getting that in the ballpark (between subs around your room and the main speakers) was modestly beneficial for me.
What are you referring to with "50ms"?
B.
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With FIR filters, flat phase response of the system is possible, even eliminating group delay is possible, but to use FIR very low takes processing time, as much as 50 ms.
For playback, no worries, the song starts 50ms after you hit "play". With live sound reinforcement it's a problem when the PA lags live stage sound by much more than 15ms as it becomes perceived as a discreet echo.
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