Creating bass weight and impact?

[kemmler3D]

There's been a lot of discussion in this post about what marginal factors might create bass impact... but let's not neglect that the original post said the SPL was as much as 30dB different between home and the concert venue. +20dB is something you'll feel 10x more even if it doesn't sound 10x louder.

I can imagine coherence of wavefronts and room modes being factors too, but sheer SPL seems likely to be the biggest factor here.

 

[ooheadsoo]

That would be at the threshold of pain, and I feel like it's not even desirable at home. Real snare rim shots feel like being able to crack your skull.

I've felt this heart grip impact even at moderate SPL in concert halls, so at least in my experience, it doesn't necessarily have to be loud.

I don't want to talk about being close to drum kits. I had forgotten my ear plugs last week and was kicking myself.

 

[Mr. Widget]

There's been a lot of discussion in this post about what marginal factors might create bass impact... but let's not neglect that the original post said the SPL was as much as 30dB different between home and the concert venue. +20dB is something you'll feel 10x more even if it doesn't sound 10x louder.

I guess it depends on the concert and your home playback. Most concerts that I have attended are rarely louder than 105dBC for any period of time.

I just played the Jazz Variants cut at what I considered to be realistic level and it measured 101.6dBC on the loudest peak. Yes, you do hear the "room" around the tympani, but I have never heard a tympani in a really dead space so they seem "right" to me. The big bass drum? Who knows... they pretty much just go boom, but in a pleasant way.

I also played a snippet of a rock drum intro. The first 7 seconds of Staind "Can't Believe" from Break the Cycle. This I raised the volume to 106.2 dBC peaks and it was like being near the stage in a small venue. Extremely loud, but pretty credible drum sound. If I still had my DD67000s the impact would have been just a bit greater, but my DIY speakers in my 24' 6" by 16' by 12' listening room did a surprisingly good job.

Luckily that drum intro is only 7 seconds long... I don't appreciate that level of aural assault for any extended period of time. I personally find the mass of distorted guitar that follow the drum intro is really unpleasant, though I imagine there are those head-bangers who would enjoy it.

 

[Kvalsvoll]

Those of you who have genuine impact, could you measure how loud you have to play for it to be sensed?

I have actually measured this, some time ago. Looks like around 85-90dB, from 10hz to 200hz. Frequency response is nearly flat, so that there is a difference about 30dB from threshold of hearing up to "feeling" from 100hz up, reducing to very close to hearing at the very lowest freq.

With music, practical listening, peak levels around 110dB should produce a quite noticeable and nice punch. But still somewhat noticeable at even lower spl, say 90-100dB peak.

What kills this, with music, is speakers that compress (peaks lost..), non-linear phase response, excessive frequency response deviations.

 

[Sokel]

Those of you who have genuine impact, could you measure how loud you have to play for it to be sensed?

About there (or higher) :

 

[neRok]

I personally find the mass of distorted guitar that follow the drum intro is really unpleasant, though I imagine there are those head-bangers who would enjoy it.

Is the impact the same whilst the guitars are going though?

I've found in the past when my room was totally untreated that solo+slow drums like that can sound good, but when the same beat occurs during the song it can get "drowned out". Maybe it's the actual mix, but I'm more inclined to believe it's room modes ringing and sound not decaying fast enough. I think decay is a problem when the beat is fast because there isn't time between notes for the energy to dissipate (how can you feel the next beat is the previous one is still bouncing around in the room), and that ringing modes are a problem when for example the drum is at 80Hz, a mode at 100Hz, and a guitar at 120Hz. In that situation the guitar can keep the mode energised, so the drum has less impact, but when the drum plays solo, it is charging the mode.

Edit: It may also be speaker related - distortion/IMD/etc. I've seen posts on this forum of people talking about their 2 ways and saying stuff like "my speakers go good on most of my music, but songs like this are at their limit", and then I listen to that song and it's pretty basic compared to my collection (like in bottom 20% of fullness/intensity). I remember when I bought my first bookshelf speakers many years ago, I was trying different speakers in the store and after listening to only 20 sec of music so many just seemed straight up incapable. So maybe there is something to that too.

 

[Mr. Widget]

Is the impact the same whilst the guitars are going though?

I've found in the past when my room was totally untreated that solo+slow drums like that can sound good, but when the same beat occurs during the song it can get "drowned out". Maybe it's the actual mix, but I'm more inclined to believe it's room modes ringing and sound not decaying fast enough. I think decay is a problem when the beat is fast because there isn't time between notes for the energy to dissipate (how can you feel the next beat is the previous one is still bouncing around in the room), and that ringing modes are a problem when for example the drum is at 80Hz, a mode at 100Hz, and a guitar at 120Hz. In that situation the guitar can keep the mode energised, so the drum has less impact, but when the drum plays solo, it is charging the mode.

I think you are onto something there. On that particular cut the wall of distorted guitar and crushed and distorted singing is so dense it is hard to hear anything distinctly. I might have appreciated this sort of thing when I was a teenager, but the distortion/noise content is just too high for my last and I certainly can't stand it turned up to 11.

 

[Mr. Widget]

I have actually measured this, some time ago. Looks like around 85-90dB, from 10hz to 200hz. Frequency response is nearly flat, so that there is a difference about 30dB from threshold of hearing up to "feeling" from 100hz up, reducing to very close to hearing at the very lowest freq.

With music, practical listening, peak levels around 110dB should produce a quite noticeable and nice punch. But still somewhat noticeable at even lower spl, say 90-100dB peak.

What kills this, with music, is speakers that compress (peaks lost..), non-linear phase response, excessive frequency response deviations.

10Hz? I agree that you need some VLF extension, but the DD67000s do not go below about 40Hz and with the right content they still sound dynamic as all get out like live music.

Earlier I mentioned the Radio Shack Mach Ones and my own Meyer Sound Ultra-X22s... both will get loud but do not give you that "nice punch". The Ultra-X20s do not compress and will play at true lease breaking levels, but they just don't have the weight that some larger systems have.

I agree that you need a well integrated and fairly extended bottom end, but as others on this thread have suggested I think the upper bass has to be supported by a certain amount of displacement and possibly a large baffle.

It is interesting. Floyd Toole and Harman have helped us narrow down a lot of factors required for excellent in home reproduction, but I am not aware of any of their work exploring why a Revel M106 with properly integrated sub can't compete with the visceral presentation of a K2-S9900 plus sub.

 

[Kvalsvoll]

10Hz?

That number is just to describe the test procedure, the tested frequency range was from 10hz up to 200hz. 10hz has no purpose for any normal music reproduction, and even for sound effects the usefulness diminishes below around 15hz.

It is the lower mid and upper bass that creates the sharp, rock-solid attack, >100hz, while weight is lower down, around 30-50hz. So a large speaker with decent capacity and a roll-off around 40hz can still provide a weighty punch on large drums.

Weighty.. try Infected Mushroom, Avratz. Feels like a windy, powerful push on a decent system.

 

[neRok]

It is the lower mid and upper bass that creates the sharp, rock-solid attack, >100hz

Perhaps @Mr. Widget can do a test with a 100Hz highpass applied to his speakers, and see if he still has impact. Will that be an effective test, or could the HP negatively affect the signal and thus any impact >100Hz?

I just tried listening to Judas Priest - Painkiller with and without my sub. My speakers in room have a null at ~80Hz, so I'm crossing to sub at ~100Hz (just above the null), and since reading this thread I've been running my sub +10dB when listening <100dB. With sub on I was getting nice "desk rumble" at ~95dB, and with it off I was getting nothing. I then turned the speakers up 10dB (so ~ SPL matched to sub) and there was a tiny bit of desk rumble. Like I said before, I don't really have body impact at my desk, but whatever I do have I had less with just the speakers doing only 100Hz and above.

Also just before I saw this live version of Painkiller that starts with a longer drum solo and sounds really good. I was listening at 105dB LZpeak in SPL logger and I think I was just getting some actual impact from it. I must be on the cusp of good impact in my room, I think my 80Hz hole is holding me back right now. I need to get around with trying different sub placement, and even though it will affect my "triangle" I am thinking of moving the speakers back in closer too to get physically closer to them too. Unfortunately my 48" monitor is really affecting my speaker placement.

 

[audiofooled]

It is the lower mid and upper bass that creates the sharp, rock-solid attack, >100hz, while weight is lower down, around 30-50hz. So a large speaker with decent capacity and a roll-off around 40hz can still provide a weighty punch on large drums.

Weighty.. try Infected Mushroom, Avratz. Feels like a windy, powerful push on a decent system.

That's a nice way of putting it and I agree. And yes, Infected Mushroom has a number of tracks with this powerful attack and weight.

The example of electronic track I provided earlier shows on the frequency spectrum that the peaks that are at 40Hz and lower are many dB higher than above 100Hz and subjectively this track has it's weight felt at really moderate levels. It is the transition from loud to very loud that sums up the attack, impact and weight at all frequencies. So I guess there is something in it that system needs to follow the signal without power compression and reach low enough in extension. Actual SPL levels for subjective tactile feel may vary but for smaller systems, going this many dB higher in output as the frequency gets lower may be a bit of a stress.

 

[Sokel]

Let's be practical.
I took this one who has some good punch along with a nice prominent bass as base:

(fight the urge to dance like a bear to it )

Then I threw it into REW to see where the bang is:




So,50-300Hz for the main bulk with the peak around 80-120Hz.
That's the whole deal.

 

[Kvalsvoll]

Perhaps @Mr. Widget can do a test with a 100Hz highpass applied to his speakers, and see if he still has impact. Will that be an effective test, or could the HP negatively affect the signal and thus any impact >100Hz?

I just tried listening to Judas Priest - Painkiller with and without my sub. My speakers in room have a null at ~80Hz, so I'm crossing to sub at ~100Hz (just above the null), and since reading this thread I've been running my sub +10dB when listening <100dB. With sub on I was getting nice "desk rumble" at ~95dB, and with it off I was getting nothing. I then turned the speakers up 10dB (so ~ SPL matched to sub) and there was a tiny bit of desk rumble. Like I said before, I don't really have body impact at my desk, but whatever I do have I had less with just the speakers doing only 100Hz and above.

Also just before I saw this live version of Painkiller that starts with a longer drum solo and sounds really good. I was listening at 105dB LZpeak in SPL logger and I think I was just getting some actual impact from it. I must be on the cusp of good impact in my room, I think my 80Hz hole is holding me back right now. I need to get around with trying different sub placement, and even though it will affect my "triangle" I am thinking of moving the speakers back in closer too to get physically closer to them too. Unfortunately my 48" monitor is really affecting my speaker placement.

100hz hp will not destroy the signal, it just removes all bass. And all weight, and most of the impact. A snare drum may survive, sort of, anything larger will fail.

Moving things around can change impact, because frequency response is affected, and also the energy/power in the sound field. At higher f, say >80hz, frequency response and phase and capacity matters, at low frequencies energy becomes more important, of course also capacity and phase still matters.

 

[audiofooled]

Another thing that comes to mind would be one particular issue when it comes to amplification and power demand. I've found a practical example as seen on this video a while ago:

And here it is, the track so heavy on the power demand:

Frequency spectrum:

In the video, peaks around 50Hz are already showing high power demand, but to me the waveform with the peak at 34Hz is much more interesting here. On the video, at about 4:28, you may see the woofers on those Harbeths showing some excursion peaks, perhaps they are a bit lower than port tuning.

Here is a zoom in on one of the waveforms (they are a bit different for each passage, also showing difference for the left and right channel, so stereo bass):

The point is, if your system has some difficult phase angles between voltage and current demand, I'm sure this track will find it. By the looks of it, I'm not even sure if this should be legal

Subjectively, these low frequency peaks have both weight, because of the low frequency, and impact because of the waveform summation at MLP. But the impact is so slow that it's just passing through my body, either pushing it or pulling it ever so slightly, depending on the waveform of the passage. I find this track a bit weird, but also very clever and unique.

If some of you people having multiple subs care to try it, I would like to hear your thoughts on this.

 

[Sokel]

Another thing that comes to mind would be one particular issue when it comes to amplification and power demand. I've found a practical example as seen on this video a while ago:

And here it is, the track so heavy on the power demand:

Frequency spectrum:

View attachment 334780


In the video, peaks around 50Hz are already showing high power demand, but to me the waveform with the peak at 34Hz is much more interesting here. On the video you may see the woofers on those Harbeths showing some excursion peaks, perhaps they are a bit lower than port tuning.

Here is a zoom in on one of the waveforms (they are a bit different for each passage, also showing difference for the left and right channel, so stereo bass):

View attachment 334783

The point is, if your system has some difficult phase angles between voltage and current demand, I'm sure this track will find it. By the looks of it, I'm not even sure if this should be legal

Subjectively, these low frequency peaks have both weight, because of the low frequency, and impact because of the waveform summation at MLP. But the impact is so slow that it's just passing through my body, either pushing it or pulling it ever so slightly, depending on the waveform of the passage. I find this track a bit weird, but also very clever and unique.

If some of you people having multiple subs care to try it, I would like to hear your thoughts on this.

I have post this track many times (also in the bass thread) as some other tracks which are interesting as these people play with the extremes.
Now comes the funny stuff.
My amps for lows (under 250Hz) are 2x600 watt (at least that's what Amir measured in the crippled Peachtree version) and 2x 300watt for mid-highs.

It's easy to sweep them and I have done so to see and measure.
There must have been some measurements I did here that show the elevated distortion of the smaller ones but that's not the whole story.
The story is I have never seen the big one clip (they both have indicators) the smaller one clipped silently and happily lots of times during my test tracks and that's not with WOW levels,just high-ish.

 

[Sokel]

Another thing that comes to mind would be one particular issue when it comes to amplification and power demand. I've found a practical example as seen on this video a while ago:

And here it is, the track so heavy on the power demand:

Frequency spectrum:

View attachment 334780


In the video, peaks around 50Hz are already showing high power demand, but to me the waveform with the peak at 34Hz is much more interesting here. On the video, at about 4:28, you may see the woofers on those Harbeths showing some excursion peaks, perhaps they are a bit lower than port tuning.

Here is a zoom in on one of the waveforms (they are a bit different for each passage, also showing difference for the left and right channel, so stereo bass):

View attachment 334783

The point is, if your system has some difficult phase angles between voltage and current demand, I'm sure this track will find it. By the looks of it, I'm not even sure if this should be legal

Subjectively, these low frequency peaks have both weight, because of the low frequency, and impact because of the waveform summation at MLP. But the impact is so slow that it's just passing through my body, either pushing it or pulling it ever so slightly, depending on the waveform of the passage. I find this track a bit weird, but also very clever and unique.

If some of you people having multiple subs care to try it, I would like to hear your thoughts on this.

Found the measurement,dirty and sloppy with REW of course but the spike down low is evident (f3 of my speakers is 31Hz so anything lower than that is insignificant and are active between low mids and passive between mid-highs.)
Serious companies that give lots of power low know what they're doing.

Topping LA90 Review (Integrated Amplifier)

I just did a sloppy test just for fun.The measurements are taken in the listening position 2.8 meters far all other things been equal,the only thing I switched was the amps.Have a look at the distortion (all the chain plus room,thats why I said sloppy).I think power has a lot to do with the...

www.audiosciencereview.com

 

[audiofooled]

Serious companies that give lots of power low know what they're doing.

Yeah, if you enjoy various genres of music, scale of power demand may go anywhere from a few peanuts and doomsday prepping, just in case you need it.

 

[audiofooled]

There's been a lot of discussion in this post about what marginal factors might create bass impact... but let's not neglect that the original post said the SPL was as much as 30dB different between home and the concert venue. +20dB is something you'll feel 10x more even if it doesn't sound 10x louder.

I can imagine coherence of wavefronts and room modes being factors too, but sheer SPL seems likely to be the biggest factor here.

In acoustic measurements (which I don't know much about), there are many aspects of the sound field which are expressed in dB, but measured by using different methods.

There is also sound intensity level which I think is more interesting for this discussion. There are also other measurements which in short overview of these books, may give a bigger picture of what else might be going on:

https://www.sciencedirect.com/topics/physics-and-astronomy/sound-intensity

This book in particular may contain some very interesting information:

https://www.sciencedirect.com/book/9780123914217/acoustics-sound-fields-and-transducers#book-info

About the book​

Description​

Acoustics: Sound Fields and Transducers is a thoroughly updated version of Leo Beranek's classic 1954 book that retains and expands on the original's detailed acoustical fundamentals while adding practical formulas and simulation methods.
Serving both as a text for students in engineering departments and as a reference for practicing engineers, this book focuses on electroacoustics, analyzing the behavior of transducers with the aid of electro-mechano-acoustical circuits. Assuming knowledge of electrical circuit theory, it starts by guiding readers through the basics of sound fields, the laws governing sound generation, radiation, and propagation, and general terminology. It then moves on to examine:

• Microphones (electrostatic and electromagnetic), electrodynamic loudspeakers, earphones, and horns
• Loudspeaker enclosures, baffles, and waveguides
• Miniature applications (e.g., MEMS in I-Pods and cellphones)
• Sound in enclosures of all sizes, such as school rooms, offices, auditoriums, and living rooms

Numerical examples and summary charts are given throughout the text to make the material easily applicable to practical design. It is a valuable resource for experimenters, acoustical consultants, and to those who anticipate being engineering designers of audio equipment.

Key Features​

• An update for the digital age of Leo Beranek's classic 1954 book Acoustics
• Provides detailed acoustic fundamentals, enabling better understanding of complex design parameters, measurement methods, and data
• Extensive appendices cover frequency-response shapes for loudspeakers, mathematical formulas, and conversion factors

And in the first link (the right column) there's short overview of this book containing some metrics with different logarithmic expressions and different reference quantities, but are also expressed in dB's.
___________________________________________

Acoustic power level (PWL)​

The acoustic power level of a sound source, in decibels, is 10 times the logarithm to the base 10 of the ratio of the acoustic power radiated by the source to a reference acoustic power.
In most countries, Wref is 1 pW (i.e., 10−12 W). This means that a source radiating 1 acoustic watt has a power level of 120 dB.

Band power level (PWLn)​

The band power level for a specified frequency band is the acoustic power level for the acoustic power contained within the band. The width of the band and the reference power must be specified. The unit is the decibel. The letter n is the designation number for the band being considered.

Band pressure level (BPLn)​

The band pressure level of a sound for a specified frequency band is the effective sound pressure level for the sound energy contained within the band. The width of the band and the reference pressure must be specified. The unit is the decibel. The letter n is the designation number for the band being considered.
____________________________________________

So there is pressure, there are levels, there are intensities, there are also some dimensionless metrics, different ratios, etc. I would say the science is very complex and who knows what is similar and what is so much different outdoors, and indoors in large venues or in small room acoustics. I'm not even sure if the same measured quantity would have the same subjective loudness or if it would feel the same on different systems, distances and locations. Many metrics of sound pressure say that 120 dB is the threshold of pain, but at what frequency or frequency band? Higher frequencies are containing more energy because they are, well, more frequent... But we feel low frequencies as more intrusive to the body and less to our hearing because our hearing is also logarithmic.

Low frequencies having wavelengths very long relative to the thickness of the wall, are bumping into it, reflecting internally and passing on the other side with relatively small attenuation. Our bodies acoustic impedance in soft tissues in not very different from that of water, reaction to sound pressure (or perhaps intensity) is level and frequency dependent and is affecting us in all sorts of ways.

 

[audiofooled]

Found a very interesting video where "Big Mick" Hughes touches this kind of subject:

Apparently it's not all about SPL (I'm sure he'd always been well equipped to be able to deliver ridiculous levels) and subs can compensate for what's "lost" with line arrays, that is, if they are made for such purpose? I don't know anything about live sound, but I suppose then the subs would have to be crossed higher?

 

[ooheadsoo]

The frequency range doesn't seem out of the ordinary: