For a long time I have been wondering - When is bass no longer bass?
What I mean is, as the frequency goes up, at what frequency do I no longer perceive Bass and instead start to hearing Midrange?
Equally, when to I stop hearing Midrange and start hearing Treble?
Then, how can this help us in the design of crossovers?
Eventually I decided to test it, so I started playing Test Tone on my computer, which has a mid-priced consumer grade stereo attached to it. I found that around 300hz, I lost all sense of bass in the tone. Then as I continued to step upward, I lost all sense of Midrange around 3khz.
Then I tried something similar on my considerably larger main stereo system and got similar results.
So, in summary, I heard the transition from Bass to Mid at about 320hz, and I heard the transition from Mid to High at about 3200hz.
But I really don't have enough data to determine if this is a constant, or just something that randomly happened to me.
So, while it is an imposition, I wondered of others could run the same test and give me THEIR impression of where they heard the transition. Of course, the amp and speakers you used would help frame this in perspective. And perhaps the room size.
Finding 1/3rd or 1/6th Octave test tone collections is not difficult. You can find them posted all over the Internet.
You findings don't have to match mine. They are what they are. But I though if we collected a few diverse samples, we might start to see a pattern.
If we see a somewhat consistent patter of when people hear the transition from Bass/Mid and Mid/High, that might lead us to give it more consideration when speakers are designed.
We seem to have a wide enough range of drivers available today, that if we fond a pattern, then we could design speakers using that information.
Today, Low-Bass/Mid-Bass/Tweeter seem far more common that the old fashioned Woofer/Midrange/Tweeter of the days of old. Are we naturally moving in the direction I suggest, or is that just coincidence?
Again, an imposition, but if we collected the impressions of a few people, like I said, we might see a pattern emerge, or we might see the idea of a pattern completely denied by the data.
However, if we could find a common range in which people perceive this transition, ...to me at least..., that implies we are finding the ideal places to cross speakers.
Just a thought.
Steve/bluewizard
What I mean is, as the frequency goes up, at what frequency do I no longer perceive Bass and instead start to hearing Midrange?
Equally, when to I stop hearing Midrange and start hearing Treble?
Then, how can this help us in the design of crossovers?
Eventually I decided to test it, so I started playing Test Tone on my computer, which has a mid-priced consumer grade stereo attached to it. I found that around 300hz, I lost all sense of bass in the tone. Then as I continued to step upward, I lost all sense of Midrange around 3khz.
Then I tried something similar on my considerably larger main stereo system and got similar results.
So, in summary, I heard the transition from Bass to Mid at about 320hz, and I heard the transition from Mid to High at about 3200hz.
But I really don't have enough data to determine if this is a constant, or just something that randomly happened to me.
So, while it is an imposition, I wondered of others could run the same test and give me THEIR impression of where they heard the transition. Of course, the amp and speakers you used would help frame this in perspective. And perhaps the room size.
Finding 1/3rd or 1/6th Octave test tone collections is not difficult. You can find them posted all over the Internet.
You findings don't have to match mine. They are what they are. But I though if we collected a few diverse samples, we might start to see a pattern.
If we see a somewhat consistent patter of when people hear the transition from Bass/Mid and Mid/High, that might lead us to give it more consideration when speakers are designed.
We seem to have a wide enough range of drivers available today, that if we fond a pattern, then we could design speakers using that information.
Today, Low-Bass/Mid-Bass/Tweeter seem far more common that the old fashioned Woofer/Midrange/Tweeter of the days of old. Are we naturally moving in the direction I suggest, or is that just coincidence?
Again, an imposition, but if we collected the impressions of a few people, like I said, we might see a pattern emerge, or we might see the idea of a pattern completely denied by the data.
However, if we could find a common range in which people perceive this transition, ...to me at least..., that implies we are finding the ideal places to cross speakers.
Just a thought.
Steve/bluewizard
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My guess is that the signal you test with will influence your choice.
Pink Noise, pure tones, music?
That said, your idea of 1/3 octave bands is a good start.
Pink Noise, pure tones, music?
That said, your idea of 1/3 octave bands is a good start.
Mathematically, the 1/3 and 2/3 points between 20 Hz and 20KHz are 200Hz and 2,000Hz. Which is only about .68 of an octave off from your subjective measurements. Fairly close.
My guess is that the signal you test with will influence your choice.
Pink Noise, pure tones, music?
That said, your idea of 1/3 octave bands is a good start.
As I mentioned, I have both 1/3rd Octave and 1/6th Octave. It works out about the same either way. So, I used test tone, and stepped through them until I heard what I perceived as a transition in the general character of the sound.
There are several place on the internet to get these test tones, just search Google. Though if you happen to be lucky enough to have a signal generator, so much the better.
Steve/bluewizard
Not cheap. 🙂
There is a point when the basses stop sounding separately, and become part of the chord. I have disposed of my scores (I know I'm not an asset to a choir any longer), but from memory it is around C below middle C.
The same goes for organ pedal notes and to double basses in a string orchestra.
It happens when listening live as well as on recordings. Must take note next time I'm in a modern concert hall to work out whether it's room acoustics, or the way we hear music, e.g. Symphony hall
Tricky business I'm engaged in here. I'm not interested in what some textbook tells me what is and isn't a bass note. I can find the frequency response of various instruments, human voice, the general perception of music by frequency ranges.
What I'm interested in is when and where the human ear hears a shift in the character of the Test Tone. As I stepped up the frequencies I could hear a characteristic of the tone shifting, at about 300hz, that characteristic that I perceived as bass was gone. Yes, it had been fading, but at about 300hz, I perceived it as gone, and I start to hear a new characteristic that I perceived as Midrange.
Here is an interactive Frequency Chart for various instruments. According to them, if you mouse over the graph -
Interactive Frequency Chart - Independent Recording Network
Sub-Bass is 16hz to 60hz
Bass is 60hz to 250hz
Midrange is 250hz to 2khz
High Midrange is 2khz to 4khz
High Frequencies are 6khz to 20khz
I'm not sure what happened to the frequencies between 4khz and 6khz. Maybe that is no-man's land. Though I suspect one or the other is a typo. I suspect High-Mid should go up to 6khz.
I don't disagree with this chart, but I'm more interested in what my ears tell me, and what the ears of other people tell them.
If I had to re-classify the above, I would say, regarding single generally full range speakers, that -
30hz to 200hz is low-bass, 200hz to 800hz is Mid-Bass, 800hz to 5khz is midrange, and above 5khz is high frequency. Though even that has its admitted flaws.
So, the point is, I can find various references that tell me what bass is and what bass is not, but I'm interested in what people's ears tell them.
I'm not really in a rush, I don't expect everyone to run out and do this tomorrow, but if it is enough to get your curiosity up, give it a try and tell us what you think.
Modern speaker designs seem to be leaning more toward Low-Bass, Mid-Bass, rather than the older Woofer, Midrange arrangement. I can see why that is, but is there an ideal place to crossover in a Low-Bas/Mid-Bass/Tweeter design?
Do I just try to match the crossovers to the drivers I have, or do I try to find drivers that fit what I perceive as ideal crossover location?
I do have a design in mind, but I doubt I will ever have the money or the tools to built it. Still a guy can dream.
For what it is worth.
Steve/bluewizard
Given that years of cobwebs drifting into my mind have made me mathematically challenged, could you possible tell me what the 1/3rd and 2/3rd points are if we start at 30hz instead of 20?
I know if I step upward in octave from 20hz vs doing the same starting at 30hz, the octave boundaries shift substantially.
The 3 octave boundaries for 20hz are 160hz and 1280hz then 10240hz.
If we start at 30hz, the 3 octave boundaries are 240hz, 960hz, and 15360hz.
If we assume 3 octaves bass, 3 octaves mid, and 4 octaves high, these would be the boundaries. Since in a single cabinet speaker system, 20hz is somewhat unrealistic, if we start at 30hz, we would cross at Low-Bass =< 240hz, and Mid-Bass =< 960hz, whether that realistically allows a crossover to high frequencies at > 960hz is difficult with anything but a large horn. Still, it might have potential. It is not that hard to find Mid-Bass drivers that are clean up to 1khz, the problem is finding a tweeter to serve this hypothetical design.
Thanks for the info.
Steve/bluewizard
Again, do you hear any bass or treble in a person's voice on the phone? Mine say no.
GM
Mathematically, the 1/3 and 2/3 points between 30Hz and 20KHz are 262.1Hz and 2,289.4Hz.
The lower frequency is 0.29 octave below what your subjective test showed, and the upper frequency is 0.49 octave below your subjective test. Pretty close agreement for an effect that occurs gradually.
According to the interactive Frequency Chart I posted, the fundamentals of a Male Voice are roughly 100hz to 1khz.
The fundamentals of a Female Voice are 300hz to a bit more than 1khz.
Interactive Frequency Chart - Independent Recording Network
That strikes me as a very narrow midrange with respect to speaker crossovers.
Primary harmonics in human voice can go up to about 8khz and secondary harmonics are in the range of 8khz to 16khz. As I interpret the graph.
Most existing 3-way Bass/Mid/High crossovers are in the range of 500hz to 800hz. The lowest I've seen in off-the-shelf crossovers is 375/3000hz.
I'm not sure about Low-Bass/Mid-Bass/Tweeter speakers. I suspect the crossover very much like a 2-way speaker, but have the addition of the Low-Bass driver, sometimes in Full-Way systems, and sometime in Half-Way systems.
Though the 3 octave span on most of these would take them much higher, most seem to cross the Mid/High in the 4000hz to 5600hz, with 5khz seeming the most common.
I have a pair of Wharfedale Diamond 9.6 which are 3.5-way with crossovers at 150hz, 1khz, and 6khz. I suspect that is a bit uncommon, but it seems to work. The Midrange is a 2" dome driver.
So, back to the main premise of this post. By your own judgement and by your own ears, at what frequency do you sense a clear transition between Bass and Mid, and between Mid and High?
I'm trying to determine if there is a consistent pattern to what we all hear, and if that pattern can be used to design speaker system crossovers?
Just a few thoughts.
Steve/bluewizard
I started out 'challenged' and been downhill ever since, but maybe this old post will help:
GM
=================
An octave is a 2:1 ratio, so 100, 200, 400, 800, 1600, etc. would each be a one octave (3dB) spread.
2^n = Fh/Fl
n = (m*log(Fh/Fl))/3.01
Fh = Fl*2^n
Fl = Fh/2^n
dB (change) = m*LOG10(Fh/Fl)
where:
Fh = upper frequency
fl = lower frequency, or the XO point in this case
n = octave spread
m = log multipler:
m = ((log10(log base))*delta dB)/(log(log ratio))
10 = 3.01dB
20 = 6.02dB
30 = 9.03db
40 = 12.04dB
50 = 15.05dB
60 = 18.06dB
70 = 21.07dB
80 = 24.08dB
Hi,
For wont of anything better as GM notes, The (very carefully
chosen) telephone bandwith of 300Hz to 4KHz is as close to
anything definitive as your going to get for bass/mid/treble.
Personally I'd say the split is bass/mid/presence/treble,
Bass is below ~ 300 Hz.
Mid is ~ 300Hz to ~ 1.5KHz.
Presence is ~ 1.5 KHz to ~ 6KHz.
Treble is above ~ 6KHz.
FWIW telephone voice quality improves a lot with an 8Khz top end and more bass.
But it goes down the pan at > 300Hz and < 4KHz, without the presence peak.
rgds, sreten.
For wont of anything better as GM notes, The (very carefully
chosen) telephone bandwith of 300Hz to 4KHz is as close to
anything definitive as your going to get for bass/mid/treble.
Personally I'd say the split is bass/mid/presence/treble,
Bass is below ~ 300 Hz.
Mid is ~ 300Hz to ~ 1.5KHz.
Presence is ~ 1.5 KHz to ~ 6KHz.
Treble is above ~ 6KHz.
FWIW telephone voice quality improves a lot with an 8Khz top end and more bass.
But it goes down the pan at > 300Hz and < 4KHz, without the presence peak.
rgds, sreten.
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Steve,
Thus far, you have been engaging in the "tricky business" of semantic differences of what various frequencies are called, while whether a certain bandwidth is called "bass" or "low mid", "hi mid" or "presence", makes no difference whatsoever to the transducers used to reproduce the pass band.
If crossovers are properly designed for the transducers employed (assuming adequate bandwidth of the transducers), the result is a flat frequency and phase response through the crossover region, the crossover points undetectable either by measurement or hearing, regardless of the crossover frequencies chosen.
The "ideal crossover location" is transducer dependent, and also level dependent, what may be a completely acceptable transition at low SPL can fall apart at higher levels if the transducers large signal response is not adequate for the SPL desired.
If money is short, just match the crossovers best as possible to the drivers you have, until you can afford something that satisfies all your audio desires.
Art
Hi,
For wont of anything better as GM notes, The (very carefully
chosen) telephone bandwith of 300Hz to 4KHz is as close to
anything definitive as your going to get for bass/mid/treble.
Personally I'd say the split is bass/mid/presence/treble,
Bass is below ~ 300 Hz.
Mid is ~ 300Hz to ~ 1.5KHz.
Presence is ~ 1.5 KHz to ~ 6KHz.
Treble is above ~ 6KHz.
FWIW telephone voice quality improves a lot with an 8Khz top end and more bass.
But it goes down the pan at > 300Hz and < 4KHz, without the presence peak.
rgds, sreten.
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