Discussion in 'Speakers' started by phil2009, Jun 24, 2009.
What brackets do they come under or in what range?
Oddly, no one really knows.
What any one person defines as low frequencies, or midrange frequencies, or high frequencies has as many variations as there are people to comment on it.
As a tangential discussion. this came up in one of the speaker building forums, and even people intimately familiar with building speakers couldn't agree.
In general, one could say any thing below 500hz is low frequency. Anything between 500hz and 2,000hz to 4000hz falls in the midrange, and anything above that is treble or high frequencies. But even in my own mind, that is not etched in stone.
There are 3-way speaker systems that cross over at 800hz. If a bass speaker, meaning a woofer, is handling a frequency does that automatically make it a bass frequency? I don't know for sure.
Now if I listen to test tones, what I perceive as bass-ish ends at around 200hz. I perceive based on listening to pure wave tones, that treble begins around 4,000hz. But that is more my perception than the rule.
Also, speaker design alters what people commonly perceive or label as bass, midrange, and treble. With standard straight forward 3-way speakers design, it seems simple. It is similar to what I described above. The bass speaker handles the bass, the midrange handles the midrange, and the tweeter handles the highs.
However, modern speakers are rarely standard 3-way speakers any more. Far more common are speakers that are not standard bass, midrange and treble, but low-bass, midbass, and highs. Or, to look at it another way, a standard 2-way speaker with an added low-bass driver. A person for whom a speaker like this is common, is going to perceive the low/mid crossover as being much lower, as is the mid/high crossover.
With the introduction of subs, it become even more difficult. With subs in the system, what a person perceives as low, mid, and high, is going to be more very low bass, midbass, and high. In this case, the low/midbass crossover is extremely low.
So, it is difficult to specify the ranges with exact boundaries.
The midrange is generally considered as the frequencies around 1000 Hz. Frequencies are a logarithmic scale: halving / doubling yields an octave, so if the midrange were two octaves, it would be 500-2000Hz. Low frequencies are generally defined negatively by saying that they don't exceed 1000Hz, with 500Hz as the typical maximal extent. Similarly high frequences don't typically drop below 2000Hz, with a 1000Hz limit.
Human hearing is 20Hz-20000Hz, degrading with age (more rapidly for males), so these two frequencies reflect the limits.
This yields the rule-of-thumb cutovers at 250Hz-500Hz and 2000Hz-4000Hz with a factor of 2 tolerance.
There is sometimes an attempt to match the frequencies with the woofer / midrange / tweeter design of 3 way speaker systems, but this is approximate at best.
Subwoofers try to cover the low end (20Hz-80Hz by definition, although many will go higher in practice to support smaller satellites). Supertweeters (above 20kHz ) are designed for the listening pleasure of your dog or pet bat, but you'll neverthless find claims of human perceptability.
See also the chart at Woofer - Wikipedia, the free encyclopedia.
I'm actually not 100% sure what your question really is, but hopefully we are addressing it.
I don't disagree with anything Mark said, he did an excellent job of covering it from a different perspective than mine.
As an potential example of Midrange, we might use the telephone as an example, since it is intended for voice and we would generally consider voice in the midrange.
The standard frequency response of the telephone is 300hz to 3400hz. So, that is generally midrange.
Since you asked this question in the Speakers forum, I have to assume it has something to do with speakers.
If you could expand on why you want to know, or how you plan to apply this information, we could probably give you more specific answer, but as it is, we are just guessing at the context.
I typically see it as follows:
sub bass : 0 > 100hz
mid bass : 80 > 500hz
mid range: 400 > 2khz
upper mid: 1 > 14khz
highs : 13 > 20khz
To my knowledge no one of any authority, like a standards organization, has actually clearly defined these ranges. Because of that, it is down to the opinion of each person and the context of the conversation, to determine what frequencies are classified where.
That said, I would make a modification to what MI55ION said, and do so without remotely implying that he is wrong.
It is hard for me to consider anything above about 6khz to be 'upper midrange'. The highest note on a piano is just under 4khz. Above this, there are virtually no fundamental notes, and certainly there are no musical instruments, to my knowledge, that can produce fundamental notes above 8khz.
So, I will make a modification to MI55ION's statement to more accurately fit my own mindset. Again, I'm not saying he is wrong, I'm just expanding the perspective based on my view of musical frequencies.
sub bass : 0 > 100hz
mid bass : 80 > 500hz
mid range: 400 > 2khz
upper mid: 1k > 6khz
high freq: 4k > 12khz
Very high freq: 10k > 20khz and above
Above 10khz we are moving out of the realm of first harmonics and into the realm of second harmonics and higher.
Again, it is not so much a matter of right and wrong, as your own perspective on the matter.
At least, laid out like this, you have a pretty good idea of the frequency ranges.
Just one man's opinion.
I was just wondering thats all cos the between the main driver and a tweater, there must be a set freq to crossover unless you can get diff tweaters that will go lower then others. But I cant see them going much lower cos there tiny things, and to be honnest I was amazed how clear and loud those things were when I ran high freq tones a few days ago, to see how bad my hearing was.
Heres another one, what are the freq range for tweaters?
There is no set crossover frequency. It is determined by the drivers.
You might find a woofer with a rated frequency response of 30hz to 5khz. But if you look at a frequency response graph you will see it starts to get flaky above 1khz. Though when properly tuned, they can be useable to roughly 2khz to 2.5hz.
LARGE horn tweeters can reach down very low. Back in they days of 15 inch woofer combined with high frequency horns in a 2-way system, it was not uncommon to see crossover at 500hz and 800hz. Usually a tweeter capable of a 500hz crossover, only went up to about 16khz.
Today, because of smaller woofers, it is common to see crossovers in the range of 1.2k to about 2.4k, though sometimes higher in a 2-way system.
Old style 3-ways typically crossed at 800hz and about 4khz.
New style 3-ways, more often than not, cross around 300hz to 500hz, and the mid/high cross is usually in the 2khz to 3khz range. As I said before, these are more of a standard 2-way with extended bass.
When you are building speakers from available parts, you have to select your drivers carefully, to make sure that not the rated response, but the real response overlaps. You place the crossover in this overlapping area, and it is what it is. You design the crossover to fit the speakers.
Keep in mind that speaker makers are also driver makers and designers. They control details and characteristic of the speaker that are beyond the do-it-yourself maker. If they need a bass speaker that has better midrange, they design a speaker to do that. But in doing so, they make it a very specialized speaker suited to one purpose in one design.
So, the selected drivers, more than anything, dictate where the crossovers must be. Though the designer has some general control of this in his design concept.
Having just thougt about it yeah, I would go along with that. Not sure why I considered 1khz > 14khz as upper mids but certainly, the higher frequencies kick in much earlier and I think you've got it spot on. I suppose the ultra high freq range you've added makes more sense too.
As I said:
Approximate was polite for may be right, may be roughly equivalent or may be totally rockers.
If you want to ask about dynamic speaker design, that's fine, but it's a totally different question and has nothing to do with frequency classification.
A cone or dome tweeter is generally considered to be anything not exceeding 3cm diameter (some sources stretch this to 3.8cm = 1.5"). This definition fails with ribbon, quasi-ribbon, radia planar and electrostatic technologies.
Generally a tweeter has a (maximal) range of 2000 - 20000 Hz, with the usual tolerance at the low end. A 3cm dome is limited to 2000Hz. The typical dome tweeter is 2.5cm.
Speaker sizes are always a compromise. Larger => deeper as it can move more air, but means greater mass. Greater mass => greater inertia => slower reponse => greater distortion at higher frequencies. Hence increasing the size effectively restricts the upper limit. Ribbon, quasi-ribbon, radia planar and electrostatic technologies avoid this dilemna by keeping mass down, allowing a single unit to handle both mid and upper frequencies.
Sorry if I got off the topic a tad their, but Im new to all this and its all very intresting stuff, and if it wasnt for you guys I would never changed to bookshelf speakers from pc speakers..
I'll add to my previous post by saying that while there are not fixed predetermined frequencies for crossover points, there are general ranges and guidelines.
For example in a 3-way, they usually try to make the midrange cover 3 octaves.
If the first crossover is at 500hz then the first octave is 1000hz, the second octave is 2000hz, and the end of the third octave is 4000hz. That's not that difficult or illogical. But let's look at what happens if we move the first crossover up slightly to 800hz (1st octave = 1600hz, 2nd octave = 3200hz, 3rd octave = 6400hz); 6400hz is pretty high for a midrange. That is starting to move into treble territory, so it is not uncommon to see these 3-way speakers crossing in the 4khz to 5khz range; 6400hz is just too high.
In two way, tweeter only reach down just so far, and woofer only reach up just so far, which leave a range in the middle where most woofer and tweeters will meet. If is down to the specific woofer and tweeter, but there is a range there between 1.5khz and about 3khz where most 2-ways will cross.
With midrange and tweeters, ideally, you usually want the crossover at least one octave, if not two, above the resonance of the midrange or tweeter. Again, that set a functional workable range for the speakers.
My point is that there are many factors and guidelines controlling the crossover frequencies. This is one of the areas that make home design of speaker incredibly complex.
I was just looking at these XTZ | Fullrange speakers • 99.36 White and thought they could easily make these into bookshelfs by just chopping the bottom off, as I can only use bookshelfs?
Another factor is the volume of air moved: the amount increases as he frequency decreases. This is why a high frequency cone/dome can be small and a low frequency cone needs to be large. The extent of the to-and-fro movement is another factor, especially with subwoofers.
There's another consequence of this. Assuming the same throw distance, we can see that two woofers of n cm moves the same volume as one speaker of sqrt(2)*n cm, or in simpler terms, a pair of 20cm woofers is the near equivalent of a 28 cm cone, but each has lower mass. We've effectively obtained an LF extension from midrange speakers. This allows "spouse-friendly" speakers only 19cm wide such as these Piegas (photographed with the grille removed) to yield reasonable bass from multiple 13cm drivers:
BTW, these speakers use a ribbon tweeter.
It doesn't work that way; the result of applying a saw will be to produce the most disgusting sound imaginable (actually, I can't imagine how disgusting it will sound). If you want bookshelf speakers, buy bookshelf speakers
You could save some money and just buy the top bit on it's own
XTZ | Bookshelf speakers • 99.26 White
What I mean is they could make them into large bookshelfs
XTZ do indeed make bookshelf versions of the 99.36; they have the model numbers 99.25 and 99.26. Click on Products -> Bookshelf Speakers on the XTZ home page for the full range.
you still dont have the 2nd driver tho
As I already explained:
If you want that extra driver, you have to give it the necessary cabinet volume. Merely reducing the cabinet volume results in it's sounding absolutely awful - or worse.
1. Sub Lows 20-100
2. Lows 100-250
3. Low Mids 250 - 500
4. Mids 500 - 1k
5. High Mids 1k - 5k
6. Highs 5k-10k
7. Super Highs 10k-20k
I like this organization because it cleanly breaks it up, you could go a few Hertz one way or another and still be right there is a 20 Hz crossover between 1&2 and up to a 4KHz blend between 6 & 7. And actually, our understanding of frequency is based on our own personal geometric location in space. So if you are short and weigh very little, the frequencies that resonate with you will be different than the ones that resonate with a body that is larger and takes up more resonant space.
Have you made all that up?
How can "sub sonic" be 0-100Hz, when people can hear down to at least 20Hz?
I realized sub lows and super highs would be better terms
It is possible for a person to hear 20hz, that doesn't mean people can. What I mean is, what is theoretically possible is not always practically possible. Though I have said this many times before, for me, anything below 28hz ceases to be a tone or a note, and is simply the Fuff-Fuff-Fuff of the cone moving. Yes, I can hear it, but it is not a note or tone. Keeping in mind my ears have been around the block a few times, so they are showing some wear and tear.
Now, Sub-sonic, which for me is functionally anything below about 28hz, typically does not appear in a movie sound track as a note or tone. Far more likely it will appear as a shock wave as the spaceship goes into warp drive or a bomb goes off or a car explodes or similar.
Even though my best speakers only goes down to a rated 28hz @ -6dB, I've felt shock waves from action movies that cause the upholstery on my chair to flex. WHAM!
I've run the test tone test several times on various speakers, and in a very broad and general sense, I've discovered the transition in sound from bass to Mid is around 320hz. Below 320hz, I still detect some sense of bass in the tone. Above 320hz, that sense of bass is gone. The transition from Mid to High is around 3200hz. That seems to have a nice summitry, and I would like to build some speakers based on that principle. Though cash being what it is, scarce, I don't see that happening soon.
As I said in the beginning, there are as many opinions as there are people to give them. But, I think we have discussed it enough to give you some sense of the general ranges of frequencies.
If we only consider common acoustic musical instruments, including electric guitars. the full range of music, meaning fundamental notes, is from 28hz up to 3951hz, which is the full range of a piano. BIG pipe organs can go lower, and Synthesizers can go higher. But those, in the extremes of their range are rare.
Middle "C" on a piano is only 262hz. "C" above Middle "C" is 523hz. Two "C"s above middle "C" (C6) is 1047hz.
A standard Guitar is 82hz to 1397hz.
Now all instruments are truly distinguished not by their fundamental notes, but by the complex harmonics that make the unique signature and sound of the various instruments.
Just a few more thoughts.
Okay, here's my take on it based on professional live audio. Firstly, I would be inclined to say that splitting the frequencies into anything more than 5 bands is pointless, as nobody is likely to make a 7 way system, even when dealing with PA designed to produce 110dB SPL at 100m+.
Typically, most PA systems (I am talking about serious PA here BTW, £200,000+ systems not what your local DJ might use in a pub) will be 4 way fully active, split like this:
Sub - 20hz - 60 (bear in mind producing lower than that at high SPL over a huge area is way more difficult than a small sub in a closed room)
Lows - 60 - 200hz
Mids - 200 - 1.3Khz
High's - 1.3 - 18Khz (again, high SPL above 18Khz is hard to do over distance and generally not needed in PA)
As you can see, these are very different to what a lot of people here have stated, showing there is no absolute rule for this.
In PA too, especially modern line arrays, the subs are separate boxes, and the main 'hangs' of PA forming are what are regarded as the full range boxes, running from 60 - 18Khz.
I know that PA, home cinema and Hi-Fi are all very different, but thought this might be of interest to some of you.
I agree with Soundmangt4, that there is no absolute rule. As BlueWizard mentioned (and I know that not everyone can hear down to 20Hz) it can differ from one person to the next, so the Sub frequency range can't be as easily determined when basing it on human hearing. Doing so would really put Sub frequencies at anything up to 30Hz, maybe 40Hz if you wanted to cover people with less than average hearing. If looking for an absolute, then I'd guess it would be set at 20Hz.
It's probably a subject that should have been left where it ended 4 years ago.
It is probably worth noting that in a PA application, each Subwoofer, and I suspect there are many, is roughly the size of a common delivery van.
Also, the 60hz to 200hz is the span of a typical Woofer. Were as 200hz to 1.3khz is the typical functioning range of a common guitar speaker. I suspect, to achieve true functional outdoor PA applications, the High Range of 1.3kzh to 18khz are covered by Horn loaded high frequency drivers.
In fact, I'll bet in many cases the entire system is horn loaded from top to bottom.
My point is, that I can see from the perspective of available drivers, why you would pick the ranges you have.
The further point is, as you allude to, is that it is not just a matter of perceived sound, or specific drivers, but also the application. A simply home use 2-way bookshelf speaker has completely different design considerations relative to a large 4-way PA system. In fact, a typical 4-way home speaker is far more likely to be woofer, midrange, tweeter, super-tweeter.
Still, thanks, I think you added an interesting perspective to the discussion.
Steve, have you tested your hearing with a pair of high quality headphones, you might actually be surprised at just how low you can actually hear. For a long time I accepted people cant really hear below 20hz, and that being with fairly good young ears, but I regularly test my hearing now and mine are still good to below 20hz. Of course it takes a pretty capable system to produce adequate levels in a room compared to headphones, but you can at least test your hearing.
What is the volume though, to be able to hear 20hz?
The lower the note is, the louder is has to be, not to mention the greater the excursion has to be.
Whether on the high end or the low end, I have to crank the volume up substantially to hear the extremes, and that is not just unique to me, that is the standard response of the human ear.
Try this next time, set a reference level at 1khz. Set that frequency so it is comfortable, but reasonably loud. Then try to hear 18khz or 25hz without adjusting the volume level. I'm going to guess, those extremes are going to be a lot harder to hear. If you can hear them at all.
According to the latest Equal Loudness Curves, to sound equal to a 1khz note at 80dB, a 30hz note will have to be 110dB. At 80dB, 30hz is going to sound substantially quieter. At 80dB, a 30hz tone is going to sound 30dB quieter. A 20hz tone is going to seem 40dB quieter, or is going to need to be 40dB louder to sound the same.
That's why I made the distinction between what can theoretically be heard, and what can functionally be heard. Yes, even with bad hearing, if you crank it up loud enough, it can be heard, but that excess volume does not represent common listening circumstances.
Plus, I never said I couldn't hear it, I said it lost all sense to tone or note, and simply became movement.
Still, I take you point and it was worth making. I don't really have great headphones because I don't use them very often. Just the basic £10 light weight models.
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