Human Ear Freq. Range and Ad in Crutchfield

dorokusai · May 2003

I saw this ad in the bathroom edition of Crutchfield the other day:

Sony's SS-LA300PKG speaker system offers stunning "Extended Definition" performance. Thanks to their 1" neodymium tweeters, these speakers provide response out to an amazing 70,000 Hz! The front and rear speakers also include a 4" woofer for crisp, accurate reproduction of the midrange and bass, while the center channel sports dual 3" woofers. All five satellites employ a unique sloped enclosure to combat distortion, and include an integral ball-joint stand that allows easy placement anywhere. The compact subwoofer pairs a 5-1/4" driver and a 250-watt amplifier to provide serious low-frequency power and precision. The compact, flexible design of this sub allows for vertical or horizontal placement

Now I don't know about you, hence the post, but isn't the human ear roughly capable of hearing only 20hz - 20Khz. Above 20Khz is ultrasound, 40Khz is about dog whistle level....and I know for sure, I can't hear a damn dog whistle. F1Nut and I were puzzled by this when he graced me with a Polk Audio SDA audition today.

Now, I understand that subsonic bass, the infrasound section of an audio signal, does exist and can in fact be "felt", but do you actually "hear" it? I have no idea, my PSW202, for some unknown reason, does not(WILL NOT) extend into that region

I just re-learned some of this information, infrasound/ultrasound/etc., from the following item I found on the internet.

http://www.iurc.montp.inserm.fr/cric/audition/english/sound/sound.htm

Now is Crutchfield making this bizarre misleading statement up?

Apparently not, which further intrigues me.

Sony website:

Complete your 6.1 and 7.1 channel Surround Sound System with Sony's SS-V831ED Home Speaker for incredible sound. This individual satellite speaker matches the satellites of the SA-VE835ED, adds Surround-Back capability, and features a 1" Extended Definition Neodymium tweeter rated to 70 kHz. Also featuring Dual 2 1/4" full-range drivers with 1" voice coils, the SS-V831ED accepts optional WS-FV10C/...

Now I realize it says "rated for 70Khz" and "rated" means just about nothing in some cases, as far as manufacturer claims, BUT don't you think its misleading, to Joe Average customer? You and I know that it doesn't matter, and I wouldn't buy this particular system regardless of its performance.

I love my Sony ES receiver and future ES additions are coming, but I am not buying fookin' speakers from Sony, no way. Especially not after this, as I see it, a misleading statement in context of advertisement.

What do you guys think??

dcarlson · May 2003

don't you think its misleading, to Joe Average customer?

Isn't that the point. If someone deosn't know any better. Sold.

VR3 · May 2003

The higher the exstention of the tweeter the more headroom (so to speak) the tweeter has. The tweeter sound much fuller than it would than a flat 20. Polk hits up to 25hz. Def Tech's hit up to 30hz. It just sounds better, you will notice this when you buy a seperate amp with your Polks. The top end is much cleaner than a 20-20 receiver. However, who on earth would buy a POS sat sony system. Id rather have bose....;)

F1nut · May 2003

I'm going to chime in on this one. As dorokusai and I enjoyed a fine cigar (Thanks) and some good tunes this topic came up. I too would like to know WTF 70,000 kHz is going to do for me? Does it start to roll off at 20,000 kHz and then continue all the way up to 70,000kHz? Someone 'splain this sheeeet.

F1nut · May 2003

AH, much fuller sound......hmmm. I know my Polk's go up to 26kHz and have a -3db rating of 20kHz, but 70,000kHz? Must be really full........of something.

dorokusai · May 2003

Well if the theory of headroom is plausible, I don't know enough about dynamic headroom to comment, wouldn't it also be plausible to say that the Sony speaker is superior to my RTi38's? or F1Nut's(No jokes here) SDA's?

Do I even remotely believe that, FOOK NO! Of course not, that would be absurd.

So back to the frequency response, and "sounding better", I am going to need a much better explanation than that.

VR3 · May 2003

20-30, i can see something that that could do, but 70....right...sony's can barely sound like speakers.................

dorokusai · May 2003

Hey Vr3, I love the signature comment you have,

F1nut · May 2003

MX,

Just to show you that Sony can produce a great speaker, click on this link.....http://cgi.audiogon.com/cgi-bin/cl.pl?spkrfull&1056067594

F1

dorokusai · May 2003

Well, I certainly think those would be worth listening to to say the least. Sony as a home speaker manufacturer still seems alien to me.

I thought someone, awhile back, posted about these speakers???

They asked if anyone had heard them personally.........

VR3 · May 2003

I have heard a similar system by sony, that was around 3,000 for the set. Sounded bad for the price, bose like even. Thanx about the sig! couldnt do it without scott!

F1, those look like cheap knock off Wilson Audio/B&W speakers.....lol! Bet they sound wonderful!

F1nut · May 2003

Yeah, I agree that one doesn't think of Sony and speakers as something that goes together. That's why Sony let their guys go full tilt boogie to come up with these and by all accounts they are great speakers. I'm not sure about someone posting on these, could have been me, but seeing as I have CRS;) I can't be sure.

MX, what system are you talking about? Not the link I posted, I hope!?!

F1nut · May 2003

Cheap knock off??? $16,000.00....eh?

VR3 · May 2003

it has a sony logo on it...;)...I would rather buy something other than sony though for that price....

abmarsh · May 2003

I guess anything worth killing is worth over-killing.

RuSsMaN · May 2003

Maybe a musician can chime in here.

I think it may have something to do with harmonics, I know these figures aren't accurate, but here is what I'm thinking. Let's say a 30Khz note is pinged, there is a harmonic at a much lower freq, say 3Khz. If the speaker cannot produce the 30Khz note (even though only your sweet clean puppy dog can hear IT), you won't get the 3Khz harmonic either.

I know this extended range hasn't been a big player until recently, but some of the newer gear and media do go out much farther than 20Khz these days, right?

Anyway, thats my theory for the day, I don't know if it holds any water though.

Cheers,
Russ

madmax · May 2003

Good thinking Russman. I'm no expert on this for sure but I think harmonics are typically higher frequencies than the fundamental. I'm not positive though. Another possibility here is that the high frequency point a manufacturer gives is normally 3db down. That means if the frequency is higher possibly it is flatter up to something that does matter? I don't know.
madmax

hoosier21 · May 2003

Russman you are on the right track.

Harman Kardon used the ultra-wide fq responce as a marketing ploy in the late 80's, "UltraWide Band" 1-100,000 or some such, the claim was just what Russman said, if you can't reproduce the extremes of the fq range you are "distorting" what is in the normal 20-20k range.

RuSsMaN · May 2003

Chuck, I can see it working with your theory also. If the harmonic is not a lower, but a higher (maybe both?) freq than the fundamental, I wonder how it might affect the perception of the initial note.

2-way, typical shelf speaker for this scenario, ok? Crossed at 2K. Once again, I'm just throwing out numbers for the sake of the discussion.

Lets say a 500Hz note is pinged, and it's harmonic is at 5Khz (higher, as you noted). I wonder how different it would sound, say if you listened to the note with only the mid-bass connected, and then listened again with both the midbass AND the tweeter connected.

With only the midbass, you'd get the 500Hz note, with the addition of the tweeter, you would get the 5000Hz harmonic of that note also. I'm sure it's subtle at best, but I wonder if it sounds more balanced, or has more (or less) 'edge' to it?

Even if the harmonic is outside our 'normal' range, I wonder how it affects the listeners perception of the fundamental, if it all?

Interesting note Hoosier.

Cheers,
Russ

Steve@3dai · May 2003

Well, to record such a frequency you would have to be at 192khz (Nyquist theory) or have an analog source. BUT, at the same time, any harmonics could be reproduced without speaker interaction and just the interaction of the air from the sound that is being produced at so many hz.

First part of my post = not full of ****
Second part = we're pushing it

Just thinking out loud. I think it's just sneaky marketing personally.

RuSsMaN · May 2003

Originally posted by Steve@3dai
I think it's just sneaky marketing personally.

Hasn't Polk marketed your beloved LSi's out into the 40Khz range for 'todays digital media'?

Nyquist and Beat theory, found these little quick hits on the topic:

Nyquist Theory

To sample or graph a SINE wave you must have at least two points in order to guess what the frequancy is... For example the ORIGIN (y=0 normally) and either a MAXIMUM or a MINIMUM value to guess the fequency. To record a frequency you must have double that in the sample rate... For example to record a sine wave of 50 Hz you need a MINIMUM of 100 samples per second to record the sine wave. This fact is called the Nyquist theory and the Nyquist frequency is the highest frequency that you can record with a given sample rate. In the case of recording with 100 samples per second the Nyquist frequency is 50 Hz.

What is a BEAT frequency ?

Guitarist use the beat frequency to tune guitars with harmonics. If a guitarist picks a harmonic on the guitar the string can only vibrate with waves conrisponding to the length of the string, by placing a finger on the string at a particular fret you create what is called in physics as a Node and AntiNodes. When playing two harmonics that are very close together you hear a rise and a fall in the perceived level of the notes due to the BEAT frequency. I will now explain what the BEAT freq is... The difference between any two frequencies will create a new frequency... The formula is F1-F2=BEAT ..... Back to relating this to Dynamic range... The BEAT frequency in simple terms is for every Hz that you go over the Nyquist frequency you will get a artifact that equals the difference between the recorded frequency and the nyquist frequency... WOW that is hard to explain in simple terms... For example if you record a 22,051 Hz sine wave with a 44.1 Khz sample rate you will get a 1 Hz rumble in your audio due to going over the Nyquist frequency. If you record a 22,080 Hz you will get a 30 HZ rumble and so on.

Cheers,
Russ (trying to make sense of it all)

TroyD · May 2003

Damn, I read something, somewhere (of course I can't remember) that essentially echoes what Russ is getting at. It's the reason that the DQ-10 has the piezo super tweeter, it's crossed over at like 18khz and supposedly extends dead flat out to infintiy........I think (and this is pure speculation) that the harmonic factor is one reason why analog is percieved to sound better than cd's...

BDT

Dr. Spec · May 2003

There are two different harmonics here:

1) A harmonic that is part of the source signal.

2) A harmonic that is generated by the speaker itself.

All harmonics are multiples of the fundamental frequency. They are never, by definition, lower in frequency than the fundamental. There are even and odd order harmonics. Nearly all music signals contain energy at harmonic frequencies, in addition to the energy at the fundamental frequency. If all the energy in a signal is contained at the fundamental frequency, then that signal is a perfect sine wave. If the signal is not a perfect sine wave, then some energy is contained in the harmonics.

If a harmonic is part of the source signal, the speaker will reproduce it - if it falls within the frequency response range of the speaker. This will of course be true regardless of whether or not the speaker can produce the fundamental frequency. This is common in subwoofers, where the source signal might contain an 18 Hz fundamental and then some harmonics at 36 Hz and 54 Hz. Unless the sub is world class, it will ignore the 18 Hz fundamental, and only play the 36 Hz and 54 Hz harmonics of the source signal.

If the harmonic is generated by the speaker itself, this is a bad thing and is generally known as "harmonic distortion". Summing and integrating all of the individual even and odd order harmonic distortions results in the "total harmonic distortion" rating, known as THD for short.

Regarding the FR of the tweeter in question - the human ear can't hear above around 15kHz-20kHz (depending on your age and how much noise related hearing damage you have incurred), so if the tweeter can play a note at 70 kHz, you will never hear this advantage. If it can play flat and clean to 20 kHz with no appreciable THD, then that is plenty good enough for anyone.

So a cymbal clash might have an 8 kHz fundamental and harmonics at 16 kHz and 24 kHz a tweeter flat to 20 kHz will play only the 16 kHz harmonic and will ignore the 24 kHz harmonic, but you can't hear that high anyway, so it's a moot point.

Now at the other end of the spectrum, a subwoofer capable of cleanly and loudly playing infrasonic signals IS beneficial and appreciated since these drivers can generate appreciable sound pressures at these frequencies and this will be perceived as a pressure on the ears and felt in the floor/couch/guts, even though it is inaudible to the human ear.

Doc

dorokusai · May 2003

Good thought provoking stuff eh?

I am sure we can get this loosely hashed out amongst us, the is Polk Forum damnit!

I think that you would be hard pressed to really notice the difference tho', high headroom or not. Each speaker is allready different, if you throw in an equation in one, who's to say it sounds better than the other, from a listener perspective.

The flatter the freq response the better? Is that a true statement? I guess if that 70Khz speaker was "flatter" than the "normal" speaker, would one presume it sounds better?
Probably not, maybe not, I don't know......I can only base judgement on one given fact:

SDA's sound better than my RTi-38's

Now that is obvious to some, I know, but the speakers do have different freq responses, so I would say at least to 26Khz(SDA), that this is a plausible dynamic. But 70Khz? Hmmmmmmmmmm

RuSsMaN · May 2003

What is the difference in 26KHz and 70Khz? Don't music octaves run on an exponential scale, ie, something on the order of doubling? Meaning that 70Khz may only be say, 2 octaves higher than 20Khz (without taking into the fact if we can hear it or not)?

And yes, (imo) from a 'purist' standpoint, the 'flatter' speaker should give the more accurate reproduction of the original recording. HOWEVER, was that original recording, recorded 'flat' to begin with?

Great discussion, great points Doc. I am curious as to why it would be a moot point, even if it is beyond our range of hearing. We are still dealing with vibrations, albiet very small, and a source/speaker playing out to that extended range, perceivable or not, *could* still have some affect on the sound we can hear, through said vibrations, no?

Cheers,
Russ

Dr. Spec · May 2003

Dynamic range, frequency response, and upper frequency limit are three entirely different things.

The dynamic range of a speaker (i.e., how loudly it can cleanly play a signal) is completely independent of its frequency response curve.

A flat frequency response curve which neither accentuates nor attenuates any part of the audible spectrum is by definition the most accurate. Whether or not you like how that sounds is a purely subjective matter.

The upper frequency limit of the speaker is not necessarily related to it's overall frequency response. A tweeter might be able to reproduce a 70 kHz signal at the same volume as a 15 kHz signal, but the FR curve might look ragged, with large peaks and dips.

That is why FR curves are rated in both frequency range and in variation off the baseline. For example, 20-20,000 Hz, with no more than a +3 or -3 dB variation across the entire range. Of course, this could mean as much as a 6 dB peak to peak variation between to given frequencies.

FR curves are normally produced in anechoic chambers where room effects will have no influence. The room will generally impart far more coloration to the sound than the inherent FR deviations of the speaker itself.

Also, the sound quality of a tweeter is far more than its simple FR. THD, IMD, wave launch and propagation and a whole host of other things way over my head all factor into how a tweeter "sounds". That is why the Vifa, the tri-lam, the silk dome, and the older Polk tweets from the SDA/SRS lines all sound different, despite have very similar FR curves on paper.

Doc

Dr. Spec · May 2003

Originally posted by RuSsMaN
What is the difference in 26KHz and 70Khz? Don't music octaves run on an exponential scale, ie, something on the order of doubling? Meaning that 70Khz may only be say, 2 octaves higher than 20Khz (without taking into the fact if we can hear it or not)?

And yes, (imo) from a 'purist' standpoint, the 'flatter' speaker should give the more accurate reproduction of the original recording. HOWEVER, was that original recording, recorded 'flat' to begin with?

Great discussion, great points Doc. I am curious as to why it would be a moot point, even if it is beyond our range of hearing. We are still dealing with vibrations, albiet very small, and a source/speaker playing out to that extended range, perceivable or not, *could* still have some affect on the sound we can hear, through said vibrations, no?

Cheers,
Russ

Yes, the octave scale is not linear, and the higher frequencies have much larger numerical gaps between octaves. For example, there is a third of an octave difference between 20 Hz and 25 Hz. There is obviously not a third of an octave difference between 15,000 Hz and 15,005 Hz.

An "accurate" speaker will reproduce the original source signal without adding or subtracting anything. If the source wasn't recorded flat, then the speaker will play it back the same way.

The only reason the FR of a speaker is generally shown to be "flat" is because the souce signal used to plot the curve is simply a bunch of sine waves strung together and all recorded at the same exact volume. So coloration of the source is never an issue when plotting the FR curve of a speaker.

Yes, we are dealing with tiny vibrations from tweeter. They are just so small in sound pressure that I'm not sure we can perceive them in any other way except audibly. I've never "felt" a tweeter play and I would assume if you can't hear it, it is a "non-event" from your standpoint. When some hits a dog whistle, it doesn't cause pressure on my ears, or any discomfort. I just stand there like a dumb **** while my dog turns his head and looks at me funny.

Doc

RuSsMaN · May 2003

Originally posted by Dr. Spec

When some(one) hits a dog whistle, it doesn't cause pressure on my ears, or any discomfort. I just stand there like a dumb **** while my dog turns his head and looks at me funny.

Doc

Agreed, but what I am still curious about, is if that freq the dog whistle is at, is the resulting harmonic of a lower, audible freq, what (if any) affect does the speakers ability to reproduce that harmonic have on the perceived sound to the listener?

I don't think its a fair comparison to say 'I can't hear a dog whistle'. The dog whistle would be the fundamental in that equation, with the harmonic(s) reaching even *further* out. (???)

Cheers,
Russ

HBombToo · May 2003

If the ear can't mechanically react for us to hear it... then how will it impact the music quality? How can there be quality if we can't sense it?

I see where your question lies Russ but if a tree falls in a forest and you were not there di it make noise as it crashed to the ground?

I liked the way Doc summed it up... We don't hear Subsonic we feal it but on the flip side, for high freq what sensory system do we have to detect the Harmonics? This is where I say there is no real impact to having an audible bandwidth out to 100 Khz. Granted from what I have seen in equipment, the higher the freq range the better the equipment is but the high freq is not engineered in but is a byproduct of sound engineering practices over 20 to 20Khz.

Just my 2c

HBomb

Dr. Spec · May 2003

Well, again, harmonics are by definintion multiples of the fundamental frequency. So they can't be lower than that.

But if you want to split hairs, the term harmonic really should be limited to a discussion of sine waves and harmonics thereof.

A musical instrument never produces "just" a single frequency. Even a single "note" from an instrument contains unique overtones and undertones collectively known as the pitch of the instrument. That is why the same note on a clarinet, a flute, and a piano are still so easily distinguishable, whereas a pure sine wave of any frequency has no distinguishing characteristics, other than the note itself.

With that said, these undertones and overtones are usually grouped fairly tightly around the note itself, and really don't stray many octaves above or below. This is known as the "sonic signature" of the instrument at any given note.

If the sonic signature does indeed possess undertones, these could be less accurately defined as "subharmonics". There are instruments than can play higher than human hearing (the pipe organ is one). If the instrument contains an inaudible fundamental note, and audible undertones, then the human ear would not "hear" the complete note.

If the tweeter cannot play the fundamental because it is too high in frequency, that doesn't mean it cannot play the undertones if they fall into the tweeters frequency range and into the audible part of the spectrum.

I suppose the inability of a tweeter to play the entire note, as opposed to just the undertones is in theory a deficiency. But it would be an inaudible one.

Let's say you can hear perfectly to 20,000 Hz.

Lets say we have a given tweeter capable of fully reproducing a 25,000 Hz ultrasonic note including all overtones (say extending to 30,000 Hz) and all undertones (say falling down to the 15,000 Hz range).

Let's say we take an identical tweeter and the very same source signal, and artifically and completely filter all frequencies going to the tweeter above 20,000 Hz.

You would not be able to tell the two tests apart. You can only hear the undertones up to 20,000 Hz, and both tweeters reproduce this perfectly. Tweeter #1 keep right on going to 30,000 Hz, but you can't hear it. Tweeter #2 stops at 20,001 Hz, but you can't hear that either. All you can hear are the audible and identically reproduced undertones.

Because a speaker can't play a note in the ultrasonic region doesn't mean it can't perfectly and correctly play any undertone notes in the audible spectrum.

Doc

RuSsMaN · May 2003

Re-read my last post Doc, I didn't say the harmonic was lower.

Fair enough, not arguing, just discussing.

Assuming what you said is true, the obvious question to arise is why then do we produce speakers, amps, sources etc, that extend (sometimes WELL) beyond what *most* can hear? If we can't hear it, and it doesn't affect the audio we CAN hear, the point is.....?

I understand what you are saying, but I'm still skeptical as to why it (extended response) is there in the first place, if it does nothing to/has no affect on, the end product (what hits our ears).

I'd sure like to hear Polk's take on the topic.

Cheers,
Russ

Human Ear Freq. Range and Ad in Crutchfield

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