typical audiophool nonsense.
more audiophool nonsense.
amusing how people who know little about a topic are always so eager to show off how little they know about it.
Actually, no. I was surprised at how vacant he sounded., like leaves rustling in the breeze. And no, I don’t normally get all audiophilishly poetic about this stuff. It’s just that in this case the remix sounded great except for the singing. It’s like the first CD release of Satisfaction. Single and LP mixes had mixed down the piano so much that I didn’t notice it for years, but the AAD version mixed it up so far it was clearly there, and sounded like Aunt Bea’s friend Clara was playing it.
Notice that I said “perceive” rather than “hear.” Infrasonic’s a no-brainer; you can perceive the lowest frequencies of a rocket launch in your chest and innards. Ultrasonic is where the research is taking place and where I had to climb out of the rabbit hole tonight.
Be clear about a lot of the claims and terminology. There are two totally unrelated forms of compression involved in music delivery.
Dynamic range compression, and information compression. It is dynamic range compression that is making modern music sound so awful. Not that there wasn’t such compression used in the past, but nowadays the excess to which it is used is ear wrenching.
Information compression tries to reduce the amount of data used to represent the music. It can be lossy or lossless. You can buy arguments with audiophiles, but once a lossy data compression gets close to a variable bit rate compression of about 300kb/s it is very hard to pick the difference on most recorded music, and when you can it is usually by listening for tell-tale artefacts that you need to be told to listen for, rather than anything that is obviously degrading the sound. The tail of the reverberant space after playing has stopped is a good place to hear them, and off sounds in percussion another.
Can you perceive ultrasonics - well yes. But not for any good reason. Ultrasonics allowed to leak into the reproduction chain early can cause all manner of intermodulation issues. You can’t hear the energy itself, but things can happen that fold some of the energy down into perceivable distortion products. There have been a number of fundamentally flawed tests or demonstrations over the years that claimed to prove the audibility of ultrasonic energy. Most fell at the first step with fundamental lack of understanding of the basics of energy spectra.
You bring up some excellent points. To hear some audiophiles speak you would think that they are having trouble hearing the grass grow over the sounds of the butterflies screaming.
The problem I really have is with dynamic compression and the fact that most artist are now actually recording their music to fit into a narrow band width. You don’t have many artist like Pink Floyd of old who would go from very soft low subtle music and then transition into extremely loud and in your face and then back down again. Much of the music today is recorded is just in your face and made to sound good on an mp3 player with headphones or streamed into a base grade car audio system. I like some of it, but most of it just gets painful to listen to after a while. But hey, thats what kids want is for me not to get their music right? :rolleyes:
Nyquist Aliasing
Nyquist frequency on a standard (44.1kHz) CD is about 22 kHz. That doesn’t leave much room for representing the difference between square and sine waves above 10,000Hz.
I doubt too many adults could even hear the second harmonic of 10 kHz nevermind higher orders.
Nyquist aliasing is the easiest mechanism to describe, and causes all sorts of issues if you screw up. The distortion products are peculiarly nasty as they are not harmonically related to the music, and so are perceivable at lower levels than harmonic distortion. Non-linear elements in the analog chain can also has issues with ultrasonics.
The difference between a square wave and a sine for human perception at these frequencies is exactly what is needed. The wider law is Shannon (his seminal paper proved Nyquist as an aside.) Humans cannot perceive any difference between a 10kHz sine with a single harmonic add and a 10kHz square wave. Naive experiments to prove otherwise almost invariably get the level of the spectral components wrong and so are doomed from the outset.
Shannon is the key to understanding most of this.
honestly, you can talk about this until you’re blue in the face, and post whatever facts available, and you won’t be able to convince people who truly believe physics doesn’t apply when listening to speakers.
Isn’t it strange that whenever we discuss human perceptions - I refer to this and to a recent thread about colour - things seem to get pretty cloudy. It seems to me that our brains are doing so much interpretation of what is actually transmitted that scientific analysis just doesn’t really work. We *know *that colour is pink, and we *know *that vinyl sounds better than digital.
Their Acoustimass speakers used smaller speakers to good effect but they required a larger box. They place a speaker inside a cabinet and port the back and front of the speaker in some kind of tuned arrangement. The down side to that is they were under driven and thus the resonate frequency of the bass speaker cone was in the response frequency range of the music played. Under the right conditions you can hear it.
It’s possible to build isobaric speakers that put one small bass speaker directly behind the other. They can knock out a lot of sound for the size of the cabinet used but you’re buying 2 extra bass speakers. Might just as well buy one decent 15" woofer and be done with it.
(researching this Shannon fellow) CLAUDE Shannon? The computer guy? Man, he had his fingers in everything.
jz78817, just to show how big an audiophool I am, on this very message board I have asserted that audio recording has been going downhill since the development of the first system for molding phonograph cylinders because before that each record was created directly by the power of the singer’s voice. Just another step from the live performance. le sigh
God bless the RIAA equalization curve; well, that and virgin vinyl.
What could possibly go wrong?
it’s called the “placebo effect.”
the “bass module” (Bose never calls them subwoofers) are 6th- or 7th-order bandpass enclosures. The design guidelines for such enclosures are well understood but it’s hard to get it right. Neville Thiele and Richard Small figured this stuff out decades ago, and their work holds true to this day.
the reason isobaric loading works is because you’re effectively doubling the moving mass (Mmd) which lets you halve the enclosure volume. You can get the same effect by taking a speaker and doubling the cone/moving mass. In both cases you have to double the power delivered. This is what Kicker did when they introduced their “Solobaric” series of subwoofers.
Thank! Clearly, I’m out of date.
Cite, please!
I’ve seen one study that seemed well-constructed, but unreplicated, that showed that Indonesian people who listen to Gammelon music could distinguish between audio with a 20kHz lowpass filter versus audio with higher frequencies intact (I forget the details, but IIRC the test system was on the order of 40-50kHz. No easy feat by itself!)
If anyone has any cites for serious scientific studies that show humans hearing much over 20kHz, please pipe up! The evidence for my hearing much over 12k is zero. I remember fiddling with speakers and a tone generator once when my son came in with a nasty look on his face, telling me to stop the nasty loud high pitched noises (which I couldn’t hear at all … but proving that the speakers were reproducing them!)
Like I said, it was taking me down a rabbit hole and I, having a life, haven’t read, much less understood, far less found support for, any of the things I’ve found so far.
IIRC prior to smart phones bring everywhere the Nokia and similar type “feature phones” could output a ringing or alert tone with their tiny speakers that was only really audible by people in their teens or younger.
Hearing test for hi pitched tones here
All I hear is up to 12 kHz (I’m 56 with what I think is perfect hearing). All the rest of the tones just have the pop and tick then the test tone begins and ends.
Story here
Well, I never said I could hear much over 12kHz! It still has to fight my tinnitus, too. 
Back to the OP, headphone version, our geek friends at DAK have earplugs with giant 13mm drivers. They don’t look comfortable when lying on ones side, but I suppose they have more bass. Like I need help with the low frequencies. :rolleyes:
I have a pair of Etymotics ER-4. They are an ear canal phone, they demand a tight seal (the up side is that they have extraordinary sound isolation) and they produce prodigious bass from a driver so small that you could miss seeing it.
And yes, that Claude Shannon. If there was a Nobel for engineering, he would have got one. His paper in signalling in a noisy channel is a must read for so many reasons. It is all about information. The duality of information in the analog and digital domains is misunderstood (or just plain not even contemplated) by many, and audiofools in particular. This one paper outlines the basis for a critical part of how the entire universe works.
That doesn’t mean you can start buying those off-brand cassette tapes; the cheapies that roll off around 12kHz. You’ll still want to hear the 1kHz beat frequency produced when a 15kHz tone interacts with a 14kHz tone:
Beats at hyperphysics
Beat frequency demonstration video
Yup, but still well below 20kHz.