So no vinyl, no valves? Does it not depend also on 'unorthodox' speakers with dipoles etc.?
I have to say I remain sceptical. Not sceptical that such an illusion can occur now and again, but sceptical that it would work with every recording in a meaningful way.
Dolby Virtual Speaker
So Dolby have taken a recipe of phase, delay, EQ processing that gives an "immersive surround sound experience", and put it in a bottle. Ordinary stereo speakers in a real room also give rise to phase, delay and EQ effects. More unorthodox speakers give rise to even stranger effects. Is this what we're really talking about, and not just low distortion?
No, it is not surround sound effects that are the goal: invisible speakers will give one an "immersive" experience, but this is because one's brain interprets all the little acoustic clues that are revealed in a low distortion playback, and conjures up a picture that matches what the microphones "heard".
As an interesting exercise, take a 30's mono swing band recording. If all's going well you can "see" the layers of the musicians stretching back from the single mic used, with the poor old drummer stuck way over yonder, at the back wall of the recording space ...
Frank
As an interesting exercise, take a 30's mono swing band recording. If all's going well you can "see" the layers of the musicians stretching back from the single mic used, with the poor old drummer stuck way over yonder, at the back wall of the recording space ...
Frank
I still remain sceptical that it is just a natural result of distortion-free reproduction. You find it works on all recordings but, as I understand it, most recordings are messed about to some extent in terms of dynamic compression, acoustic 'spotlighting' etc. Also, recordings themselves vary in their quality in terms of distortion regardless of the playback system, so why is that not intruding on the illusion?
I was thinking you might have built them
First impression for me was that your system was in a different leaque of transparancy than any I have heard.. It had an Ultra clear window into the recording space.. Highest speaker invisibility I've experienced and a point source too..
As I'm not new at this, long term listening would be required to reveal any negative characteristics that can be lurking.. Just Saying.
WOW! $80k upstream
I travel to michigan on occasion so I might bug Earl, so I can hear DBA in action..
I didn't like 801D diamond tweeter but I wouldn't use B&W for making an overall judgement on a technologie...
Yes, messed up recordings, the recent stuff, is hard work. I have Adele 21, and I thought I wouldn't be able to get this overcooked recording to "simmer down" at first, but finally got there. The more the producers add layers of manipulation the worse it gets, because you have to be to hear "through" all that fiddling to to get a grasp of what is understandable, at an intuitive level, as "natural" sounds. Less extreme processing is much easier for the head to decipher.
Yes, distorted recordings are interesting: I believe the process here is that the mind very rapidly adjusts to, and accommodates the "style" of distortion of the recording. But if it has to contend also with a very different sort of distortion in the playback chain, this all becomes too much, intermodulation becomes excessive and the brain closes down - your mind concludes it's a "terrible" recording.
In other words, so long as you don't overload the processing mecanism of the ear/brain you will get good sound, and invisible speakers because the cues are still there, along with the distortion. There are halfway houses on this, people say that a system "sounds OK", but they develop listener fatigue very quickly: the brain is working flat out on decoding the sound which has a relatively non-obvious distortion, but it becomes exhausted from the effort over a relatively short period of time ...
Frank
Yes, distorted recordings are interesting: I believe the process here is that the mind very rapidly adjusts to, and accommodates the "style" of distortion of the recording. But if it has to contend also with a very different sort of distortion in the playback chain, this all becomes too much, intermodulation becomes excessive and the brain closes down - your mind concludes it's a "terrible" recording.
In other words, so long as you don't overload the processing mecanism of the ear/brain you will get good sound, and invisible speakers because the cues are still there, along with the distortion. There are halfway houses on this, people say that a system "sounds OK", but they develop listener fatigue very quickly: the brain is working flat out on decoding the sound which has a relatively non-obvious distortion, but it becomes exhausted from the effort over a relatively short period of time ...
Frank
Hi CopperTop,
I was only talking about distortion in speakers.
My current speakers have the lowest distortion of all the speakers I have/had and they give me the most immersive sound of all.
I get that immersive sound only with hardconed low distortion drivers like Accuton and Visaton alu.
I have also some speakers with paper and poly drivers but they miss that immersive sound.
They miss the ability to project the recording environment into my room.
Amplifiers are another story, good designed solidstate or valve amps are both great, it depends more on the circuit, PS and the used components.
Now I'm using a full loaded F5, but my KT88 valve amp with interstage phasesplitter are also able to let me hear it, just a little more smoother
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Linear in particular. I find that HD, MP3 artefacts, noise and small amounts of crosstalk don't tend to affect this in a way I could be sure of..
And spoil the image of twin turbo chargers?
We're talking about two kinds of ambience here though, that on the recording and the listening room reverberation however if you're hearing it off the wall, the off-axis higher frequencies peaking above the mid-hf dip may be a problem.
Silence through speakers
An audiophil (-phool) friend of mine once pointed my attention to another phenomenon that can be heard beyond a certain quality level: the room acoustics will change as if it breaths, when you turn on the amplifier but no input signal applied. Just like you opened a window in the night when everything is silent outside. Perhaps the loadspeaker/amplifier absorbs some room noise? To be honest, I never experienced it...
An audiophil (-phool) friend of mine once pointed my attention to another phenomenon that can be heard beyond a certain quality level: the room acoustics will change as if it breaths, when you turn on the amplifier but no input signal applied. Just like you opened a window in the night when everything is silent outside. Perhaps the loadspeaker/amplifier absorbs some room noise? To be honest, I never experienced it...
Amazing speakers! But I looked up the price of the mid driver... cough... it's... $907!! Would you not be curious to hear how they would sound driven actively with DSP, phase/delay correction and all that stuff?
THD in drivers isn't often dwelled upon. The fact that Accuton give you the specs presumably shows they're good, but I just couldn't justify that price.
However, this discussion is reviving my interest in neural network-based pre-distortion. The thing is, what level of THD do you get from a typical measurement mic, without spending thousands? Is there any other way to measure a driver's THD?
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Do you have a large window near your speakers? Even a couple of bags of roofing batts (unopened) in the corners behind your speakers can give you a clue how this might sound. I think a speaker itself would not do much because it is too small.
I bought the Accuton drivers 2 years ago, then they were only "500$"
The high price of the C173-6-090 is partly due to the neodymium magnet and the high sensitivity.
Accuton has also more reasonable priced drivers with a normal magnet and lower sensitivity like the C173-6-191E Troels used in his design.
For the moment I don't feel(hear) the need for going active
The crossover that I designed sounds very good and uses very good components.
Problem with active is that I need 3 very good amplifiers then, but active seems to mature, hypex has a nice new DSP product, maybe my next project
For the moment PJ Harvey is singing in my living room
The high price of the C173-6-090 is partly due to the neodymium magnet and the high sensitivity.
Accuton has also more reasonable priced drivers with a normal magnet and lower sensitivity like the C173-6-191E Troels used in his design.
For the moment I don't feel(hear) the need for going active
The crossover that I designed sounds very good and uses very good components.
Problem with active is that I need 3 very good amplifiers then
, but active seems to mature, hypex has a nice new DSP product, maybe my next project For the moment PJ Harvey is singing in my living room
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The most physical invisible speakers I made in around 1988.
30mm CNCed and polished acrylic OB line source dipoles (Infinity emit).
The most acoustic invisible speakers I made in 2009.
My own AMTs and 8" drivers in a 60mm polished corian OB dipole.
I started in the 60ties with pressure chamber, went to ventilated in the early 70ties, then to TL in the late 70ties, and electrostatic OB dipole in the early 80ties... The last decade I have made some BLHs to have tested that.
I have used OB dipoles the last three decades for obvious reasons.
Hi fas42,
On "Adele 21, Rolling In The Deep" I clearly hear echos in her voice.
Get "Adele, Live at the Royal Albert Hall" much more enjoyable to listen to
Regards,
Danny
Frank,
The inverse distance law (double the distance, loose 6 dB) was a good reason the "poor old drummer (was) stuck way over yonder"
If a speaker is accurate in terms of frequency and phase response, and has a fairly uniform dispersion pattern which remains the same with frequency, or slowly widens from high frequencies to low, it can convincingly convey the sense of depth and location that the recording's original spatial reverberant cues provide.
The more controlled the pattern of the speaker over the listening area in terms of level and frequency balance, the more one hears the recording's spatial cues, rather than the room location of the speaker.
I provided a humorous (to me) example of an "invisible speaker" one Halloween using a very narrow dispersion horn (only 11 degrees from about 2000 Hz up) located about 15 meters from the sidewalk the kids walked by on as they went trick or treating.
As the kids would come in to the range of the horn covering around 2 meters of the sidewalk, I'd whisper or make cat meowing noises in to the microphone/mixer/amp driving the horn. I was in a darkened garage, I could see them but they could not see me.
The close-miced sound would make the kids stop and look in every direction looking for the "ghost" whisper or non-existent cat that sounded like it was located within inches of their location, even though the actual source of the sound was up a hill 15 meters away.
By initially adding reverb to my voice, then reducing the reverb to dry sound I could also create the illusion that the ghost voice was coming from a distance and then getting right next to the "target".
The "invisible speaker" was so convincing that many of the kids (and a few of their parents) took off running. Some went in the direction they were headed, others turned around.
As you mention in #65, the tendency of many recording engineers to use different (artificial) reverbs on individual voices and instruments often destroys or confuses any locational cues.
Art
I've thought of doing pre-distortion at various times, but I feel the complexity of all the factors that impinge on the situation just makes it too complex a task. If you get it reasonably right for one type of recording, at one volume level, then it could just sound "wrong" for everything else.
As Terry indicated, I have what most would consider a "junk" system at the moment, very deliberately. It would have thrown in the bin by a family member because its DVD replay was failing, but I was curious to find out if even "low-life" electronics could be enhanced by intelligent fiddling to deliver convincing sound. Early experiments were encouraging, so I've persisted.
Now, this has rubbish speakers by most people's standards, the sort of thing that gets thrown in a PC package as monitors. But, the drivers are decent quality and the plastic box is shaped enough to give the carcase reasonable rigidity, no nasty resonances even at high volumes.
I mention all this, because the THD of the speaker itself, if measured, would of course be nothing special at all. But, this distortion is of a type that doesn't get in the way of the musical message -- as our EnABL proponent points out even cheap speakers can make it, the disappearing act, happen. As far as I'm concerned it has always been a whole system issue, I've hear too many superb speakers sound atrocious at times to think otherwise.
Frank
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Oh, dear ... I wonder who was the biggest "kid" here,
...Yes, I appreciate the drummer had to be kept well away from the relatively simple mic's of the time.
I do wonder about this dispersion pattern with frequency thing that is made so much of here in the forum. I have never, ever worried about such things, I just take standard box speakers, stick them in a spot that happens to be convenient in the room, and proceed. What I do worry about, a great deal in fact, is that they are coupled to very significant mass. I have loaded them up with significant weight on top, used Blu-Tack and spikes as appropriate to make sure the carcase vibrational energy has a path to be drained away through. Right from the beginning it was very important to me that the volume could be raised to realistic levels without the sound degrading ...
Frank
What? I can't laugh at something funny?
Of course not! Golden Speaker.
From that, I still don't think we are talking about the same thing. Would be hard to tell without being there with you and listening to the same thing.
If by "standard box speakers" you mean small full range speakers, the dispersion pattern will simply gradually reduce in beamwidth as the wavelength approaches the piston diameter, which is OK.
What is not OK from an "invisible speaker" standpoint is varying dispersion patterns per frequency, common in most multi-way cabinets, as the reflections off the walls varying with frequency give aural triangulation clues to the location of the cabinet.
Yes, that may be the theory of it, and when a speaker is on the edge of being "invisible", every subtle variation could have a big impact on how it's subjectively perceived, I can certainly appreciate that. However, when I first experienced the disappearing act, it bowled me over, it was a night and day change: I immediately went frantic, popping my head every which way, back, forth, over the top of the speaker, along the sides, I would probably have tried crawling along the ceiling if I could, to see if it still happened, it was so bizarre an experience.
Triangulation clues just don't cut it, when the mind has "decided" to believe in the illusion, in my experience ...
Frank
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