Stereophonic phantom imaging theory

Please choose the option which you agree with

  • I hear all sounds coming from a single horizontal plane

    Votes: 10 32.3%
  • I hear sounds coming from more than one single horizontal plane

    Votes: 20 64.5%
  • I cant tell

    Votes: 1 3.2%

  • Total voters
    31
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Administrator
Joined 2004
Paid Member
It does :) I'm using mine for comparing different speaker configurations.
Cool! I've got to hear one, then. How well does it do the phantom image trick? Or does that depend on the speakers and room you've modeled?

My main worry with the Smyth is that I don't want to have a replica of someone else's room and speakers, however good they may be. I'd rather have it simulate the perfect speaker and room, if there is such a thing. Or is that asking too much? I guess a virtual model of a great room would be OK, it's the speakers that worry me.
 
What is "correct"? Can you yell me that? If I have speakers and whatever else upstream that can reveal more differences in space than headphones, how is that wrong? Wherein lies the distortion? How is that "weird"? I find it very real and very convincing, so do others who've heard it. And it changes from one recorded space to another. If it were some weird trick or distortion, it would always sound the same. It does not.

I've heard the same argument many times, it's not new. "Oh, it's just a trick." Really? Darn good trick that can produce lifelike images of things big or small, loud or soft, flat or full and different from one record to another.

Some people have a very narrow view of what they imagine is "correct." A sort of slavish devotion their own idea of the signal. That works well enough with sources and amps, but not speakers. The real world is not like that. I hope some day you get to hear it, you'll not forget it nor doubt it again. But it will spoil you for typical dull, flat, non-resolving systems forever after. It's a blessing, and a curse. ;)

Headphones are special in that you don't have problems with room interactions. That's a major source of problems in hifi. Secondly, headphones are usually single point sources, which is ideal.
Speaker on the other hand deviate from these ideals because the room is usually a culprit because the bass muddles the mids and the imaging is affected by the room. Even worse, the speaker is a multi way which uses a crossover. You should see what a crossover does to a signal. You also have the problem of multiple sources instead of a point source. If you are not preserving the original signal, it is not in accordance with the tenets of hifi is it? If that's what you like, fine but it's not hifi.
 
Well Audiophile.....
Unless you are strictly speaking of binaural recordings, I'm afraid I can not agree with you as far as the topic of this thread is concerned.
As far as stereophonics using headphones. You will not get an accurate image unless you believe there are little people playing instruments and singing in your head!
;)
 
Administrator
Joined 2004
Paid Member
If that's what you like, fine but it's not hifi.
You seem to have a very narrow idea of High Fidelity. Some people do, it's a choice.

Since you have chosen the name "The Audiophile" perhaps it behooves you to read the old "Revue de l'Audiophile" magazine published in Paris 1977-1995. Good friends of mine and I was part of the crew in the 1980s. If you don't read French, perhaps you can find some translations online. Very worthwhile reading and might help you shake your rigid view of "Hi-Fi." If you want it shaken, that is.
 
I guess a virtual model of a great room would be OK, it's the speakers that worry me.

anywhere you can get ~1/2 hr in the sweet spot, can plug in the Smyth box - people even rent time in mastering studios

you could offer to "demo" it to your local Audio club, at well heeled member's homes, maybe even a high end store' demo rooms
 
You seem to have a very narrow idea of High Fidelity. Some people do, it's a choice.

Since you have chosen the name "The Audiophile" perhaps it behooves you to read the old "Revue de l'Audiophile" magazine published in Paris 1977-1995. Good friends of mine and I was part of the crew in the 1980s. If you don't read French, perhaps you can find some translations online. Very worthwhile reading and might help you shake your rigid view of "Hi-Fi." If you want it shaken, that is.

This lack of rigid view in the hifi industry is precisely the problem we face today. How many permutations of speaker designs are we going to continue seeing being brought into the market? You are right, I do not support an anything goes attitude. Speakers should not be seen as musical instruments. They ought to be designed to reproduce the largest possible variety of sounds. Yet there are many constraints in bandwidth, polar response and ability to recreate 3d space. The phantom image is an complex psychoacoustic illusion. It cannot possibly exist in more than a single sweet spot. That is a severe restriction imposed by the theory. But the 'anything goes' culture has created speakers which supposedly widen the sweet spot.
Its also produced speakers whose cabinet ring and resonate whereas others would argue a speaker should be as inert as possible. There are many double standards and I am sick of it.
 
Last edited:
Administrator
Joined 2004
Paid Member
Your comments presuppose that there is only one engineering solution to any given problem, and that the possibility of perfectly accurate reproduction exists - it doesn't, limitations in materials, physics and room acoustics, not to mention limits in electronics and media all get in the way. I haven't even mentioned human perception or the economic aspects of all of this.. :D

Like you I don't think speaker systems should be musical instruments OTOH I don't believe that you would want to live with my interpretation of what is right anymore than I would want to live with yours.
 
Your comments presuppose that there is only one engineering solution to any given problem, and that the possibility of perfectly accurate reproduction exists - it doesn't, limitations in materials, physics and room acoustics, not to mention limits in electronics and media all get in the way. I haven't even mentioned human perception or the economic aspects of all of this.. :D

Like you I don't think speaker systems should be musical instruments OTOH I don't believe that you would want to live with my interpretation of what is right anymore than I would want to live with yours.

Which bit of my comments presuppose those two things?
The 'problem' in question in this case is 'perfect reproduction of sounds'.
Yet you say the possibility of that does not exist. If the 'problem' doesnt exist it doesnt make sense to solve it?

I did not presuppose that there is only one solution. I believe that the audiophile community do not have a well defined problem to even attempt a solution. The reason is, sound is subjective and there will be variation in what ought to be defined as perfect reproduction. But that is no excuse. Humans are fallible so we resort to measuring equipment to support our subjective views. And therein lies another problem in that we do not fully understand how to relate measurements with our subjective experience.
My view is that we should seek to address these issues. The differences in speakers ought to be getting smaller and smaller if we are making progress. Instead what we see is a new speaker coming out every year which claims to be a vast improvement over its predecessor. We see increasing divergence. Part of this must be deliberate subterfuge for economic purposes as you mention
 
Cool! I've got to hear one, then. How well does it do the phantom image trick? Or does that depend on the speakers and room you've modeled?

My main worry with the Smyth is that I don't want to have a replica of someone else's room and speakers, however good they may be. I'd rather have it simulate the perfect speaker and room, if there is such a thing. Or is that asking too much? I guess a virtual model of a great room would be OK, it's the speakers that worry me.

The Realiser doesn't "model" the room, it measures the transfer functions between speakers and listener and applies that filter to the playback signal. It also corrects for headphone response errors by measuring the transfer function between listener and headphone.

Here's a netcast about the Realiser:
Home Theater Geeks 136 | TWiT.TV
 
Just another Moderator
Joined 2003
Paid Member
I've certainly heard 3D phantom images. Though not so much on music. Usually with DVD's or even plain old stereo television (and no I don't have surround just two front speakers).

The one that surprised me the most was when I heard a voice actually behind me (I turned around) and then on the TV the person walked into the scene from behind the camera position...

I also thought that there was a helicopter outside up very high one time, then the chopper came into view (up very high) on the TV screen.

Recently watching a movie a car sprayed gravel when cornering hard on a dirt road and I heard it falling on the floor off to my left.

Thunder is another one that I often hear coming from outside the house when it is on the sound track. Not always it depends on the recording.

Funnily enough the one thing I've not heard is depth behind the speakers... perhaps because they have always been too close to the back wall....

My new room though (I've moved house) is too echoey... I think I'm going to struggle to get good imaging :(

Tony.
 
Having just read about envelopment, I'd say no. It's mostly what's happening between the speakers that is 3D, not the space in the rest of the room. Although the sound does spread past the speakers left and right, the 3 dimensionality is mostly between the speakers. You'll hear left and right, depth and height. When it's really good, there is a sense of dimension to individual sounds, like a singer or an instrument. That's rare, but does happen.

Sounds outside the speaker is easy to do, just flip the polarity if one speaker. :) I've heard some amazing effects that way, alas it all but kills the center vocals.

We are then on the same page! By 3D i initially understood real 3D sources 360 deg.. :p
We then experience exactly the same thing, holographic and fairly realistic sound shapes between the speakers, for ex Chesky's Jen Chaplin.
Outside the stereo zone, yes, happens too, with very specific sound processing, Q sound and such but not on "traditionnal" mixes..
 
Last edited:
Lolo,

Looking at my TV set and its stereo standard loudspeakers (drivers 17 cm with tweeters), sounds often seem to emerge further at left than the left loudspeaker real location or further at right than the right loudspeaker real location, or even vertically.
I think that this is only due to well mastered effets at the production process.

Same thing here too! My bedrom is untreated yet and the TV is right in the middle, the reflexions make the sound as coming from the sides, the speakers are behind the screen. Funny one! :) I guess I could add a soundbar to use the effect even further..
 
my system does decent depth but not height. sometimes I think I hear a bit of vertical delineation but nothing extraordinary. I think it's a matter of good room acoustics, I have a smallish room, untreated, with not much space to play with positioning.
I can't say I have heard striking height resolution even with very expensive systems so I try not to give it too much thought.
I think depth is more important and it annoys the hell out of me when the singer hides behind the drum kit or puts his/her head inside the snare drum. mostly because of crappy recording, never happens with good ones.
wrt height only thing that really bothers me is the levitating bass drum.

but even worse are the unstable or unrealistic images, guitar strings that are meters long, cymbals collapsing in space to become part of a vague cloud of sound between the speakers etc. audio hell. fortunately my systems doesn't get that disease.
 
Administrator
Joined 2004
Paid Member
Again, check out la Revue de l'Audiophile. No singing cabinets there, quite the contrary. Sand filled, double walled, 25mm marine plywood is more like it. Electronics that are simple and well engineered.

If you have the chance, find a dealer in your area who has the Utopia line of Focal speakers set up in a good space. That's the easiest way I can think of for you to hear what I'm talking about.

Don't fall into the trap that people who have experiences other than yours, are wrong. That's faulty reasoning. Don't automatically assume that others have a certain point of view, you can easily be wrong. E.G., assuming that anyone in this thread wants a speaker that is a musical instrument or adds something to the signal. You are probably confusing us with someone else.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.