Soundstage

[Cosmik]

Your antipathy against dipole radiation speakers seems very odd and out of real world to me. Many natural sources of sound have a dipole nature, and so do many musical instruments.

Yes, someone made that point before, and indeed it might be possible that a dry recording of certain instruments would benefit from a dipole speaker in terms of ultimate holographic reproduction of that instrument as though playing in your room. But the aim of a speaker is not to impart upon the whole composite recording the same quirky effect - just as a quirky frequency response wouldn't really show up on a single voice (it would just sound like a change in the formant of the voice), but would show up much more clearly if overlaid on multiple voices and instruments.

I could make exactly your point by saying "Why shouldn't an audio system comprise multiple random transducers pointing in different angles, because that is what an orchestra looks like, acoustically."

By all means justify a dipole speaker as a quirky effect, but in terms of using dipoles as exemplars of soundstage, they are no different from a DSP-based artifical spaciousness effect or whatever. If the question is what stereo soundstage should resemble, dipole speakers are not the example we should be referring to. Dipole speakers in many rooms will give us unstable soundstage effects that extend beyond the speakers, plus some 'in-head' effects. If we regard these as 'genuine', and overlook the phasiness, etc. then people may think that their monopole speakers are falling short. They're not: their monopole speakers may well be producing a beautiful stable text book stereo soundstage that produces no uncomfortable sensations with head movement, even for listeners who are sensitive to 'anti-phase' (as I believe some people are).

A Google search for "phasey" or "phasiness" and "dipoles" produces quite a few relevant results, so I don't think I am alone in noticing it.

 

[Sergei]

Do you have any hint of what "high enough" could refer to in the measurements territory?

No, I don't recall seeing a peer-reviewed article with measurements regarding this. It doesn't mean they don't exist, it means I didn't have a need or curiosity to search for them.

The insight comes mostly from audio mixing practice. Applying distortions to enliven vocals is common. For instance, compare voice of Rihanna on "Diamonds" song with her voice in "Battleship" movie.

One needs to be careful to not overdo it, especially if there are several vocalists, and thus some or all of them are panned to the sides. Too much distortion may result in turning an orderly song delivery into a wild party, with more apparent vocalists, jumping all over the scene.

Conversely, applying too much of harmonizing pitch shifting may result in several vocalists apparently merging into one, and occasionally splitting again, creating yet another type of disturbing sound stage.

Then again, as I mentioned, sometimes weird and disturbing sound stage is exactly what producer wants. Listen to Harry Potter movies scenes involving the He Who Must Not Be Named for outstanding examples.

 

[Sergei]

Once you visit a recording studio and discuss recording process with a recording engineer you may change your mind.

Exactly right. Also, you'd change your mind about a lot of things once you go through the whole process yourself: tracking the musicians with multiple microphones, mixing, and mastering.

I'm an amateur recording engineer and mixing engineer. I am at a beginner level in mastering. Yet I tried to learn from the best, and visited quite a few recording studios. As it relates to this conversation:

Never once I saw a professional studio using dipoles.

Mixing studios don't tend to bother too much with controlling reflections. Using near-field to mid-field monitoring (one arm length to three arm lengths from speaker to ear) takes care of that. They do viciously suppress standing waves though. Corner bass traps abound.

In addition to what is done in mixing studios, mastering studious strive to carefully eliminate all reflections that may reach the engineer's sweet spot. They also strive to use as geometrically simple and symmetrical room layouts as possible. Sound traps for all frequencies are obsessively applied.

I have yet to meet a single professional audio engineer who doesn't understand exactly what he or she is doing to the sound signal. Their level of understanding of music and acoustics tends to be, well, professional.

The "evil" men pushing the drastic dynamic range compression and other "sins" are actually producers. They have to do it, as they need to make sure that the records destined to be popular sound decently on mass-market systems, including the cheapest ones in moving cars.

Most audio engineers judge themselves and their peers not on how "faithful" the records are, but on how well the records fit what producers asked for. Producers are also the ones who balance what musicians want to hear with what will sell the highest number of copies.

An example of what audio engineers regard as "one of the best mixes of all times" is Grenade by Bruno Mars. Not only does it masterfully convey the intended emotion, it also sounds darn nearly exactly same on every sound system I listened to it through - a very sophisticated DSP went into that.

If sound engineers (recording, mixing, mastering) are asked to create a masterpiece that may only sound well on a high-end system, they do precisely that. An example of that is Fields of Gold by Sting. It sounds "meh" on cheap systems. It is drop-dead-gorgeous in a mastering studio.

Lightly-processed acoustic sound records is a narrow niche. The best records in this genre do indeed make you feel like the live instruments and vocalists are performing right next to you in a real room. Mark Waldrep of AIX records is a widely acknowledged master of this.

The majority of popular music is heavily processed. At extreme, there may be no human performers involved: witness the Hatsune Miku phenomenon (https://www.washingtonpost.com/ente...557cdc-7ed3-11e8-b660-4d0f9f0351f1_story.html).

My take on dipoles: they may enhance some music pieces which are otherwise too plain for the listener's taste, yet such enhancement is not universally beneficial for all music and to every listener. Basically, they are a condiment. Do you want to eat absolutely everything with Ketchup?

 

[Duke]

You are starting from an existing type of (Frankenstein) speaker, and throwing out the challenge to show that it is OK to produce the arbitrary effects that it does, rather than starting at a definition of what a speaker should do and sticking to it. Show me *why* a speaker should spray anti-phase out of the back rather than building such a speaker and retrospectively trying to justify it.

I'm going to hope that you are genuinely curious, that your skepticism is accompanied by open-mindedness (this being a "science" forum rather than a "dogma" forum), and that I have done a really poor job of explaining.

First, my definition of "what a speaker should do": Imo the job of the speaker system is to get both the first-arrival sound and the reverberant sound as perceptually correct as possible.

(If you would like a more philosophical definition of what a speaker should do: Imo the goal is to create the perception of hearing live music, or as close as possible [even if the recording never actually existed as a live performance].)

I'm not going into detail about everything that goes into getting the first-arrival sound right. But let us note that, relevant to the topic of this thread, we get our primary localization cues from the first-arrival sound, after which the Precedence Effect kicks in, suppressing directional cues from the ensuing reflections.

What matters in the reverberant field is sometimes counter-intuitive, so I'll go into a bit more detail here. Most of the sound that most people hear in most rooms is reverberant sound, and most of that reverberant sound started out as off-axis energy. While the reflections contribute relatively little to image localization, they contribute to loudness, timbre, and spaciousness. Done right they can enhance clarity (by giving the ear multiple "looks" at complex sounds, according to Toole), and done wrong they can degrade clarity.

As a general principle, we want the reverberant energy's spectral balance to track that of the first-arrival sound (some reduction in the high end is okay). The reason is, if the reverberant energy is over-emphasizing some part of the spectrum, it makes that part of the spectrum sound louder than it otherwise would have. This skews the perceived tonal balance accordingly and can degrade timbre and clarity and contribute to listening fatigue.

The arrival time of the reflections also matters. Early reflections are generally detrimental to clarity (according to Geddes and Griesinger), though early sidewall reflections can broaden the stereo image a bit, which many listeners enjoy (Toole). In general the earlier the reflections arrive, the more detrimental they are to clarity (Griesinger). In general reflections that arrive roughly 10 milliseconds or more behind the first-arrival sound (that figure comes from Geddes) are beneficial to timbre and spaciousness without any significant downside.

So to sum up:

1. We want all reflections to be spectrally correct regardless of whether they are early or late.

2. We want to minimize early reflections (I'm siding with Geddes and Griesinger, rather than with Toole, on this).

3. We want to encourage beneficial late reflections.

In most rooms, a wide-pattern monopole speaker will generate a lot of early reflections (bad), and a lot of late reflections (good). The spectral balance of the reverberant energy is usually skewed as the radiation pattern usually varies significantly with frequency (bad).

In most rooms, a narrow-pattern monopole will generate fewer early reflections (good), but will correspondingly have less energy arriving as late reflections (not so good, but imo still better overall than a wide-pattern monopole). The spectral balance of the reverberant energy is usually pretty good.

Positioned well out into the room, good dipole speakers generate relatively few early reflections (good) and a lot of late reflections (also good), due to the backwave energy arriving "late". The spectral balance of the reverberant energy is usually good, as that backwave energy is full-spectrum.

As shown by researcher James M. Kates, dipoles generally have smoother in-room bass than monopoles.

When set up properly, good dipole speakers interact with rooms in a way that is arguably more psychoacoustically beneficial than most monopole speakers.

Dipole speakers often have issues in efficiency, bandwidth, bass impact, sweet spot size, power handling, size, cost, and real estate requirements which make them impractical for many people. Just like virtually everything else in speaker design, there are tradeoffs involved.

Does this answer your question?

 

[oivavoi]

Exactly right. Also, you'd change your mind about a lot of things once you go through the whole process yourself: tracking the musicians with multiple microphones, mixing, and mastering.

I'm an amateur recording engineer and mixing engineer. I am at a beginner level in mastering. Yet I tried to learn from the best, and visited quite a few recording studios. As it relates to this conversation:

Never once I saw a professional studio using dipoles.

Mixing studios don't tend to bother too much with controlling reflections. Using near-field to mid-field monitoring (one arm length to three arm lengths from speaker to ear) takes care of that. They do viciously suppress standing waves though. Corner bass traps abound.

In addition to what is done in mixing studios, mastering studious strive to carefully eliminate all reflections that may reach the engineer's sweet spot. They also strive to use as geometrically simple and symmetrical room layouts as possible. Sound traps for all frequencies are obsessively applied.

I have yet to meet a single professional audio engineer who doesn't understand exactly what he or she is doing to the sound signal. Their level of understanding of music and acoustics tends to be, well, professional.

The "evil" men pushing the drastic dynamic range compression and other "sins" are actually producers. They have to do it, as they need to make sure that the records destined to be popular sound decently on mass-market systems, including the cheapest ones in moving cars.

Most audio engineers judge themselves and their peers not on how "faithful" the records are, but on how well the records fit what producers asked for. Producers are also the ones who balance what musicians want to hear with what will sell the highest number of copies.

An example of what audio engineers regard as "one of the best mixes of all times" is Grenade by Bruno Mars. Not only does it masterfully convey the intended emotion, it also sounds darn nearly exactly same on every sound system I listened to it through - a very sophisticated DSP went into that.

If sound engineers (recording, mixing, mastering) are asked to create a masterpiece that may only sound well on a high-end system, they do precisely that. An example of that is Fields of Gold by Sting. It sounds "meh" on cheap systems. It is drop-dead-gorgeous in a mastering studio.

Lightly-processed acoustic sound records is a narrow niche. The best records in this genre do indeed make you feel like the live instruments and vocalists are performing right next to you in a real room. Mark Waldrep of AIX records is a widely acknowledged master of this.

The majority of popular music is heavily processed. At extreme, there may be no human performers involved: witness the Hatsune Miku phenomenon (https://www.washingtonpost.com/ente...557cdc-7ed3-11e8-b660-4d0f9f0351f1_story.html).

My take on dipoles: they may enhance some music pieces which are otherwise too plain for the listener's taste, yet such enhancement is not universally beneficial for all music and to every listener. Basically, they are a condiment. Do you want to eat absolutely everything with Ketchup?

Interesting comment. But speaking as someone who has used active studio monitors at home quite a lot, who dabbles in making music and who knows quite a lot of people who work with sound professionally, I don't think this "wow let's look at the professionals and see what they do" take is necessarily a thing to strive for (apologies if I simplify your views here). Mixing and mastering professionals seem to me to be just as prone to being biased and being victims of fashion or habit as the average audiophile.

For one thing, mixing and mastering engineers seem to prefer different environments - mixing engineers currently prefer drier acoustic environments, mastering engineers currently prefer wetter acoustic environments (there was a study which showed this some time ago, but I can't be bothered to find it). So who are the ones it is more "correct" to emulate - the mixing or the mastering engineers?

Also, the major studios have undergone different periods, where different kinds of acoustics were in vogue. Were the professionals right when the "live end dead end" thing was all the rage, or are they more right now when Northward rooms seem to be the gold standard? (which follow a different philosophy)

If you look at discussions over at Gearslutz, quite a lot of them seem to be rather "audiophile" in their obsessions - they discuss DACs, ADCs, interfaces and other gear stuffs quite a lot, even though all of these things should be audibly transparent by now. And things are hyped up or down and go in and out of fashion - one year it's the passive Amphion monitors, the next year it's the Kiis. And so on.

This is not to say that they don't know what they do. Many sound pros are very skilled, of course. But it just seems to me like the determining factor is the human factor, more than the acoustics or the gear. Good sound engineers with good skills produce good stuff, and are able to make good sound quite irrespective of the acoustics or gear they work with. After all, good sound and good recordings can be found in almost every decade of modern recorded music, even though the equipment and the acoustics used in the studio/recording venue has been varying wildly.

As for the relevance to us/me/audiophiles, I'm wary of arguments such as "oh hey, nothing like that has ever been used in a studio"! For professionals, gear and acoustics is a tool. For me in the home it's all about musical enjoyment.

 

[mitchco]

Agree with @Krunok and @Sergei - spent +10,000 hours as a recording mixing engineer "back in the day." Myself and the folks I worked with, all tried to get the best possible sound as most of us were in it for the creativity and passion doing what we love. The process of recording, mixing and mastering is both art and science. In my experience, folks (and musicians) that have never been to a recording studio or sat through the creative process are always surprised saying, I never knew about all of the details. And while we can hear through rooms, listening to ones creation in a "properly" acoustically designed control room, built from the ground up with no vibrations, no standing waves, proper diffusion, and extremely low ambient noise floor, makes it really hard to listen in ones typical living room

The only studio/control room I know that uses dipoles is Barry Diament's: http://www.barrydiamentaudio.com/

 

[Juhazi]

I think that Cosmik and Sergei are excaggerating the effect that dipoles give. If you sit at two arm's lenth of dipoles in a studio (or even at home), they sound just like monopoles. A room with RT>0.6 also will most propably be too lively for dipoles.

In some other thread F. Toole showed his listening setup and room at home and said that he prefers multichannel recordings and mild spatial effect processing of stereo, for most recordings. He obviously isn't a fundamentalist, more a hedonist

I have noticed that some recordings will clearly suffer from dipole effect, but they are rare. The caveat of dipole speakers is that I can't switch the effect off, like the Dolby ProLogic Music effect that I used a lot before making the dipole speakers.

 

[oivavoi]

I'm going to assume that you are genuinely curious, that your skepticism is accompanied by open-mindedness (this being a "science" forum rather than a "dogma" forum), and that I have done a really poor job of explaining.

First, my definition of "what a speaker should do": Imo the job of the speaker system is to get both the first-arrival sound and the reverberant sound as perceptually correct as possible.

(If you would like a more philosophical definition of what a speaker should do: Imo the goal is to create the perception of hearing live music, or as close as possible [even if the recording never actually existed as a live performance].)

I'm not going into detail about everything that goes into getting the first-arrival sound right. But let us note that, relevant to the topic of this thread, we get our primary localization cues from the first-arrival sound, after which the Precedence Effect kicks in, suppressing directional cues from the ensuing reflections.

What matters in the reverberant field is sometimes counter-intuitive, so I'll go into a bit more detail here. Most of the sound that most people hear in most rooms is reverberant sound, and most of that reverberant sound started out as off-axis energy. While the reflections contribute relatively little to image localization, they contribute to loudness, timbre, and spaciousness. Done right they can enhance clarity (by giving the ear multiple "looks" at complex sounds, according to Toole), and done wrong they can degrade clarity.

As a general principle, we want the reverberant energy's spectral balance to track that of the first-arrival sound (some reduction in the high end is okay). The reason is, if the reverberant energy is over-emphasizing some part of the spectrum, it makes that part of the spectrum sound louder than it otherwise would have. This skews the perceived tonal balance accordingly and can degrade timbre and clarity and contribute to listening fatigue.

The arrival time of the reflections also matters. Early reflections are generally detrimental to clarity (according to Geddes and Griesinger), though early sidewall reflections can broaden the stereo image a bit, which many listeners enjoy (Toole). In general the earlier the reflections arrive, the more detrimental they are to clarity (Griesinger). In general reflections that arrive roughly 10 milliseconds or more behind the first-arrival sound (that figure comes from Geddes) are beneficial to timbre and spaciousness without any significant downside.

So to sum up:

1. We want all reflections to be spectrally correct regardless of whether they are early or late.

2. We want to minimize early reflections (I'm siding with Geddes and Griesinger, rather than with Toole, on this).

3. We want to encourage beneficial late reflections.

In most rooms, a wide-pattern monopole speaker will generate a lot of early reflections (bad), and a lot of late reflections (good). The spectral balance of the reverberant energy is usually skewed as the radiation pattern usually varies significantly with frequency (bad).

In most rooms, a narrow-pattern monopole will generate fewer early reflections (good), but will correspondingly have less energy arriving as late reflections (not so good, but imo still better overall than a wide-pattern monopole). The spectral balance of the reverberant energy is usually pretty good.

Positioned well out into the room, good dipole speakers generate relatively few early reflections (good) and a lot of late reflections (also good), due to the backwave energy arriving "late". The spectral balance of the reverberant energy is usually good, as that backwave energy is full-spectrum.

As shown by researcher James M. Kates, dipoles generally have smoother in-room bass than monopoles.

When set up properly, good dipole speakers interact with rooms in a way that is arguably more psychoacoustically beneficial than most monopole speakers.

Dipole speakers often have issues in efficiency, bandwidth, bass impact, sweet spot size, power handling, size, cost, and real estate requirements which make them impractical for many people. Just like virtually everything else in speaker design, there are tradeoffs involved.

Does this answer your question?

Just a subjective note: I'm very picky when it comes to stereo setups, and usually I walk away feeling that it was "fake" and didn't sound like the real thing (live unamplified music - I'm mostly a jazz and classical guy). I have heard dipole setups which didn't convince me, and which sounded "phasy", like Cosmik says. But some of the very few setups I've heard which have convinced me that I was listening to an actual real musical event have been dipole setups. It was exactly the combination of clarity and envelopment which I liked, which is how I also perceive real acoustic music.

I've never owned dipoles myself, and this is all subjective, of course. I'm not sure what to make of it theoretically. But I have - FWIW - become subjectively convinced by dipole setups on a couple of occasions, at least.

 

[Duke]

I think that Cosmik and Sergei are exaggerating the effect that dipoles give...

It is intuitive to think that adding a bunch of out-of-phase energy to what's on the recording must be a sonic disaster.

Psychoacoustics is often counter-intuitive.

When you're in the middle of an argument, defending your perfectly logical beliefs while attacking the seemingly insane claims of someone else, that someone else is probably the last person in the world you're going to listen to. So I have little expectation of changing Cosmik's mind. His criticisms of dipoles rely on emotionally-charged language rather than scientific information, and I don't begin to have the energy to match him there.

But some of the very few setups I've heard which have convinced me that I was listening to an actual real musical event have been dipole setups. It was exactly the combination of clarity and envelopment which I liked, which is how I also perceive real acoustic music. [emphasis Duke's]

You have perfectly described what a good dipole system can do when set up properly. Translated into more technical terms, dipoles can get the first-arrival sound and the reverberant sound perceptually correct.

Thus as you describe, dipoles offer the possibility of having BOTH clarity and envelopment. Not that dipoles are the only way to get there... but that would be another post for another day.

 

[Cosmik]

But some of the very few setups I've heard which have convinced me that I was listening to an actual real musical event have been dipole setups. It was exactly the combination of clarity and envelopment which I liked, which is how I also perceive real acoustic music.

I'm not saying that's not possible - just as I wouldn't rule out the "SuperWide Stereo (TM)" button from producing a fantastic novelty effect on some recordings. I'm just asking what the theoretical justification is for a speaker that generates a spray of antiphase on all recordings. Sure, if you place it ten feet from the front wall, the antiphase quirks will be less pronounced; if you play around with soft wall hangings, etc. no doubt it will be even less pronounced. But... there's still no theoretical justification for it unless special post hoc mitigations are conjured up.

P.S. I've been making recordings since I was 5. Still got them! Built and used many, many of my own mixers, reverb units, digital delay lines, samplers, etc. etc. Been doing it all my life. Which is why I probably know that it is possible to hear a better version of a recording than the 'engineer' ever did.

 

[Duke]

...there's still no theoretical justification for it unless special post hoc mitigations are conjured up.

Well done. You have characterized all of my technical arguments as "post hoc mitigations" and dismissed them as being "conjured up", so you don't need to actually engage and refute any of them.

How about we call a truce and agree to disagree?

 

[Cosmik]

Well done. You have characterized all of my technical arguments as "post hoc mitigations" and dismissed them as being "conjured up", so you don't need to actually engage and refute any of them.

How about we call a truce and agree to disagree?

I'm not specifically picking on you. I'm stating what I believe a speaker should do, and why I don't believe that dipoles are being justified on theoretical grounds. If you wanted to define why a speaker should be a dipole, then I would be interested - rather than just saying that existing dipoles are often adequate and sometimes generate a really nice effect. If the justification is that a speaker without a back is easier to design without resonances, etc. then that would be another way of approaching it.

There is a speaker often discussed in these parts that also generates anti-phase from the rear - using separate drivers - but the designer has stated the reason why he has done this. The assumption (on my part) is/was that the 'antiphase' doesn't escape into the room. I hope that's the case .

 

[KSTR]

I'm just asking what the theoretical justification is for a speaker that generates a spray of antiphase on all recordings. Sure, if you place it ten feet from the front wall, the antiphase quirks will be less pronounced; if you play around with soft wall hangings, etc. no doubt it will be even less pronounced. But... there's still no theoretical justification for it unless special post hoc mitigations are conjured up.

I see the playback via dipoles in a room as another valid alternative projection mechanism. If it sounds good and convincing, creating a nice and seemingly proper auditory illusion (and it can do this very well, IHMO), it is valid. As are Omnis, Trinaural Upmixing, etc. In a home-HiFi setup for recreational use anyway.

 

[Duke]

For one thing, mixing and mastering engineers seem to prefer different environments - mixing engineers currently prefer drier acoustic environments, mastering engineers currently prefer wetter acoustic environments (there was a study which showed this some time ago, but I can't be bothered to find it). So who are the ones it is more "correct" to emulate - the mixing or the mastering engineers?

This is a great and valuable insight into the fact that different tools (in this case different speakers + different acoustics) are called for in different situations, even at the highest professional level.

I've designed custom mastering monitors with apparently good results, but when I looked into mixing monitors I found something unexpected: Many of the most successful mixing monitors are deliberately NOT flat. They intentionally emphasize specific portions of the spectrum, either to throw a spotlight on that area, or to encourage a mix with a subjectively pleasing tonal balance as the engineer compensates for the speakers' baked-in emphasis. Despite reading several books on the subject I never felt like I had a good enough handle on exactly "where the goal posts are" to design a worthwhile mixing monitor. And besides, engineers want mixing monitors that have some popularity so they can discuss using them with others who have relevant experience.

 

[Burning Sounds]

I'm not specifically picking on you. I'm stating what I believe a speaker should do, and why I don't believe that dipoles are being justified on theoretical grounds. If you wanted to define why a speaker should be a dipole, then I would be interested - rather than just saying that existing dipoles are often adequate and sometimes generate a really nice effect. If the justification is that a speaker without a back is easier to design without resonances, etc. then that would be another way of approaching it.

I debated whether to join in here as we've had this discussion before (more than once).

Here's some bedtime reading for you

http://www.linkwitzlab.com/publications.htm

 

[Duke]

If you wanted to define why a speaker should be a dipole, then I would be interested

Did you read post number 104 above? You previously dismissed my explanations in that post as "special post hoc mitigations" that I had "conjured up", and that post contains background information relevant to my answer of your question here.

In post number 104 above I went into some (admittedly limited for the sake of brevity) detail about what matters, what a dipole can do well that matters, and also mentioned things that dipoles typically don't do well. So the answer to "why a speaker should be a dipole" is, a speaker should be a dipole if the things it does well are higher priorities than the things it doesn't do well, and if there is no obviously better and more cost-effective way of doing those things. See also post number 108 by oivavoi above.

I'm stating what I believe a speaker should do...

Which is... ?? Please be specific.

... and why I don't believe that dipoles are being justified on theoretical grounds.

Please clearly state exactly what it is dipoles do wrong and why it is wrong. Try to leave the emotionally-charged statements out. Anyone can make emotionally-charged statements disparaging something they disagree with, but that gets in the way of useful communication. Let's find out exactly where we disagree about loudspeaker design, and if we fail to find common ground, at least we will understand one another.

I have done you the courtesy of making an honest attempt to answer your questions. I invite you to do the same.

... rather than just saying that existing dipoles are often adequate and sometimes generate a really nice effect.

I never said that. Please don't put words in my mouth. It seems to me like you're trying to make me look stupid.

Good dipoles set up well aren't adding a false perception of something that wasn't on the recording to begin with. Rather, they allow you to perceive something that is already there on the recording but was being masked. The sense of envelopment that oivavoi mentions in post number 108 above could not possibly be synthesized by the few milliseconds the backwave is delayed in its bounce off the wall. That would be psychoaoustically impossible. Rather, the envelopment information was ALREADY on the recording, and was UNMASKED when the dipole speaker resulted in less "small room signature" being super-imposed on top of the recording.

Let me say that again another way, and in a bit more detail. A good recording has all the information on it that we need to hear both clarity and a sense of envelopment & immersion in the acoustic space of the recording (whether natural or enhanced or synthesized). So the envelopment/immersion cues are reaching our ears (assuming a good recording), but our ears are getting mixed messages, and a different message is dominating. That unfortunately dominant message is what could be called "small room signature". "Small room signature" comes primarily from having lots of early reflections.

Now this next part is imo a big deal:

There is a key we can use to unmask that envelopment/immersion information: The ear/brain system judges the size of a room by the time delay between the first-arrival sound and the "center of gravity" of the reflections. If we can shift that "center of gravity", we can accordingly shift the ear/brain system's perception of room size, and therefore shift the "room signature" which is superimposed on the recording. A properly set up dipole speaker does just that: It pushes this "center of gravity" back in time (because of the time it takes for the backwave energy to arrive at the listening location), and so we get less "small room signature". Since the ear/brain system is now getting a much weaker "small room" message, the envelopment/immersion messages on the recording can now dominate our perception. This is not adding a pleasing "effect"; rather, it is removing a veil that had been obscuring information which was there all along.

And this arguably has implications for "soundstaging".

Cosmik, I don't really expect you to believe me; one might even say that I'm making extraordinary claims and respond with a call for extraordinary proofs. But please try to refute my arguments instead trying to make me look stupid. There are a lot of links in my chain, maybe pick one and really break it instead of just mocking it.

 

[Sergei]

I don't think this "wow let's look at the professionals and see what they do" take is necessarily a thing to strive for (apologies if I simplify your views here).

Yes, it is oversimplification of my views. Of course the goals and thus approaches and tools used by creators are generally different from those of consumers. My point was that learning from professionals, including learning through doing, is generally beneficial for improving the "quality of consumption culture", if you wish.

Mixing and mastering professionals seem to me to be just as prone to being biased and being victims of fashion or habit as the average audiophile.

I would posit that professionals are less prone to being biased or affected by fashion regarding the tools they use. Habit, yes, I guess that would affect them more than audiophiles, for the obvious reason of the habit reinforcement activities being much more frequent.

For one thing, mixing and mastering engineers seem to prefer different environments - mixing engineers currently prefer drier acoustic environments, mastering engineers currently prefer wetter acoustic environments (there was a study which showed this some time ago, but I can't be bothered to find it). So who are the ones it is more "correct" to emulate - the mixing or the mastering engineers?

Also, the major studios have undergone different periods, where different kinds of acoustics were in vogue. Were the professionals right when the "live end dead end" thing was all the rage, or are they more right now when Northward rooms seem to be the gold standard? (which follow a different philosophy)

Good points indeed. Professionals are humans too Still, this is nothing compared to the audiophile fads, which may ramp up out of nowhere and completely die out in the course of few months.

If you look at discussions over at Gearslutz, quite a lot of them seem to be rather "audiophile" in their obsessions - they discuss DACs, ADCs, interfaces and other gear stuffs quite a lot, even though all of these things should be audibly transparent by now. And things are hyped up or down and go in and out of fashion - one year it's the passive Amphion monitors, the next year it's the Kiis. And so on.

I'm not sure how professional these particular Gearslutz participants are. One of the most striking things for me personally is how budget-conscious professional audio engineers are these days. The era of fat audio production budgets is long gone. My take is that such fashion-driven discussions are more characteristic of the musicians and engineers transitioning from more amateur to more professional phases of their careers.

This is not to say that they don't know what they do. Many sound pros are very skilled, of course. But it just seems to me like the determining factor is the human factor, more than the acoustics or the gear. Good sound engineers with good skills produce good stuff, and are able to make good sound quite irrespective of the acoustics or gear they work with. After all, good sound and good recordings can be found in almost every decade of modern recorded music, even though the equipment and the acoustics used in the studio/recording venue has been varying wildly.

As you know, the sound reproduction gear the professionals use is split rather sharply onto two varieties: (1) The most accurate they can justify buying, used for "looking into" the mix for hours and hours without fatigue, and (2) trashy contraptions meant to simulate the worst varieties of consumer gear, used for much shorter periods of validating the mix.

I would say that the first variety of gear tends to meet at least minimal requirements of sonic transparency. Not to put Mackie down, yet in my limited experience the highest-end Mackie gear is something that professional sound engineers here in Northern California would consider the lowest fidelity gear acceptable for serious work.

As to the high end, it varies wildly, with all the usual suspects already mentioned on this thread, and many more. If I were to pick up a workhorse most often encountered around here, that would be large 3-way ATC monitors, such as SCM100ASL (http://atcloudspeakers.co.uk/professional/loudspeakers/scm100asl-pro/).

ATC was established in mid-1970s, with the first notable customers including Pink Floyd and Supertramp. ATC reached the holy grail of sonic transparency for piano and vocals by mid-1990s. So, it's been quite a few decades of excellent gear being available to professionals. Once again, the fact that I didn't encounter something doesn't mean it doesn't exist, yet in my experience almost all professionals have been using sonically transparent gear for quite a while.

As for the relevance to us/me/audiophiles, I'm wary of arguments such as "oh hey, nothing like that has ever been used in a studio"! For professionals, gear and acoustics is a tool. For me in the home it's all about musical enjoyment.

This is perfectly fine of course. However, it is helpful to keep in mind at all times what's going on. What is happening at most homes is yet another stage of mastering: applying equalization, reverberation, non-linear distortions etc. As long as these sound transformations are applied consciously, skillfully, and in moderation, music consumers may achieve excellent results on certain music fragments.

In other cases, even seemingly innocuous sound augmentation can utterly destroy the original intent of the music creators. Getting back to concrete example: when I listened to the Fields Of Gold inside a mastering studio, it was immediately apparent that the creators were conveying the mood through what appeared as a grainy fabric of space, being slowly perturbed by a lazy wind. On some lesser systems, the effect was gone, replaced by a nondescript elevation of the noise floor.

 

[oivavoi]

Yes, it is oversimplification of my views. Of course the goals and thus approaches and tools used by creators are generally different from those of consumers. My point was that learning from professionals, including learning through doing, is generally beneficial for improving the "quality of consumption culture", if you wish.

...

Excellent and logical response!

 

[Cosmik]

Which is... ?? Please be specific.

Basically to be a single acoustic source with uniform directivity at all frequencies, reproducing the signal as it is recorded in the time domain not just 'spectrally correct' - as much as is possible. (See my user profile for the full version!)

Please clearly state exactly what it is dipoles do wrong and why it is wrong.

1. They create reflections that do not resemble the direct sound and are therefore breaking mechanisms within human hearing that rely on similarities of envelope shapes and polarities of wavefronts to be perceived as reflections and not new sound sources - essential for correct imaging and soundstage.
2. They create direct comb filtering that reflects from surfaces around the speaker
3. They create egregious comb filtering that changes dynamically as the listener moves, heard as 'phasiness' and in-head effects
4. They create indirect comb filtering from interactions of the positive and negative reflections
5. In order to reduce (but not eliminate) some of these negative effects, they become more difficult to position in the room.

I never said that. Please don't put words in my mouth.

As I was careful to say earlier, I was replying to the whole open baffle 'school', not anyone in particular.

 

[RayDunzl]

As a panel (dipole) user, I must post this again...

Unsmoothed dipole (MartinLogan) black (foreground) vs JBL LSR 308 in my not-treated-like-a-monitoring-studio musical enjoyment and experimental labmotorium:

To my eye (and ear) one looks far more disturbed than the other, and it shows up in the "soundstage". It's not the speakers making those nulls, it's the reflections.


Same for a zoom on the impulse response, where the levels after the impulse are relative to the direct sound (100%)

The dipole reflections are (at most) 26dB below the direct, and the largest JBL reflections are at -14dB, a significant difference.


To me, the "soundstage" is less focused with the JBL than with the MartinLogan, when critically listening at the sweet spot. For casual listening, it's a toss up, I can't reliably tell them apart when I think "Did I leave the Krells running ($$$) or are the Economy JBLs online now?", and I use both depending on whatever.