Maybe there is a difference between "good for music" and "good for HT"

KEW

KEW

Audioholic Warlord
The question is how wide? Some speakers are flat off axis to 30 degrees, then a roll off begins. Some are flat to 45 degrees, some to 60, some to 75+. Assuming if all of them rolls off without any peaks or troughs, and they have identical on axis FR, they will sound different, but which one is best?
I don't have anything other than personal experience (which is subjective) to back it up, But I have always felt that the presentation of omni-directional instruments benefits from an omni-directional speaker and something like Chris Botti playing trumpet from more directional speakers. Logically it makes sense that if the trumpet were broadcast into the room in an omni-directional manner, something would be off about the presentation...and if a violin were played over a speaker with fairly directional waveguide, the ambience from room reflections would be off.
It has been my experience that a more aggressive (more directional) waveguide increases imaging. It is also my experience that a violin played in the room (with eyes closed) is not so tightly pinpointed as a trumpet that is pointed in my general direction!


PS - I am talking in simple stereo. Some of the multi-channel options attempt to recreate the acoustics (with delay/echos for the surrounds) of various venues and I don't know how that would interact with the reflections produced by omni-directional speakers vs more directional speakers.
 
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JerryLove

JerryLove

Audioholic Samurai
I don't have anything other than personal experience (which is subjective) to back it up, But I have always felt that the presentation of omni-directional instruments benefits from an omni-directional speaker and something like Chris Botti playing trumpet from more directional speakers. Logically it makes sense that if the trumpet were broadcast into the room in an omni-directional manner, something would be off about the presentation...and if a violin were played over a speaker with fairly directional waveguide, the ambience from room reflections would be off.
I don't agree that's logically obvious.

The characteristic of an omni-driectional instrument is that you'll hear reflections and, depending on the recording space, the mic did hear those reflections.

An omnidirectional speaker means that, not only will you hear two different sets of reflections (the trumpet bouncing off the wall in the room it was recorded in, and the trumpet bouncing off your wall),but you'll hear reflections of reflections (the bounced sound from the recording room wall bouncing off your wall).

But wait: it gets worse!

Put in a large number of channels (realistically, it can be two) and now you are mixing indirect sound and their bounces.

So trumpet hits right mic, then left mic, then bounce hits right, then bounce hits left (add in all your surrounds).

Now you've both both primary and reflected noises coming from multiple speakers but then bouncing off everything in your room.

Logically: it becomes a hot mess. In reality??? I don't know.

It has been my experience that a more aggressive (more directional) waveguide increases imaging. It is also my experience that a violin played in the room (with eyes closed) is not so tightly pinpointed as a trumpet that is pointed in my general direction!
Do you like headphones?

PS - I am talking in simple stereo. Some of the multi-channel options attempt to recreate the acoustics (with delay/echos for the surrounds) of various venues and I don't know how that would interact with the reflections produced by omni-directional speakers vs more directional speakers.
That would be the topic of this thread :)
 
KEW

KEW

Audioholic Warlord
I don't agree that's logically obvious.

The characteristic of an omni-driectional instrument is that you'll hear reflections and, depending on the recording space, the mic did hear those reflections.

An omnidirectional speaker means that, not only will you hear two different sets of reflections (the trumpet bouncing off the wall in the room it was recorded in, and the trumpet bouncing off your wall),but you'll hear reflections of reflections (the bounced sound from the recording room wall bouncing off your wall).
If you listen to the sound of a trumpet and say the player slowly spun around, you would hear an entirely different sound as he pointed toward and away from you. The spectrum is different, not just the volume.
With a true omnidirectional speaker, the elements of the sound of the trumpet pointed at you (typically the trumpet would be pointed in the general direction of the microphone) are being reflected off of the wall behind the speakers, which is a situation that would never happen with a real trumpet.

I will agree that the reflections in a residential room are not consistent with a typical live venue. On the other hand a studio recording is a different animal.

I understand what you are saying - in theory, if we were close to properly catching all of the sound (with reflections) via multi-channel, an anechoic chamber would become the ideal listening room because the speakers would provide every sound we would want/need!

Sorry, but I rarely listen to headphones, ever. When I was younger (HS - living with my parents) I used headphones often and got used to their presentation, but never listened from the standpoint of critically evaluating their presentation vs speakers for imaging, etc.

My Mirage Omni OMD-5's are not great speakers, but in my experience, they bring something fairly dramatic to a string orchestra that an otherwise more capable directional speaker cannot.

Do you have a chance to A-B speakers with dramatically different dispersion characteristics? Give it a shot if you can.

But to your point, it is indeed a complex and convoluted issue, and it is not reasonable to consider it "logically obvious"!
 
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S

shadyJ

Speaker of the House
If you listen to the sound of a trumpet and say the player slowly spun around, you would hear an entirely different sound as he pointed toward and away from you. The spectrum is different, not just the volume.
With a true omnidirectional speaker, the elements of the sound of the trumpet pointed at you (typically the trumpet would be pointed in the general direction of the microphone) are being reflected off of the wall behind the speakers, which is a situation that would never happen with a real trumpet.

I will agree that the reflections in a residential room are not consistent with a typical live venue. On the other hand a studio recording is a different animal.

I understand what you are saying - in theory, if we were close to properly catching all of the sound (with reflections) via multi-channel, an anechoic chamber would become the ideal listening room because the speakers would provide every sound we would want/need!

Sorry, but I rarely listen to headphones, ever. When I was younger (HS - living with my parents) I used headphones often and got used to their presentation, but never listened from the standpoint of critically evaluating their presentation vs speakers for imaging, etc.

My Mirage Omni OMD-5's are not great speakers, but in my experience, they bring something fairly dramatic to a string orchestra that an otherwise more capable directional speaker cannot.

Do you have a chance to A-B speakers with dramatically different dispersion characteristics? Give it a shot if you can.

But to your point, it is indeed a complex and convoluted issue, and it is not reasonable to consider it "logically obvious"!
I would say that the sound of an instrument should entirely be a property of the recording, not the speaker. The sound system should recreate the environment of the recording. So whatever sound is intended to be conveyed should be able to be conveyed by an accurate sound system. The speaker's directivity shouldn't have a role in the sound character of the recorded instrument, that should have been accomplished in the recording.
 
ski2xblack

ski2xblack

Audioholic Field Marshall
I can not understand why I seem to be the only designer as far as I can tell that has built speakers with continuously variable BSC. In other words the BSC is isolated to a separate channel and fed to the speakers as such. It can be precisely set for a given location by measurement and listening.
I see a striking similarity between your approach and that which JBL employs in their top tier Synthesis rigs (specifically that bsc and final tonal tweaking is done with the speakers in situ, where they're going to live permanently, and individually by speaker),so, hey, not only are you not alone but you're in rather good company.

As for wide vs. narrow dispersion, it's a matter of taste and what exactly you're trying to pull off. I personally really like what controlled directivity, narrower dispersion speakers can do (in a nutshell, "more source, less room"; near-field type sound at greater than near field distances; expansive and stable soundstage via heavy toe-in, the time/intensity trading trick, something which wide dispersion speakers just cannot pull off).
 
TLS Guy

TLS Guy

Audioholic Slumlord
The question is how wide? Some speakers are flat off axis to 30 degrees, then a roll off begins. Some are flat to 45 degrees, some to 60, some to 75+. Assuming if all of them rolls off without any peaks or troughs, and they have identical on axis FR, they will sound different, but which one is best?
Well I find wide dispersion speakers give a much better sense of space. Narrow dispersion speakers over image. If you are in a concert hall and close your eyes you will find that imaging is not overly precise. Mainly the highly directional brass, especially the trumpet section is easiest to localize, and the same for good speakers.

Good dispersion gives a wide sound stage.

Here is the dispersion pattern of my speakers, and this is measured from on axis to 90 degrees, the black line.



So the off axis to 60 degrees follows the axis blue out to 9 KHz, and even at 90 degrees to 5.5 KHz. The droop at 15 K is not the speaker but omni mic.

This is the axis and impulse response, the latter showing good time alignment with rapid decay.



Similarly the center channel.



Dispersion.



Due to the through wall design of this speaker a 90 degree off axis measurement is impossible to obtain. One thing you can see which is common with coaxial drivers, is that the off axis response if often a bit smoother than the on axis response. The cone is a wave guide to the tweeter and on axis you get symmetrical reflections from the cone (wave guide) which is inclined to result in more nulls on axis than off.

In any event the result is good for HT and music including opera. For HT speech is natural and the effect is to be like being an invisible interloper in the room.

The biggest defect is the imbalance in perspective between sound and screen. The soundscape is so much wider then the screen and the room. The sound appears to come from way beyond and outside the room boundaries. When in the zone watching opera I sometimes actually think I'm in the opera house and come back to reality with a bump. Movies with well recorded sound tracks can also produce some vast sonic soundscapes, far outpacing what the screen can produce.

As I think you all know I do not design for the multi mic and track studio pop/rock productions. I don't like it honestly, and certainly could not evaluate a speaker with it as the source. I don't pretend to understand it or claim any interest in it. However mix engineers continue to find their way here and and seem very enthusiastic about the sound.

As you probably know I'm on the move and have been dismantling the studio these last three days. It will be rebuilt in the Twin Cities metro in Eagan. An engineer who frequents is trying to twist my arm to place a 16 channel wall XLR box in the wall of the upper living room which will be adjacent to new studio theater for recording. The DAW with WaveLab supports a full studio environment including talk back. Play back would be easily possible in the studio and the living room, as my very nice basement system will move to that room. Beefier subs might have to be built though for that system. So it would be a minimal addition.

When I get time I will give an update and start a thread. I have been busy with all this to say the least and had a very unusual health issue over the last months, now resolving after some surgery. I will go into all this if I get time.

This all complicated by a really long, yes long, 8 months winter that has been brutal in the Northland for cold snow and everything nature could throw at us. There is more sleet/snow in store for the coming days, although we have had a couple of the first nice Spring days this week. So hope Springs eternal. Benedict lake iced out yesterday having been frozen for over five months. The larger lakes are still frozen. Anyhow the upshot of all this is that our construction is two and half to three months behind schedule.
 
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I

ichigo

Full Audioholic
Well I find wide dispersion speakers give a much better sense of space. Narrow dispersion speakers over image. If you are in a concert hall and close your eyes you will find that imaging is not overly precise. Mainly the highly directional brass, especially the trumpet section is easiest to localize, and the same for good speakers.

Good dispersion gives a wide sound stage.

Here is the dispersion pattern of my speakers, and this is measured from on axis to 90 degrees, the black line.



So the off axis to 60 degrees follows the axis blue out to 9 KHz, and even at 90 degrees to 5.5 KHz. The droop at 15 K is not the speaker but omni mic.

This is the axis and impulse response, the latter showing good time alignment with rapid decay.



Similarly the center channel.



Dispersion.



Due to the through wall design of this speaker a 90 degree off axis measurement is impossible to obtain. One thing you can see which is common with coaxial drivers, is that the off axis response if often a bit smoother than the on axis response. The cone is a wave guide to the tweeter and on axis you get symmetrical reflections from the cone (wave guide) which is inclined to result in more nulls on axis than off.

In any event the result is good for HT and music including opera. For HT speech is natural and the effect is to be like being an invisible interloper in the room.

The biggest defect is the imbalance in perspective between sound and screen. The soundscape is so much wider then the screen and the room. The sound appears to come from way beyond and outside the room boundaries. When in the zone watching opera I sometimes actually think I'm in the opera house and come back to reality with a bump. Movies with well recorded sound tracks can also produce some vast sonic soundscapes, far outpacing what the screen can produce.

As I think you all know I do not design for the multi mic and track studio pop/rock productions. I don't like it honestly, and certainly could not evaluate a speaker with it as the source. I don't pretend to understand it or claim any interest in it. However mix engineers continue to find their way here and and seem very enthusiastic about the sound.

As you probably know I'm on the move and have been dismantling the studio these last three days. It will be rebuilt in the Twin Cities metro in Eagan. An engineer who frequents is trying to twist my arm to place a 16 channel wall XLR box in the wall of the upper living room which will be adjacent to new studio theater for recording. The DAW with WaveLab supports a full studio environment including talk back. Play back would be easily possible in the studio and the living room, as my very nice basement system will move to that room. Beefier subs might have to be built though for that system. So it would be a minimal addition.

When I get time I will give an update and start a thread. I have been busy with all this to say the least and had a very unusual health issue over the last months, now resolving after some surgery. I will go into all this if I get time.

This all complicated by a really long, yes long, 8 months winter that has been brutal in the Northland for cold snow and everything nature could throw at us. There is more sleet/snow in store for the coming days, although we have had a couple of the first nice Spring days this week. So hope Springs eternal. Benedict lake iced out yesterday having been frozen for over five months. The larger lakes are still frozen. Anyhow the upshot of all this is that our construction is two and half to three months behind schedule.
I think the downside of wide dispersion speakers is they sound brighter than their FR would indicate, perhaps because the high frequency notes hang around longer (combination of direct sound plus more time delayed reflections). Computeraudiophile had a article recently (link: https://tinyurl.com/y555dv4z) where the author discussed 2 speakers, JBL 4722 and Kef LS50 which were matched to the same target curve and the LS50 sounded brighter due to the lower directivity even though they measured nearly identically in room after EQ.

It seems to me then narrow dispersion speakers have an advantage in that they make brighter recordings sound more forgiving.
 
3db

3db

Audioholic Overlord
I think the downside of wide dispersion speakers is they sound brighter than their FR would indicate, perhaps because the high frequency notes hang around longer (combination of direct sound plus more time delayed reflections). Computeraudiophile had a article recently (link: https://tinyurl.com/y555dv4z) where the author discussed 2 speakers, JBL 4722 and Kef LS50 which were matched to the same target curve and the LS50 sounded brighter due to the lower directivity even though they measured nearly identically in room after EQ.

It seems to me then narrow dispersion speakers have an advantage in that they make brighter recordings sound more forgiving.
I partially disagree. Room acoustics play a much bigger roll and if properly controlled, the highs would not be hanging around. The hanging around is as you state is caused by sound waves reflecting off of walls. Saying that, narrow dispersion speakers would be easier to place in a room than wide dispersion speakers because of the refections. Anoechic frequency response of the speakers determines the fundamental behaviour of the speaker, especially if there is an emphasys of the high frequency components in its response curve.
 
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TLS Guy

TLS Guy

Audioholic Slumlord
I think the downside of wide dispersion speakers is they sound brighter than their FR would indicate, perhaps because the high frequency notes hang around longer (combination of direct sound plus more time delayed reflections). Computeraudiophile had a article recently (link: https://tinyurl.com/y555dv4z) where the author discussed 2 speakers, JBL 4722 and Kef LS50 which were matched to the same target curve and the LS50 sounded brighter due to the lower directivity even though they measured nearly identically in room after EQ.

It seems to me then narrow dispersion speakers have an advantage in that they make brighter recordings sound more forgiving.
That is the complete opposite of the truth and totally contrary to my experience.

In a concert hall as you move away from the source, then HF falls faster with distance. So in a well balanced system that has wide dispersion, then the HF falls as you move further back from the speakers, as it should. However if the speakers have limited off axis sound, then at the listening position there will be excess HF energy.
That is why Audyssey flat, that attempts to make the sound flat at the mic listening positions, sounds really dreadful.
 
JerryLove

JerryLove

Audioholic Samurai
I would say that the sound of an instrument should entirely be a property of the recording, not the speaker. The sound system should recreate the environment of the recording. So whatever sound is intended to be conveyed should be able to be conveyed by an accurate sound system. The speaker's directivity shouldn't have a role in the sound character of the recorded instrument, that should have been accomplished in the recording.
That's impossible to actually do. Sound from speakers will interact with the environment. The dispersion from your speaker will be some value between 1 and 360.

Your best bet is headphones or an anechoich chamber and a lot of speakers.
 
JerryLove

JerryLove

Audioholic Samurai
Well I find wide dispersion speakers give a much better sense of space. Narrow dispersion speakers over image. If you are in a concert hall and close your eyes you will find that imaging is not overly precise. Mainly the highly directional brass, especially the trumpet section is easiest to localize, and the same for good speakers.
But id you are sitting outside and close to a group of players, you'll find that imaging is very precise.

You can reduce imaging on speakers via a the recording (esp in multichannel setups); but you cannot add imaging the speakers lack.

This would seem to suggest that highly-directional speakers would be preferred to wide-dispersion speakers in, say 7.x.4 setups while the same might not be true with 2.x setups.
 
K

Kasperlab

Audiophyte
Having build loudspeakers now for over sixty years, I have a few observations.

1. The better the speaker the less fussy it will be.

2. Being able to accurately produce human speech, not just clear speech, is probably the single most important attribute of a speaker. It is also by far the most difficult task for a speaker. If it achieves this it will more likely than not be good for everything else.

3. An extended smooth frequency range for the total system, and well integrated, is vital for truly natural reproduction.

4. Wide dispersion I think is correct and the off axis must closely mirror the axis response especially in the mid band.

5. I think the transition of the speaker from omni pole to dipole is a huge issue. You get it right under one set of measuring conditions conventionally. This transition is crucial for natural speech. My research has shown that this varies by position from boundaries. This is really what you would expect. I can not understand why I seem to be the only designer as far as I can tell that has built speakers with continuously variable BSC. In other words the BSC is isolated to a separate channel and fed to the speakers as such. It can be precisely set for a given location by measurement and listening. This is a feature of my front three and I think a very major reason for the fact these speakers are good for everything and have really natural clear human speech. I do regard this as a major game changer in accurate reproduction. I suspect the reason it is not done, is that it does add complexity and can not be done with only passive crossovers.

6. Finally even slightly muddy resonant bass ruins everything.
Interesting observations, I agree overall. I would add that placement and balance of levels is extremely important to get the best out of any speaker system.
BTW, what is BSC?
 
ryanosaur

ryanosaur

Audioholic Ninja
Interesting observations, I agree overall. I would add that placement and balance of levels is extremely important to get the best out of any speaker system.
BTW, what is BSC?
I think Baffle Step Compensation.
 
Matthew J Poes

Matthew J Poes

Full Audioholic
That's impossible to actually do. Sound from speakers will interact with the environment. The dispersion from your speaker will be some value between 1 and 360.

Your best bet is headphones or an anechoic chamber and a lot of speakers.
In recording work, this is referred to as virtual environment recreation. It's the idea that the recording is trying to recreate an acoustic environment. In studio design, the preferred method for a virtual environment mastering room or control room is a non-environment room such as my preferred controlled image design which focuses on eliminating virtual sources.

Your last point is basically what they do and is also a design criterion for dedicated listening rooms. When building a multichannel room for someone, be it for music or movies, that kind of room needs to be basically anechoic. I prefer to treat the term anechoic in a pedantic way, so let's call it quasi-anechoic.
 
Matthew J Poes

Matthew J Poes

Full Audioholic
My view on this topic is that it is possible to have an ideal music and movie room using the exact same room and speakers. I reject the notion that some speakers are good for one or the other. In my view, if that is true, then the speakers are flawed. If a speaker is well engineered with ideal measured performance, it can do music or movies equally well.

As for the room, the difference is about music or movies, but about 2-channel vs multo-channel. WIth a 2-channel room, what your goal should be is to recreate the acosutics of the original venue, captured in the recording in your room by tricking the brain. Cues in the music mix with natural reverberation in your room to give you the sense of being there. Thus a 2-channel room shouldn't be very dead. You want a generally elevated RT-60 and to keep a lot of reflections in there. Otherwise, the original venue is lost.

Now that isn't to say that people don't sometimes prefer heavily treated rooms for 2-channel. It creates a more closed in and precise image. Yes the environment is lost from the reproduced sound, but some folks like that. That is fine, it's their system. I would argue that isn't accurate however, since that isn't how the music was recorded or how the original event or real event exists.

For multi-channel, the speakers do all the heavy lifting with regard to reproducing the virtual environment, and in that case, like I mentioned in the last post, you want the room to be basically anechoic. Very dry. This helps minimize the speaker/room interaction and avoids the rooms natural reverberation from contaminating that of the recordings. In a completely theoretical sense, this is a far better solution than 2-channel. It is impossible to fully and accurately recreate the "real" event with 2 speakers. Multi-channel is the only way to do that, and it works very well. We just have such a lousy catalog of surround music that it isn't really viable as a major mainstream idea. But...that is beside the point. Purely from an accurate music/movie recreation tool, multi-channel is far more accurate.

What this means is that if you create a room for 2 channel and put a multi-channel system in it, it will not sound ideal. The speakers will interact with the room too much and it will take you out of the real event, distracting you with your room's own reverberation (which will also color the sound unnaturally). On the other hand, if you build a dedicated multi-channel room that is heavily treated to be basically anechoic, it will be far too dry for 2-channel and won't sound good with the majority of music. What Toole suggests and what David Griesinger ultimately developed as a solution is the use of a high-quality upmixer (i.e. Logic7). The problem is, most upmixers suck, Logic7 is one of the only natural sounding ones that handle the reverberation in the recordings correctly (many sum it to mono canceling half of it, especially at lower frequencies).

My dedicated space is more for multi-channel than for 2-channel. The room's RT60 is a very flat .2 seconds, which is really low. In fact, when all of the treatments are in place, its closer to .17 seconds down to about 70-80hz, rising from there. When the panels are removed, the value rises to around .4 seconds. As @shadyJ can tell you, I'm constantly playing around with the treatment in my room, moving them around, even for different speakers.

As for the impact of dispersion on imaging, I believe that a speakers dispersion pattern directly impacts it's imaging. I believe that a wide dispersion speaker creates a broad/wide and diffused image. As the dispersion pattern narrows, the imaging becomes more specific and pin-point. At the extremes, I think that narrow dispersion CD speakers create very pin-point laser like imaging (which I happen to like). Panel speakers do this too as they have VERY narrow dispersion. On the other hand, something like the MBL 101e's will create a very large and diffused soundstage. I can totally see why people would like this, especially for large symphony recordings. But...I happen to think this isn't very accurate or realistic. It's not my favorite speaker.

Since I think the reason the dispersion impacts imaging is related to the "virtual sources" concept, I also think you can impact this with absorption (though I would argue that if you want to treat the first reflection points to improve imaging precision, just get a speaker with more controlled and narrower dispersion, it works better (absorbers aren't all that good at absorbing evenly). If you really like that larger than life image and can't afford the MBL's, just place your speakers right next to a wall, maybe even angle them toward the wall a bit. It will have a similar effect. Buy a second set of speakers and aim them at the front wall behind the speakers and you are good to go. Same idea. Spray sound everywhere and turn all the walls into virtual speaker sources.
 
Matthew J Poes

Matthew J Poes

Full Audioholic
That is the complete opposite of the truth and totally contrary to my experience.

In a concert hall as you move away from the source, then HF falls faster with distance. So in a well balanced system that has wide dispersion, then the HF falls as you move further back from the speakers, as it should. However if the speakers have limited off axis sound, then at the listening position there will be excess HF energy.
That is why Audyssey flat, that attempts to make the sound flat at the mic listening positions, sounds really dreadful.
I don't think this is an accurate statement nor does it make a lot of sense? What are you trying to say here?

A wide dispersion speaker doesn't fall off toward the side as much as a narrow dispersion speaker, that is the definition of wide vs narrow dispersion. The amplitude level stays more constant with angle in a wide dispersion speaker.

The in-room measurement of a speaker is depending on it's dispersion for exactly this reason. A wide dispersion speaker sprays more sound energy around the room and the added reflections increase the reflected sound ratio, which shows up as excess energy in the steady-state response. If the speaker had perfect dispersion, the DI was totally flat and at 0, it would simply cause the amplitude of the steady state to be louder (Assuming a totally reflective room with negligible air absorption of HF's). However in real rooms with real speakers, the response doesn't do this and instead, the increased energy is higher as you go down in frequency and the speaker becomes more omni-directional (and the room more reflective).

A speaker that has constant directivity that is narrower than a typical direct radiator, like my Geddes or the JBL M2's, all with around a 90 degree -6dB angle, there won't be any excess HF energy at the listening position. In fact, with such speakers, which have a fairly flat DI but elevated pretty high at 6-12dB's, the in-room response tends to have a more aggressive tilt to it. That comes from the fact that there is less reflections at higher frequencies (but those speakers still become omni-directional at LF's so the amount of LF energy still rises just like it would for a normal speaker). However, as I have mentioned before, that is a measurement anomaly, not what you hear. You do hear the LF rise as the LF reflections are still early relative to the period of those frequencies, but at mid and high frequencies your brain filters those reflections out and so both wide and narrow speakers would tonally sound the same (assuming both have a flat anechoic response and flat DI (meaning the off-axis response shape matches the listening axis shape).

Concert halls and any other large acoustic space is not a good analogy to a home in my opinion. The acoustic nature of large spaces is dramatically different from small home spaces. There is no natural way to recreate that. Large concert halls have massive amounts of HF absorption from the air alone. The reverberation times are huge, something that would be impossible in a home.
 
JerryLove

JerryLove

Audioholic Samurai
My view on this topic is that it is possible to have an ideal music and movie room using the exact same room and speakers.
Thus a 2-channel room shouldn't be very dead. You want a generally elevated RT-60 and to keep a lot of reflections in there. Otherwise, the original venue is lost.
For multi-channel, the speakers do all the heavy lifting with regard to reproducing the virtual environment, and in that case, like I mentioned in the last post, you want the room to be basically anechoic. Very dry. This helps minimize the speaker/room interaction and avoids the rooms natural reverberation from contaminating that of the recordings.
I realize you went to some considerable length to then address the incongruity in the above statements (with your discussion of Logic 7); but I think that might breeze by my original point.

If you want a high level of room interaction (your 2-channel scenario); a wide dispersion speaker facilitates that.
If you want a low level of room interaction (your Multi-channel scenario); a low dispersion speaker facilitates that.

You speak of using processing to take a multi-channel, low-interactive room and play successful 2-channel music; but, while I think that's an important topic, it seems tangential. Your room-speaker interaction [and correct me if I'm mis-stating your position] should be different in a 2-speaker setup than in an 11-speaker setup. I assert that the room itself is only one part of that pairing.
 
JerryLove

JerryLove

Audioholic Samurai
In a concert hall as you move away from the source, then HF falls faster with distance. So in a well balanced system that has wide dispersion, then the HF falls as you move further back from the speakers, as it should.
What?

I can understand why you would want your listening experience to sound like you were in the concert hall.

I don't understand why you would actively want to move around your (concert hall sized?) room and have the sound *change* as though you were moving through the concert hall. That's not only impossible, I cannot picture why it would be desirable.

If I wanted to do that: I need anechoic recordings of the instruments and a computer that can virtually place them. Then I can use position tracking and a headset to move around the virtual space.

However if the speakers have limited off axis sound, then at the listening position there will be excess HF energy.That is why Audyssey flat, that attempts to make the sound flat at the mic listening positions, sounds really dreadful.
The math would not seem to support that.

In a 0-degree speaker, 100% of my HF would be coming from the speaker. If I moved from 1m to 2m, I'd lose 3db.
In a 360x360-degree speaker: I'll be getting HF from the ceiling, floor, and all the walls. In every case, all that indirect sound will be moving > 1m to get to me and me... so me moving 1m farther from the speaker will result in <3db of sound loss.

In other words: HF will roll off more slowly on a high-dispersion speaker than a low one.

Some examples.
Sound hitting the wall 1m directly behind the speaker is travelling 2m to get to me. Me moving back 1m means it's now travelling 3m to get to me. That's less than a doubling.
Sound bouncing off the wall 2m behind me is travelling 5m to get to me. Me backing up 1m actually reduces that to 4m.
 
H

Hobbit

Full Audioholic
From my experience, my DefTech's were great for HT and great for filling the room with sound. Having said that, their imaging and sound stage size doesn't compare with my KEF's.

In fact, I was never able to completely dial in my DT's for 2 channel music. There was always some tracks where instruments "wandered" or you couldn't pinpoint an instrument or singer. With the KEF's, and sitting in the sweet spot it's like a band in front of you. Every instrument is where it should be.

I have seen omnidirectional speakers that try and correct this by allowing the user to turn off the non forward facing speakers.
 
KEW

KEW

Audioholic Warlord
I would say that the sound of an instrument should entirely be a property of the recording, not the speaker. The sound system should recreate the environment of the recording. So whatever sound is intended to be conveyed should be able to be conveyed by an accurate sound system. The speaker's directivity shouldn't have a role in the sound character of the recorded instrument, that should have been accomplished in the recording.
I'll agree that in a perfect world this should be true and may be the objective; however, the reality is instruments have directivity and to think that the directivity of the instrument is somehow captured and maintained all of the way to our ears without any regard to the directivity of the speaker or the playback environment seems a bit of a stretch.
 

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