Speaker Imaging - Do you hear a line, or do you hear an arc??

I have a very expensive customized listening room so acoustics are not an issue (it’s always been the speaker which limited my imaging/soundstage equipmentwise). I note that the 50’s/60’s small jazz recordings were commonly left, right track recordings with a soloist in the center (especially Rudy Van Gelder's). Funny though, my hi end tube preamp replicates what is on the recording with sharp left and right sound at the mike sound while a switch to my lesser EAR 864 preamp spreads the sound out in a line from speaker to speaker but lacks 90% of the depth of the hi end pre-amp (custom made). The more accurate sound is the hi end unit but the lesser unit is very pleasant sounding albeit inaccurate. That same period large jazz and orchestral recordings sound best with the most filled in sound between speakers and good height (placing instruments on various levels on a recording stage if not on a flat stage). Vocalists vary from 4’ to 6’ high, probably many of my recordings are inaccurate in height where the majority are heard at ear level. Left and right recorded strings and soloists are often at the plane of the speaker. Hence, better/newer speakers would help my sound (mine are 25+ years old and not SOTA but really fantastic for $2500).

don_c55  That is one of the three reasons I stopped using stats after more than 20+ years.  My wife couldn't enjoy (or me) the sound to the sides.  I purchased big dynamic speakers instead.  The Von Schweikert Ultra 9 and 11 speakers are so special as they permit a huge seating area with tremendous depth and width beyond the speaker positions.  I hope to replace my Legacy Focus with the VR55K in the future and enjoy superior width and depth as well.

It depends in varying degrees on the recording, how deep and how wide the stage is and how well placed are all the instruments and vocals, but always, my Maggie 1.7s disappear from the performance. On good recordings, regardless of where I set or stand, the vocals and instruments stay focused in their space and on a stage behind and beyond the plane of the speakers. I did spend a great deal of time and effort in room treatment and speaker and equipment set up - important with Maggies....Jim

the closer they are to the speakers the more your image is anchored on the
speakers while forming a "U" between the speakers (speaker output is reinforced with short delay reflections).

That's probably at least partly my issue.  << sigh >>

Harrylavo made some excellent recommendations, if I may paraphrase:

- We want to minimize the early sidewall reflections, ideally with distance.

- We want to minimize the early reflections off the wall behind the speakers, again ideally with distance.

- We want to re-direct the early reflections off the wall behind the speakers so that they don’t bounce directly towards the listening area.

If I understand correctly, the idea is to manage early reflections in a way that reduces what might be called "small room signature". By that term, I mean the aural impression of being in a small acoustic space, rather than in the acoustic space (or "soundstage") on the recording. (Notice Harry is not advocating absorbing these potentially detrimental early reflections - I’ll come back to why his is such a good idea in a minute.)

There is in effect a competition between the acoustic signature of your listening room and the soundstage on the recording. The acoustic signature of the room is primarily conveyed by the first reflections, and the acoustic signature of the (typically much larger) recording venue is primarily conveyed by later-arriving reflections. Notice this key aspect of harrylavo’s recommendations: He is NOT using absorption, so he is PRESERVING the beneficial late-arrival reflections! (In particular, he is preserving the SPECTRAL BALANCE of these late-arrival reflections).

How is the ear/brain system able to pick out these soundstage-signature reflections on the recording from the later-arrival reflections that come from all around the room?   By matching the spectral balance of these reflections with the spectral balance of the first-arrival sounds.  Thus it is important that these reflections be spectrally correct, or nearly so. To the extent that absorption alters the spectral balance of reflections by selectively absorbing shorter wavelengths, it is weakening the soundstage signature we’d like to enjoy.

I’m not saying that absorption is always a bad idea, and often it makes a worthwhile net improvement, but if we can find a benign acoustic solution to detrimental early reflections - like harrylavo’s recommendations - ime that facilitates hearing the soundstage on the recording. Not to mention the richer timbre we get from a well-energized reverberant field.

So imo the more we can do to minimize small room signature without degrading beneficial late-arrival reflections along the way, the closer we can hope to approach that elusive "you are there" kind of presentation.

Duke

The basics are pretty simple, in my experience and based on audio science.  I've been fortunate to be able to experiment with a wonderful array of spaces:

*  Sidewalls -  the closer they are to the speakers the more your image is anchored on the speakers while forming a "U" between the speakers (speaker output is reinforced with short delay reflections).  For best imaging, you should for all intents and purposes have no side walls within many, many feet of the speakers.

*  Wall behind speakers:  The further away, the more "depth" you will perceive when it is recorded on the recording.  The closer behind, the less depth.  (Of course, you have also to pay attention to room nodes for accurate bass reproduction.)

*  Prevention of center "cross-contamination".  Experiment with center reflections from the wall behind the speaker.  To experiment, put a six foot high stack of empty boxes with one corner ("v") centered and facing out behind the speakers.  This breaks up reflected diffusion from between the speakers.  In a real room, this can be approximated many ways, including a "v" shaped two panel screen if needed.

This is the simplified basic.  It can be approximated different ways with room treatments.  If you are lucky, you can even arrange a living room this way.

While I agree with the room and speaker placement within it doesn't explain the differences in imaging from different speakers placed in the same place. The revel salon 2's were the most particular in my room, imaging was always recording dependent, but the soundstage was elusive with them. the big ushers imaged wide and deep but very little height. the revel f52 were the most intimate imaging speakers i've ever had in this room placing singers and instruments solidly in space while capturing panning effects intensely. There's been several quality speakers down here with their own personality,   the current residents manage to erase the walls and put me in the middle of the performance.  Roger waters, amused to death for example the phase thing had different results with each speaker. A speakers ability to capture my imagination and allow me to create the image can hide many other shortcomings and I don't know if there's a measurement for it yet.

A fair number of LPs/CDs contain a photo of the group/orchestra playing while being recorded.
When listening to the recording, have you been able to correlated what you hear with what you see?

Only valid if the recording is mic'd stereo. If the session has several microphones, all bets are off there is any correlation, but some multi-mic sessions could be correctly panned and mixed to reflect player positions.

Mic-per-chair orchestra recordings don't usually image well and suffer the additional defect of 'strolling' wherein the perspective changes when a player or section is featured.

with a lot of recordings … the vocals are placed further back than the instruments

On pop records this is probably incorrect except for solo guitar, sax, etc.
On live opera, correct.

I definitely experience a 3D arc soundstage from a lot of recordings, with some elements of the recordings projecting as far as 15ft behind the speakers. Something I have noticed with a lot of recordings is that the vocals are placed further back than the instruments. It sounds impressive but not always as I think it should sound. This could simply be a common ‘style’ of recording, but I think it might be less apparent if my listening position was further away from the speakers. Unfortunately, the constraints of my room means my listening position can only be 7ft away from the speakers. 

OOPS,  Just saw the last sentence:  B&W 803's with 10" subs underneath, time aligned placement, slightly sunken room open to main room, with identical amps driving all four speakers with separate, identical preamps on, shall we choose, Rosie O'Grady's Direct to Disc (Aphex enhanced of all weird things), "Good Times Jazz Band", a late 1970's recording by the large house band at Rosie O'Grady's Good Time Emporium in Orlando.  This recording has everything from a triangle intro on "Japanese Sandman" to a romping tuba extended solo on "When You're Smiling". (All Audire electronics including head amp, 125/250/400 (8,4,2 ohms) wpc x 4, with an often used Hafler amp and preamp, for comparison.)

The best recordings have instruments pinpointed in three dimensions. 

yes, but the listener does not move so all the room reflections are also time displaced. If one moves their seat, reflection times change as well.

IMO, this helps account for the popularity of the egregiously awful compact cassette among retrophiles. A head misalignment of 0.375 thou. introduces a channel time delay of 0.2ms

However; & this is the interesting bit... if I adjust time delay of one channel by varying degrees (DSP), say only 0.2ms (a tiny amount!) then the soundstage changes quite dramatically.

poppycock. Time delay will shift the image to one side. 

Interesting topic & something I once played around with quite extensively.

Oftentimes what we hear is an amalgam of various separately tracked & mixed instruments/voices, not necessarily recorded in the same acoustic space - so the soundstage can be somewhat artificial.

Soundstage depth (could be called an ’arc’) is ’correctly’ represented when the original recording & mastering contains it, speakers are fully time coherent & the room changes very little of what they produce ....In my experience, a very rare occurrence in domestic situations.

I have an accurately time and phase coherent setup in a heavily acoustically treated room. Many recordings do contain a holographic soundstage with considerable depth & most times instruments or voices are layered within that soundstage. Many other (2 channel) recordings sound artificial and ’flat’ to varying degrees and I guess this is just a true representation of the original source.

However; & this is the interesting bit... if I adjust time delay of one channel by varying degrees (DSP), say only 0.2ms (a tiny amount!) then the soundstage changes quite dramatically. Imaging is slightly less precise but the feeling of depth (& now width) increases very noticeably - almost as if in a larger more cavenous space. The ’arc’ becomes deeper & wider.

Playing around with increasing levels of time delay, even between different drivers creates all sorts of phasey ’soundstage’ effects, almost to the point where the whole room becomes an ill defined soundstage - impressively 3D but not natural. I once played part of a live album to a friend where I had deliberately delayed the entire left channel by 1.7ms and he couldn’t believe how we seemed to be inside the venue - diffuse but all around us (something I would never do other than as a demonstration of just what timing incoherence can do).

I concluded that prior to using DSP & room acoustics, much of the ’soundstage’ I used to believe existed was actually a function of the inherent inaccuracies created by the system/speakers & room. Often impressive but actually rather artificial.

With my system as it is now, I accept that what I hear is a truer representation of the original even if that means some recordings are no longer flattered by various phase and timing effects.

First...THANKS Eric....for so darn many thought provoking threads that you have started!

I agree with the hemisphere/half bubble description.  No doubt that often the slightest change in speaker positioning will affect the overall sound...sometimes significantly. 


And, the straight line, arc, hemisphere soundstage is maybe most significantly influenced by what the recording engineer did with ambience, echo, reverb and delay....and then how your speakers and room interpret/project what he intended.

For a long time, I was obsessed with the soundstage...but realizing that perfection is probably an illusion in this area, once I had a good stage, I turned my attention to tone...especially piano, drums, horns and voices.

Very interesting indeed and in my experience, probably true ...If what you said is right, and I think so Geoffkait, the good news is my journey begins....Like you said already... It is a good news because even if I had already a musical 3-d audio system, new improvement will show with experiments and with time... In the meantime I love music like never before...My best to you...

P.S. And yes it is a hemisphere....

You’re close, very close. It’s a hemisphere, half a bubble. If it was a sphere we’d hear things below the boundary of the floor. 😬 The soundstage is also defined by the density, transparency, gestalt/organization of the images, solidity of the images and accuracy of the shape of the images. Just when you think you have a good soundstage along comes a guy like my customer no. 1 who has completely REDEFINED what is possible for a soundstage. Everyone else, sadly perhaps, is at least two paradigms behind the power curve.

 With a good recording,I would say more like a bubble. Height,width,and depth. Images expanding beyond physical boundaries. That's the stuff that makes me love this hobby.

@ieales- thank you!
@erik_squires - hope you finish it soon, and do reward yourself!

Tom

I have a pretty big room....10' ceilings....12,000 cubic feet.  Speakers are Salk Veracity STs...9' apart and 30" out from the rear wall.  No room treatments...lots of glass, ceramic tile, and drywall...with a few area rugs and furniture....normal listening volume around 80db...max peaks of 85db.


As of now, I don't stream...only CDs.  Almost never is the soundstage for a whole CD an arc...but almost every CD has at least one song that has lots of depth and could be described as an arc.

Here are just two "arc" examples from some really old CDs...Al Stewart, "On the Border - Live Version"  and Steppenwolf, "Hoochie Coochie Man".

Or, a little more recent....Josh Turner, "Long Black Train"

Mostly, I would describe the overall sound as sitting at one of the front tables at a medium size club...you can perceive/recognize depth, width and height and occasionally when the song was mixed with a lot of ambience, it almost seems like immersion. 

Tom :

Thanks so much for remembering me. I think you are the third person who ever took any of my advice! Getting good sound with minimal effort and cost is a goal I have for myself and like to share. I'm glad I could help you.


I could make things better here, I'm just ... settling. I had plans to donate furniture, and make a lot more space in the living room, turning the stereo around and re-positioning the 5 panels and 2 bass traps.


Unfortunately the Vet's org won't take furniture this big, and most want me to pay to ship to them, so I'm probably going to junk some big pieces as I downsize, and just thinking of that wears me out. :)


I should make it a priority and reward myself with a nice new rack from Butcher Block Acoustics.


Best,
E

My system is very modest but sounds wonderful ... because of the room treatment and meticulous attention to the setup.

probably no need for "to me"

If only people would realize it's the room!

As a recording engineer, I mostly didn't give a rat's patoot about the hardware. The room however...

Erik-
Thank you for the kind words.
Sorry to hear about your lack of a listening room. Especially a shame since you were the first person here to mention any kind of room treatment to me several years ago. You said try hanging some blankets on the walls. Well, I did just that and was amazed at the difference it made. Thus began my quest of focusing on the room more than the gear. My system is very modest but sounds wonderful to me because of the room treatment and meticulous attention to the setup. 
And thanks again for helping me get better sound than I've ever had before (going way back to the 70s).

Tom

"I think it would be difficult to know how your system is staging without extremely intimate knowledge of the recording." READ the second post in this thread. The tests listed remove all variables, associated with the source(ie: microphone techniques, venues, etc) and provide references, which obviate the need for listener familiarity with the recording.   Again: all that’s only for those interested in finding out, if their systems(and/or ears/brains) are up to the task, given a recording that contains the info.

ieales.
IMO, most HiFi haven’t a clue as to what constitutes an accurate presentation. Lord knows that most shops are incapable of an accurate presentation.

>>>I heard a system a few days ago that puts everything else to shame. If you could hear what I heard with my ears. Great soundstage has almost nothing to do with brand names. Everything is relative. - A. Einstein

Amen.

IMO, most HiFi haven't a clue as to what constitutes an accurate presentation. Lord knows that most shops are incapable of an accurate presentation.

As far as rack and TV, if they are covered and treated to be non-resonant, they do not seem to present much of a problem. IMO, the mains must be forward of the screen and rack

I think it would be difficult to know how your systems is staging without extremely intimate knowledge of the recording. Significant details are needed to know if you are getting an accurate representation. I suppose if you have heard good staging then it exists and if you havent it doesnt.

No rack between speakers.
No TV in room.

This is the most important starting base to getting good imaging, left/right, up/ down, back/forward and outside the speakers.

Cheers George

Tom:
Good point. Very good point. I haven't had a great listening room in ages. :(

Erik

Some people dont believe time cohesion is real

pretty much what Eric [bdp24] said.
System: BiWired Spica TC-50 polyprop recap. Lead shot filled spiked stands. Speakers attach to stands w 4 Isolate It 50 Duro 0.25 x 2.25 circular pads. Kimber 2.5m BiFocal-XL. cd6006, passive LC1, passive XO1. 2x ML 800x w 10kg anti-skating.

Specifics:
Test discs never told me anything well recorded program couldn't tell better. Attend plenty of live acoustic music, get the image right for a well recorded large orchestra at full steam in a good hall and everything else is a doddle.

On a well set up system depth should approximate the space, be it hall or digital. It should draw you into the music as if you could walk up on stage.

An excellent set of a wide variety of well recorded material in good halls with a fairly consistent sonic is Louis Frémaux - The Complete Birmingham Years. Of course you have to like French music in English halls.

Note also, when a sound seems to be coming from farthest away, it’s pretty much always centrally located (center back).

IMO, this is a system failure. Back in the 90's, we did tests with 32bit digital processors, adding even or odd harmonics @ the CD 16bit bit 0 level. Even harmonics spread the backstage and push the image back, odd bring the image forward and triangulate it back to a point. The even push back can be solved by speaker placement, the odd triangulation cannot.

Other failings, mostly time coherence, cause the image to be too tall, tilted fore or aft.

IMO, a great many systems AT ANY PRICE are incapable of any semblance of correct imaging because their time coherence is non-existent.

Before room treatment-
     Definitely an arc.
     Center image not settled in the center.
     Little or no depth of soundstage.
     Images seemed to be easily perceived from left speaker, area 
     between the speakers, and right speaker, ie- the speakers did not 
     "disappear".
After room treatment-
     Front line well established.
     Sides of soundstage extending beyond the edges of the speakers.
     Nice depth of stage extending beyond front wall (the wall behind
     the speakers).
     Center images well-established, solid and 3-dimensional.
     Soundstage is now taller, wider, and deeper and appears more
     of a box instead of an arc.
     Front of stage either appears in front of speakers, in line with
     speakers, or behind speakers, depending on recording.
     All images seem more 3D, more round, less flat.
     Speakers disappear convincingly.
Room treatment on all four walls plus ceiling.
Dedicated listening room.
Dedicated AC line to room.
All gear plugged directly into wall.
Speakers are Vandersteen 2Ce Sig IIs.
No rack between speakers.
No TV in room.
Dire Straits and Pink Floyd always sound very well recorded, as do most classical and jazz.
Most rock and pop sound surprisingly good now that the room and setup were established for best sound to "play the room".

Tom

     

Speaker Imaging - Do you hear a line, or do you hear an arc??

Mines seen not heard, and if good should be seen as a 3 dimensional picture in front of you, with height, width (even outside the speakers) and depth, in my case 15ft back as I have no wall behind the speakers, or equipment racks between the speakers.

too busy listening to the music

With the SACD Gaucho by Steely Dan, the band is in the living room.  Speakers are Martin Logan Clarities, Magnepan DWMs crossed over at 75hz to 2 10's and a 12 in three boxes.  I recently put a 1/2 inch lift in the rear of the MLs, brought the soundstage from a 4 to 5 foot height to about 6 foot height now.  The MLs are 5 feet from the rear wall and 4 foot from right sidewall.  Left speaker side wall is about 18 foot away in the dining area.  The MLs are slightly toed in and the DWMs are on the inside.


The goal was clear, coherent sound with decent bass at any volume.  I have two musician friends that sit mesmerized by the SACD's presentation.  The journey has been long and satisfying. 

a lot of it depends on the recording. I have Lynn Stanley at 45rpm and she is in front of  the speakers with the band behind her. Some of my D2D recordings do the same. 45 rpm reissues of The Doors are like being in the studio with them - listen to Jim whispering on Riders on the Storm. 

Aside from the numerous variables (all of which have already been mentioned and discussed), optimally, Yes, an "arc" with depth that more-or-less resembles an orchestra, a classical chamber group, a jazz ensemble, folk and Delta blues music. As for rock, it’s so heavily amplified and listened to at such high SPL, I’ve never noticed all that much of a sound stage: just a wall of sound.

I agree.  Not sure about a "line" or an "arc" in an image.  What I get is nothing at all like that.  I don't hear the speakers at all.  What I hear is the soundstage with instruments all over in proper depth / position on state and side-to-side positioning.  The soundstage is not located between the speakers but rather is outside of the space between the speakers.  Almost everything is behind the line between the speakers except those reproduced sounds that are close to the listening position.

I have observed that sometimes a flattening of the image between or behind the speakers have come from distortion, but that's not always the case.  Sometimes it's just the way the music was recorded.

I don't understand the reference to straight line or arc.  My sound stage is as random as every recording. Mine is so immersive that i often find myself hitting mute because i feel like i heard something or someone around me . Often i turn my head straight to the side thinking someone else has entered the room.(55’x35’x15’h) Certain  program material can lead me to believe i am surrounded with my  2.0 perceived directionality . I’m not a word smith but i know what i mean. 

In nearfield listening, dependent of the mikes engineering process on the audio record, image is between my speakers with a depth that extend beyond the wall (my speakers are at 10 inches of a wall with one almost touching a column(not ideal)...In regular distance listening the image float forward and with a depth, and sometimes sit at the exterior of the speakers and not only forward toward me...the rules is simple: speakers must disappear behind 3-d music...Then, nor a line neither an arc, but a 3-d sphere for each instrument in an all enveloping sphere behind my wall...


With my headphone the depth also is 3 d with each instrument in his 3-d space...They are so good that I prefer almost listening with them...Normally I prefer speakers to headphones...


Exept for the naturalness of the musical timbre of voices and instrument, I valued more imaging, and 3-d holographic... It takes me 5 trying experiment and purchase with headphones to discover only one to my total satisfaction and it was the one that cost the least money, then beware before buying... I owns 2 Stax. one hidfiman he 400, Akg 340 and AKG 701... My best was for sure the 60 bucks new Fostex TH 7 b...Modified and tweaked it best them all others on almost all counts...


I know now that money dont buy you necessarily the best audiophile system possible for the price, but tweaks will, cleaning methods for resonance, room treatment, controls of noise levels are paramount and imperative with any audio gear at any price, and acoustic controls of the room...

Soundstaging should not be a line or an arc!

It should be ‘beyond the walls’ and with three dimensional individual images.
Not flat ‘paper cut outs’ staggered in space.

Best enjoyed in a dimly lit room, in the right psychological mood, with sonic clarity of good equipment.

It may be realistic or totally fantasy, depending on type of music.

The best speakers for big, realistic soundstage, are big panels (Magnepan or electrostatic), that focus the sound to a "sweet spot" like a lens.

When listening to a system you feel images well, how do you perceive the sound stage?

With my ears.

Do you perceive it as a rectangular space on which the speakers sit, or does it sound like an arc, going further back towards the middle?

With which recording?

Dodecahedron.

The dog barking on Stereophile test disc 1 sounds well outside and to the rear of my speakers (diagonally back and away, pretty much into the front corners of the room).  I suppose that counts...