PerfectImage ... This maybe a little late but here goes. To get a better handle on what reflections really mean in the sound space take a look at what F.Alton Everst says later in his book. Start on page 298 in Chapter 16 "Sound Reflections in enclosed Spaces" and also again in Chapter 19 starting on page 343 through the end of the chapter. Pay particular attention to Table 19-2 and the formula for calculating the reflection level and the delay. Use this information in conjunction with Figure 16-4 and 19-6 from research conducted by Olive and Toole and I think things will become much clearer – no pun intended. The information in scattered a little in his book, but it is worth digging for – Cheers, Dan |
craig, i can't say exactly *why* yure getting this effect, specifically w/those components inwolwed, but it woodn't surprise me that ewe could get more total *depth* w/any of 'em in yer system, if ya then start playing w/the speaker locations/sound treatment. to me, these changes sound like a step in the right direction - even if ya dint like the immediate result of the increased forwardness, etc. playing w/the speaker positioning may wery vell get the soundstage back behind the speakers where ya like it, while *also* increasing the perception of depth further back past yer rear wall. yust a thought... regards, doug |
Thanks PI, but my system is sounding great. My above post is a bit confusing. I got that big, bloomy, forward, diffuse soundstage only when I was auditioning the components listed above, and was wondering if anyone else has ever experienced that phenomenon. This condition happened with each of the items noted. I did not audition them all together, but individually. My listening position is at 9-9.5 ft., and I do not use a sub. Cheers. Craig. |
Craig I would love to help you with your set up but I need to know two more things. Where is your chair and if you use a sub where is that?
Doug: Great point and I am still thinking out my reply. |
Craig, your room and set-up is very similiar to mine. I'm 1 foot shorter, (always behind the big guys) I have been playing around with different powercords and footers lately. Each time I do anything the presentation changes. The past 2 weeks my system has been perfect!!!!! So in the true audiophile manner I had to try a different cone on my tube pre-amp. I lost the magic that fast. So I put the others back, but I cann't quite find the same point they hit the pre-amps bottom plate. It's close but not quite, so I came out to play computer. The point is, even the finest adjustment on a high resolution system like we both share will alter the presentation. Speaker placement we all are aware of, location is critical to success. It's the tweeks that create the magic, not a new amp. Keep trying suttle alterations, maybe go back to a base point, old powercord, new tubes or whatever. I'm sure it's as suttle as a cone moving 4mm. Good luck, keep us posted. Your continuing the high value of this post with your input. J.D. |
.....false alarm about the voting/rating thing on my part. At some point I just didn't close "the window". I completed rating each post-- must have taken 10 minutes. Cheers. Craig. |
I really think this is an excellent thread and posts. I didn't know how to rate all the "good stuff", so I decided to just give everyone a +1 for content and a +1 for delivery. I got about 1/3 of the way through the posts, and the "system" wouldn't accept any more ratings by me. I suppose a question for Agon?? But thanks to all for content and delivery-- I think this is what this forum was meant to be. I can contribute a question. On several occasions (with component, PC, and tube changes) I have gotten a huge, forward, diffuse, very airy, and IMO, a very unnatural soundstage. This was caused when using (1) ML 331 amp, (2) SF Line 3 pre-amp, (3) API power cord on McCormack DNA-2DX amp, (4) ESP Essence PC on DNA2 amp, (5) putting NOS Amperex 7308 tubes in 2 positions in my standard SF Line 2 pre-amp. The "normal" image in my system is very solidly behind and between my Vand. 3As with soundstaging depending on CD, eg Lucinda Williams "Car Wheels on a Gravel Road" soundstages wall to wall, and a few others do this as well, but in my case most soundstaging is just between speakers. My 3As are on a short wall of my 14 X 22 room. Center to center about 80" apart and about 3 feet from sidewalls, and 4.5 ft. from front wall. I definitely do prefer this laid back presentation, but have really wondered about the huge, forward, diffuse soundstage with equipment changes. It absolutely amazed me that a single PC or tube change could do this. It seemed more possible with a major component change, ie the amp and pre-amp noted. Any thoughts, comments? Seems like this question fits this thread. Thanks. Craig |
perfectimage, while ewe may be right that *some* speaker mfr's try to recreate the pre-recorded soundstage by purposely using reflection-points, i think that the vast majority of speaker mfr's try to voice their speakers *without* using reflection points. i believe it was acoustic research that produced a speaker designed to use a rooms' sidewalls as reflectors (was the model called the magic?). it actually had a side-firing driver, angled, so as to bounce sound off the side-walls. but, i believe that designs such as these are in the minority - it wood be nearly impossible for a designer to try & determine yust *where* the reflection-point wood be in such a vast array of differing end-user room-possibilities. better to design for *no* reflection point, & if an end user *has* these unwanted reflection-points, due to small room, or other unknown variables, then that user can reduce its impact w/proper sound-treatment. yust my opinion, doug |
You are right that the speaker is recreating the recoreded sound stage. I think though that it does it through perposly useing reflection points. |
You are right that the speakr is recreating the recoreded sound stage. I think though that it does it through perposly useing reflection points. |
Acoustic theory is based on a perfectly shaped sound wave. The better the equipment or source the more accurate a sound wave will be created. A bad recording or a bad piece of equipment will distort this wave giving you different results. |
Much better communicated Sedond. I think the sidewall reflection does smear the image, damn your good. |
jadem6, i'm pretty much w/ewe on this, except, i'd say not *even* in a dead room, but *especially* in a dead room. quality speakers and electronics have the ability to transmit this info if it's on the recording, *if* the info isn't smeared by competing 1st-reflections of a room, which will confuse the ear-brain & ruin these subtle cues. thus, my opinion that *no* sidewall reflections is key to a wide soundstage. regards, doug |
Perfectimage: What was the name of the book and Author again?
I really would like to read it but fear it might be a cure for insomnia. I will, however, give it a read.
Thanks in advance for your attention to this detail.
Rob |
If side wall created the image outside the speakers, I should hear that more when a insturment is at the far right. That just isn't the case, I can have an insterment loudly playing far right and here nothing outside the speaker. I believe it's the enviroment within the studio and the sidewall locations in relationship to the mikes. If I had a recording with information telling the speaker theres sound 10' right, even in a dead room I think I'd hear it. Just my guess? |
I admit, yours and Sedonds, arguments are impressive. Sedonds obseravtions and your argument about imaging off the floor is what got me rereading again. I found myself quating from what I remember reading and couldnt answer all of your questions. Its been a couple of years since I read the book and I am a little rusty. Acoustics are very complex and I think it breaks down to an overall understanding then individual properties. I will try to find the passage that covers that specific question. But Just because its in a book doesnt mean we cant question its intergrity. |
Can't argue with the quotation from the acoustics book, but it's a giant step to say that those reflections are what create coherent sonic images outside the speakers. Another way to look at or experiment with the issue is to consider if you diminished the importance of reflections by setting your system up for listening in the nearfield (assuming your speakers work well in the nearfield). Would your lateral soundstaging degrade? Or perhaps improve? |
These debates have me rethinking and rereading.
"Reflection from flat surfaces"
"Like the light/mirror analogy, the reflected wavefronts act as though they originated from a sound image. This image source is located the same distance behind the wall as the real source is in front of the wall. This is the simple case - a single reflecting surface. In a rectagular room, there are six surfaces and the source has an image in all six sending energy back to the receiver. In addition to this, images of the images exist, and so on, resuting in more complex situation. However in computing the total sound intensity at a given receiving point, the contributions of all of these images must be taken into consideration."
Taken from the Master Handbook of Ccoustics. by Alton Everst Pg 193
I hope this is clearer then my explanation
|
soundstage *depth* is a whole 'nother issue - but basically similar tings are happening: ya wanna optimize the speaker placement w/the wall behind 'em, usually it's a compromise w/floor-standers & monitors on stands: further from the back-wall gives better image-depth (& worse saf), closer placement increases bass-response at the expense of image-depth (& saf improves!). ya also wanna sit far-away from the rear wall. of course, small rooms are aided w/strategic sound absorbtion & diffusionn when you or the speakers get closer to the walls than ya'd like. if ya got the space for it, subs can help in speaker placement for optimum sound, imho, cuz ewe can place the monitors for optimum-depth while placing the subs for optimum low-end response. i believe this can improve the *monitors*, even if they're full-range floorstanders - i had my thiel 3.5's set-up this way, before i got my present small merets, & they never sounded better - that 10" woofer was better higher up the frequency range when it dint have to go down to 20hz, and the marchand x-over is more transparent than the thiels' equalizer, that i was able to ditch. it's amazing how big speakers like thiels can disappear when out in the middle of a room! :>) for optimum image height, go for a carpeted floor between ewe & the speakers, nothing else between yew & the speakers, & as high a ceiling as possible, or sound treatment on the ceiling between ewe & the speakers. kinda extreme... :>) |
As to Ben's question, how can you get a sonic image outside the speakers, I guess I'm more surprised by soundstage height and depth. There, you also get sounds that are not right on the line segment between the speakers, but your system doesn't even get to use left-right ear differences to perform that magic. If you play your music through Monaural, you'll still hear height and depth, although in comparison with also having the side-to-side information available, it seems kind of dull. If you have an instrumental voice only through, say, the left channel, the instrument will seem like it's positioned at the left speaker. But, paradoxically, if you also have that instrument coming through the right channel, faintly and with the right quality and time relationship to give the proper spatial cues, you can push the instrument's position out past the left speaker. At least, that seems to me to be the way it works. It's easy to see how these subtle spatial cues can get trashed accidentally or deliberately in the recording process and also lost in the playback process. Obviously, I agree with Sedond on this one. Sure, room reflections do all kinds of things to the sound and soundstage, but I think it's accurate reproduction of spatial cues that produces a good soundstage. If surface reflections generated soundstage, why haven't I ever heard instruments or voices coming from the floor? |
hi perfectimage, i agree w/what y say above, especially: "All your observations are obvios traits of a great ear...." ;~) seriously, i tink your 1st paragraph sums it up pretty well, & also sums up why i 1st disagreed w/ya - i am fortunate enuff to have a large listening-room, where the 25'-long wall is the *short* wall. this allows placement for optimal *precise-image* placement, knowing that the soundstage width is only limited by quality of the software, speakers, & electronics - i will *never* be placing the speakers close enuff to the side-walls to adwersely affect soundstage width. your statement about moving speakers to get that optimum position - far enuff away from each other, yet not too close to the side walls, is typical of smaller listening spaces, & what i used to do before i moved to a house w/a large room a few years ago. i feel best results in a smaller room wood be to start with trying to optimize the distance between the speakers vs-listening distance, and then heavily treat the side-walls at the 1st-reflection-point. i believe that the room is by *far* the single-most important piece of equipment in an audio system. regards, doug |
I think the problem lies in my inability to explain it. There are so many varibles to acoustics. I think when you are moving in the speaker you moving it closer to its sweet spot. You wouldnt put the speakers side by side and you wouldnt put them against the wall. The best spot will be wherever that paticular speaker and the room work best with each other. Like when you focus a camera manualy. To much either way makes it out of focus.
When you move the speaker you are also changing its reflection points all over the room. The ceiling, back wall, front wall, and floor. There are also secondary reflection points which are also changed. The other reflection points are the reason you dont want your speaker the same distance from the side wall that it is from the back wall. Or that when you tow in your speakers you dont want the back facing the corner. They all have a drastic effect on each other
Also the end of the sound stage isnt the furthest point you hear an instrument imaged. Its the size of the room that your system sounds like its playing in. The neaunces that makes your system sound like it is in a bigger room are the also the benefits of good imaging.
I cant stress how great that book is. It breaks down frequency, sound waves, and will even give you basic mathmatical equations to plot resonate modes for your room. It even gets into what would happen if you put your system in a feild. All your observations are obvios traits of a great ear. That combined with the knowledge of that book would give you a great set up. A properly set up system is by far the largest upgrade you could ever make. |
thanks for the tip, perfect image. regarding "convincing me", i guess the only way i could be convinced, would be to hear imaging improve as a speaker is moved closer to a side-wall! :>) 'til now, as previously said, i've found the opposite to be true. perhaps, i'm misunderstanding a bit, if you define *precise imaging* as something that comes at the expense of a wide soundstage. i've found this to be true when comparing different models of speakers - i.e.: some models seem to have a wide stage at the expense of specific image placement across the stage, while others' image specificity is more precise, w/the soundstage rarely extending past the edges of the speakers. (i'm searching for *both*!) but, even regarding these distinctions, i have found *both* to be improved the farther away a speaker gets from the side-wall. regards, doug |
Sedond. We are never going to convince each other so I wont push anymore. You have very keen observation skills and although I cant convince you maybe I can help. I highly recommend The Master Handbook of Acoustics by Everest. Its a heavy read at times but very imformative and covers all of the topics we were discusing. Enjoy!! |
david99: it's easiest, of course, to measure from the edges of your speakers. the measurements that usually count most, tho, are from the center of your speakers (if alingned or approximate center if not) and the vertical mid-plane of the surface(s) to which the drivers are attached. but, as sedond notes: "the farther the better" is the general rule of thumb, no matter how you measure. |
perfectimage, ewe say: "The further from the wall the speaker gets the less defined the image gets...." this is precisely where i disagree, & think the exact opposite is true. in *my* experience, proximity to side walls, & to a lesser extent, back walls, is what ruins imaging in many speakers. the sound-absorbent wall treatments need to be at the 1st reflection points specifically to *remove* the wall. in my listening room, the speakers are ~5' from the rear walls, ~8' apart, & ~9' from the side walls. i sit ~10' from the speakers, with ~23' behind me to the rear wall. with my 25'-wide room, there's no way *any* speaker is gonna image outside the side walls, and i wouldn't even want an image that wide - it'd be way-too-unnatural. the *depth* of the soundstage, however, often *does* sound like it extends beyond the wall behind the speakers, tho. but, this is not unrealistic. regards, doug ps - david, sorry i'm not more specific - my measurements here are approximations. i *do* think it's best to keep as far away as possible fro the side-walls, tho, &/or use sound absorbtion at the 1st reflection point if they're anywhere near the speakers. monitors too far from the rear walls can lose lo-end reinforcement w/o subs, so there can be a soundstage-vs-bass compromise regarding how close/far to the rear wall ya wanna have the speakers... |
Anyone?? when you speak of distance from wall to speaker, is it wall to tweeter,wall to the outside of speaker or wall to inside of speaker cabinet? What about front wall measurements! Wall to back of speaker or front? |
I was trying to break things down to simple terms. You are right that there is a limit. The further from the wall the speaker gets the less defined the image gets. It will only project so far. If it wasnt the walls you wouldnt get a bigger soundstage in a bigger room with the same system. That is also why room treatment goes on the walls because it needs to be at the reflection point.
If you were to put your system in a feild it would sound completely different. I have never done this but I have always wanted to. I also think that, set up right, any speaker will image beyond the wall and I have been able to accomplish this with every pair of speakers I have owned including some real cheapies.
Of all the varibles of high end audio acoustics is one of the most important. Ask anyone with a didicated listening room what they think. Rooms, walls and ceiling, are layed out in a way to articulate sound and dissapate excess. This is all based on where the walls and ceilings are relative to where the speakers are. The reflection points. |
no, perfect image, i beg to differ - speakers would image *best*, if there's *no* sidewall - i.e.: if they were outside. in my current set-up, my monitors are ~9' from the side-walls, & there is *no way* that i have imagining 9' beyond the outside walls! w/my ~25' wall, that would make the image ~43' wide!?! kinda rediculous, imho. *sometimes*, on *some* recordings, i get images that make for a soundstage ~18'-20' wide. this is about the best i'm gonna get (or even want, for that matter). if i were to put my current set-up into a narrower room, extensive sound absorption would be necessary on the side walls to get similar soundstage width. very few (if any) speakers will image even outside their own cabinets, let alone outside the side walls, if placed w/in 2'-3' of an untreated side-wall. |
Yes you are right. The further the speaker is from the wall the further it will image but it is the wall that creates that image. As you move that speaker in the soundstage widens in direct relationship of the distance betwen the wall and speaker. Room treatment just makes the sound wave react in a way that "tricks" the sound in working as if it was in a bigger or better room. If the speaker is two feet from the wall the image will be two feet beyond the wall. If the speaker is five feet from the wall then the image will be five feet beyond the wall. This is of course broken down to simple terms and there are numorous factors to also consider for overall soundstaging. |
I agree Sedond, I have experienced stable images 6 feet outside the speakers when I placed my speakers on the long wall giving me side walls that were 9 feet away from the speakers. |
perfectimage, perhaps i'm mistaken, but it's been my experience that sidewalls in close proximity to the speakers is what kills imaging, unless absorbent treatment is properly used, especially at the sounds' 1st-reflection point. i have found that most speakers image best when well-away from walls. |
Ben. The sidewalls are what reflects the sound back to create a image beyond the wall. The image created will be as far past the wall as the speaker is as far from the wall. Ex. If your speaker is two feet from the wall then the image will be two feet past the wall. |
I believe it has to be aural illusion. All we are hearing is the reproduction of the sound in the studio or hall. We hear what the microphones hear, right? That's why on the Copland disk my music room sounds 100' wide. I'm reproducion the sound of the room in relationship to the microphones. The sound isn't really in my fireplace or next door in your flat. That's my non-scientific explaination, and I might stick with it. |
Yet again I'm reading beyond the side walls-really how can this be possible outwith aural illusion? |
Inspite of knowing that there is no such thing as soundstage depth (but certainly left to right imaging spread) that real live music (for small group, jazz or quartet ), the effect certainly is desirable.It just seem that we are getting our money's worth. For a live Classical Orchestra there certainly is depth in real life, albeit not as deep as some systems manage, it is pleasant to have it all the same. Although on some recordings the pitch definition could be not as clear as what you would like. That is the cost of having unnatural, but desirable, soundstage. Even My Dunlavy V's manage extra-wide soundstage beyond sidewalls on certain recordings(buena vista social club for example), but it is rare in my case. |
For those of you who answered the questions, thank you. |
Could someone explain how it is possible for the soundstage to extend beyond the side walls? Is this an aural illusion? Staying in a flat I wouldn't like to think my next door neighbours were getting some of my soundstage,would seem a waste to me. |
Copland 100 on Reference Rec. "Fanfare for the common man" the entire hall is there, front, sides and around. I think alot of the RR recordings extend the stage. |
I found the sound stage is very dependence on the recording or mastering process. If you have Roger Water's "Amused to Death" or "Casino Royale" then you have have sound stage beyong the speakers. With "Amused to Death" you'll actually get 180 degree surround sound effect. It's pretty cool. However, in classical music, I have yet to find a recording that will project the sound stage beyond the speakers in a convincing matter. If you know of one, please let me know. |
BY THE WAY IT IS HILLYG@AOL.COM |
CORNFEDBOY PLEASE CONTACT ME. I THINK WE HAVE SIMILAR EQUIPMENT AND I WOULD LIKE YOUR ADVICE ETC. |
I don't think you can have too wide or too deep of a soundstage as long as you don't give up imaging. My soundstage is simmilar to Cornfedboy, well beyond the side walls and very deep, on some recordings (Dr. Johnson - RR sound test) the back wall is 30' deep. I have a fireplace 7' back from the speakers, I've often thought the singer is in the firebox! Very cool. |
The soundstage should change with different recordings. If your system reproduces a huge soundstage when appropriate, but does not exaggerate intimate recordings it is a blessing not a problem. Does it sound natural, does it sound like music? Thats the only question. The only answer can be found by listening to live music. I bet lots of listeners wish they had such a "problem". |
A wide and deep soundstage is important. You can have too much of a good thing if you get a wide deep soundstage at the expense of placement/timbre accuracy in the soundstage. On a good recording on a good system the instruments should have weight and presence and be placed accurately in 3 dimensions. If the instruments are blurred or seem to have a “haze” around them then you might want to start tweaking. Most, if not all, live music I have heard were not set up with soundstage in mind at all. Cheers - Dan |
Is soundstage really that important? You should pay more attention in the tonal balance and the musicality aspect of the system. If you get them right, it pays big time. |
Interesting question. It's generally accepted that the wider and deeper recreation of the acoustic space your system cam produce, the better. However, it's been my experience that at live acoustic concerts I don't hear any soundstage information. The sound of the music is so entwined with the sound of the space that it's impossible to distinguish between them. This level of reality is impossible to reproduce within another acoustic space (your room). |
jtinn: it's difficult for me to imagine an audio system's producing "too much soundstage." the width of the perceived image, like many other things, is affected by the quality of your components and the attributes/frailties of your listening enviroment. my speakers are just over 7 1/2 feet apart center-to-center and are placed some six feet from the side walls and rear wall. with a number of sources, the image doesn't just extend to the side walls but well beyond them. more typically, the depth of the perceived image is well behind the rear wall of my sound room. how do i compare this to a live performance? i usually can't unless i'm listening to a live performance of a familiar group or orchestra. studio recordings reflect the production and engineering more than a "reality" you might expect. drums, for example, are frequently recorded in spaces isolated from other instruments and vocalists. tracks are often recorded in different venues and then melded together in a seemingly coherent whole. i have a few discs through which i test an unfamiliar system's sound stage. generally, i begin with a couple of well-recorded acapella pieces: two of my favorites are by the fairfield four and the persuasions. on superior systems in good sound spaces, you should be able to close your eyes and "see" each singer placed properly in a straight or curved line that shifts slightly as the performers move in relation to their assigned microphones. for testing depth of image, i have a few other favorite discs. two of these (among many) are lt. kije on refernce recordings (lp and cd) and fanfare for the common man on telarc cd. from these i move to some rock pieces, including by way of example, the pink floyd tracks from the burmester test disc (vorfurings-cdii). these recordings should seem to come from everywhere, even behind your head. for image size, i generally rely on recordings with solo acoutic guitars; one of my favorites is "treetop flyer" from stephen still's stills alone. if, after all this, i want to get some fix, however flawed, on how a system compares to live performances, i put on two discs with which i have great familiarity, both by the eagles: hell freezes over (cd) and eagles live (japanese vinyl). no, you can't, IMO, get too much soundstage but can produce unrealistically large images of voices and instruments--elephant-like is my description. (after reading this, i fear i may have strayed a bit off topic here but hope you'll find my experiences helpful, nonetheless.) good hunting. -kelly |
