Imaging beyond speaker position?
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Bronze Member Username: Wasserman12Post Number: 67 Registered: Jul-06 | I have noticed that my speakers often image beoynd their position. I understand how imaging can occur in between speakers, but how is it that my speakers can create sound that appears to come from well beyond them? Its an effect that I would like to emphasize, or at least bring out to its fullest. Are there any factors that control this effect? The Speakers are NHT SuperZeros, paired with a small 8" sub. I've noticed that the effect occurs mostly in higher pitched, relatively low volume sounds, such as hand claps, or the stacatto choir passages in Steve Reich's Music For 18 Musicians. Thanks in advance for any thoughts. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 10235 Registered: May-04 | . You will first have to decide what is responsible for "imaging". Out of phase information can easily be misplaced by your ears to the extent you believe sounds orginate from positions unlike anything real. By manipulating phase relationships between channels the engineer can get sounds to occur very deep in the soundstage, well behind the listener or off to either side. So, you'll have to realize what is causing these sideways images and whether they are actually a good thing or a problem in the system. Speakers typically have drivers out of phase with one another through the crossover frequencies and the electronic components in your system are very likely to have phasey, time shifted response. Phono cartridges have enormous amounts of phase shift at high and low frequencies both. As a rule I've found components that maintain absolute phase relative to the input signal will normally throw a wider image with more specificity and palpability than components that have poor phase response. The phase might be shifted 180° but the signal is delivered to the outputs with good overall phase integrity. Such equipment typically does well on measurements which look at square wave response, slew rate and rise and settle time. Speakers that maintain the relationships of the incoming signal are often simpler designs though not exclusively so. Pulse response will normally show whether a speaker might have a wide soundstage. Tightly matched speaker pairs (through their frequency range) will almost always do well in the soundstaging department. My LS3'5a's had a driver spec that was maintained to + or - 0.5 dB. The pairs matching had a spec of + or - 1.0 dB. Well recorded material places images several feet outside the outer boundaries of the speaker proper and three of the four walls of the room disappear with players frequently appearing in my driveway to the outside the left channel speaker or inside the closet to the far right. Of course, the recording must have these images placed properly for a well designed and built system to mainatin the identical "image" from source to speaker. With even the best system the room can still destroy the final results if symmetry is not maintained in set up. If you are listening to studio production numbers, you will be dependent upon the post production engineer to weave a credible image from the many disparate parts. If you are listening mainly to acoustic music, the skills of the engineer in choosing and placing microphones will make all the difference in the final result. A recording made with a Decca tree will sound very different spatially than a recording made with conincident hypercardiod mics assuming a final two channel mixdown. . |
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Gold Member Username: NuckPost Number: 6798 Registered: Dec-04 | saved that to file. |
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Silver Member Username: James_the_godDoncaster, South Yorkshire England Post Number: 432 Registered: Jan-05 | What equipment do you own Jan. Since you seem to the forums 'guru' Im just curious. If you own too much to list, what do you use as your main system? Cheers |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 10242 Registered: May-04 | . I've kept what I own away from the forum for my own reasons. I use McIntosh tube amps and British monitors but it's not a system that is common to this forum and most of it is older than a quite a few participants on this forum. It suits my needs musically and that's all that matters to me. . |
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Gold Member Username: NuckPost Number: 6809 Registered: Dec-04 | Like Rolls Royce says...sufficient. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 10244 Registered: May-04 | . I should probably clarify that pair matching is what is important in speakers. My LS3/5a's and other speakers which can project images beyond their borders are not required to be perfectly flat in their response. The 3/5a's have a well know lump in the midbass that ups the ante about +3dB relative to the midband. Speakers such as the Wilson Maxx have a rather rolling in room response that doesn't look very promising on paper but still the speaker does many things correctly and, from all reports of those who have heard the Wilson set up properly, it can project an image well beyond its outside edges. Therefore, you would assume tight tolerances from side to side are the most important requirement for this sort of spatial playground. Now, I will inform you that Tim Forman's Alegria Audio speakers, both the Ling and the Emma, did quite well in my main system as far as replicating the spatial effects I hear with the 3/5a's. While very good speakers, Tim does nothing beyond buying quality components to make side to side matching tolerances anything special. Additionally a pair of KEF Cresta 1's that I payed $199 the pair do wonderfully well and are the speakers I pair with my six watt T-amps. I was to say the least knocked out when I first played "Kind of Blue" through that combination. Also, the Insignia coaxials that I now use in the HT room were quite surprising when paired wih the Macs or the T-amps, to the extent a friend who had just purchased a $1200 pair of Linn speakers was left incredulous, with images that were nearly the equivalent of the 3/5a's in terms of placement within and outside of the room. That would lead me to question the influence of the equipment in front of the speakers on spatial effects. A former member of this forum who felt all electronics sound basically the same used to argue only speakers can "image" and I understand this is a commonly held belief on the "everything's the same" forums. My sales and personal experience of driving low priced speakers with high priced electronics would indicate this is horse hockey but everyone gets to believe almost whatever they want until they decide to change their mind. I would add inert cabinets tend to project substantial images without bloat. Resonant energy would appear to be the enemy of well placed images and the 3/5a's and the Wilsons are both marvelously calm when rapped with your knuckles. But then again, the cheap KEF's and the Insignias are hardly what anyone would call "inert" cabinetry. Go figure! . |
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Silver Member Username: Mike3Wiley, Tx USA Post Number: 347 Registered: May-06 | I think I read in Jan's post that there is a belief that the electronics (components) do not contribute to imaging, only the speakers have an effect. Phooey. When I used my Creek 5850 SE as a pre-amp into my Carver I had imaging up the a&$. Way to much, over the top. The Rogue Tube amp brought me back to reality. I also believe imaging is relative to the engineering of the recording and your system will represent it to the best of its ability. I have outside the speaker imaging with my Gallo's but I also have a system which provides a sound where my speakers "disappear". As I post this I am listening to Kraftwerk - "Autobahn" on the Linn. Very interesting if you like electronics. A lot of playful activity between the speakers with marginal "beyond the speaker" imaging in the playback. Different when I listen to Roger Water's "Amused to Death" where the horses leading the stagecoach try to trample me, or the Ferrari comes from outside my house and leaves the media room through the opposite wall. The Gallo's have a hollow-cast, aluminum chassis filled with Gallo's patented S2 technology air-density treatment. So I'm thinking bloat is not a factor nor is resonance which is probably why one of the reasons I like them so much more than my Monitor Audio Silver 8i's. Reading Jan's post I understand more as to why I have sound that goes to infinity and beyond. Well not maybe quite that far.  |
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Gold Member Username: John_aLondonU.K. Post Number: 4664 Registered: Dec-03 | eugene asks: how is it that my speakers can create sound that appears to come from well beyond them? It's a good question! Here are two links from the Institute of Sound and Vibration Research at University of Southampton Virtual Acoustics Project There are some demonstration Stereo Dipole wave files under "Download" in the menu to the left. They are very good and nicely demonstrate the virtual source being outside the angle of the speakers. Even on my computer! Virtual Source Imaging Human Localisation It seems to, from all this, is that the simple answer is that the the brain calculates the position of a real source of sound from the Interaural Time Difference (ITD) and Interaural Level Difference (ILD). That is, the difference in time of arrival, and in level, of a sound as it is detected at our two ears. So a HiFi can fool us into hearing a virtual source of sound that seems to have a position we get from the just two speakers, and the position can be outside the speakers. This ITD is probably the reason why we need good time and phase coherence in our systems - a real sound has a whole spectrum of frequencies. From the virtual source, these should all arrive at once from one speaker, with the time delay from the other speaker being exactly the same at all frequencies if we are to believe that the sound came from one source. I've noticed that the effect occurs mostly in higher pitched, relatively low volume sound I think the higher pitch comes from the fact that the wavelength is short and in the same ballpark as the inter-aural distance. It is well known to owners of subs that we cannot determine the direction of sources of low frequencies alone. It could be that "low volume" helps because then there are fewer reflections from the room to complicate the issue. Hope this helps! |
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Gold Member Username: John_aLondonU.K. Post Number: 4665 Registered: Dec-03 | Also How We Localize Sound from Physics Today. |
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Silver Member Username: Mike3Wiley, Tx USA Post Number: 354 Registered: May-06 | But John, Mike pleads, it was so much easier for me to think "but that is the the way they meant for us to hear it", instead of a real physical linear scientific factual cause and effect. Half kidding. I am sort of winding down and had to turbo charge the neurons in my brain, those still around, to interpret your post. Thanks for the delineation! BTW I am only virtual office occaisonally, everything else is real. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 10248 Registered: May-04 | . John - Not to discount your research but the facts presented in those articles would suggest that all speakers which are placed properly in a symmetrical room should be capable of locating sounds outside the speaker boundaries. How then do you account for speakers that cannot do this trick? This sort of soundtstaging is far more common than not when dealing with lower priced/quality equipment. . |
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Gold Member Username: T_bomb25Dayton, Ohio United States Post Number: 1569 Registered: Jun-05 | From what I have come to realize is that source has a lot to do with imaging and some speakers dont pull off this trick as Jan said,British and Danish,european monitors do this better than any speakers I know of regardless of price.Jan's legondary BBC monitors are one of the best ever made at soundstaging and imaging you even heard him mention his budget Kef Cresta 1's,same goes for my Wharfedale Diamond 8.1's and my newly aquired Eltax Monitor III's,thes are all exceptional at soundstging and imaging and spatial detail,you will be supprised how a good frontend will take a budget speaker,you can make a lot of your buddies envious for the money they have spent on their speakers. |
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Gold Member Username: NuckPost Number: 6843 Registered: Dec-04 | TW, I looked at the Eltax monitor 3's, they are a lot of money into Canada. |
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Gold Member Username: T_bomb25Dayton, Ohio United States Post Number: 1571 Registered: Jun-05 | Give AudioWaves in Trinidad,California a call they were $275 shipped for free in the U.S. they are the only place in the U.S. that carries them.So how did you see them for? |
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Gold Member Username: NuckPost Number: 6851 Registered: Dec-04 | .So how did you see them for? OK, I'm gonna call you on that one, TM, I usually type that . From the website, shipped direct. LOL! |
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Gold Member Username: T_bomb25Dayton, Ohio United States Post Number: 1572 Registered: Jun-05 | Nuck Call audiowaves 1-800-510-4753 |
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Gold Member Username: Stu_pittIrvington, New York USA Post Number: 1756 Registered: May-05 | In my experience, everything contributes to imaging. But, the amin thing has to be the recording itself. Jan's Emma CD showed my just how big a soundstage can be. Different rooms have different reflections, which can cause numerous problems, which will rear their heads in the imaging department. Placing speakers will have a lot to do with it. How many times have you heard '...I moved the speakers a few inches further apart and the image snapped into place.' My turntable images far better than my old CD player did. My new CD player can image better than my turntable can, at times. My TV as a source (connected through very long RCAs into my integrated amp) can image pretty well. My wife noticed it one time when we were watching a movie with some classical music in the background. Through my stereo, the sound and 'imaging' of TV programs is so much better. Voices are much closer to poeople's mouths. Off screen effects truly are off screen. My interconnects help imaging. My old Monster interconnects threw off my center. Voices and drums were repeatedly about half a foot off center. Sizes of instruments (voices included) are much more realistic with my Audioquests than the Monsters. While speakers have a lot to do with it, they're not soley responsible. Audition different systems with the same speakers in the same room. The imaging and soundstaging will change. But, even though imaging may be better in some systems, its not the only thing. A lot of people get caught up in imaging and soundstaging when buying speakers. Just because they do this well doesn't mean they'll do other things well. I'd sacrifice some imaging and soundstaging for better pace, rythym, and timing. That's only one trait. |
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Gold Member Username: John_aLondonU.K. Post Number: 4666 Registered: Dec-03 | Jan, Not to discount your research but the facts presented in those articles would suggest that all speakers which are placed properly in a symmetrical room should be capable of locating sounds outside the speaker boundaries. No, they don't claim that. In the 1st audio file -- "track 1" -- the guy explains that it may not work for various reasons, and one is that the two speakers do not have exactly the same frequency response. http://www.isvr.soton.ac.uk/FDAG/vap/html/download.html Also there is this "ReadMe"; http://www.isvr.soton.ac.uk/FDAG/vap/html/readme.html I must say that is not so clear. If I understand it, the idea is to put your speakers quite close together so the listening angle is about 10º. Then there is a good chance of reproducing the virtual source outside that angle. In the second test, the guy walks all around a dummy head. Getting the sound coming from behind the listener. I think this could be a good test for speakers and electronics, too, as in the discussion above. Especially for matched frequence response and phase coherence. |
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Bronze Member Username: Wasserman12Post Number: 68 Registered: Jul-06 | I'm glad that this thread has generated so much discussion. I appreciate everyone's input. As regards the stereo dipole experiments discussed above, I suggest that people try listening to those sample tracks exactly as intructed. I tried it, with the speakers centers 35 cm apart, sitting 2 meters away, and the soundtsage was unbelievable. I have never experienced hearing a sound coming from well behind me before, but the effect was utterly convincing. The effect seemed greater than what Jan describes achieving with his t-amp. PS. Do you use a power amp with the T-amp? |
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Silver Member Username: Alright_boyPost Number: 177 Registered: Jan-07 | I agree with Stu. It all starts with the recording. Everything downstream contibutes. But speakers, including their placements, are the most critical component. You can change the imaging by moving one or both ever so slightly or by changing your listening position. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 10256 Registered: May-04 | . "The effect seemed greater than what Jan describes achieving with his t-amp. PS. Do you use a power amp with the T-amp?" The soundstaging I described is what I hear with either the T-amp or the McIntosh tubes, whether I use my usual pre amp (tubed) or the passive pre amp in eiher Tripath based amps I own. So, the benefits of this type of staging are consistent with the electronics I typically have in my system. Though not as well done with the lower priced Sony SACD player I own as with "better" players I have available for my system, the soundstaging is still wide and deep on any recording I play that has the capacity for such reproduction. As Stu's comment suggests the Emma Demo CD was chosen with just such staging in mind. The T-amps I own have the capacity to be used as either a full integrated amplifier with a passive pre or as a straight power amp. Either method gives convincing soundstaging. Without the information carefully placed on the source disc, there can be nothing that follows. Excellent mono recordings will give a sense of width and depth placement that exceeds what most people expect from a single microphone pickup. One of the best I have in this regard is "Elvis at Sun Recording Studios", a recent remaster of Elvis' original mono recordings done by Sam Phillips' son. On vinyl this recording is convincing proof that mono offers a presence unlike the typical AM radio sound quality people typically associate with one channel reproduction. The early Mercury and RCA three microphone recordings (intended at the time for enhanced stereo employing a center speaker) still stand as hallmarks of stereo reproduction fifty years after they were done. (The SACD issues of these recordings offer the consumer the only opportunity to hear these excellent recordings as they were originally intended by the producers and engineers involved in the sessions.) By everyone's admission, the techniques employed in those recording sessions were discontinued due to financial pressures to simplify and reduce set up and recording time. Multichannel recording techniques allow the engineer to patch mistakes where the original recording techniques meant the performers played and should a mistake occur everyone began again with fresh recording media. Since everything begins with the recording, I would suggest anyone interested in how microphone selection and placement affect the final result read what some of the experts have to say about how to properly get the sound from the studio to the master tape. http://search.yahoo.com/bin/search?fr=ybr_sbc&p=microphone%20placement http://search.yahoo.com/bin/search?fr=ybr_sbc&p=microphone%20selection http://www.deccaclassics.com/music/mercurylivingpresence/about.html http://www.soundfountain.com/amb/mercury.html As Tawaun noted the LS3/5a's, as with most mini-monitors, excell at soundstaging. What makes the 3/5a's unique in this regard is not only their "legendary" status in audio history (proclaimed just this month in Stereophile as still competitive with the best of the best) but that they are now quite anachronistic in their design. The new fangled clones of the 3/5a's from Spendor and Harbeth have what are considered de rigueur designs for contemporary cabinet construction while the original 3/5a's and their immediate successors from Stirling have tweeters recessed behind the cabinet facia and woofer mounted from the rear of the front baffle. All things modern say the 3/5a's should not be able to do what it manages. . |
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Silver Member Username: Alright_boyPost Number: 179 Registered: Jan-07 | Funny you should mention mono recordings. I have frequently experienced depth in the better ones, but I can't say that I have noticed much if any width. |
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Gold Member Username: NuckPost Number: 6867 Registered: Dec-04 | JBJ, the recordings themselves are the key, I think.Jan's Decca reference is valid for an evaluation. So Jan, with the Rodgers in place, most of your stuff presents itself with stage and image? |
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Gold Member Username: T_bomb25Dayton, Ohio United States Post Number: 1574 Registered: Jun-05 | Another speaker as good as the great BBC Monitors at imaging and soundstaging is the Pro Ac Tabblelite Reference 8 their absolutely stunning in this regard to,along with the Totem Arro's.The Epos are very good to,the Acoustic Energy AE 1,is another great speaker at this neat trick infact one of the best,so are the Odyssey Epiphony,many of you on here have heard me rave about them in the past,they have a new design now,but I've never heard them,my Wharfedale Diamond 8.1's do it to so the Mission M31i,Jans Creta 1, but all 3 lack the detail to be able make it totally believeable,the 9.1s are a tad bit better in this regard as is the Epos els 3,dont forget about the Harbeths and Spendor's both companies had designers from BBC along with Epos.For Budget speakers or any speakers for that matter the Eltax Monitor III's are close to what Jans babies do,the Acoustic Energy AE1,and Pro Ac Tabblelite Reference 8 at soundstaging and imaging I've ever heard,thats a helluva lot of ability for a speaker that costs $275 bucks along with their other emense talents you can nearly get to those 3 greats abilities for much cheaper! |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 10258 Registered: May-04 | . "So Jan, with the Rodgers in place, most of your stuff presents itself with stage and image?" Yep! But also with the KEF's, the NSM's I own, an 20 year old pair of Boston Acoustics A40's($150) and the $40 a pair Insignias. My point is all these components along with the T-amp and the Mac tubes and the $129 Sony SACD as well as the $1k players all present similar but not identical soundstaging. And I have had excellent width and depth and image placement for decades. So, other than the recordings themself, where does this sort of soundstaging occur? What is responsible for "creating" this type of dimension? Because I've been in high end demo rooms listening to far more expensive systems than mine and I've not heard the same sort of width and depth in many of those instances that I get with consistency in my simple set up. . |
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Silver Member Username: ExerciseguyBrooklyn, NY USA Post Number: 943 Registered: Oct-04 | Jan, Have you written about the Insignias (that are now $70+)? |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 10259 Registered: May-04 | . No, there are several write ups and discussions available on the web which center on the Insignia coaxial. They all point to the main problems with the speaker, which is the cabinet construction. The curved cabinet looks good and in theory should offer some potential gains in terms of dissipating, or not allowing, certain panel and box resonances. In reality the curvature of the cabinet is made by way of multiple kerfs cut into the interior MDF which leave not much more than the veneer layer as the remaining panel. In short, the cabinet looks much better than it sounds. (Keep in mind for the purposes of this thread, inert cabinet construction is considered a must have when discussing speakers which disappear, yet the Insignias do an impressive job, narrowing the soundstage by a minimum, in my main system.) It is up to the Insignia user to determine what to do with the oversized and poorly constructed port. I chose to block it and raise the enclosure tuning rather than listen to the port noise. A subwoofer is a necessity in a HT application so this isn't a problem in my case. Additionally, the crossover can be modified at little to no cost (though everything is relative when speaking of a product I purchased on sale for $20 each) to give smoother response through the shared frequency bands of both woofer and tweeter. Finally a bit of felt added to the "horn" in front of the tweeter smooths many of the reflections caused by the woofer and similar use of some felt bits adds a small amount of mass to the woofer's termination to the surround giving better midrange performance. The speaker is still dynamically challenged by more expensive products and will require a subwoofer in most applications. I purchased two pairs and set them up as dipoles which gave better soundstaging and dynamics than a single pair. Eventually, the plan is to build a decent wedge shaped enclosure which uses a single coax driver front and back. But these are in my HT room which is where good enough is sufficient for what I require. The speakers are not difficult to listen through, they have a rather laid back presentation, and that is more important to me (in this case) than many other factors which I find bothersome in most inexpensive speakers. For $40 the pair they are worth the cost and they replaced some Polks which had cost far more. The Polks had received good reviews but, after living with them, they were still just another pair of Polks. . |
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Gold Member Username: Thx_3417Bournemouth ... Post Number: 3543 Registered: May-05 | The further you move away from the fronts the less and less the stereo image becomes. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 10260 Registered: May-04 | . "The further you move away from the fronts the less and less the stereo image becomes." ? |
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Gold Member Username: Thx_3417Bournemouth ... Post Number: 3547 Registered: May-05 | Yes wasn't you aware of that its worse case sometimes but I think I've solved it here. |
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Gold Member Username: NuckPost Number: 6895 Registered: Dec-04 | Brilliant, Holmes! |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 10262 Registered: May-04 | . I did notice the Honda that went past on the next block didn't have much of a soundstage coming out of it. |
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Gold Member Username: Thx_3417Bournemouth ... Post Number: 3548 Registered: May-05 | God damn foreign cars never pan well over right channel. |
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Gold Member Username: NuckPost Number: 6902 Registered: Dec-04 | The stereo in the cavalier presently possessing me to go out in the hotel parking lot and shank it's tires has wonderful depth, although the driver, not so much. |
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