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Bronze Member Username: Wasserman12Post Number: 45 Registered: Jul-06 | Since I've started assembling my stereo, the main thing I've been trying to achieve is (what I've come to understand is described as) a wide soundstage and good imaging. The speakers that I have now are quite inexpensive, though, to my ears, are not seriously lacking in most respects, in terms of detail and coloration. However, despite being set up in a manner that should be conducive to good soundstage and imaging, I find them to sound extremely directional: that is, I can always tell that the sound is coming from the speakers, and seems to hang in the air right in front of them. The sweet spot, such as it is, where the stereo effect begins to take shape and I experience some semblance of a stereo image, where some air gets between the instruments and they take on dimension, is distressingly small. How is it that better speakers image more effectively, and what factors inthe design and performance of the speakers themself enhance the effect? I worked for a while in stereoscopic photography, and have found that the greater the detail of the two opposing photographs, the more subtle and life-like the illusion of depth becomes. I can only assume that this is the case with the stereo sound. Is it simply that the more detail in the sound the more subtle the brain's resolution of the discrepancies of the right and left ear's stimulus? In stereoscopy, the greater the discrepancy (within fairly narrow limits) the greaer the illusion of depth. But my intuition tells me this reasoning does not obtain for stereo sound. Anyone wanna share their understanding? When I was a kid, I used to move my dads big cheap sony loudspeakers so that they were facing each other, about 2 feet apart, and lie down with my head right between them and get lost in the amazing stereo image that resulted. I'm trying to get that same experience today, without having to lie down on the floor and get in everyones way. |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 1749 Registered: Sep-04 | Eugene, I'm no expert, but my understanding is that the auditory centres of the brain work out audio imagery from the slight time delays between the same signal arriving at each ear. It is true that higher performance speakers usually enjoy better resolution which makes the image more palpable, but it's not the main contributor to imaging as far as I can tell. My experience with speakers tells me that speakers with wider dispersion are the ones which offer wider sweet spots and those with narrower dispersion seem to suffer from narrower sweet spots. They also usually require far more toe-in than those with wider dispersion. The corollary of this is that speakers with wide dispersion should not be toed in or only toed in a little! This is because if you toe in a speaker with wide dispersion then the image collapses into the middle and slight movement out of the sweet spot immediately snaps the image to the speaker closer to you or render it in front of the speakers. If yours are modern speakers, they probably have quite wide dispersion. You should start by having them square to the sweet spot location. If there is no image and it's vague, begin to toe in only very slightly. At every adjustment check the image from the sweet spot. At some point it should snap into focus. The less you toe in, the wider the sound stage will be. If you want image depth, try to pull out the speakers from the back wall. If the speakers are close to the back wall (6 inches or less), then the back wall acts as a reflective surface and interacts with your main signal to flatten the sound stage. By pulling the speakers away from the wall (18 inches is a good place to start), the initial reflection is both weaker and further out of phase with the main signal. This should provide more depth to the image. That said, some speakers are designed to use the back wall for bass reinforcement. These are the exceptions to the rule, although they do generally sound a little flatter than their counterparts. These placements have an effect on something else which many people simply don't pick up on - timing. Too much toe-in often causes the music to become muddled more easily and for bass to become ploddy. Too little toe-in causes the instruments to have more air than they should have, almost like they're playing at different times in different places. The object of the exercise is to end up with a cohesive, representative soundstage where the instrumentalists sound in their space but where they also sound like they are playing off each other. It's best to use a live or simply recorded track for this aspect. Another thing to bear in mind is volume. There is usually a certain volume required to 'fill the room', below which the sound seems bound to the speakers and above which the sound becomes strained as it over-energises the room. As to your kid-experiences, many people can't cope with the 'image-in-the-head' experience of headphones (effectively what you had). The image from speakers is quite different and should have more body because the spacial differences are more accurate in that scenario. I hope this helps a bit. Regards, Frank. |
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Bronze Member Username: Wasserman12Post Number: 46 Registered: Jul-06 | thanks Frank- I'll try out your suggestions. I'm going to be springing for some new speakers soon- I hope that will help too. I appreciate it- E |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 1751 Registered: Sep-04 | By the way I forgot to mention that usually they need to be fairly well spaced out - just not too much or you'll get the 2-speaker syndrome again. No more than the distance of the speakers to you. Regards, Frank. |
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Gold Member Username: Timn8terSeattle, WA USA Post Number: 1146 Registered: Dec-03 | I agree that placement has a huge impact on performance, as do room effects in general (reflections, etc.). Frank's suggestions are very good and should be tested. I believe whether a speaker is highly directional (single driver, dipole) or not has less of an impact. Low end speakers tend to not image well because of distortion and poor frequency response characteristics. We may need to qualify that a bit. Just because a speaker is inexpensive doesn't mean it's poorly designed and unable to image well. The "headphone experience" is not how I would define imaging. Imaging to me is the system's ability to allow the listener to easily determine what instruments are playing and where they are located in the soundstage. I think the "headphone experience" can be so enjoyable because of the absence of the room and the associated "noise" it adds to the music. However, I also think that successful integration of a system into a room can surpass the "headphone experience". |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 9474 Registered: May-04 | . http://www.gcaudio.com/resources/howtos/speakerplacement.html If you haven't studied how to set your speakers up for best performance, it is well worth the time to read through a few of the various methods used for finding proper placement in your particular room. And, remember, where you position your chair is as important as where you place the speakers. Keep both well away from boundaries to open up the soundstage. http://www.stereophile.com/reference/50/index.html "soundstaging, soundstage presentation The accuracy with which a reproducing system conveys audible information about the size, shape, and acoustical characteristics of the original recording space and the placement of the performers within it." "imaging The measure of a system's ability to float stable and specific phantom images, reproducing the original sizes and locations of the instruments across the soundstage. See 'stereo imaging'." I agree that inexpensive speakers can still do an impressive job of soundstaging and imaging. I presently have a pair of Insignia speakers that I bought from Best Buy for $39.95 the pair that are doing an exceptional job of both qualities. A friend who has recently bought a pair of Linn speakers heard my Insignia's and was, in his words, quite upset at what we both got for our money. I also did a set up at a friend's house of a pair of Sony speakers that retail for about $50 per pair that did a nice job of disappearing. In the last few years computer programs and Chinese production have made less expensive components perform very well. But I have never heard a cheap speaker sound very good. The box draws attention to itself due to the resonances that inhabit cheap speakers. So keep your expectations in line with what you presently own and understand somethings are the very reason more expensive equipment exists. And even inexpensive speakers require pretty good amplification to perform at their best. I don't believe dispersion has much to do with soundstaging in general. Dispersion will have a drastic effect on how large the listener's sweet spot will be but some speakers with very wide dispersion have disappointed me in their ability to create a believable presentation. Too often wide dispersion speakers have too many reflections bouncing around the room to allow good soundstaging. In my experience symmetry is important to improving you system's ability to project a believable spatial presentation. Placing speakers in a room with uneven dimensions or oddities which cause uneven reflections will diminish even the best system's ability to bring performers into your space or you into their's. If the left speaker is five feet from the wall, the right speaker must be five feet from the wall, not four feet ten inches. Get a tape measure, some masking tape and a laser level before you begin setting up your speakers. Make certain you have your speakers as close as possible to identical measurements for both sides and away from your listening position. Get you speakers and your chair away from the walls. A one third placement into the room is what I consider the best location to begin with. Measure the length of the room and place the speakers at the one third position into the room. This location is often the best for bass response and will give the deepest soundstage possible in your room with your equipment. If you decide to change the location of the speakers, this position should give you an idea of what you are giving up. Not all rooms are going to allow decent "stereo" sound. Too many reflections from room surfaces are going to disrupt what your ear perceives as the correct time cues. If the room won't allow good sound, it doesn't really matter what you buy until you fix the space. . |
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Gold Member Username: Joe_cAtlanta, GA Post Number: 1103 Registered: Mar-05 | Amazing, you still keep coming up with great info Jan. I never would have though that 1/2"-1/4" made a difference until I tried. Cool stuff thanks. |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 1752 Registered: Sep-04 | I appreciate that wide dispersion causes more reflections which can affect the soundstaging (and timing) of the music. I still maintain that stage width and stage uniformity is usually improved with wider dispersion loudspeakers, although this is affected by those reflections. Therefore, our approach to installations has changed somewhat in the last couple of years. We tend to recommend placement with speakers shooting across the shorter room dimension rather than shooting down the length. This cuts down on sidewall reflections dramatically and really makes for a much cleaner presentation. in the old days, it was more usual to recomended shooting down the length with more severe toe-in. Just a thought... Regards, Frank. |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 9501 Registered: May-04 | . Frank - It almost sounds like you're taking a one size fits all approach to your installs now. Firing speakers across the short dimension of the room has the benefit of near(er) field listening for most situations, but less stage depth in my experience. My preference is to gain the depth by placement and then obtain the width by treatment. But that isn't always an option in many domestic situations. I doubt anyone will reach a decision as to whether wide or confined dispersion results in better soundstaging. Designers don't seem to have reached a conclusion as both sorts of speakers are still available. Very wide dispersion can cause problems in a rising in room high frequency content made up mostly of reflections which,as we stated, tend to smear the sound and add a glare to the overall presentation. My personal preference has been for speakers that fall in between the two extremes. Both my Spica Angelus and my LS3/5a's have tweeters which are capable of fairly wide dispersion when left to their own devices. However, in both cases, the actual dispersion of the tweeter is limited by felt damping pads surrounding the tweeter. This damping minimizes reflections while allowing for a tweeter that has few discontinuities across its bandwidth. I won't tell you these are the only speakers I've heard with exceptional soundstaging and imaging properties, but they are both at the top of my list of dynamic speakers which have the ability to emulate dipoles, electrostats and ribbons, the last two having somewhat limited horizontal dispersion. Additionally, as the damping material on the front baffle of the Wilson Watts has increased in efficiency, the speaker has continued to produce more believable soundstaging. On the other hand, I still cannot get used to the ultrawide dispersion of any Thiel design I've heard in the last few years. Dampening the room severly is the only good solution I've seen to their peculiar brand of problems. . |