http://www.psaudio.com/ps/tips Everyday tech tips for audiophiles. en webmaster@psaudio.com Copyright 2008 2008-12-03T15:32:41+00:00 http://www.psaudio.com/ps/tips/could-your-chair-or-sofa-damage-your-systems-performance/ http://www.psaudio.com/ps/tips/could-your-chair-or-sofa-damage-your-systems-performance/#When:14:32:41Z You may not have this problem, but you might know someone who does! As the guy who wrote the owner's manual for the ARC/Magnepan Tympani 1Ds, I thought I pretty much knew it all when it came to installing these speakers and getting the most from them in any room. That's why I'll never forget the humbling lesson I learned in my lofty role as an audio "guru." Here's what happened: As a high-end dealer in the early '80s, I had sold a pair of Magneplanar Tympani 1D loudspeakers for use in an Audio Research system. I went out to install the system (which I always insisted on-and your dealer should do it for you as well). I always carried along a 1/3-octave real time analyzer so that I could quickly see where the bass standing wave problems were located in the listening area of the room. In less than an hour, I had found the best place to locate the speakers (somewhat tricky due to the negative bass waves emanating from the rear of the speaker), and the best place for the listening seat. Using my basic 3-step installation technique in Tips #74-77 , plus the information outlined in Tips #78-89 , I worked to get the sound to where I'd be proud to send a prospect over to my client's house to hear what the Maggies sounded like in a home. As I left, my client was effusively thanking me for getting him better sound than he thought was possible. I was a hero. A week later, he called me to complain about a "thickness in the midbass." I don't know if you are old enough to remember the Tympani 1Ds, but bass definition and timbre were their best qualities (Harry Pearson, writing in The Absolute Sound , adopted the T-1D as the bass unit for his soon-to-become-famous no-holds-barred hybrid Infinity QRS/Tympani 1D system). There was NO WAY we could have a thickness in the bass! My client must have changed some component or something (in other words, I was convinced it couldn't be my installation...). Well, I finally stopped by later that day, expecting to point out the offending component. But nothing was changed in the system. And boy, was the upper bass thick! I got out my trusty RTA. Sure enough, there was at least a 6 dB peak at about 125 Hz. Where did this come from? Well, I couldn't figure it out, but as I moved the RTA about two or three feet in front of the listening position I'd selected (and even marked!), the bass peak gradually disappeared. So we moved the seat forward and, just to be sure, listened to hear what the guru (me) had fixed. Oh, no, the peak was back! I measured the response behind the listening seat where we had originally determined was the best seat in the house (literally). Now the peak was almost gone! Anyway, I started to think I was on Candid Camera . I was looking so foolish. Then I noticed it. My client had a new sofa. When I had set the system up, we had used an occasional chair for the listening/voicing sessions. This sofa had a tightly stretched back panel (leather/leatherette). It was stretched so tightly, it produced its own tympanic sympathetic resonances at 125 Hz. Removing the sofa solved the mystery. So check out any system where the seating could cause a similar effect. I'm still surprised at how many systems can be affected. Jim Smith 2008-12-03T14:32:41+00:00 http://www.psaudio.com/ps/tips/choosing-a-good-listening-room-size/ http://www.psaudio.com/ps/tips/choosing-a-good-listening-room-size/#When:14:24:01Z There are some basic listening room sizes that work well. You can find them on the Internet. But it's also possible to build rooms that have been designed on some mythological dimensions that have issues in the bass. Here's a dimension for a medium-to-small listening room that has relatively smooth bass for a room of its size: 19' L x 14' W x 10' H. These dimensions, when entered into a room acoustics spreadsheet, work out amazingly well. Fortunately, I'd heard somewhere about these dimensions and built several listening rooms this size before I knew about any of the spreadsheet programs. Without exception, they worked well for rooms in this size category. You want rooms that have the fewest adjacent standing wave issues as possible. I'm referring to the "boundary effect" region (roughly from 300 Hz down to the lowest audible frequency in your room). If you're thinking of building your own listening room, I recommend that you locate a sound contractor who has a track record of success. It's a good idea to arrange to listen in a room that he has designed, if possible. I do especially recommend Rives Audio. http://www.rivesaudio.com/ Of course, there are many other variables to consider, including such things as air handling and electrical service. If you have no luck finding a contractor, you can contact PS Audio, and, within certain time constraints, we can make some useful suggestions. Jim Smith 2008-12-03T14:24:01+00:00 http://www.psaudio.com/ps/tips/over-50-and-wondering-about-your-hearing/ http://www.psaudio.com/ps/tips/over-50-and-wondering-about-your-hearing/#When:14:19:50Z This tip is from Jim Smith's tech tips. I'll never forget these intertwined events. It was in the early 1980s and I was recording the Alabama Symphony for the Birmingham National Public Radio affiliate. Several leading union musicians (from the Symphony tape committee) and the conductor would visit my shop one night each month. I'd play back the master recordings that I had recently made of concerts that were to be broadcast. Their job was to pick the best performance. Then I would prepare the broadcast master from my 30 I.P.S. analog master. I came to know and to spend some time around the conductor. I'd say he was in his middle '70s at that time. In our informal meetings, he'd have a problem with discrimination , which is common for older folks. In this case, discrimination is the term for being able to listen to someone and understand him while others are talking at the same time. Before I tell you my main point, you need to know one more thing: It's REALLY LOUD on stage with a full orchestra when it's playing power music . I once went out onstage while doing a test recording during a dress rehearsal for Gustav Holst's The Planets . As luck would have it, it was during "Uranus," one of the loudest sections. I had measured the sound pressure levels in the audience. I knew they were about 95 dB. But up on stage, standing next to the conductor with all the brass and percussion wailing away, I was shocked at how loud it was! It felt like my hair was being blown back like that old Maxell tape ad! Of course, someone who has been exposed to these incredible sound levels for 50 years is bound to have significant hearing damage. Add to that the age factor, and this man should have been lucky to hear an ambulance siren! During our listening sessions at my shop, he always picked up on problems, often before the much younger musicians. Furthermore, in the middle of a Beethoven Symphony #6 rehearsal, I saw him tell a second violinist several rows back to retune. On more than one occasion, he'd have to call somebody on a blown entrance when there was a full orchestra wailing away! It always amazed me that he could hear so precisely during the playback sessions and during the rehearsals. My point is that age, and even exposure to lifelong loud levels, seems not to be the only indicator as to whether a trained listener can still hear. For example, I often sit with younger men and women, teaching them about sound, or just kicking back listening to music. I'm 63, but I can reliably hear things that they miss entirely. Don't worry if you're past 50. It just means that you're experienced! 2008-12-03T14:19:50+00:00 http://www.psaudio.com/ps/tips/avoid-a-large-sweet-spot/ http://www.psaudio.com/ps/tips/avoid-a-large-sweet-spot/#When:17:42:08Z Why you should be sour on a wide "Sweet Spot" for two channel playback by Jim Smith. A wide sweet spot is almost like having your own harmonic distortion generator! There's simply no way a serious listener should be satisfied to sit more than a foot away from the 'equal path length intersection' (center point) of sound from a pair of loudspeakers. Inter-channel phase and timing information has just been badly compromised, destroying instrumental timbres. How is it that Audiophiles will accept only phase and time-aligned loudspeakers and then expect to sit off the acoustic center-point, totally destroying the inter-channel phase/time information? Look at it this way.....First, since you probably know this stuff, please forgive the simplified averaged wavelengths, but for purposes of illustration, let's assume that a 1100 Hz tone (or harmonic) has a length of about 12 inches. Then 550 Hz is almost 2 feet in length (from the top of the sound-wave crest to the top of the next). And 2 kHz is almost 6 inches in length, 4 kHz is 3 inches, etc. Now imagine that a female vocalist is recorded with her image centrally located in the stereo stage. If you sit two feet off center, that means that any fundamental notes and their harmonics from at least 500 Hz and above have been altered, some dramatically, some slightly. This is audible, and it's depressingly measurable! Before we examine the disastrous effects, let's look at what's happened to cause the problem... But wait a minute! What about imaging? OK, let's say that now you're about a foot closer to the left speaker than you are to the right one. Imagine a centrally recorded image that is reproduced at equal volume (amplitude) from both speakers in order to give the illusion of a precise center image. Without going too far into recording techniques or speaker dispersion patterns, a panned mono center image (such as is produced in a studio) may appear to have shifted left somewhat. While a center image recorded from a stereo pair of mics seems to 'stay put' a little better. But these are phantom images at best, lacking in the ultimate richness of tone and body. Here's why... It's not the potential 'image wander' that's troublesome. It's the harmonic distortion! (Technically, it's not distortion, but the alteration of harmonic relationships.) The positive cycle (top of the wave crest) of a 1000 Hz overtone arrives at your ear from the (closer) left speaker before it does from the right one. There'll be an audible - and very measurable - change at that frequency (or harmonic overtone). Should the distance be equivalent to a half-wavelength further (6 inches), then that particular overtone (harmonic) will arrive exactly out of phase. And you know how your stereo plays less bass when the speakers are out of phase? Well, the effect is exactly the same - a reduction in level at that particular frequency. Avoid a large sweet spot Why is this important? You've heard of voiceprints. That's where a recording of your voice can be used to positively identify you, no matter how hard you try to shift the sound of your voice. How does it work? The unique relationships of vocal overtones are different for each voice. For example, the first harmonic may be 87.3% of the fundamental, the second just 48.1%, the third 54.7%, etc. The exact relationship of these overtones (their relative strength, compared to the fundamental) is the identifying 'genetic code' of your voice. Well it turns out that all instruments and voices have their own particular set of harmonic ratios. That's how we know to differentiate two different instruments that are playing exactly the same note - say A (440 Hz). And that's how an original Guarneri will be chosen over a 'replica' - it's all in the 'tone'- which is actually the harmonic - or overtone structure. So, if you're sitting where the path lengths are significantly unequal from the left and right speakers, you are absolutely guaranteed to hear wild shifts in the harmonics, meaning that an instrument or voice will not sound exactly as it should. This is not just some subjective acoustic theory. It's not only audible; it's also measurable in your room at your listening seat! The sad fact is, you've just altered your system's harmonic relationships. So why did you buy all that stuff with 'vanishingly low distortion' if you're going to introduce a far worse version by not sitting in the center point where the path lengths are equal? Incidentally, this is an incontrovertible law of physics that is part of the good - and the bad - of stereophony. From a perfectionist's standpoint, it doesn't matter if your loudspeakers produce a smooth response off-axis. The varying wavelengths at a listening position off the acoustic center will always produce uneven response on centrally recorded images (actually all images, but it's easier to think about the centrally recorded image for the purposes of illustration). Here's a simple test for you. Put on a Sheffield or other disc that contains pink noise in both channels (pink noise is best, because it contains equal energy per octave, just like music). If you can, put your preamp in mono. Stereo or mono, what you want is equal amplitude in each channel. Now, from the center position, slowly move your head to the left or right. That huge change in mid/treble tonal balance is exactly what happens if you sit off axis. And because the wavelengths vary according to frequency, the varying time arrivals of harmonics also produce an unpredictable cancellation effect (well, it is predictable in that it's never a good thing). And a 'wide sweet spot' isn't really so sweet... Now that we've told it like it is, let's also admit to having absolutely wonderful experiences listening to music while others have occupied the best seat. If a system has dynamics, if it's effortless, if it at least starts out being pretty accurate timbrally, then it can be quite listenable off-axis. Just remember that the phantom image produced off-axis in stereo is only an approximation. Sweet, it ain't! 2008-11-04T17:42:08+00:00 http://www.psaudio.com/ps/tips/fine-tune-your-tonal-balance/ http://www.psaudio.com/ps/tips/fine-tune-your-tonal-balance/#When:17:36:26Z Most audiophiles know that - by aiming a loudspeaker a bit off-axis (perhaps to crossfire behind you a foot or two) - they can take the 'edge' off the sound.  Especially when compared to aiming the speakers directly at the primary listening seat.  Here's a method of fine tuning your system's tonal balance with a few minutes of speaker setup, by Jim Smith. For some loudspeakers, aiming straight ahead results in the best overall frequency balance.  Generally, when this is the case, the manufacturer or their dealer will make a point of advising you of this. But did you know that stereo separation - often a matter of a few inches - can make a significant difference in perceived 'warmth?' Most audiophiles would suggest moving the speakers a bit further apart (to get closer to sidewalls for bass reinforcement) as a way of warming up the sound. But 30 years of experience contradicts this idea. Getting a bit closer to the sidewalls may add more bass (and more unpleasant reflections), but the overall sound often gets thinner.   Actually, if your sound is a bit thin, and you'd like a bit more fullness, mid-range body, or warmth, the best way is often to bring your speakers a few inches closer together. I've encountered situations where only an inch or so toward the center gave me the balance I was looking for. Of course, when you do this, it changes your speakers' toe-in slightly.  Now they'll be aimed more to the center, so if you've already picked the best angle of your speakers for toe-in, you'll need to toe them out just slightly to accommodate for the move. And you may just find that you don't need the speakers toed as far off-axis as you thought when you originally settled on the toe-in   After doing this for hundreds (maybe thousands) of people, I was still baffled as to why this subtle adjustment in separation should do what it did. About 18 years ago, I observed the effect when experimenting with spaced omni microphones. This was when I was engineering on-location symphonic recordings (where an inch or two difference in separation could yield a warmer or cooler sound). From that experience I at least developed a theory about what's happening. We perceive warm or cool sound to some extent by the amount of energy present in the lower mid-range/upper bass. Well, the wavelengths of these frequencies are fairly long, say 2'-6' in length. If we bring our speakers a bit closer together, the reproduced sound 'couples' ever so slightly better, slightly shifting the sonic temperature to 'warmer.' Whether the theory is correct or not (and I sure don't know), I can guarantee that you definitely can change the balance of your system with subtle changes in loudspeaker separation and toe-in.  And the same change often renders more presence as well. Next is another related observation, that some may not agree with at all.  In this case, it definitely comes down to taste.  But hey, we're talking about mine... In the past 30+ years, I've visited countless manufacturers, reviewers, knowledgeable audiophiles, musicans, etc.  I've also listened to hundred of systems in dealer showrooms and at various Hi-Fi shows. On more than one occasion I've felt it necessary to ever-so-politely point out an alternative loudspeaker set-up.  I don't mean overall seating and loudspeaker placement (we'll get to that soon in this series).  No, I'm still staying with this month's topic of tuning or voicing with stereo separation. Personally, I find that a lot of pretty darn smart audiophiles go for pin-point stereo imaging. You know what kind of sound I mean.  The stereo image is displayed precisely across the room, almost in tiny little pin-points of sound... Instruments take up their own definite little space on the soundstage.  You may very well have your system set up that way right now. And that's fine, if that effect is your ultimate goal. The thing is, I find that the very wide separation required to get that sort of imaging is usually too great, in the sense that it thins out the tonal palette of the music.  I know you've experienced or at least read this, but we NEVER get that pin-point imaging in any normal seats at a live concert.  So what's most important to render a musical event so compelling that you are touched by the music? For me, and for a growing number of music lovers, after dynamics, it's presence and TONE.  And you can make an orchestra (or band or any vocals and/or instruments) sound bleached out, thin, and totally uninteresting by going too far in your quest for pin-point imaging. Sometimes a very subtle adjustment back from pin-point can get you the best of both worlds.  But I'd rather have great dynamics, presence and tone from a mono system that tiny little pin-points of sound spread across my room that are anything but rich and engaging.  There, I said it!   2008-11-04T17:36:26+00:00 http://www.psaudio.com/ps/tips/setup-a-speaker-grid-for-placement/ http://www.psaudio.com/ps/tips/setup-a-speaker-grid-for-placement/#When:17:31:59Z Stereophony depends on precise time arrival from each channel to a centrally located listening position. So, as you move your speakers around in the room, you’ll need a temporary floor grid to keep from arriving at erroneous conclusions. Here’s an accurate technique from Jim Smith: Find the position (from side to side) where you’ll be sitting (we’ll discover the front-to-back position in Part 4). If your room is symmetrical, and you plan to sit in the middle, measure how wide the room is; divide that measurement by two, and that’ll be your centerline. I recommend you use tape that can be lifted easily from carpet or flooring. Lay down your tape on a line between the general speaker placement area to the general listening area. You’ll have to move the seating furniture out of the way while you’re installing your grid.  If your room isn’t symmetrical, decide on how far you think you’ll want to sit from the nearest sidewall. Mark it on the floor (assuming your seating has already been removed). Measure the distance. Now, at the speaker end of the room, mark the floor at the same distance from the sidewall. This is your centerline, from the listening area to the speaker area. At the speaker end of the room, mark the floor every six inches or so away from the centerline, beginning in the area where you generally suspect the speakers may be placed. Now, swing your tape measure or laser measurement device from the general listening position on the centerline so that it crosses the speaker spacing marks you’ve just laid down.  Place some marks on the floor that represent about six inch intervals - varying distances from the proposed sitting area. It doesn’t matter if you don’t end up sitting there; we only need an equal path length from the centerline to aid us in moving the speakers repeatedly and equally. At the end of the next part, you’ll be making some fine adjustments in speaker position, with considerably less than six-inch increments. At this final point, you’ll need to recheck your measurements from your centerline for final positioning. But for now, we want to establish a starting reference to build our foundation. 2008-11-04T17:31:59+00:00 http://www.psaudio.com/ps/tips/speaker-placement-instructions/ http://www.psaudio.com/ps/tips/speaker-placement-instructions/#When:17:18:18Z This three-step technique will get you to a satisfying sound faster than any other system we’ve seen.  It is written by Jim Smith. The three steps must be followed in this order. 1. Bass 2. Image 3. Frequency response/tonal balance OK, what do we do at each step? First, you’ve got to get the bass generally pretty good. This means that if you have a full-range speaker, it should reproduce the deepest bass with the greatest smoothness. Why does the bass come first? Until you know how far away you’ll be sitting (speaker position and listening position), how can you proceed to step 2, getting the best stereo image? And we’ve seen that we can make some adjustments in the overall frequency balance with subtle changes in position (separation and toe-in). But first we’ve got to at least establish the distance to the speakers from the listening seat before we can begin to decide how far apart we want our speakers. (1) The best bass—a throwback to early TVs. Here’s how long I’ve been teaching this technique for getting the best bass… I started out using a TV analogy that asked the installer to compare this step to the tuning methods from TVs of the ‘60s and early ‘70s! Those TVs had a “fine tuning” knob and “channel selector” switch. Here’s the analogy: Finding the best placement for the speaker in the room is a bit like fine tuning for best reception. But finding the best place to locate the listening seat is a bit like using the channel selector! In other words, the most important consideration (whenever possible) is to discover where in the room you should sit to take advantage of the least negative room interactions (obvious peaks and dips in the bass), and the most positive room interactions (the most extension and attack without annoying overhang). This is because your room will have obvious standing waves developing in the bass region (we’ll call this region 25 Hz to 250 Hz). These standing waves are very measurable and they are quite audible as resonances or ‘suck-outs.‘ They exist due to your room’s particular geometry. Moving a speaker forward and back in the room can make a noticeable difference in the bass. But moving the seat forward and back the same distance in an average room will result in much more dramatic differences in bass performance. Although these resonant room frequencies can be considered axially, tangentially, and obliquely, our primary concern here is with axial. These consist of destructive (to varying degrees) waves and constructive (to varying degrees) waves. A destructive standing wave is produced when two or more wavelengths meet at a point in a room, and—due to the time arrival of these waves—some will arrive slightly (or even directly) out of phase with others. The varying time arrival is based primarily on room geometry (for example—length of the room vs. height). This results in a cancellation of frequencies at that particular point in the room. Destructive standing waves produce dips in frequency response. Conversely, constructive standing waves can produce peaks in response. The following system assumes you’ve placed the speakers in a generally acceptable position in the room: A simple way to prove this theory is to put on a CD recording with a repetitive bass line (preferably the upright acoustic bass—maybe Ray Brown). You’ll need to move your listening seat out of the way, perhaps to the side of the room. A note on the recording – select a piece that plays bass notes up and down the scale.  While it’s playing on repeat (that’s why I chose CD as the source), walk back and forth slowly through the larger proposed listening area. You’ll notice dramatic differences in bass quality and quantity in a space of +/– 2-3 feet. Listen closer and you’ll find the smaller ‘window’ of acceptability for that particular bass line. Once you’ve found the best spot to locate the seat (again, only for that particular series of bass notes), you’ll notice that moving the speaker forward and back an equivalent difference makes much less of a difference. This is all to say that your room resonances are going to be pretty much the same for most likely speaker placements, so find out where in the listening end of the room these resonances are least objectionable, and that’s where you’ll sit. A quick note on finding the overall best bass listening position in a room—the quickest way to do it is with a real-time analyzer, preferably 1/3 octave. You’ll need to use pink noise as your source, set on the slowest filter, using flat or C-weighting. You’ll need to run its SPL level at least 20dB over the room noise floor, so as to avoid any unrecognized interference with your measurements. You’re only looking at the region from around 25 Hz up to about 250 Hz. You’ll notice immediately that fairly small movements forward and back in the room are very obvious on the display as the various peaks and dips become quite easy to see. Don’t have a RTA sitting around? Try to borrow or rent one for a few hours. By the way, I do NOT recommend using a Radio Shack SPL meter and test tones for this procedure. Actually, if the tones were 1/3 octave pink noise bands, it could perhaps work, but unfortunately the Radio Shack meter simply isn’t very accurate in its frequency response.  And the RS mic suffers from proximity effect, unlike an omni (which is the preferred pick up pattern for a microphone in this application). You could use the test disc and your ears, though! Can’t find a RTA, or you’re uncomfortable technically with the idea of looking at how your room behaves in the bass resonance region? Then find several recordings of music representative of the stuff you like to hear, and adjust for the best bass by listening while moving back and forth in the general listening position. What you’re listening for is the majority of the bass reproduced with the notes neither emphasized nor diminished. You’re also listening for the deepest bass. But sometimes the price for getting the deepest bass in an average room is an uneven bass response in the region where most bass notes occur. This is where you’ll have to pick the best compromise to your ears. At this point, you’ll find that a difference of six inches or less forward or back will usually present you with a choice of the bass compromise you prefer. Once you’ve discovered this listening position that is least affected by room resonances, mark this spot (or at least measure how far it is to the wall behind you and write it down).   Now you can play with fine-tuning where the speakers go to make the bass better. Once you have that position to the point that is best to your ears, you’ll need to recheck the listening position a bit to make sure that a slight distance forward or back isn’t necessary now. (2) Imaging and the X-files Finally you’ve established—pretty closely—where you’ll be, and approximately how far away the speakers will be. Once you know ‘X,‘ you can start to work on ‘Y.‘ X is the distance from your ear to the plane of the tweeter (should be equidistant from the listening seat to each speaker). Let’s say X is 10 feet. A general guideline is to start Y at about 80% of X. Y is the distance from the center of the left tweeter to the center of the right. We use the tweeter because it’s the primary source for directional cues (imaging). A note on separation—this is to your taste. I personally like Y to be about 83% of X for most speakers. For planar speakers, Y may be smaller, maybe as small as 70-75% of X. Some companies want you to use an equilateral triangle (X and Y are equal in distance), or greater. I suggest playing a mono source like female vocals and keep pulling the speakers apart until the voice becomes a fairly precise point between the speakers. Pulling it apart any further results in a too small voice or one that now begins to come from each speaker. Bring them back to the point where it worked, switch from mono to stereo and check out the image. This technique assumes you’ve established a “grid” on the floor so that movements are the same for both channels. The other test is simply to notice when the female voice starts to sound unacceptably thin.  Then voice the separation by tonal balance, as well as image precision.  Once again, it’s a compromise.  You have to decide what means the most to you. (3) Frequency response/tonal balance Remember how we said that changing the separation could yield a cooler or warmer sound? And how toe-in can also dramatically affect balance (particularly high frequency balance)? Well, now you’re at that point (this assumes that your speakers are either nonadjustable, i.e. tweeter lever control, bass level control, etc., or that you’ve selected the nominal ‘flat’ position as a starting point). Here’s an example—and listen, it’s just an example—you might feel quite differently. I find that if I set up most direct radiating speakers on an equilateral triangle, the sound (for my taste) is usually too lean. I can hear all the tiny sounds in the soundstage, but it’s become a precise, almost mechanical sound. It’s not ‘relaxed’ for want of a better word. It makes great Audiophile stuff, but the sound just doesn’t have the body and warmth that I hear with live music. And yet, I know highly respected reviewers and manufacturers who prefer to listen with Y being greater than X. That’s why it’s your taste—remember, it’s not about some notion of ‘accuracy,‘ it’s about the music and you. Step 3 is the final fine-tuning that will make the difference for you. One final note—some Audiophiles adjust toe-in to make the speaker seem to ‘disappear.‘ This is usually not on axis, but aimed to crossfire somewhere behind your head, or even aimed straight ahead. This is your call as well. I recommend going for the musical balance before going for an audiophile sound effect, but sometimes you can get both, so go for it if you like… This should get you pretty close to a satisfactory set-up. There are even smaller increments of adjustments that can pay significant dividends, but that’s a topic for another time (I call it ‘Playing the room’). 2008-11-04T17:18:18+00:00 http://www.psaudio.com/ps/tips/try-different-seating-heights/ http://www.psaudio.com/ps/tips/try-different-seating-heights/#When:17:11:42Z Don't forget to listen at different seating heights and or speaker tilt back (which achieves the same thing). If you have the ability to experiment with different seating heights or tilting the speaker forward or backwars, do so. Sometimes raising or lowering your listening position slightly can produce a more neutral and more alive sound. There are generally two or three reasons why this may be true for your system. First, it's not uncommon for standing waves to affect your sound vertically.   Note that if you do plan to change the listening position's height, be sure that it's standing waves you're hearing and not different time arrival and related crossover/phase relationships from the drivers! A way to check that aspect is to slightly tilt the speaker backward or forward to see if what you're hearing is predominantly an audible effect from the relationship of the speaker's vertical height/angle to the listening seat. You should do this anyway, whether or not you change your seat height.  With planar speakers, it's equally important.  That's because, apart from standing waves, there's another issue to be considered called "beaming" which has to do with the tweeter. There's usually a quite obvious 'best' speaker elevation for speakers on stands.  Going by the manufacturer's recommended stand height is only a good starting point.  That's because the manufacturer has no idea what your exact listening height (seat height plus your body height) will be. About the only speakers where this might not need to be considered would be any concentric array (separate tweeter located within the bass/mid's voice coil, ala KEF and some others).  We've found that it's rare you'll be at the correct height for just about any speaker - on a stand or not - concentric drivers or not. The only other speaker design where it may not be as noticeable is when the tweeters are beside the mids (horizontal relationship vs. vertical).  But that one is a whole 'nother topic... And side-by-side line arrays for tweeters and mids may need to be tilted to find their optimum angle, just as planars.  Seat height may be critical here as well. Since we only have a narrow range of adjustment that we can make vertically, it's nice to at least know what is possible, if you so desire to address it. Consider finding the right height and then building a platform (if necessary) to raise your sofa or chair height to the perfect position. Please, do remember to try speaker tilt before trying seat height!  It's not uncommon for both to make an improvement. The reason why the effect may be noticeable enough for you to have a preference is that 'floor bounce' may be introducing a cancellation at some point.  The slight movement simply shifts the frequency slightly so that you may prefer (or dislike) the sound at a different seating heights. 2008-11-04T17:11:42+00:00 http://www.psaudio.com/ps/tips/ac-polarity-and-speaker-placement/ http://www.psaudio.com/ps/tips/ac-polarity-and-speaker-placement/#When:17:08:02Z Don't consider speaker placement final until you've discovered the correct AC polarity for all components. Incorrect AC polarity from just one component can make your system sound harsher than it should because the components change of reference ground point of the internal power supply transformer. Usually it's on the shield side of connectors and interconnects. Since this shield is common to both channels, it can present a slightly 'grungy' center fill that you may not notice until it's been eradicated. If you have carefully set your speakers up for a precise stereo image, and then you correct the AC polarity, depending on the polarity's interaction with the other components, you may get a 'hole in the middle' when the artificial center fill (mono) information is removed. With some systems, we've found the need to bring the speakers an inch or two closer together to correct for what had been a false center fill. Try it and see what you think... PS Audio's How to Section offers an in-depth step-by-step guide to help you get absolute polarity correct.  You can click here to visit our How To Section. 2008-11-04T17:08:02+00:00 http://www.psaudio.com/ps/tips/be-careful-where-you-place-equipment/ http://www.psaudio.com/ps/tips/be-careful-where-you-place-equipment/#When:17:06:30Z Don't place your components, especially source components, in areas where there are bass reinforcement modes. Try to avoid placing components (especially source components) in areas where the bass is very strong or exaggerated due to standing waves. CD transports and turntables lose their life and dynamics when they're being bombarded by resonance inducing bass frequencies. Most vacuum tube electronics are especially prone to adverse effects with such placement. In fact, it's even possible to induce acoustic feedback with turntables that are improperly located when the system is played at higher levels (assuming loudspeakers with reasonably extended low frequency performance). The problem is that we almost never reach that obvious level of deterioration (acoustic feedback), but we approach it. Because it's gradual as we increase volume, it's easy to miss the creeping degradation of the life and dynamics of the sound. Not to mention the bass becoming less articulate. The absolute worst two places to locate source components, and for that matter, most vacuum tube electronics: 1. In a corner 2. Anywhere on the wall behind you That's not to say there aren't other areas where unwanted bass energy may collect, but these two areas are almost certainly among the worst in any room. Move your source components and any vacuum tube electronics out of these areas and listen to how much more effortless the presentation seems to be (and with better bass). 2008-11-04T17:06:30+00:00