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First, I think we can all agree that we enjoy listening to music more when we are in a mental state of relaxed alertness and focused concentration, than when we are distracted, annoyed, or preoccupied with other things. And we can agree that the purpose of audiophilia (the pursuit of better sound) is to allow us to hear further into our recordings, with greater clarity and resolution of detail, so that we may connect with the music on a deeper intellectual and emotional level.
I would argue that many of the "rituals" audiophiles perform prior to listening -- particularly those involving "tweaks" with no measurable or conventionally explicable effect on the electrical signal or the acoustics of the room -- may produce actual and positive psychoacoustic benefits insofar as they help induce a mental state of relaxed concentration. In such a state of mind, the audiophile may indeed "hear" greater resolution, depth, PRAT or whatever from his system, since he is more focused on the act of listening and more connected to the music. The "tweaks" may further be effective in inducing such a state, proportionally to the degree that the audiophile BELIEVES they will result in sonic improvements, and this belief may in turn be proportional to the amount of money one has spent on the tweaks. Let us not discount the power of suggestion, simply because it cannot be readily measured or quantified.
We can compare this situation to the use of the I Ching. The book of the Ching contains a number of short chapters, filled with good generalized practical advice (particularly if one is a medieval Chinese official, trying to advance in the imperial court), and one could easily open the book at random and start reading. BUT, it is customary to throw the yarrow straws to arrive at a hexagram which leads you to a particular chapter. The ritual of throwing the straws helps focus the mind, so that you will think more deeply about the advice in the selected chapter. It also helps if you believe that the ritual somehow invokes mystical forces which lead you to a particularly relevant chapter.
I notice this sort of phenomenon when I listen to vinyl records vs. CDs. I can just pop a CD in the drawer and push "play." Highly convenient, and great when I just want background music while I do other things. With a record, I have to carefully remove it from the sleeve, place it on the TT, clamp on the Sorbothane record weight, dust it with the deep-cleaning brush, zap it with the anti-static gun, lightly brush the stylus, position the stylus over the groove and drop it in, close the dust cover, and only THEN be able to sit down and listen, knowing I'll have to get up in 20 minutes and turn it over. With that amount of preparation (akin to throwing the yarrow straws), I am much more inclined to just sid down, listen closely, and concentrate on the music.
I suspect the same principle applies to other ritualistic activities, like cleaning all the electrical contacts once a month (which MAY result in a tiny reduction in resistance and capacitance), installing resonance damping/isolation devices over/under components (which MAY reduce some forms of low level distortion), or placing various wood, metal, or stone gimcracks and doohickeys around the room (which probably don't do anything on the physical plane). If you BELIEVE that these ritualistic activities will improve your sound, then you probably WILL hear improvements disproportional to the actual physical effects of the tweaks, since you have prepared and focused your mind to do so.
v.i.
Million miles from home.
If I may join you in idle speculation, I believe that some are inclined to believe in believing while others are inclined to believe in physics and engineering. I'm strongly in the latter camp so you may take my comments with a grain of salt. BUT, I believe that both camps are 'right' and that there is a continuum betwixt the two with a slushy transition region.
Even beyond the engineering/belief divide there is one with respect to ritual. For instance the very things that you trot out that form part of your love of records, the ritualistic cleaning, kissing etc, are the very things that cause me to feel frustration, disdain, and loathing of the medium. On the other hand I can say that the Sheffield Labs CD's of their direct to disk recordings don't sound nearly as good as the records. BUT, those are old transfers, I suspect that a newer transfer, especially to hi-res would. In general I taped most of my records and listened to them from R-R or on Cassette, turning the damn things over was beyond the pale as was the fussiness. To each his own. The point is don't count on all of us sharing your penchant for ritual.
At the risk of offense, I'd suggest that most audiophiles are largely clueless concerning how to go about measuring phenomena with unknown causes. Few have the knowledge, experience, test equipment or inclination to do so and often find it easy to ascribe that which they can't measure or understand to 'belief'. If there is one common denominator amongst those that believe that most tweaks are mystical (i.e. belief based) it's that they haven't really tried to measure, understand, or isolate their effects. Now I'm not saying that in my infinite wisdom I have or can do so. But at least I understand the most likely reasons I can't. The prime one is laziness but right behind is not feeling a pressing need to. If I'm not producing whatever the tweak is it's just a hobby. Also I don't currently have access to the full range of test equipment which would make discovery easier.
So there you have it, the other side heard from.
Rick
Hiya Rick:
I'm strongly in the physics and engineering camp myself. Gotta be, as a DIY speaker hobbyist who relies a lot on measurement and mathematical modeling.
"Even beyond the engineering/belief divide there is one with respect to ritual. For instance the very things that you trot out that form part of your love of records, the ritualistic cleaning, kissing etc, are the very things that cause me to feel frustration, disdain, and loathing of the medium."
Heh heh. I bet you're not one of those 'philes that goes in for demagnetizing your CDs, painting the edges green, or putting rubber rings or mats on them, then. I think people who do that are actually trying to recover some of the lost ritual of prepping a record. And I actually only play records once in a while -- CDs have made me as lazy as everybody else -- BECAUSE of the nuisance factor. But when I do play them, I sure pay attention and enjoy them.
"I'd suggest that most audiophiles are largely clueless concerning how to go about measuring phenomena with unknown causes. Few have the knowledge, experience, test equipment or inclination to do so and often find it easy to ascribe that which they can't measure or understand to 'belief'. If there is one common denominator amongst those that believe that most tweaks are mystical (i.e. belief based) it's that they haven't really tried to measure, understand, or isolate their effects."
As a generalization, that's probably correct. But those of us in the "objectivist" camp tend to focus on tweaks that DO make a measurable and quantifiable difference. Things like speaker placement, acoustic room treatment, damping of unwanted resonances, keeping RFI and EMI out of the signal path, etc. This is about empirical evidence, not belief. But even here, some ritualistic elements may come in. If you've just spent a couple of hours humping a pair of big heavy speakers around the room, until you found the position where the soundstage snaps into focus JUST RIGHT, you're gonna sit down and really ENJOY listening to those speakers, more so than if somebody else did all the setup work for you, because your attention has become more focused. Same story when you've been fooling with bass traps all afternoon and finally hear that 80Hz boom go away, or you just put ferrite beads on all your cables, and really can hear less background hum/hiss with your ear right up to the speaker.
So I don't think we're on different "sides" at all. I'm basically a meterhead, but kinda interested in the more shadowy realms of psychoacoustics as well, and curious what others mignt think on the topic.
"tweaks that DO make a measurable and quantifiable difference [like] keeping RFI and EMI [(by)put(ing) ferrite beads on all your cables] out of the signal path, etc. This is about empirical evidence, not belief."
"I think people who do that [demagnetizing your CDs, painting the edges green, or putting rubber rings or mats on them] are actually trying to recover some of the lost ritual of prepping a record."
Assuming that I haven't altered your meaning by compacting those two statements, and I don't believe that I have, then I don't see a substantive difference. In both cases they are behaviors based upon empirical evidence. Do you really think someone is going to continue taking the time to color disk edges or mess with mats on the player if they haven't found that it improves the sound?
It seems to me that you 'believe' in beads but don't 'believe' in markers. I presume that you've tried markers and mats and they didn't make any difference in your system. True? The 'in your system' clause is important because that's all a single data point will give you.
Your experiences aren't directly transferable because the things being affected are usually not controlled parameters during device manufacturing AND are often system specific. The implementation details of a CD player for instance can make all the difference in whether mats, markers and mirrors, or whatever and/or z-beads will improve performance. My take is if you can hear a difference, it does, if you can't, it doesn't, or it doesn't do so to a significant extent in you system for your ears. To muddy the waters, even the CD is part of the system and some may be more susceptible to the effects of mats et al than others.
I'm a pragmatist. Empirical is good. Objective is gooder (objective in the sense of correlated measurements). Three things make objective gooder: 1)it furthers understanding, 2)it can be controlled in production, 3)it aids in optimization. BUT if it's just MY stereo and MY ears and a rabbit's foot laying on the amplifier oriented to magnetic north improves the sound, guess what?
I've probably got several decades of electronical experience on you and I strongly encourage you to not dismiss others observations just because they seem silly or you can't imagine a mechanism. Sure, they may be bogus, but my experience is that most of the time they aren'. I've learned to apply this initial working hypothesis: believe the observation, ignore the explaination.
Disclaimer: I do use Z-beads and I don't paint disks or use a mat, but that doesn't mean I shouldn't or that what I'm doing is optimum. It's just a combination of empiricism and wont.
Rick
Some good points there.
Actually, I don't dismiss anything out of hand. I HAVE tried greening the edges of discs, and in my system (Rotel CD player/ Parasound preamp/ Adcom amp/ a variety of speakers) it sorta-kinda-halfassed-maybe made a slight audible difference. Not enough to say for sure. Surprisingly, I DID hear a distinct difference on the very low-end system (Technics CDP/ mid-'70s Sansui receiver/ anonymous monkey-coffin speakers) at the local used record store, when we compared two copies of a Simon & Garfunkel CD, one greened and one not. Difference? Yeah. Improvement? Couldn't say for sure.
Resonance-absorbing CD mats make some sense in theory, because they may damp vibrations that cause increased jitter. But after hearing a couple of horror stories about said mats getting off-center, caught in the mechanism, and really goobering up the works, I shy away from them.
My most recent "tweak" involved putting a 20-pound concrete Buddha (two bucks at a yard sale) on top of a large dictionary on top of my subwoofer. Just with my fingertips, I can feel that the top panel of the sub box resonates a bit less than it does with nothing on it. And I seem to hear a greater improvement in bass tightness and definition than I would expect just from that amount of damping. I have to wonder, is the sonic improvement entirely due to the resonance damping, or is part of it psychoacoustic? I mean, the Buddha just looks so SERENE sitting there. He makes me smile, and maybe puts me in a better mood to enjoy listening.
"Actually, I don't dismiss anything out of hand." --- Excellent. Suspecting that something may not matter isn't nearly the same as dismissing it.
I too haven't tried a mat, same reason, I can just visualize all too clearly what might go astray.
Taking Geoff's list from below...
Schumann frequency generator:
Sort of tried it. I fed an appropriate loop that I happened to have laying around with a function generator. It definitely had an effect, I almost immediately started feeling woozey. I turned up the frequency a little and the wooziness cleared up. The second frequency was about the nominal S. resonance. Stopped test. I don't regard this as a stereo tweak, more a mental one and a little scary, but interesting.
demagnetizer for CDs and LPs:
Tried my old RadioShack one, no effect. But I've been told that it's not powerful enough.
crystals:
Guess I've tried a little. UncleStu said that tourmaline was especially good and I happened to have a piece of ore with a decent lug of it sticking out that I had scavenged from the tailings of a mine. So I put it on my receiver in the study and found that it sounded better doing the normal on/off testing. I also ran across a chunk of basalt that was almost the same size and shape and tried that, it didn't seem to help and certainly wasn't as pretty. A lot of people believe that crystals help reduce interference essentially as an E field equivalent of lossy ferrite. They may be right, it would be fun to investigate. But in this application I suspect that the mechanism is acoustical reflections from the surface of the crystal. Physically it's nearfield to the speakers and the system is very sensitive to small changes in that area. On a related topic I bought one of the ceramic wallplates that were were in vogue a while back as affecting the sound. Screwed it to the outlet in the same system and it affected the sound alright, it made it worse. I found just having it laying around hurt the sound, but again it was nearfield to the speakers. I haven't tried them in other positions in the room but suspect that they might provide some improvements in the right spots. Guess you can see where I'm going with this. I think small, hard, objects given to specular reflections or high-Q inband resonances can affect the perceived sound far more than one would expect.
Red "X "Pen, Mpingo disc, siver holographic foil, clever little clock, cryogenics, ion generators:
No experience. One of these days I may splurge and buy the unbelievers kit or whatever it's called from May and play with it.
The thing is tweaks run the gamut and lumping them obscures the issues. But it's all fun. As a speaker tinkerer you have probably already found what a tremendous difference nearfield reflections and diffraction can have on sound. I've been enjoying this hobby for decades and one of the things I can see is that the commercial speaker manufacturers have come to realize and address this issue. Speaker cases are much smoother and swoopier these days.
Rick
you're using a head demagnetizer, the radio shack model should be strong enough. I've used a cheap bulk tape eraser for many years now.
You're right about the effects of small reflective devices. The crystals go beyond simple reflection though as I have successfully used them contained within equipment chassis where they are out of range of the the playing speakers. They also work exceeding well when adhered to the back of a speaker magnet inside the speaker cabinet.
In your example, the larger crystal may be definitely affecting the reflective properties, but it would be a simple thing to drape a small hand towel over it to reduce the reflective properties, wouldn't it?
In the case of many Tweaks, a lot is dependent on the resolution of your system. I am not saying that you need to spend a lot of money on your components, but a system of carefully matching components and wires can certainly create a relatively inexpensive system which can sound very good. I do notice a number of computers have deliberate fudge factors built in, particularly older CD players with an RC network to roll off the top end ( actually even modern very expensive units often incorporate this) Proper shielding with something like ERS and the removal of that RC network at the output can really dramatically transform many players.
The Schumann generators is quite interesting. It is supposed to be tuned to 7.8 Hz or thereabouts. This corresponds pretty much directly with the Theta brain wave activity, and as a matter a-f fact a little research shows that many great singers in the past: Caruso, Galli Curci, etc employed vibratos in about the 7.1 to 7.4 Hz range ( from their existent recordings). Even more interesting is the Physical property of entrainment, discovered by non other than Christian Huygens way back in the mid 1600's. Huygens realized very early on that a group of pendulums set swinging at different times will eventually coordinate their swing times.
Quite interesting, as there is still no explanation in physic which accounts for this phenomena. It means that perhaps the Schumann generators are creating an entrainment procedure for everything in the room including the listener ( it is a well documented fact that a group of women working closely together will eventually tend to have their menstrual cycles at about the same times, so entrainment may not necessarily be limited to non animate objects).
Incidentally research early on shows that a weak low level EMF field applied to plates a couple inches away from the ears has had noticeable effects on the subjects ability to judge time, particularly when the frequency is about the Scumann range.
St
Could that be another name for a Schumann generator?
Yea, you're right Stu, I could rather easily shield the rock from acoustic affects. Guess I should try it. I go through spells of wanting to understand things and others of not giving a hoot why stuff works and just enjoying that it does.
I do want to understand the business of using crystals to absorb energy better. Darn, I just remembered that the receiver I need to use to do so died a few months ago. Sigh. Well if I can get it running again maybe I can learn more about them.
A lot of bodily processes are electric, from our CPU and nerves to cells trying to 'know' when the wound is healed. I don't think that anything besides our heads are being affected by the LF activity. My guess is that the frequencies that have the most effect at any given time could be predicted by doing an EEG first to see what our current clock frequencies are. Whether received directly (electrically) or aurally, the result is electrical activity in the brain from an external source that is close to one of it's clocks. The Fem thing is probably olfactory. It's interesting how our older senses like smell, thermal sensing and hearing are all simultaneously dismissed and yet assaulted nowadays. Sight is currently the only one that gets any respect, the others seem to be regarded as crude and primitive. Instead of respecting the older ones which have very highly evolved survival value they are now overwhelmed with damaging noise, stinking perfume and dryer sheets, and cold, drafty HVAC systems. No wonder we seek the solace that good sound and music provides...
Rick
Why is it almost always the science and measurement crowd that has difficulty getting good results with tweaks like the green pen? LOL.Have you ever had a chance to use or hear any of the other "controversial tweaks" - like the Schumann frequency generator, Red "X "Pen, Mpingo disc, siver holographic foil, clever little clock, demagnetizer for CDs and LPs, crystals, cryogenics, ion generators and such, you know, the ones that make audiophiles' heads spin like the little girl in The Exorcist? You can say, "I avoid them like the plague," or "They're the work of the devil," it won't hurt my feelings. LOL
Also, I disagree with you that resonance absorbing CD mats make sense, since most audiophiles would probably say that the Reed Solomon error correction codes would take care of any errors, vibration produced or otherwise.
Edits: 09/08/09 09/08/09
"Why is it almost always the science and measurement crowd that has difficulty getting good results with tweaks like the green pen?"
Because we're less easily duped?
"Have you ever had a chance to use or hear any of the other "controversial tweaks" - like the Schumann frequency generator, Red "X "Pen, Mpingo disc, siver holographic foil, clever little clock, demagnetizer for CDs and LPs, crystals, cryogenics, ion generators and such, you know, the ones that make audiophiles' heads spin like the little girl in The Exorcist? You can say, "I avoid them like the plague," or "They're the work of the devil," it won't hurt my feelings. LOL"
Whoah. One category at a time.
Digital clocks (whether or not treated with fairy dust), lamp dimmers, and anything else that emits airborne RFI or puts it into the power line ARE the work of the devil! I don't want anything near my system that increases background noise.
My Zerostat gun IS an ion generator. That's how it neutralizes the static charge on records. I've also played with it on CDs and wires, with no apparent benefit.
I used to be an avid rock collector, so my mantelpiece is covered with all sorts of crystals, geodes, thunder eggs, and polished agates. The only audible effect I ever noticed was that they buzzed and rattled when things got really loud. Putting a folded towel under them solved that problem.
I have a bulk tape eraser (demagnetizer). I tried it on a couple of CDs, when I first heard of that tweak. No audible effect, as expected.
But what do I know? My car DOES seem to run better after being washed and waxed.
hierarchy to audio tweaks.
Many tweaks induce relatively small changes in a system and if your system is not corrected for larger errors, the smaller ones may not be audible at all. The analogy I like to make is that if you start off with muddy water, no matter how much sugar and lemon you add, the taste will still be bad.
The most important aspect to any tweaking is to achieve a relative phase and time alignment of your speaker system. If you an not hear changes in signal polarity in your system, then something is very wrong. Those other factors must be corrected prior to performing any other tweaks because a system out of time and polarity alignment will smear rather than reveal the detail which is possible.
Achieving such a fundamental change, IMHO, means often recalibrating an entire system, something which many listeners would rather not do, because of the time and cost involved. It is important that the fundamental set us be attended to or else, the listener is apt to simply spend too much time and money working around these faults.
I, for one, would not recommend Mpingo discs or crystals on speaker system where drivers are out of polarity to each other. I have seen this attempted and the results are mixed: somethings get better, some things get worse, and the net conclusion is that it is a draw.
I specifically mention the polarity issue because after 20+ years of attending CES, I have rarely (only once, as a matter of fact) met any exhibitor or reviewer who seemed to be sensitive to polarity issues. I have in speaker designer's rooms and asked them to reverse polarity of the speakers ( easy to do with some CD players or DAC's ans most were surprised that 1.) I could detect a difference in sound without actually making a comparison, and 2.) that any polarity changes were actually audible.
Therein lies an important issue. If you are spending thousands of dollars to achieve "realistic, live" sound, we have to address fundamental issues. If such issues are not addressed, the mistake is carried forth and you end up "treating" a symptom, not necessary effecting a cure.
It would be a grave error to condemn what others hear without being aware of shortcomings within your own system first. I do know know what your personal system comprises of, so please do not take my comments personally. But adding a big carburetor to a stock four banger Pinto is not going to make it into a super muscle car. The same applies to many audio tweaks.
Stu
. . . is one of those "iffy" areas of perception. It has been proven in blind tests that a small percentage of the population (mostly professional musicians, with perfect pitch for what that's worth) CAN consistently hear the difference between normal and reverse polarity, but only with certain instruments like trumpet and chimes. The majority of people can't ever hear the difference, and a few can hear it sometimes but not always--possibly depending upon the resolution of the playback system.
You can easily configure your system for correct polarity, if you know which components do and do not invert phase. For instance, if your source component is known to output the signal in correct phase, but your pre-amp inverts phase, and your power-amp inverts it again, you know to hook up your speakers to the amp in "normal" phase (+ to +, - to -). But you're still at the mercy of your recordings, which may or may not be in correct polarity. In the case of multitracked recordings, some instruments and voices may be in correct polarity and others reversed.
There is a 50% chance any selected system will out of phase (polarity) for a randomly selected disc.
Of course ! Mathematically it it either in absolute polarity or not, hence the 50% deduction. That being said there are production values which may alter the polarity of the final recordings. I pointed out the example of the Commitments. An analysis of Phil Spector's Wall of Sound concept also reveals that he places the background instrumentals in inverted polarity and the singers in correct polarity, so where does that leave your statement?
The 50% probability does not apply, but an understanding of the effects and the cure is important for the listener to understand. Your statement betrays an listener who does not hear inversion. That as I previously posted is not uncommon ( my statement that after attending 20+ years of CES exhibitions, I have rarely met any exhibitor who can readily hear inversion). That being said, when I have used the exhibitor's equipment and demonstrated the difference, most could hear the sonic change. I distinctly remember one designer saying to me that while he was familiar with the concept and theory he had never bothered to actually play with the absolute polarity, although he was using a CD player with a digital polarity switch.
Many listeners fall into the same trap. They know all about the theory, and the possible ramifications, but neglect the most important part, and that is the actual comparison of a live instrument with their electronically recorded counterpart. While it is definitely easier to hear polarity with instruments which have a harder attack ( Brass and Woodwinds) the inversion of polarity also has an audible effect, however subtle, on the harmonic structures of even bowed instruments. If [phase and time alignment are not addressed, then the perpetual audiophile search for musical "accuracy" becomes a farce. Any tweaking becomes questionable because the results on a system with either mixed polarities or inverted polarities will, by its very nature, obscure many changes.
As for the 50% chance suggestion: consider this. Why does every Chesky CD chronologically issued before JD 63 exhibit correct polarity and every one after appear to be inverted (including their second test CD)? Why is it that the Mercury Living Presence CD reissues are phase correct when produced by Dennis Drake and become inverted after he is replaced? Why are most of my Philips and DDG LP's inverted, along with my Deccas?
In fact the RCA LP's recorded for them by Decca (Faust, Witches Brew, etc) are consistently inverted in polarity compared to the 1s versions of the recordings they made in the US.
Why is that the Hales Revelation series of speakers have their midrange inverted in polarity to the other drivers, as well as the Alon speakers? Why is this deliberate design choice so common (oh, I know the reasons given: the inversion produces a smother sine wave plot over the range of the driver since the inversion induces cancellation at the crossover overlaps creating what is heard as a steeper roll off slope). The technology is here and the means to make phase and time coherent speakers has long been availble. The one factor which holds back this development is that the listeners, both reviewer and the lay person, have not been made aware of the issue. This allows confusion to reign in the market place and a concerted push towards a standardized ideal is simply obfuscated.
Stu
I can hear, and I claim no special ability, differences in absolute polarity with even a $300 stereo receiver (HK) and a pair of $400 speakers (Sonance 622C), since my speakers are relatively phase and time aligned ( not perfect but close enough). Modern commercial recordings routinely mix polarity in order to achieve certain sound effects.
The question is if you do not "hear" such effects then certain tweaks will have little auditory benefit. Using an excuse that the majority of listeners can not hear the difference would be akin to marketing a water downed wine simply because the majority of the population can not tell the difference anyway.
In my years of running an audio store, education leads to recognition, but few are willing to undergo the education. Some of my regular customers, without perfect pitch at all, can quite easily recognize absolute polarity issues, but the problem, IMHO, is that many speaker designs employ driver assemblies with no semblance with time and phase regularities. One need only glance at the impulse tests given by Stereophile magazine to realize that, and that alteration of time constants is absolutely not what happens in real life.
Again, I reiterate: if your system does not have transducers with relatively time and phase aligned drivers, the "search" or "quest" for perfect sound is one doomed to failure.
As such, mixed polarity recordings abound, simply because listeners are too confused or lazy to comprehend the issue. For pop recordings absolute polarity is often used, as earlier stated, for sound effects. If you want an ethereal effect, invert the polarity. If you are singing a duet and the featured singer may not be as good as the partner invert the voice of the partner so that it smears the diction. A good example is the movie "The Commitments". The recently re released Director's cut, includes the director's comment that in order to make the singer sound really good, the polarity of the background singers and instrumentals were inverted to make his voice stand out.
However, the lack of knowledge of such effects exacerbates the problem. Producers use inversion even for orchestral music and classical recordings which shouldn't have to employ such "tricks". It also leads to listeners going on a absurd "quest" in search of the perfect recording and playback equipment.
The best example is the pronouncement of The Absolute Sound's editor claiming that the Canadian version of the Holly Cole Trio's "Don't Smoke in Bed" Cd was superior to the American. The trio has the piano in one polarity and the voice and bass in another. The Canadian version is simply reversed.
But again look at the impulse test results in Stereophile. The woofers are often many milliseconds behind the tweeters and often out of polarity. Do you see the magazine reviewers making any fuss about the issue? Most utter inane banalities on the quality of the sound, but are not really searching for constructive criticism. A speaker with a woofer retarded in time is often described as having big bass, simply because the bass notes stick out.
Some will claim that it can not be achieved, to which I simply point out that even the cheaper Vandersteen speakers achieve relatively accurate time and polarity alignment (not saying they are perfect as they have issues of their own).
Sorry I can not be an apologist for the general listener. If you search for "accurate" sound and spend thousands and still can not achieve it, then you are deserving for not educating yourself further.
Stu
"But again look at the impulse test results in Stereophile. The woofers are often many milliseconds behind the tweeters and often out of polarity.
Some will claim that it can not be achieved, to which I simply point out that even the cheaper Vandersteen speakers achieve relatively accurate time and polarity alignment (not saying they are perfect as they have issues of their own)."
Time and phase alignment (not the same thing) are noble goals, that some multi-way speaker designers strive for even at the cost of other serious compromises. The usual strategies -- stepped or tilted-back baffles, combined with first order electrical filters (as in Thiel and Vandersteen) -- may result in a pretty impulse response, but ONLY on a very narrowly defined vertical design axis. Raise or lower the measurement mic (or your head) by a couple of centimeters, and watch (hear) that beautiful impulse response go to hell. Add to this the lobing in the vertical polar response, typical of shallow crossovers, and you will measure/hear response dips around the crossover frequency, caused by phase cancellation, just a little bit above or below the primary lobe of the vertical design axis. (The shallow highpass slope may also allow too much energy to reach the tweeter below crossover frequency, resulting in audible distortion even at moderately loud SPLs).
These are inherent problems with ALL multiway speakers where there is vertical and horizontal separation between the drivers -- particularly mid and tweeter, where wavelengths are quite short in the crossover region. A coaxial mid/tweeter assembly is a better solution, and has been under constant refinement for years. The new Thiel unit, where the flat midrange ring radiator does not horn-load the tweeter, looks quite promising. Distance between woofer and midrange matters less, since the wavelengths around crossover frequency are so much longer. The multi-axial Cabasse "eyeball" drivers eliminate even this separation.
Even so, a perfect impulse response is likely ever to be seen ONLY with single driver speakers, be they dynamic or planar.
Phase tracking between drivers in a multiway system is a separate, but related issue. Look at the phase vs. frequency trace of ANY speaker driver made, and you will see that the phase goes through several 360 degree rotations over the operating range of the driver. When you're crossing one driver to another, the trick is to get the two phase responses to line up through the crossover region. Generally speaking, if you get excellent phase tracking, you will get a ruler-flat summation in the frequency response through the crossover region, and vice-versa. But the SYSTEM phase will still rotate with rising frequency. So the absolute phase of the speaker's acoustical output will still only match that of the electrical input signal at certain frequencies.
It's all compromise, and there's no free lunch.
Do you hear polarity inversions?
It is fine to know the theory (which I am quite familiar with, BTW), but do you hear inversion and its issues? I owned a pair of Martin Logan Quests ( and previously had Sequels and the CLS, and was plagued by the fact that their woofers are inverted to the panels. Being bi wireable, that was a simply issue to resolve. Strangely, although one would expect a huge hump in the crossover region where the two drivers overlap, there was little to annoy me and the timing alignment more than made up for any hump that may have happened on occasion.
Phase is indeed constantly changing depending on the impedances of the voice coils and such, but I find that so long as it remains within 90 degrees or so relative to each other, the sound emitted is far more coherent than one which starts off 180 degrees apart. I do not pretend to be an apologist for the various speaker and crossover designs. It has been my observation that too many are overly enamored of the results printed out from their computer and too little emphasis is placed on the the resolving transducers on the sides of your head.
Stu
PS look at the impulse test for the Vandersteen Quattro and then look at the results of the Thiel 3.7: remarkably similar and yet one uses a simpler driver design. The problem can be addressed and resolved: listeners have to train themselves to be aware of the issue.
Hiya Stu:
With the normal/reverse polarity tracks on the Chesky test disc, I can hear some difference with headphones, though in a blind AB test I probably couldn't readily identify which is which. I can also hear some difference on the little speakers I built last year for outdoor listening, but only consistently so outdoors, when the neighborhood is quiet. Indoors, despite a reasonably well-treated and acoustically "dead" room, not so consistently. Room effects seem to overwhelm the subtle difference.
Like you, I prefer speakers where all the drivers are connected in positive polarity. The only situation where drivers NEED to be connected in reverse polarity is with a true 2nd (or 6th) order crossover: in that case, the filter-induced 180 degree phase shift necessitates reverse electrical polarity in order for the drivers to be acoustically in phase and sum flat AT crossover frequency. Put both drivers in positive polarity and you will get a huge response suckout, NOT a hump. Of course, you get a couple of octaves out, either side of xo, and they're out of phase, which means higher harmonics will be inverted 180 degrees relative to their fundamentals. Not really a recipe for natural sound.
With good, smooth, wideband drivers, I can usually achieve a quasi-LR4 response with a 1st order electrical filter plus Zobel on the midbass, 2nd order electrical plus L-padding on the tweeter, both down -6dB at the chosen crosspoint, AND keep both drivers in positive polarity. The slightly "relaxed" lowpass electrical transfer function somewhat alleviates the time-misalignment of having the drivers flush-mounted on a vertical baffle. It's also quite easy to work in baffle step compensation with this arrangement: you calculate an oversized series inductor on the lowpass that will be down -3dB at the frequency where the baffle diffraction step is up +3dB, and then figure your crosspoint to the tweeter about two octaves (-12dB down from the midbass driver's reference sensitivity) above that. Quite easy to model, even with basic design software.
BTW, do you know of a published impulse response on the Dahlquist DQ-10s? Those, to my ears, are among the most "natural" sounding speakers I've ever heard, other than Quad ESLs. John Dahlquist obviously put a great deal of effort into the driver spacing on those, apparently trying to optimize time & phase coherency.
Don't know of any such test results o for the DQ-10.
One factor which distresses me about the DQ-10s is the non symmetrical spacing of the the individual drivers and the fact that the speaker is not made in mirrored pairs. I find that speaker symmetry is quite important for my ears. I particularly dislike when tweeters are made off set to the other drivers. I find that the propagation of the sound field will be symmetrical about a line drawn through the tweeter and midrange drivers. Thus if the tweeters are mounted inboard that line converges in the center between the speakers and thus throws a significantly lower sound stage. If mounted outboard, it throws a soundstage that is high in the middle but droops at the periphery outboard of the the speakers.
The interaction of the drivers among themselves also creates a large amount of distortion through their interaction Mounting the drivers in a single line column vertically seems to reduce the inter driver action.
Incidentally it is quite easy to demonstrate this interaction and the issues it creates. I believe the bulk of the issue comes from cancellation between the drivers, when the same wavelengths meet 180 degrees apart on the speaker baffle. That's when any crossover frequency overlap result in cancellation, generally. You can easily hear this feature and manipulate it to your advantage by creating a small "dam" between drivers on the baffle about half way between the drivers. A length of putty about a 1/8th of an inch high is all you need. This will prevent the air flow diametrically opposed from interacting and you will hear a noticeable rise in the area where the crossover frequencies overlap. By moving this dam closer towards one driver you can increase or decrease the dispersion of the air flow from that drivers and thus effect a user controllable tone control of sorts.
Stu
"One factor which distresses me about the DQ-10s is the non symmetrical spacing of the the individual drivers and the fact that the speaker is not made in mirrored pairs."
Yeah, that driver layout IS kinda wacky, but in the design iteration I have (and I believe there were several?), the tweeter is mounted on a recessed (time-aligned?) baffle directly above the upper (dome) mid. The lower (cone) mid is over to the side, about a foot away, however. At the crossover frequency between the lower and upper mids (around 800Hz?), the wavelength is just about long enough to make that separation inoffensive. But any lobing in the polar response between the two drivers WILL occur in the horizontal rather than the vertical plane. The lower mid operates in "muffled dipole" mode, with a thick felt pad over the back, which complicates things further. The crossover frequency between woofer and lower mid (around 250Hz?) is presumably low enough that the slight horizontal offset (about 30 degrees off vertical) won't matter. The horrid piezo superscreechers were mounted on the corner of the lower mids' baffles -- who knows why? -- but I got rid of those, along with their entire leg of the crossover network, and mounted some old JVC ribbons, crossed in at 12.5kHz, to the side of the dome tweeters. (Thanks, Dave Elledge, for both the ribbons and the crossover component values). I would have preferred to mount them above, for the good reasons you cite, but they wouldn't fit behind the grill that way. And these things are boot-oogly without the grills -- naked Vandersteens are Miss America by comparison. Supposedly the ScanSpeak 9300 is a drop-in replacement for the old Phillips tweet, and precludes the need for a supertweet, but that mod is down the road yet.
I do need to swap the side-by-side baffles around on one of the speakers, to mirror-image them, but that's another "down the road" project. Involves replacing -- or splicing -- a whole lot of wires. I measured and sketched out all I would have to do, and got a serious attack of the dont-wannas. I did put felt anti-diffraction rings on the tweeter faceplates, and felt blocks on the edges of the midrange baffles (similar to your suggestion with the putty). I also replaced all the old crossover NPE caps with poly-film types, of higher voltage rating and tighter tolerance.
But as weird as they are (and as many of the truly innovative vintage designs were), I still seriously LOVE the sound of these speakers. Yeah they're inefficient low-impedance power hogs, but DAMMIT they draw me into the music! I'm an acoustic musician, and know well the live, unamplified, nearfield sound of fiddles, guitars, banjos, flutes, mandolins, string basses, pianos, etc., from many a gig and informal session. The DQ10s reproduce the sound of these (and presumably other) instruments, from good recordings, with remarkable ease and naturalness.
Also, they WERE among the first "audiophile" speakers that got people rhinking about imaging and soundstaging. I suspect, as you suggest, that the weird driver layout adds it's own effects to the perceived soundstage, but they nonetheless sort out all the parts in busy arrangements rather well. Perhaps I'm biased by all the work I put into restoring these, after getting them for nearly free, but I'm extremely happy with them.
So, let me get this straight. You tried all those tweaks and none of them worked? Well, that would certainly explain the attitude.
I'm thinking of two reasons why you had no success with the tweaks you tried. See if you can guess what they are. :-)
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