Love Is Always Better the Second Time Around: The Sanders Sound Systems 10e Hybrid Electrostatic Speaker

[tmallin]

Room Dampening Experiments

Knowing that Sanders recommends not using much room dampening behind the speakers, I tried removing all the foam pictured in the photo in post #7 above. I also tried reinserting just parts of the foam.

Subjectively, I must say that the Sanders 10e does in fact sound remarkably fine in this room even without any acoustic foam damping. As with the Dutch & Dutch 8c, I could live with that sound. I could even see how many listeners might prefer the undamped sound.

But even to a greater extent than with the D&D speakers, with the Sanders the frequency balance remained basically the same. Imaging remained precise and very focused. The staging and overall presentation gains even more size and depth becoming truly HUGE.

Really the only downside is that my small undamped room adds reverb to all the sound, even when it's not in the program. Thus, when a radio announcer in a studio talks, instead of the sound of someone speaking in a well-damped control room, I hear someone talking in a very reverberant room--my small room with a lot of bare wall area. Adding enough padding eliminates this second-venue-effect added reverb while still keeping the presentation quite large, open, and three dimensional.

Unlike with most other speakers in this or other rooms, a lack of damping did not produce audible slap echo. The "clap track" test on the Sheffield/XLO/RR test disc did not gain much extra "zing" following the claps, remaining pretty close to the single transient one hears from this test via headphones. But despite the lack of slap echo, the overlay of my small room's now-reverberant signature on studio announcers' voices was unmistakable--shockingly obvious, in fact--and, to my ears and sensibilities, was totally unacceptable.

In the low frequencies, the undamped room had subjectively more impactful bass, which has been true in this room with previous speakers as well.

I did find that eight 2' x 4' absorbing foam panels in the corners behind the speakers (rather than the 12 I had been using) was subjectively sufficient to eliminate the excess reverberation I heard on studio announcer voices. However, in the end, I preferred the presentation and frequency balance with my original arrangement of 12 panels behind the speakers. With that arrangement, as viewed from the listening position, the absorbing panels appear to extend a a foot or so to the left and right of my view of the speakers. With just eight panels, the absorbing panels appear from the listening position to be about the same width as the speakers so that they are basically invisible behind the speakers.

REG's review of these speakers noted: "And of course one can damp the backwall, too, if desired. This will change the balance of the room sound—one can adjust to taste and to the overall “softness” or “hardness” of the room. To my mind, the best results are obtained by making the backwall a combination of absorbing and diffusing. (I would not recommend something like a glass wall without curtains behind.)"

I may reacquire some additional diffuser panels from P.I. Audio to experiment with a combination of diffusion and absorption on the wall behind the speakers. Or maybe it's time to try some large potted artificial plants in the room corners behind the speakers. I definitely understand the appeal of the HUGE presentation that appeared in my room without the absorbing foam. For some listeners, that may indeed carry the day.

But, for my ears, I need some way to eliminate that excess reverberation on what should be "dry" sounds. I want "you are there" sound, not "they are here" sound, especially when the "here" is a small reverberant room like mine currently is without sound absorbing foam.

 

[tmallin]

Input fron Roger Sanders

I contacted Roger Sanders, expressing my joy at the sound of his 10e speakers and referring him to this discussion, in case he wanted to post here himself. Roger said he prefers not to participate in forums, but obviously read all that I had written and commented in detail on several issues. His comments, as usual, are very well thought out and helpful. Thank you, Roger, for your insightful comments!

Gain Settings

In response to my observation that the Sanders seemed to play louder than other speakers for any given setting of my Lumin X1's digital Leedh-processed volume control, he suggested that I could lower the Master Gain of the dbx LMS unit to allow using the Lumin's digital volume control in the higher parts of its range. Roger said that my comment is contrary to most users of the Sanders equipment. Most users have asked for more gain. Thus Roger's default setting of the dbx LMS as he delivers it is to have the Master Gain set at +6 dB.

Now, while Leedh processing is great, I strongly suspect that, like any digital volume control, the Lumin's will sound a bit better when operated with less attenuation. Before adjusting the Master Gain of the dbx LMS, most of the time, with most programs, for a level of about 83 dB at the listening seat (as measured by the SPL meter in the Audio Tools app of my iPhone) I was running the Lumin's volume control around 40 to 50 on its 100 scale.

The Lumin App also offers its own solution to volume adjustment which alters the maximum volume level attainable to a certain percentage of the 100 scale. While that certainly works to move the Lumin's master volume setting upward, my tests suggest that the transparency of the Lumin's volume control does not benefit from using this maximum volume percentage control. Thus, I generally have not used it.

The Lumin App also offers the option to lower the maximum output level of the Lumin from 4 volts to 3 volts. That, too, allows higher operating settings of the Leedh-processed volume control for any given SPL. However, as I've commented above, I and some other Lumin users find that using the low output setting slightly degrades the Lumin's sonics. Therefore, I do not use that either.

Roger Sanders' suggestion, however, seems to work very well indeed. The adjustment is super simple to make via the dbx Driverack VENU360 app. Simply click on the In1 and In2 icons and slide the displayed Master Gain slider down from Sanders +6 dB default to any lower level you want. Roger Sanders suggested I try 0 dB and that worked perfectly. Now the setting of the Lumin Leedh-processed volume control is about 15 to 20 clicks higher for any given SPL. That still leaves enough volume adjustment so that the "quietest" programs (such as BBC 3 and WILL) have enough volume adjustment to reach the levels I require if the Lumin's volume control is set at 80 or higher.

And I think the system actually sounds yet a bit more dynamic, clearer, and more three dimensional this way. It probably has to do with gain structuring. This setting allows more gain to be applied at the source end and less gain at the amp's input from the dbx LMS. Whatever the reason, this suggestion from Roger Sanders worked out extremely well for me.

Magtech Lights

I mentioned that I have used black electrical tape to cover over the bright Sanders logo on the front of the Magtech amps. I also do this with most other front panel lights on equipment I own since I find bright front panel lights distracting while listening, especially at night when the room lights are low.

Roger Sanders suggested that I didn't need to use the tape. I could just turn the panel lights off. To do so, I would remove the lid from the amplifier. Inside there is a ribbon cable connecting the logo light circuit board on the face plate to the power supply board. I could turn off the lights by just unplugging either end of the ribbon cable from its socket. There is no lock on these connectors. They are held in place just by the friction on their pins so you can just gently pull the cable out of its connector. If you want to restore the lights, you can plug in the cable again at anytime in the future. The connector is keyed so that you cannot insert it incorrectly.

Good to know! Other Sanders Magtech users may want to adopt this solution to this "bright blue light" problem. For me, however, I think I'll leave the light connected for now. It makes a very soft blue glow on the hardwood floor beneath the amps because just a bit of light escapes from the narrow gap between the face plate and the bottom plate of the amp. At night, that lets me know the amp is on and operating without being distracting.

Room Damping

Roger Sanders commented that I use vastly more damping in room than any of his other customers do. All this damping absorbs the highs, which is why I find the highs rolled off when I'm not on axis with the speakers. Roger said most of his customers leave their rooms undamped, so do not suffer significant loss of highs. He said that of course, damping does have a significant effect on the imaging in the sweet spot; this is a very personal thing and most customers find the imaging at the sweet spot just fine without turning their room into an anechoic chamber. However, he said I am right in saying that the more you suppress room acoustics with damping, the cleaner will be the sound at the sweet spot. As Roger says, fortunately, the Precedence Effect is so effective at minimizing this problem that most customers do not find any need to use more damping.

As I acknowledge in a prior post, I can well understand why most people would leave their rooms undamped with the Sanders 10e speakers. Except for my sensitivity to reverberation added by my listening room's "second venue" effect, I would probably do the same--the speakers sound that good without any room damping. I don't want to give anyone the impression that Roger Sanders is incorrect in his view on this or that his other customers are just deaf. If you buy the Sanders 10e, I strongly urge you to try them both ways--without room dampening and with some damping. My own preference is, as Roger says, very personal and may also relate to my small room's acoustics.

[Continued in next post]

 

[tmallin]

Applying AEQ Settings Above 1 kHz

Roger Sanders sticks by his view that all AEQ recommendations for parametric EQ above 1000 Hz should be zeroed out. As in my case, he generally finds that the AEQ will tend to suppress the highs more than needed.

Roger says it is better for customers to leave the highs linear and then make specific adjustments to the highs via the parametric equalization settings (PEQ function of the dbx LMS) if they wish. Roger says this usually will result in better sound than relying on pure luck by letting the AEQ equalize the highs poorly in particular rooms. I can indeed verify that the PEQ settings, such as the presence range dip (bell curve centered at 3 kHz, -4.2 dB, Q = 3) as well as the high frequency shelf filter Roger recommends in the 10e instruction manual (slope = 3, starting at 3 kHz and magnitude of -2 to -3 dB) both do in fact work well to subjectively to eliminate any perceive high frequency brightness.

Equalizing Bass Dips

My own findings over the years agree with what Roger said: dips in the bass frequency response due to room resonances are almost imperceptible unless they are extremely severe. It is the resonant peaks that are obvious. So cutting the peaks are very important while boosting the depressions has little effect.

As Roger stated audiophiles usually strive for perfection by wanting to use EQ to correct for bass depressions. While they are well-intentioned, there is a significant risk of amplifier or woofer damage if this is carried to an extreme. Since these depressions have very little audible effect on the sound, it is wise to minimize boost at the deeper bass frequencies.

This is especially so if you tend to listen at head-banging levels. Such Sanders customers often damage their speakers as well as their hearing. The damage to woofers in 10-series speakers is one reason Sanders was forced me to switch to using aluminum woofer cones.

However, if one is sensible in their listening levels--especially if they are in a small room and listen close to their speakers--as I do, then one can use much more bass equalization. Your room is small and you listen close to the speakers. Sanders' rule about limiting bass EQ below 100 Hz to a maximum of +4 dB is a number that will work for the general public, many of whom listen at head-banging levels and have large rooms. Sanders also knows that most listeners will not notice if the equalization fails to fully compensate for bass depressions since our ears are so insensitive to bass dips (as opposed to peaks).

Sanders also suggested that 10e users can easily monitor the woofer power by observing the metering lights on the dbx LMS. While users may not like to see the metering lights flickering, they are there for a reason. That reason is to monitor the signal levels so that you do not cause digital clipping in the VENU360. Sanders has set the clipping levels in the VENU360 so that the meters also show when the amplifier is clipping. You should never see the red meter LEDs flashing. The meters should only show green, although the second highest LED is amber, which is okay as it is there just to warn you that you are almost at clipping as an additional 3 dB will cause the top LED (the red one) to flash.

Roger thus suggested that I remove the light blocker from in front of the VENU 360 for at least awhile so I can monitor what is happening as I play music. Once I am familiar with what the meters are showing am confident that you I'm operating within safe levels, then I can block the lights again.

I did follow Sanders's advice on this. Out of five green LEDs, I never see more than three LEDs flashing on the electrostatic panel outputs or more than two LEDs flashing on the woofer outputs. Thus, all should be well.

 

[DonH50]

Wow, what a great series of posts, Tom! I have not spoken with or met Roger in many, many years despite him moving just up the road a ways from where I live now (he was in GA, I think, when I met him so long ago). I had always sort of figured on a pair of 10-somethings but never got around to it, and since replacing my Maggies with Revel am not planning any changes now.

I usually damped the back wave to reduce comb filter effects that simply drove me crazy (a short drive).

I suspect the closer seating in the smaller room accounts for much of the sonic difference you hear, though of course dialing in the room/speaker curves in the DSP can certainly play a large part. For dipoles, my own Maggies and the various ESLs I heard through the years in my system and others, I always preferred a really large (for homes) room or closer seating to achieve immersive sound. There's just something magical about sitting in the sweet spot close to a pair of good panels.

I completely agree with Roger on compensating bass dips with EQ. Most room correction programs wisely do not even try. If due to a room mode, which includes most large dips (nulls) in the deep bass, then dumping EQ does nothing but waste power, crush the dynamic range of the speakers, and results in hugely over-bassed sound in the rest of the room. I know you know, but for others, a null is when the direct and reflected waves combine out of phase and cancel, essentially 1 + (-1) = 0 and you have a null. If you amplify by ten, then you get 10 + (-10) = 0 -- no audible gain, but a heckuva lot of wasted power and headroom in the speakers!

Toole and others agree with not compensating the direct sound above the bass region since that effectively changes the characteristic response of the speakers. I have and have not, depending on the room, speakers, and preference of the day. I agree with the premise that a good speaker will have good direct sound and we should not mess with it, but my room and sometimes tastes say otherwise.

Thanks for the reminder and refresher! - Don

 

[BillK]

KostasP, as a follow-up to my post #22, in particular see Roger Sanders' article, "An Electrostatic Speaker System Part 1" from Speaker Builder magazine back in 1980. There he explains why a full-range electrostatic speaker just can't do the bottom couple of octaves of bass even when massively equalized. He also discusses comparative listening tests where even doubters were won over to the idea that using a proper transmission line cone woofer in a hybrid electrostatic arrangement sounded better than a full-range electrostatic speaker.

To me, the issue with using a coned woofer with electrostats or other panels is not so much the "sound" per se but the quality of it.

Perhaps it's just me, but no matter the system I have always been able to hear the transition between any panel and the cones. I don't know quite how to describe it except the character of the bass loses the openness of the frequencies generated by the panel.

To be sure, it can sound good but it always is a noticeable difference to me; whether that in fact bothers you or not is a personal thing, not unlike the way I can always detect the sonic signature of a horn.

Personally I've always been very impressed by Roger's demos at RMAF until the selection gets more bassy, and then the discontinuity makes something just sound… "off" (to me.)

The same was true when Apogee tried mating their panels to subwoofers near the end of Apogee's run; I could always tell.

Note this type of thing isn't exclusive to panels; for more than a few conventional speaker driver models the switch from tweeter to mid is noticeable and annoying to me as well, and often results in what I call beaming - where the sound of say a solo trumpet in one channel does not sound like it's coming from "over there" but rather from that speaker cone right there.

Bowers & Wilkins speakers speakers demonstrate this a lot, even, unfortunately, their new 801/802 D4 series which otherwise throw a wonderful soundfield.

Focals seem to avoid this until you move high enough in the range that they use the EM driver, and at that point for whatever reason the EM driver makes its presence known in the same way.

FWIW, I've never, ever heard it from a Vivid Audio speaker.

 

[DonH50]

IME, which is only of Roger's older models, his speakers exhibit much less of that transition continuity than other hybrid ESLs. IMO that is because he crosses to the woofer about an octave below where many others (e.g. ML) cross over thus it is approaching the transition frequency from a line'ish to a point'ish source. ML used to be horrible (IMO) a decade or two ago; the more recent models seemed to be better but I have extremely limited exposure to them. That discontinuity is one thing that led me to Magnepan instead of ESLs -- with a few exceptions, of course. Full-range 'stats (Soundlab) don't have that issue, though without compensation in the panel itself (which Soundlab, Quad, and others do) dispersion gets wonky as you move from bass to high treble frequencies.

FWIWFM - Don

 

[dan31]

Nice write up Tom. I enjoy reading your experiences and how they evolve as you get more time with the systems changes. I listen in a small room in the near field as well. I have stuck with the Harbeth M40.1 as they just work and sound nice and full at medium to low volumes. The Sanders speakers sound like a big step up.

 

[tmallin]

As I've noted, my listening room is quite small, about 13' x 11' x 8'. By my calculations, the square feet of its surface area including walls, floor, and ceiling is about 670 sq.ft. I have foam damping on 96 sq. ft. of it, which is about 14%. I have polystyrene diffusion panels behind the listening seat covering about 48 sq. ft., a carpet covering about 2/3 of the floor, plus a couple of CD racks and a bookcase. It thus seems like I'm probably within the 15% to 30% rule of thumb as to absorption which Roger Sanders notes in his excellent Technical White Paper on Room Acoustics and Treatment. However, contrary to Roger Sanders' general recommendations, I do have the acoustical foam directly behind the speakers as viewed from the listening seat.

Given my small room, perhaps the Precedence Effect is not fully operative even at my listening distance of 58 inches. The speakers are only about 64" from the wall behind them. The bounce-back delay may not be quite long enough to make the reflections totally unobtrusive. That may be part of the reason why I subjectively prefer a good amount of absorption behind the speakers.

Measurements taken within an anechoic chamber do not include any reflected sound, at least down to the low frequency absorption limit of the chamber, which typically is about 80 Hz. But we don't listen in such chambers so, Precedence Effect or not, the real-world subjectively perceived frequency balance for speakers in home listening rooms (at least the small one I have now) will be somewhat dependent on room reflections. For example, omnidirectional speakers like an MBL or Morrison will not have the same perceived frequency balance in an undamped room as the Sanders highly directional 10e even if they measured the same in an anechoic chamber or out of doors. Generally speaking, I have found that the more widely the high frequencies are dispersed, the brighter any given anechoic frequency response will sound in a real undamped small room like mine.

Now, in a large room this may be less troubling. But in a small room like mine where I can get the speakers at most about five feet away from the walls, the reflective paths are short enough to still allow the reflections to color the perceived frequency response at least a bit. With wider dispersion speakers, the room reflections color the response much more, of course. That is why I find the Sanders 10e speakers so appealing even without any EQ or room padding. But, perfection seeker that I am, I do find that in my small room some room padding and/or EQ is helpful, even at the sweet spot, with a lot of recordings--the bright-ish ones, which I think are a large number of recordings indeed.

Some may question why my Lumin X1 streamer has such a high output voltage--4 volts. But I don't think the Lumin X1 streamer is badly designed. It has high output so that it is sure to put out enough voltage to drive most any amp to full power without the added gain stage one usually gets via a preamp. That's the way Lumin recommends arranging one's system--preampless, and I agree, having tried systems set up with preamps and without preamps many times over the decades. With a 4-volt output from the streamer, one obviously does not need any additional gain from the preamp and the Lumin X1 streamer's power supply is more than adequate. But I agree that for amps of normal sensitivity, much less tube amps which usually are designed to put out full power with less than a volt input, the 4 volt output could be viewed as excessive.

The solution, as in pro-audio situations where all source components put out really high voltage, is to put an attenuator between the Lumin source and the amplifiers. This was taken care of in the electronics built into my prior Dutch & Dutch 8c speakers. There was a gain control built into the input of the active amplification circuit. With the Sanders speakers the master gain control of the LMS in effect acts as an input volume control for the Magtechs in my system since there's no preamp between the LMS and the Magtechs. Thus, by having high gain at the source (Lumin) the noise/distortion can be turned down by running the LMS just hot enough to drive the Magtechs to the power level I need for the SPLs I want. Proper gain structuring for an audio system calls for "hot" sources with minimal gain from the amp. The "hot" output from the Lumin allows this in conjunction with the master gain of the dbx LMS.

At this point in my listening life, I care a lot less about how the speakers sound outside the sweet spot than I did a decade ago when I owned the 10c. This may not have been clear in my prior posts in this thread and I wanted to clarify that. Like REG, I am now a sweet-spot-only listener. I do not listen "casually" in my audio room. If I am in there listening to music, I am sitting in the sweet spot. Thus, I don't really care how the 10e's sound in the rest of the room, only in the sweet spot, and I want that sweet spot as sweet as possible. That's why I prefer the room damping behind the speakers in my small room. While I do listen to the system from down the hall as background music while I'm working at my computer desk, the perceived frequency response down the hall, while a bit rolled off in the highs, is just fine for background listening. If it were super fidelity, it would be distracting and thus no longer "background" music.

In addition to radio studio announcer voices, I use the "clap track" on the XLO/Reference Recordings Test & Burn-In CD (formerly called the Sheffield/XLO Test & Burn-In CD) to test for slap echo and damp the room accordingly. The "clap" should originate from the speakers and you should listen for the echo from your listening seat. It does little good to clap your hands from the listening seat and listen for slap echo. This "clap track" recording ideally should be absolutely echo-tail free and sound through speakers the way it sounds through headphones: a single quick transient clap with absolutely no trailing sound. Anything added to the end is being added by your listening room acoustics responding to your speakers' output. I pad the room until I get results fairly close to what I hear from it via headphones. Getting it to sound the same through speakers as it does through headphones would truly require an anechoic chamber!

 

[gleeds]

Wow, quite a journey, and thanks for sharing all this. Everything old is truly made new again!

Roger and I worked together in the early 2000s. I fell in love with Roger's original Eros speakers the first time I heard them in a small hotel suite at the HiFi show at the New York Hilton. Since then his technology and product have gotten progressively better and better, e.g. the UltraStat arc-proof panels, the Magtech fully regulated amplifiers, the crossover arrangement, and the superfine cabinetry made by local craftsmen. As always his service and accessibility are second to none.

The bottom line is even though I import and sell many of what I consider the worlds finest loudspeakers there are precious few speakers I would rather be caught in the sweet spot with........ than Roger's amazing10e's!

 

[MtnHam]

I am pleased to hear another voice for electrostatic speakers, and that you mention Sound Lab. As a Sound Lab enthusiast (and home based dealer) for over 20 years, I am amazed at how little they are known or acknowledged. I, and other members of the cult, consider them to be the best of all!

Tom, you and any other WBF members are welcome to visit my SanFrancisco listening room and experience them yourself.
Tom B.

 

[Hear Here]

> I thus began casting about for an ultimate room-ignoring speaker, especially in the mid and high frequencies.

> In the world of high-end speakers, it is rare that moving from $12,500/pair speakers to $27,000/pair speakers will produce more than a 100% increase in perceived quality.

I wouldn't admit to or pretend to have read all your thesis on your new Sanders speakers, nor earlier similar thesis on the D&D, but I have to pick up on a couple of points you have made.

If the new Sanders is 100% better than the earlier D&D and that was (no doubt from your description) 100% better than your previous speakers and in turn we must presume that each of your many new systems is much better than the previous one, we must infer that either you started from a truly crummy original system, or (more likely) you just love a regular change in musical rendition.

Frankly I find it hard to believe that each of your speakers is so much "better sounding" than the previous one. If you've had a number of systems between the Sanders 10c to 10e and each is better than the previous one (by as much as 100% per change), then I must conclude that it's really not the sound quality that other listeners would agree with but a difference in sound that you personally are enjoying. You have become "tired" of the familiar sound of your last speaker and welcome enthusiastically the new "different" sound! I applaud (and possibly envy) this enthusiasm, but I would bet a pound to a penny that if you had your last 10 systems and a room full of listeners, and switched the speakers in turn, your audience would reach totally different conclusions that you have reached.

I don't mean to offend in any way and, as I say I admire your enthusiasm that is so keen that you put pen to paper so generously - on these new speakers and in almost identical fashion with the Dutch & Dutch - and perhaps earlier speakers too, although this would have been before I joined this forum!

Anyway the main thing is that you are totally content with and love the music you hear. I can't wait till you tire of the 10e and find some new speaker that thrills 100% more than the Sanders! It will surely happen in time!

Your other quote above regarding "an ultimate room-ignoring speaker" leads me to a suggestion based on my own experiences recently - by coincidence with hybrid electrostatics powered by Magtech. This type of speaker isn't "room ignoring" - far from it. The most room ignoring TYPE of speaker, I would suggest is a horn. My room is 945 sq ft, roughly semi-circular with low ceiling and floor-to-ceiling glazing and the speakers are placed mid-room either side of a structural column. Speakers therefore have no rear wall to salvage much of the rear-firing sound that ELS rely on. These new speakers (despite built-in Anthem room correction) just sounded disappointing compared with my ancient Avantgarde Uno horns. I sold (at huge loss) the new Martin Logans and kept the Avantgardes, until I found better speakers to replace the Unos. Guess what - Avantgarde Duos, then the latest Duo XDs. Despite owning Avantgarde speakers since 2002, I've not ever tired of them, although I have tried to find better ones. Martin Logans, QUAD, Quadral and others have been home trailed, but none bettered my faithful old Unos. The local D&D distributor admitted that these speakers would not suit my room either. If you want “ultimate room ignoring speakers", you should try some good horns. Their physics immediately single them out as likely to be good at ignoring room associated problems.This doesn't mean they are easy to set up, but once this is done, I doubt you'll want to look elsewhere for a decade or so

Good luck with your new speakers (have you ever thought of these - https://www.facebook.com/Blankonu-607051549422202/ ?) and we look forward to your next adventure. Peter

 

[tmallin]

I'm sure you're correct that part of my moving on is just a yen for something new and different. I admit it in most of my new speaker threads. My estimation of quality increase surely may be exaggerated by that yen as well.

But I do think that in the context of my small room I've hit on one incredibly important factor in my personal perception of sound quality from the sweet spot. And that factor is narrow dispersion above the bass range. I value that more these days because, as I stated back in post #2 of this thread:

"My recent forays into high-end headphones have also convinced me that there is nothing like an electrostatic driver for low distortion and clarity of sound without overbearing brightness or etch. And, while the stereo imaging and staging presented by headphones is not generally as pleasing or natural as that from stereo speakers, totally removing the room from the equation yields countervailing benefits in terms of the lack of early-reflection-induced distortions/grit/edginess, and extreme stability of imaging and staging. Thus, moving toward speakers which interact less with the room seems a good move. That is why I had so much subjective success in my current listening room with such speakers: the Janszen Valentina Active, the Gradient 1.4, and, most recently, the Dutch & Dutch 8c. Ideally, I want speakers which combine the lack of room effects headphone listening provides with the pleasingly natural "out there" sonic presentation of speaker listening."

Horns have no back wave, but they have full frequency dispersion over the angle defined by the mouth of the horn, which is usually about 90 degrees. Beyond that angle, yes, high-frequency horns roll off sharply. But I'd estimate that the Sanders are full range in the highs (that is, the top two octaves from 5 kHz up) out to only about 10 degrees off axis for a total dispersion of maybe 20 degrees in the front. I just tried listening to one panel facing it from very close up while the other was muted. I did not have to move off axis much at all before the high frequencies disappeared. While not quite like a laser beam, they disperse highs perhaps like a searchlight or a lighthouse lamp--VERY directionally. Once you damp the back wave with the type of foam arrangement I use, these are by far the most high-frequency directional speakers I've heard in my room or elsewhere.

That includes the Janszen Valentina Actives, which use flat electrostatic panels in a box, not dipole radiators, so they had very little high frequency emission to the rear if I turned off the Air Layer side mounted dome tweeters. But since the panels of those are much narrower, the frontal dispersion in the highs is much wider.

I'm not against horns. Some sound pretty good. The shallow horns that typically are called "wave guides" these days can be truly excellent. That's the way the Dutch & Dutch 8c's control high frequency dispersion. That worked extremely well for my small room.

But, going for broke on the idea of keeping the room surface reflections from contaminating what I hear from the sweet spot and ignoring how the speakers sound outside that spot led me inevitably (back) to the Sanders 10e. In my small listening room its fascinating, mesmerizing, how the Sanders 10e sweet-spot experience combines my goal of electrostatic headphone clarity and lack of room effects with an extremely pleasing, huge open sound that is both "out there" in front of me and has much stronger wrap-around envelopment on recordings where phase is manipulated than any other two-speaker stereo set up I've yet heard either in this room or elsewhere.

 

[dan31]

Tom what is the average SPL for the Sanders at your position? A or C for spl. I ask as my room seems to allow for louder listening, but my position has me enjoying low to mid 70’s spl A scale. If I switch to the C scale it’s up into the 80’s. This is about as loud as I listen. Routinely much lower in the morning and evenings. Some speakers need to be turned up to enjoy.

 

[Hear Here]

> But, going for broke on the idea of keeping the room surface reflections from contaminating what I hear from the sweet spot and ignoring how the speakers sound outside that spot led me inevitably (back) to the Sanders 10e.

Well, that's precisely (yes, 100%) why I stick with horns.

They are surely the most directional TYPE of speaker available. The sweet spot is small (that should suit you in your room with a single carefully-placed listening chair) and horns are very tolerant of peculiar wall features, largely because their sound is so directional and it doesn't depend (to advantage or disadvantage) on wall reflections. Their bass enclosures (Avantgardes anyway) are closed boxes, so adding to the system’s room-ignoring ability. My speakers sound poor when I'm in the parts of my room (dining and kitchen) that are behind the speakers.

My experience of electrostatics (granted limited to Martin Logan and Quad) indicates that this is the type most influenced by room surfaces. Half their energy is projected backwards and this needs to be junked (by absorbing panels, etc), or harvested by a rear wall 4-6 ft behind the speakers. Either way, you have lost your aim of your speakers being of the "ultimate room-ignoring" type. You either treat your back walls to totally junk the 50% of its energy that fires backwards, or you harvest it by having a suitable reflective back wall!

My room (previously described and considered very “difficult”) has no artificial wall treatment but since moving in 12 years ago (when acoustics were appalling), adding carpeting of 30% of the floor, hanging curtains (always open) and sensible and appropriate amounts of soft furnishings, I now have a speaker system that is not improved by electronic room correction systems, In fact the reverse, the sound now has a higher “tingle factor” (or ME factor as JS aims for) is higher without a Dirac, RoomPerfect or MARS filter engaged. That for me has confirmed my view that horns are ideal if one wants an “ultimate room-ignoring speaker”. I’m not suggesting that horns are good in all rooms, or even yours, but they must surely be the type that most closely meets your quoted idea! Peter

PS - Omni-directional speakers could be considered as the ideal room-ignoring type, but my listening tests (unfortunately none in my own room) indicate that imaging is so compromised (even at what should be the sweet spot) that I never experienced the tingle / ME factor when listening to omnis. Pity as they would clearly sound very much better than horns when I'm seated behind my speakers.

 

[tmallin]

Dan31, see this post for my prior discussion of listening levels.

I have no idea how accurate my quick-and-dirty SPL measurement technique is, but at least I've been consistent for several years now. I hold my iPhone close to my nose, screen toward me, and use the Audio Tools app's SPL meter (the display of which looks like the old Radio Shack Analog SPL meter) and use C-weighting, Slow settings. I look at the instantaneous SPL being displayed and after some period of seconds, I look at the peak levels the meter measured during that time.

Long before I read about Dave Katz's level recommendations for monitoriing/mixing/mastering, I found myself just "naturally" gravitating to levels at instantaneous levels using this method of around 83 dB with peaks in the 85 to 87 dB range for longer-term listening. That's for fairly compressed material.

On classical music, good luck on picking an "average" level since the dynamics easily may shift 20 dB or more from soft moments to immediately following loud moments and back again quite quickly. What I do for classical material is attempt to adjust the type of music I'm hearing to my "remembered" concert hall levels from a fairly close up seat. I realize that's quite inexact, but that's how I do it and since I try for a "you are there" effect from my home audio reproduction, that seems reasonable.

I believe that those who listen in relatively undamped rooms will likely be listening at somewhat lower measured SPLs than those who damp/diffuse room reflections as I do. The reverberation from "hard" surfaces will tend to add to the apparent loudness, at least a bit and probably more if your speakers have fairly wide dispersion.

Like most other electrostatic speakers, the Sanders 10e does not have to be "goosed" to high volumes in order to hear fine detail. Most good speakers these days have decent low-volume audible detail, but electrostatics are special in this respect. Still, their special transparency does nothing to counteract Fletcher-Munson effects. Unless you listen loudly enough, the tonal balance will seem "off," as in thin without a proper low frequency foundation.

Sure, I occasionally listen more loudly than the 83 dB I mentioned. For very brief periods for "testing" or just for thrills, goosebumps, kicks, etc., the meter might say peaks are in the 90 to 100 dB range. Late at night or when I otherwise don't want to disturb my wife, I can listen much more quietly with measured levels on compressed jazz material averaging around 60 dB and peaks less than 65 dB. But, at those low levels, F-M dictates that the frequency balance will be wrong, as in insufficient bass.

 

[tmallin]

The more I listen to the Sanders 10e speakers, the more I see and hear that Roger Sanders is entirely correct in terms of his advice to ignore the dbx LMS's AEQ recommendations for filters centered above 1 kHz. As Sanders advises, any such parametric filters the AEQ function implements should be manually ignored by zeroing out any recommended corrections for filters above 1 kHz.

Ignore the "Result" curve shown by the dbx app or front panel LCD screen. Ignore the supposed measured response of the speakers above 1 kHz, even if you are use a decent measuring system like OmniMic V2 or REW. Trust your ears. The speakers do not need correction above 1 kHz.

Yes, you may prefer to damp some portions of the room as I do and add diffusion to parts of the room as I do. Such room treatments may well make the sweet spot even sweeter. Try experimenting with room treatments and judge for yourself. One size most probably does not fit all. My small room may well react quite differently to such treatments than a larger room. My personal preferences as to the liveness of the listening room may not suit your personal preferences. You may not care a hoot about how radio announcers sound if you can make most music sound even more open and three dimensional by leaving your room relatively "live" and undamped.

Yes, experiment with room dampening. But I'm now convinced that the inherent response of the speakers above 1 kHz should be left as is for best-sounding results. Sure, some or even a lot of programs may sound a bit bright to you. If so, it is easy enough to engage the PEQ function to insert a high frequency shelf filter as Sanders' manual recommends, or insert a presence-range dip as I have also suggested. But, on good recordings, nothing like that is needed. Thus the foundation equalization, the one formed by the AEQ function, should remain unaltered above 1 kHz.

 

[tmallin]

Other comments from Roger Sanders:

Roger Sanders previously told me:

"I have set the clipping levels in the Venu 360 so that the meters also show when the amplifier is clipping. In short, you should never see the red meter LEDs flashing. The meters should only show green -- although the second highest LED is amber, which is okay as it is there just to warn you that you are almost at clipping as an additional 3 dB will cause the top LED (the red one) to flash. "

I told Roger that I understand this to mean that the Magtechs won't be clipping as long as the red lights don't flash. I then asked Roger what this implies, if anything, about the safety of the power levels being sent to the woofers? If the red lights don't flash, does this mean the woofers are safely within their excursion limits? Or does this just have to be monitored in some other way?

Roger helpfully responded:

"The Magtech amplifier has sufficient power to destroy any speaker. However, this is only going to happen if the power is applied continuously. Since musical peaks are very short, you won't damage the speakers even if you drive the Magtech very close to maximum power when playing music.

"The only exception to this is when playing extremely deep bass below 30 Hz. Such low frequencies provide adequate time to drive a woofer beyond its excursion limits when driven by 1,000 watts like the Magtech can deliver. So if you are listening very loudly to huge pipe organs that will reproduce extremely low bass [and, I imagine, certain electronic music which uses substantial sub-harmonic synthesis] listen for woofer distortion that would indicate you are hitting the excursion limits of the woofers and reduce the level if necessary to prevent such distortion.

"The main point of watching the meters for clipping is to get an idea of the output limitations of the system. You should avoid clipping at all times. If you find that you are clipping the equipment, then you are asking the system to play louder than it cleanly can. Not only will this degrade the quality of the sound, but it shows that you probably are damaging your hearing. And clipping produces a huge amount of harmonic energy, which can generate so much heat that it can melt woofer voice coils. So check the meters to be sure that you are not driving the system too loudly. As long as the red lights are not flashing, you should be fine."

Note that the flashing output meters can be observed not only on the front panel display of the dbx VENU360, but also on the output monitoring screen of the dbx Driverack VENU360 app. Thus, I don't have to remove my light blocker from the chassis to occasionally monitor the output power relative to the speakers and amps capabilities.

As I said previously, I never see more than 3 out of five of the green lights flashing for either the electrostatic panel output or the woofer outputs so I seem to be operating the system well within its considerable SPL capabilities. Listening from close up in a small room definitely has its advantages, and this is one of them.

 

[youngho]

Yes, you may prefer to damp some portions of the room as I do and add diffusion to parts of the room as I do. Such room treatments may well make the sweet spot even sweeter. Try experimenting with room treatments and judge for yourself. One size most probably does not fit all. My small room may well react quite differently to such treatments than a larger room. My personal preferences as to the liveness of the listening room may not suit your personal preferences. You may not care a hoot about how radio announcers sound if you can make most music sound even more open and three dimensional by leaving your room relatively "live" and undamped.

Just out of curiosity, have you tried diffusion behind the speakers and absorption behind the listening position, as per Linkwitz's recommendations?

Room Acoustics

The acoustic behavior of rooms at different frequencies. The loudspeaker's polar radiation pattern determines its interaction with the room and the accuracy of sound reproduction. Reverberation time as most important parameter for a room's acoustic behavior.

www.linkwitzlab.com

 

[tmallin]

No, I have not tried that yet. Linkwitz has the, to me, somewhat odd idea that a dipole is not a dipole unless the sound from the backside of it is allowed to reflect off the room services or at least be diffused off of them. Yes, part of the “open“ sound of a dipolar panel is the rear wave from the speaker interacting with the listening room.

However, in a small room like mine, I have found that reflections off the room surfaces are not helpful to the replication of a “you are there“ music listening experience. In a small room like mine, hearing reflections of the listening room walls is not, in my experience, conducive to hearing the sound recorded. What you hear is the second venue effect of your own listening room’s small-room acoustics, not the sound of a large space.

Now, for larger listening rooms then I have experience with, that may be helpful to a feeling of realism. However, in my own experience in smaller rooms, especially this quite small room, absorption near the speakers works best to create a “you are there“ listening experience.

Besides the openness that the rear wave of a dipole creates, dipoles interact less with the listening room‘s room modes . Of course, this does not matter much above the bass frequencies, but can’t hurt.

In addition, dipoles reflect much less energy from the side walls and the floor and ceiling of the listening room. This positive aspect of dipole sound generation is very helpful even in a small room, no matter whether you absorb the back wave from the dipole or not. I take full advantage of this aspect of dipole speakers in my listening room.

 

[youngho]

No, I have not tried that yet. Linkwitz has the, to me, somewhat odd idea that a dipole is not a dipole unless the sound from the backside of it is allowed to reflect off the room services or at least be diffused off of them. Yes, part of the “open“ sound of a dipolar panel is the rear wave from the speaker interacting with the listening room.

I've combed through his website to look for an explanation for his recommendation. Based on https://www.linkwitzlab.com/rooms.htm#rear radiation, https://www.linkwitzlab.com/faq.htm#Q31, and statements like in https://www.linkwitzlab.com/AES123-final2.pdf, I believe that the argument is that uneven (through the use of foam or relatively thin) attenuation is more likely to distort the spectrum of both reflections and cancellation effect, whereas diffusion is more likely to preserve that spectral energy (though some attenuation does occur with QRD and PRD devices). In addition, I wonder if the relative randomization of direction and phase from diffusion of the backwave may also help create the impression of greater distance in terms of the back wave reflections. Finally, Linkwitz argues for a reversal of the LEDE setup and mentions cognitive work, which is often cited in preserving both a reflective floor and front wall (though with soffit-mounting) in control rooms, with the addition of ceiling and rear wall (I never understood the latter) diffusion elements for maintenance of "self noise" in front-to-back rooms.

However, in a small room like mine, I have found that reflections off the room surfaces are not helpful to the replication of a “you are there“ music listening experience. In a small room like mine, hearing reflections of the listening room walls is not, in my experience, conducive to hearing the sound recorded. What you hear is the second venue effect of your own listening room’s small-room acoustics, not the sound of a large space.

I believe that Linkwitz would argue that the relative directions of the reflections is very important, especially from the wall behind the listening position. The Salmi recommendations for dipole setup that Linkwitz mentioned in the second link above were interesting.

Now, for larger listening rooms then I have experience with, that may be helpful to a feeling of realism. However, in my own experience in smaller rooms, especially this quite small room, absorption near the speakers works best to create a “you are there“ listening experience.

Besides the openness that the rear wave of a dipole creates, dipoles interact less with the listening room‘s room modes . Of course, this does not matter much above the bass frequencies, but can’t hurt.

In addition, dipoles reflect much less energy from the side walls and the floor and ceiling of the listening room. This positive aspect of dipole sound generation is very helpful even in a small room, no matter whether you absorb the back wave from the dipole or not. I take full advantage of this aspect of dipole speakers in my listening room.

I was curious to know if you had tried it, but it seems like you've mostly stuck with your preconceptions here, even to the maintenance of a floor rug when there are supposed to be less effect from floor reflections.