Electrostatics

[manisandher]

I just love the idea of a single driver (with no x-over or box) being driven by a high-quality SS or valve single-ended amp. Simplicity in a nutshell.

I heard the Quad 2905s in a shop and loved them. Has anyone had any experience of electrostatic speakers bring driven like this?

Mani.

[superdac]

Hi,

Interesting question. In my view the answers depends fully on which kind of musical portrayal you want to come 'alive' in your room(-acoustics), by the way, this is also the case with other mechanical instruments that moves air for the sake of musicmaking in a living room. As a more than 30 year user of electrostatics (Quad 57 and/or big and tall Audiostatics) I can compare those with 'normal' speakers (2,3,4 way with passive cross-overs). In my view it all comes down to listening habits or needs, room for placement (away from walls!), possibilities of some room treatment or rearranging objects, your 'normal' listeningposition and last but nog least the way in which your family members cooperate with your personal 'hobby goals'. Before giving any advise I want to ask you to tell some more with respect to your music choice, listening habits (e.g. very loud, 'realistic' or easy listening), room and/or acoustic surroundings. Electrostats are quite demanding in that respect and have some restrictions, but when you can manipulate your acoustic surroundings and speaker/listener position they can deliver a very good and involving musical performance. But Single Driver and/or Open baffle speakers can do that also (those are also very simple ways of moving air, but they also have some room requirements and drawbacks).  May be your Wilsons are already a quite good compromise. First requirement would be in my view is to try the Quads out in your own home, this is based on a quote from Peter Walker (the disigner of the early Quads): (refrased by me): it is the room that speaks to you.....

pieter.

[manisandher]

Hi Pieter,

Wow, you have a lot of experience in this area and I'd really appreciate learning more about your experiences.

Right now, my wife and I are looking at houses to buy - and a criterion of mine is a separate room suitable to turn into a dedicated music/hifi room. It would be really helpful if you could give me your opinion of the following:

1) how large does a room really need to be in order to have electrostatics working at their best?
2) would they work better on a wooden or carpetted floor?
3) how tolerant are they of side-wall and rear-wall placement?
4) how well do you think my Pass Labs Aleph 4 (100wpc single-ended class-A) could drive them?

FYI, I like listening at realistic levels to all kinds of music. Timing and timbre are things that I'm really striving to get right. In this respect, I'm looking for something that can match my Stax headphones, I suppose. I'm not interested in something that will shake the house down (I still have my current system which does this plenty well enough for me).

Looking forward to your reply,

Mani.

[SeVeReD]

Closest I've come to this type of speaker (which isn't very close I guess) are the Genesis 2s (xover 'tween tweeters/ribbon).  For me, it came down to rock... at the time I couldn't get the weight, impact, crunch I expect from rock.  If all I played were string quartets or classical they would have fit the bill wonderfully.  They were plenty loud,,, I guess I just like the sound of dynamic speakers better.

My room is 16*22*8 ... I would have liked it bigger all around (18*25*8 maybe? )  Here's a brief on it.
The garage was rebuilt to be the music room. Concrete floors with medium carpet/pad; Ceiling uses massive beams to hold two 1" wall-boards sandwiched together with damping compound and lots of screws, Heavy use of plaster with broom swirls, thick pink insulation on top (attic); Walls are 1" wallboard hung off the studs with Z-channel sandwiched with damping compounds and a 1' layer of Tectum on top(the product name, looks like compressed shreaded wheat), plaster & sand mixture spread thin over Tectum walls http://www.tectum.com/interior_walls.htm , corners have 45 degree insets with ~6" holes in the wallboard/but not the 1" tecum on top, blown in insulation in walls, carpet with medium pad; Electrical- upgraded service entrance goes to 150 watt subpanel for system (all copper wire), 6 25 amp dedicated and tweaked lines all on the same leg and balanced by 'non noisy' lines...
I go back and forth on the 4 Room-tune products I have and I have a bunch of blinds I've cut into a sorta 3d shape for diffraction... they work well I think.

[superdac]

Hi Mani and Severed,

Your mails makes some things more clear as a start for advise and helps me to bring some order in my own experiences of the past decades. It is a rather long story, but it is also a complex audio phenomenon. It is a strictly personal view, so there may be many other views and opinions to be found on the internet or within the xxhe group. So look with some relativity into the following text.

First a reaction with respect to the mail from Severed, but those personal views are also relevant for your own list of wishes when looking for a house, that needs to have a good structural basis for a dedicated audio room.

Indeed, a ribbon embedded within a dynamic speaker is another concept for making enjoyable music. The full range kind of ribbons I have heard (some Magnepans and Apogee) sound really good, but have a little different blend when compared to full range electrostats. All hybrid speakers with dynamic low and an electrostatic panel for low mid and higher I found not a compromise that is to my taste. Also full range esl in combination with one dynamic sub, never heard on with a sub par side.

By the way my musical taste is quite broad, but the most enjoyment I get from classical music/acoustical jazz and some good recorded pop (mostly live). Realistic sound levels I think should be referenced by experiences in real concerts. Sound levels in the home are in my view always compromised because a room can not exactly mirror a concert hall or a fully equipped recording facility. You can only strive to a musical quality sound level with such an impact at home that it creates some illusion of ‘real’ performances. Within that frame I think ESL can be used as an instrument (there are other ways to Rome, I know).

That instrumental quality is the reason I choose for a full range ESL in combination with a extra ESL subwoofer par side some 15 years ago (one full costly revision a couple of years ago, electrostats needs sometimes maintenance, open ESL also do not like smoke or other in house air pollution from candles or kitchen activities; Quads are as far as I know not fully open for attracting dust, so that is a pre with respect of usability and lifespan). Big ESL’s are quite an obstacle in the living room but for me still a good compromise, accepting all the compromises for positioning and listen position. My actual room is around 60 sqm. Although, all is relative, really good dynamic speakers are also rather big and needs space to ‘sing’, may be except corner horns like the great Klipsh Eckhorn (heard them once in a not so very good acoustics (too small a room) with  e.g.  some tracks from ‘Wish you were here’, very impressive).

At the beginning I used the big ESL’s on the ceiling of my formerly house in a dedicated audio/video room. Very impressive, but (as in most room situations) you have to accept a ‘hot seat’. ESL’s in my experience are rather directional, more than other concepts. Two way dynamic speakers had less problems with the acoustics of that ceiling with pointed roof, but delivered not the openness and transparency of the ESL and/or that ‘extra’ that gives me the illusion to be right in front of the performance and the performers (Listen to Jazz at the Pawnshop and you understand me). 

Severed: with respect to your wall treatments, as far a I understands them. I think in general you have to be very cautious with room treatment because in my experience sometimes you create or disclose just other problems while solving one problem in isolation. Nothing new for you I assume. In my dedicated room, in the end and after much experiments with different materials and techniques for diffraction and/or absorption with the goal of manipulation of direct/indirect reflections it was a revelation for me to dismantle most of them and start all over again. I treated the thick concrete floor with fixed soft under layer plus thicker carpet, made the roof construction more stiff with appropriate iron clamps and used a minimum of movable reflection panels just under the roof walls. I also decoupled the ESL panels more from the concrete floor. A ceiling with a pointed roof is acoustically not optimal, so I had to look for compromises.

The treatment also revealed for me that the system provoked in the ‘old’ situation quite some for me hidden resonances that obscured and troubled the sound field as a whole! In the end the goal was also not the ultimate perfection (whatever that is, but sometimes you have some vague and high ambitions……), but I was seeking for ‘the most enjoyable and musical mix’. Personally I found at that time a comfortable mix of attributes to make music, confirmed by others.

Also, the old story from experts has lead me to a successful mix: less is generally ‘more’, also with respect to manipulation of room acoustics. ‘Less’ here means ‘just enough’. So to preserve a good level of liveliness in the sound field I used only so much intervention in the front/back/side secondary reflections that there are no flutter echo’s anymore and there is a natural decay.

A useful instrument for me personally is to clap hard in your hands in the middle of the room and at the listening position. When the direct, indirect and decayed sound is well integrated/not irritating or aggressive and repeated claps sounds natural/undistorted to your ears you are moving in the right direction to tame some of the acoustic room problems in the musical most critical area’s (the lows are another chapter). After that I use some tracks with well known soprano aria’s (Callas/Madscenes, Schwartzkopf and Norman/Strauss) to check the acoustic balances. When those soprano’s (with all their expression, dynamics and power) sounds communicative without flutter echo’s, unnatural ss sounds and/or irritating sound levels you have another start point to go any further.

Listen also to some classical male voices and/or a male newsreader BBC to investigate the lower voice registers. All need to sound natural and not as if the men have a cold or sound nasal.

After that I use quality tracks from different Piano’s, Cello's, Organ, different Guitars (classic but also modern with metal string (try Michal Hedges). After that some more complex orchestral works and a capella choir. In the end, I try different very good recorded and for me well known tracks with jazz, popular songs, opera scenes and live rock. An important symptom for progress is my wish to listen to the whole performance. When I want to change too quickly from track, get bored or irritated there is a problem. The personal rationale behind this musical test strategy or diet is, that I use my own observation abilities and my own ears to come close to the preferred mix. It helps me also to stay away from listening to (short but impressive) sound bites. Also building up from rather simple to very complex is helping with problem determination and problem solving (sometimes simply accepting the actual quality level!). As a closing test I ask(-ed) my wife or children or friends to give their merciless unbiased view.

Well what is the point of telling this all, because it is only my personal experience with my musical favorites and sound producing context. Well I hope I have given you some insight in the process you have to go through after you have a room to start with and bring the ESL’s in the setup. This process is very time consuming and not always rewarding, not to say it has also its financial burden. So you must be rather motivated.

With respect choosing a dedicated audio room and your choice for one of the latest incarnations of a Quad ESL I want to kick in a open door first: look for a room not too little and not too big!

A little room will give you all kinds of acoustical problems and a very near field listing position with little possibilities for repositioning. All ESL’s in my view needs space around them to build up a good sound field (they use by principal front and back waves), too close to walls will likely prohibit a coherent spectrum of frequencies, resonances and reflections. ESL’s needs also quite careful positioning in the vertical and horizontal room panes (toeing in, with sometimes placement on a higher level (try a chair, it does wonders with the 57 model) or tilting of the back by which you change all the reflection angles a little). ESL’s needs in my view also enough room to deploy adequately the lower notes and to make use of the start, arrival and decay times of the back waves.

With a too big room you will have soon power problems, that’s the reason why the Quads comes with two models. Tests/reviews that I know of advises that moderate rooms (say around 40-50 sqm) are suitable and also you must not use ESL for high power presentations or disco like levels (the new Quads shut down when the output level is too high! That is not without reason, it is the border of their ability to move air without getting destructed).

When your definition of ‘realistic’ means that you want full acoustic deployment of dynamics beyond the 95-100db level, do not even think of ESL’s, no matter what kind of room. But when you are staying within adequate levels so they can produce a good musical portrait, they can deliver. Look also at 6moons site or the quad.uk site for some  additional review and advise (may be you have already done that). When your dedicated room is a little smaller you should absolutely look at the other model. I never heard it myself, but from some Dutch professional reviewers (with a preference for all kinds of classical music) the smaller one had better musical results with the smaller model than with the bigger one. The smaller one gives a more coherent sound field they say and is less prone to overpowering a room in the lows. It also comes closer to ‘less is more’. But the proof is in the pudding.

In the end I strongly advise you to look for a quality retailer that gives you the chance to try them out in your own dedicated room. Quads are like other ESL’s quite pricy instruments, so a home trial belongs to the customer service in my view.

When I was in your position I would look for a room of around 45 sqm with unequal seizes. That last thing is a general rule, not only for ESL. A (nearly) square room or pne that is too narrow but long gives all kinds of unwanted resonances, especially in the (mid-)lows and lower bass.

You should also look for a room where the short side wall are more or less symmetrical (for the processing of the back waves and the left/right balance so that staging not becomes a problem), the long side walls are not too different qua acoustic attributes (e.g. not a very absorbent wall at the left and an all glass or concrete wall at the right without any curtains, the ceiling/floor should have also some different material.  The last can with a carpet on a rather stiff floor or with a wooden floor with some loose carpet(-s). The last solution gives you some flexibility in manipulation of reflections while preserving the liveliness of the room. Put some furniture in the room, not too much, start with experiments with some wall ornaments or curtains (all (re-)movable, only a small lamp at the ceiling (I learned my lesson). When you have a loose parketfloor, you have to fully decouple the ESl's, otherwise you create a situation where your whole floor acts like a resonant pannel! You need little imagination to point to the audible consequences.

Avoid a room with a ceiling that has only a function to hide the real ceiling because that kind of ceilings (with their empty caves) give very weird and unwanted acoustical results, the same is the case with very thin and acoustical nearly transparent sidewalls, some frequencies will simply pass trough and will not be reflected in a desired way (you will have only some kind of music in the other room!).

Your listening chair should be easily moved on the ax in the middle of the room, function is just to find out what the most preferable distance is relative to the position of speakers and front/back walls. From this rather basic start point you can start with your audio journey.

Prepare the room temporarily with a simple two way speaker on stands used in the rig that is buildup with a very good source, no DSP at all, no power line measures/tweaks for the moment, normal adequate IC/speaker cable (preferable as short as convenient). Start to use the Pass Labs, ESL’s loves Class A amps with good power supplies and stable voltage management. When those amps are electronically OK than I expect that they are a very good starting point. You can win more in my view at the side of the source/preamp and inroom/position manipulation/tweaking than with another high end amp is my humble expectation. This preparation is necessary because otherwise you listen to the Quads in a very sub optimal situation to begin with.

When this start combination functions at their top let than the Quads come in. Try both models out in the same electronic and room setup, so you can compare the initial results and explore your taste with respect to the performance of the Quads in real audio circumstances (a storeroom is the least situation to determine the qualities of speakers in my view, you simply can not project that in store behavior to how they will perform in your own dedicated room).

May be you should also give the Quad setup a try out in your living room, just as reference, it gives you also some feedback around the results in the dedicated room. When you have the Quads for several days on trial place them for a start at minimal 1 m from the back and 1,5 m from the side, toe them in a little. From there start your own track choices. After you have familiarized with this setup start with fine tuning. All ESL’s, the Quads also, are vulnerable to placement in the room (in my experience more than dynamic based multi systems). A little experiment can do wonders, take your time and you will be rewarded. The fine tuning can at best be executed with someone who can helps you so that one person can stay in the listening position while the other moves the speakers or some objects that can influence the mix of reflections and resonances. Mostly a couple of cm back or forth, a little less or more space between the speakers, some more toe in or some replacing of wall treatment is enough to get everything at its place. 

Oh, one last remark with respect to your dedicated audio room. When a suitable seized dedicated room is too ambitious I strongly advise you to explore the possibility to integrate an ESL based setup in your living room (and use a high quality dynamic based two way system in your smaller dedicated room, those systems  are more simply to integrate and a little more forgiving in my view in that room situation).

With respect to ‘something that can match my Stax headphones’: well this is a difficult one, because headphone listening is principally something else because you cutt off all acoustic influences and problems of a room radically and you listen from a totally other much more closed in perspective to a recording, also much less forgiving for little shortcomings in system synergy. In fact you listen with some kind of a magnifier very directly into the captured sounds on the recording. I see the differences as two totally different ways to explore and enjoy music, each with their pro’s and con’s. When I try out a headphone/amp/source combination I use the same reference cd’s as with an in room system. Mostly I want the same kind of involvement with both ways of playing around. So a piano must sound with both instrumental concepts ‘live like’ and ‘involving’, both ways have to tell me the musical story in a way that I can create a temporarily believable musical illusion of ‘being there’.

For me this storytelling was a good time investment in ordering some processes and expiriences. I hope it will helps you in your decision making and steps in your audio journey.

When you still have questions I will try to answer them from my personal standpoint and lessons learned from some experience due to all the pitfalls in constructing my own home audio setup. I hope XXHE will soon contribute another chapter to my own journey.

Pieter.

 
For more reference information look at:
6moons (practical review of the 2905 model)
Quad.uk
Diyaudio, section ESL
Linkwitz Audio (roomacoustics)
Pass DIY (several articles that attacks some audio myths)

[SeVeReD]

Very, very good read Superdac.
quote
"A useful instrument for me personally is to clap hard in your hands in the middle of the room and at the listening position. When the direct, indirect and decayed sound is well integrated/not irritating or aggressive and repeated claps sounds natural/undistorted to your ears you are moving in the right direction to tame some of the acoustic room problems in the musical most critical area’s (the lows are another chapter). After that I use some tracks with well known soprano aria’s (Callas/Madscenes, Schwartzkopf and Norman/Strauss) to check the acoustic balances. When those soprano’s (with all their expression, dynamics and power) sounds communicative without flutter echo’s, unnatural ss sounds and/or irritating sound levels you have another start point to go any further."

I use handclaps a lot to help build a natural sound.  Having someone (my poor daughter) walk around the room doing different types of claps (cupped/sharp only words I can think of) while you hang by the "sweet spot" was very helpful to me.
One thing I found, even with my forward shooting dynamic speakers, is that anything in the middle of the soundstage above knee height you'll hear (think tall equipment stands between the speakers), and I would think even more so with an ESL.  That goes for stuff on the wall behind the speakers.  I have my equipment basically on the floor using "Brightstar sand boxes w/ 1" acrylic platforms" and butcher blocks.

Room acoustics and where you place stuff is very important!  I once had a person come over to my house who owned the same speakers as I do.  He wanted me to come over to see if I could help him achieve the same musical presentation I had.  He was sure he just needed to buy another amp or something of the sort.  He had the left speaker firing into a couch on the side wall no more than 5 feet from the speaker!!1  When I told him that there was no way he was going to get a balanced presentation as long as that couch was there ... well he just didn't really listen, insisting his wife had to have the couch there, and going back to talking about equipment changes... I told him, I'm sorry, but I couldn't help him.

[superdac]

Severed: Thanks for your kind words.

I fully agree with your statements that a good presentation is something that can only be achieved with changing room/speaker interaction/placing. A common pittfall is bying new equipment and/or cables (mostly heavier components, more power, nicer outlooks, more pricy etc) to solve some problem that lies elsewhere. Many high end retailers and equipment reviewers stimulate this kind of uncertainties and lack of insight so that dollars, euro's and pounds roll their way. I myself fall into several pittfalls of the same kind, lessons learned I now try to achieve better results with less costly means. Many 'good' but a bit older components have hidden qualities, I believe.

In my little hobbyroom (14 sqm) I experimented with decoupling of some two way systems, in combination with an old but very good cambridge cd player and an integrated little tube amp (pp, only 8w max). At first a rather mediocre result, nothing special. But decoupling those two way speakers and the complete frontend by using some natural corc discs and alluminium coins gave much better results. I also have decoupled the hanging lamp at the ceiling! I exchanged it for a flat plafoniere. Only because that original thing in the middle of the ceiling and in the midds of the soundstream just above the listening position gaves some strange echo effects, discouvered by accident, but afterwards quite logical. Lesson: experiment with changing object or with cheap ready available materials (your local stores for rebuilding houses gives many opportunities for next to nothing compared to the absurd pricing of the so called Hifi solutions).

The trick in my case is/was in my view to isolate/decouple unwanted resonances between 'hard materials' trough interuption by way of using different contact materials with totally different resonance caractaristics. From relative hard material into a strong metal point into relative soft but stable natural cork to hard material. The natural corc discs were made from those disc you use for isolating glases from moist vulnarable wood. Every household store or Ikea has them. Blue Tack (a kind of soft rubberisch material) is also a very interesting isolation material to break resonance paterns, an old trick by the way not invented by me.  May be you already have experimented at some places in you system with this kind of materials, if not I advise you to do it. I found the results great fun. More so because it is no voodoo, it is repeatable and demonstratable to the unknown.

I want also to comment on your remark about your little daugther. She is not 'poor' in my view. You give here a great role in the audio scene, I expect she loves it to play that role. I find it an interesting way to integrate education/paternal attention and looking for progress in an audio hobby. She learns at very early stage to enjoy music replay and sees what instrumentally is needed to arrange in the room to do it the right way. My own children has grown up with my audiohobby (also the deploying of some mad things!!) and get at a early stage familiar with the actions to arrange quality music in the living room. It has payed them dividend in their later lives, they both love good music replay without expiriencing much real concert (no funds for that at that time) and they were much ahead of their peers at school.

Pieter

[manisandher]

Hi guys,

I need more time to respond to Pieter's post in the way I'd like. But for now, thanks for all your insights Pieter - really interesting (and sensible) stuff...

Mani.

PS. I'm very familiar with the magical properties of Blue-tack!