James has given permission to me to quote him on his recent purchase of the CLX. He was so impressed by them during the recent Montreal Audio Show in April that he decided to get a pair for himself. here are his thoughts:
Martin Logan CLX Review
I purchased these speakers after being exposed to them at the 2009 Montreal Audio Show in the Bryston/Martin Logan Room hosted by our dealer Son Ideal. They sounded terrific at the show and I already own the Quad 2905's and felt it would be a great time to compare two of the best of the current electrostatic speakers out there. I will not bore you with all the descriptive technical stuff - suffice it to say it's all available online - http://www.us.martinlogan.com/speaker_intro/clx.html
First off, different speaker technologies sound different to me. Line Sources, Point Sources, Omni, Planar, etc. all present a different perspective due to their specific radiation pattern and room interface issues. Also I find that the specific driver material used in a speaker imparts a particular sound characteristic that rides on the music. I set the speakers up in listening room 3, which is a 16 by 23 by 8-foot room. I have listened to the Quad 2905's, the Magneplaner MG20's, the Thiel 3.7's, the JBL 1400 Array's, the Magneplaner MG3.6 and 1.6's and the PMC IB2's and MB2's in this room over the last few years.
The CLX's needs serious break in time. The manufacturer suggests a minimum of 100 hours at 90dB (which is fairly loud). I assume it is to allow the compliance of the panels to acclimatize and the crossover components to settle in. I found the sound changed a lot during this burn in period and I would not recommend any critical listening or positioning efforts before hand. In fact I am in to 200 plus hours now and they're still changing!
The CLX's are a 'dipole' design that radiate in a figure '8' (eight) pattern. The CLX though has a small twist on this because the midrange/tweeter panel is curved so its radiate pattern deviates a little from the traditional dipole polar response. Large planer speakers tend to suffer from what is call the 'venetian blind' effect which is to say there are holes in the sound-field created by the fact that the different size drivers in the planer speaker start to constrict their polar response as the frequency goes up. So in other words, as the woofer driver in the panel gets near the top of its frequency range - lets say 300Hz - the on and off axis response starts to 'beam' a little. That's why the goal with any multi-driver speaker is to try and prevent these changes in polar response from interacting in a negative way as one specific driver transitions to another (woofer to mid --- mid to tweeter etc.).
In the CLX the curved mid/tweeter driver, which operates from 360Hz and up, does not exhibit the typical beaming that most panel speakers have and acts more like a line-source than a dipole. In fact I measured the polar response of the mid/tweeter panel and it is very flat and uniform over about a 60-degree arc. So the side wall reflection becomes more of an issue with the curved mid/tweeter than it would be with a typical dipole but the smooth dispersion available from the cylindrical mid/tweeter driver is a big plus. The bass panel measured down to about 40Hz in my room with reasonable output - which is very good for a full range electrostatic speaker.
Set-up:
OK let's get to the set-up. Being a dipole over most of its range means the back wave from the speaker has to be taken seriously. The manufacturer recommends placing the speaker 4 feet from the front wall and 2 feet from the sidewalls with the mid/tweeter panels on the inside and angled so that you're listening to the inner 1/3rd of the mid/tweeter panel. I tried them on the outside but the image was way to diffuse. I suspect the reason placement 4 to 5 feet from the front wall is recommended is because it nulls out a front wall boundary frequency bump.
Also one of the main issues with the back wave from any dipole is the dreaded 'haas effect'. The ear will 'integrate' the first arriving sound with an early arriving sound if the early arriving sound is within 10-15ms from the first arriving sound. This prevents the ability of the ear/brain to differentiate which is the first arriving sound and which is the first reflection. In a good concert hall in row 12 center the arrival time of the first reflection will exceed 100ms. So if your early reflection in your listening room falls below 8-10ms your soundstage goes to pot. Also early arriving sounds can affect the level of the perceived sound as well. Some people are bothered by this 'hass effect' more than others but generally most audio people feel a delay of somewhere around 8ms or more is a good place to start when setting up your speakers if image placement and focus is important to you. So in the case of the CLX's the 4 foot distance from the rear wall means about 8ms of delay in the sound bouncing of the rear wall and reaching your ears at the listening position. Sound travels at approximately 1 foot per ms so 4 feet back and 4 feet forward means a delay of 8 milliseconds from your listening position. 5 Feet would give you 10 milliseconds and so on.
I had been using point source speakers in my room prior to getting the CLX's so I had to fiddle around a fair bit to get the soundstage dialled in. I added some absorption ( 4 inch foam) on the front wall (not too much though). Relative to a point source the CLX's image is still more diffused and images are a little larger and less defined. An important point to remember here is that all of these observations are in MY ROOM (16x23x8). A different room will exhibit different results but I think the comparison between a point source and a dipole/linesource would still apply in a relative sense. I ended up sitting 10 feet from the speakers with the speakers 8 feet apart (edge to edge) 4.5 feet from the front wall and 2 feet from the side wall and angled in about 15-degrees. This gave me the best soundstage with the maximum amount of width.
James Tanner
V/P Bryston
Second part:
How's it sound:
Electrostatics do have a sound of their own (as do all speakers in my opinion), which I think is a function of the materials used in the drivers, the polar response and the way they 'pressurize' a given room. The sound from an electrostatic is softer and more delicate. I have owned a number of electrostatics and other panels over the years and they all exhibit a kind of 'credit card' or 'etched' quality in their sound (Mylar?). It is something that you feel enhances the listening experience of detracts from it - depends on the particular listener. The sound can appear very very detailed at first but over time may begin to sound a little chiselled. The CLX's have some of this and there is a kind of 'sssshhhh or raspy-ness' to the sound at times but certainly no more than any other electrostatic speaker I have heard.
I find the CLX's provide a deep soundstage at the expense of a wide soundstage (again relative to a point source in the same room). The soundstage extends back and out from the plane of the speakers. It does not project the sound at you like a horn system would for instance. The ability of the CLX's to project images beyond the sides of the speaker will be very much dependent on the particular recording and the size of your listening room. My guess is that having to position the mid/tweeter panel at the recommended '1/3rd' position and on the 'inside' limits the amount of distance you can spread the speakers apart before you start to lose your center image. A lot of images outside a speaker are artificial in that they are in actuality very strong early reflections from the sidewalls and not part of the actual recording. Speakers that have very strong off-axis response can appear to have a more expanded soundstage by using the side walls to reinforce the off axis energy so that a strong phantom image appears along the side wall. One of the things that all speakers do is 'couple' to themselves based on the distance thy are apart from each other. There can be as much as an 8dB reinforcement of the energy in the 80-250Hz region if the speakers are very close to one another. By manipulating the distance between your front stereo speakers you can vary the amount of mid-bass in the room (further apart less mid-bass - closer together more mid-bass). So with the CLX's your trying to maximize the power range between 80 and 300Hz as well as optimize the image placement and soundstage size as you play with their position in the room.
The CLX's do not have the intensity in the so-called 'power range' to the same degree as more traditional dynamic speakers. Most panel speakers tend to sound a little 'lean' through this frequency region. The CLX's have less of this thinness than any other electrostatic I have heard. There really is a sense of fullness and body to the sound that helps make the speaker sound much more tonally palatable. If you push the speaker too hard though it starts to loose this balance but if used at reasonable listen levels it is very well controlled indeed.
Where the CLX shines is the dynamic range it is capable of. For an electrostatic it is truly outstanding! They claim the efficiency is 90dB and I believe it. I played some Yello and I could not believe how loud I could play it without feeling like the speaker was being stressed. Don't get me wrong - it's not in the league of a big dynamic or horn speaker but it leaves other electrostatics I am aware of in the dust. If you over do it the speaker will start to sound 2-dimensional with constricted dynamics. Within a reasonable power range though it really does have a 'kick' to it that the Quads can only admire. If your listening tastes flow more towards full range large scale classics, heavy metal or movie sound tracks then the CLX's may not be your cup of tea. If your tastes are more light classics, jazz, folk rock and pop then the CLX's are exceptional. Voices are really superb and there is no sense of hardness to the sound as you turn it up. Strings are excellent and trumpet and sax are to die for. Going from 'soft to loud' is as good as I have heard in most speakers and better than any other electrostatic I am aware of assuming you do not push past their dynamic limits of course.
Subs?:
I tried the CLX's with a pair of powered subs I had available and it was a frustrating experience to say the least. I felt I could 'flesh out' the sound a little on the bottom octaves (below 60Hz) but it seemed to throw off the coherency and speed of the panel on it's own. I ended up scrapping the sub idea and continued listening to the bare panels. Again if your looking at a home theatre setup or high sound pressure levels then the sub(s) will certainly provide a more robust sound then the panels can on their own. To some degree I think 'sub or no sub' will be the salient point for most people when it comes to the CLX's. The ability to use and integrate a subwoofer will be mandatory for some and irrelevant for others. Martin Logan has a sub dedicated to the CLX's so that may be my next move. One of the problems is that even though you insert a sub that helps add body to the very low frequencies (60 to 20Hz) integrating it with the power response of the panel between 60 and 300Hz is a problem not easily solved.
As the CLX's have broken in I have become more and more taken with their ability to sound natural, detailed and dynamic beyond any other electrostatic I have ever owned. They are a great tool for discerning what is going on in the rest of the signal chain and are a real plus for someone like myself that spends countless hours listening and discerning differences between audio components. I am looking forward to discovering more sonic nuances as I continue to listen through them.
James Tanner
Bryston
Martin Logan CLX Review
I purchased these speakers after being exposed to them at the 2009 Montreal Audio Show in the Bryston/Martin Logan Room hosted by our dealer Son Ideal. They sounded terrific at the show and I already own the Quad 2905's and felt it would be a great time to compare two of the best of the current electrostatic speakers out there. I will not bore you with all the descriptive technical stuff - suffice it to say it's all available online - http://www.us.martinlogan.com/speaker_intro/clx.html
First off, different speaker technologies sound different to me. Line Sources, Point Sources, Omni, Planar, etc. all present a different perspective due to their specific radiation pattern and room interface issues. Also I find that the specific driver material used in a speaker imparts a particular sound characteristic that rides on the music. I set the speakers up in listening room 3, which is a 16 by 23 by 8-foot room. I have listened to the Quad 2905's, the Magneplaner MG20's, the Thiel 3.7's, the JBL 1400 Array's, the Magneplaner MG3.6 and 1.6's and the PMC IB2's and MB2's in this room over the last few years.
The CLX's needs serious break in time. The manufacturer suggests a minimum of 100 hours at 90dB (which is fairly loud). I assume it is to allow the compliance of the panels to acclimatize and the crossover components to settle in. I found the sound changed a lot during this burn in period and I would not recommend any critical listening or positioning efforts before hand. In fact I am in to 200 plus hours now and they're still changing!
The CLX's are a 'dipole' design that radiate in a figure '8' (eight) pattern. The CLX though has a small twist on this because the midrange/tweeter panel is curved so its radiate pattern deviates a little from the traditional dipole polar response. Large planer speakers tend to suffer from what is call the 'venetian blind' effect which is to say there are holes in the sound-field created by the fact that the different size drivers in the planer speaker start to constrict their polar response as the frequency goes up. So in other words, as the woofer driver in the panel gets near the top of its frequency range - lets say 300Hz - the on and off axis response starts to 'beam' a little. That's why the goal with any multi-driver speaker is to try and prevent these changes in polar response from interacting in a negative way as one specific driver transitions to another (woofer to mid --- mid to tweeter etc.).
In the CLX the curved mid/tweeter driver, which operates from 360Hz and up, does not exhibit the typical beaming that most panel speakers have and acts more like a line-source than a dipole. In fact I measured the polar response of the mid/tweeter panel and it is very flat and uniform over about a 60-degree arc. So the side wall reflection becomes more of an issue with the curved mid/tweeter than it would be with a typical dipole but the smooth dispersion available from the cylindrical mid/tweeter driver is a big plus. The bass panel measured down to about 40Hz in my room with reasonable output - which is very good for a full range electrostatic speaker.
Set-up:
OK let's get to the set-up. Being a dipole over most of its range means the back wave from the speaker has to be taken seriously. The manufacturer recommends placing the speaker 4 feet from the front wall and 2 feet from the sidewalls with the mid/tweeter panels on the inside and angled so that you're listening to the inner 1/3rd of the mid/tweeter panel. I tried them on the outside but the image was way to diffuse. I suspect the reason placement 4 to 5 feet from the front wall is recommended is because it nulls out a front wall boundary frequency bump.
Also one of the main issues with the back wave from any dipole is the dreaded 'haas effect'. The ear will 'integrate' the first arriving sound with an early arriving sound if the early arriving sound is within 10-15ms from the first arriving sound. This prevents the ability of the ear/brain to differentiate which is the first arriving sound and which is the first reflection. In a good concert hall in row 12 center the arrival time of the first reflection will exceed 100ms. So if your early reflection in your listening room falls below 8-10ms your soundstage goes to pot. Also early arriving sounds can affect the level of the perceived sound as well. Some people are bothered by this 'hass effect' more than others but generally most audio people feel a delay of somewhere around 8ms or more is a good place to start when setting up your speakers if image placement and focus is important to you. So in the case of the CLX's the 4 foot distance from the rear wall means about 8ms of delay in the sound bouncing of the rear wall and reaching your ears at the listening position. Sound travels at approximately 1 foot per ms so 4 feet back and 4 feet forward means a delay of 8 milliseconds from your listening position. 5 Feet would give you 10 milliseconds and so on.
I had been using point source speakers in my room prior to getting the CLX's so I had to fiddle around a fair bit to get the soundstage dialled in. I added some absorption ( 4 inch foam) on the front wall (not too much though). Relative to a point source the CLX's image is still more diffused and images are a little larger and less defined. An important point to remember here is that all of these observations are in MY ROOM (16x23x8). A different room will exhibit different results but I think the comparison between a point source and a dipole/linesource would still apply in a relative sense. I ended up sitting 10 feet from the speakers with the speakers 8 feet apart (edge to edge) 4.5 feet from the front wall and 2 feet from the side wall and angled in about 15-degrees. This gave me the best soundstage with the maximum amount of width.
James Tanner
V/P Bryston
Second part:
How's it sound:
Electrostatics do have a sound of their own (as do all speakers in my opinion), which I think is a function of the materials used in the drivers, the polar response and the way they 'pressurize' a given room. The sound from an electrostatic is softer and more delicate. I have owned a number of electrostatics and other panels over the years and they all exhibit a kind of 'credit card' or 'etched' quality in their sound (Mylar?). It is something that you feel enhances the listening experience of detracts from it - depends on the particular listener. The sound can appear very very detailed at first but over time may begin to sound a little chiselled. The CLX's have some of this and there is a kind of 'sssshhhh or raspy-ness' to the sound at times but certainly no more than any other electrostatic speaker I have heard.
I find the CLX's provide a deep soundstage at the expense of a wide soundstage (again relative to a point source in the same room). The soundstage extends back and out from the plane of the speakers. It does not project the sound at you like a horn system would for instance. The ability of the CLX's to project images beyond the sides of the speaker will be very much dependent on the particular recording and the size of your listening room. My guess is that having to position the mid/tweeter panel at the recommended '1/3rd' position and on the 'inside' limits the amount of distance you can spread the speakers apart before you start to lose your center image. A lot of images outside a speaker are artificial in that they are in actuality very strong early reflections from the sidewalls and not part of the actual recording. Speakers that have very strong off-axis response can appear to have a more expanded soundstage by using the side walls to reinforce the off axis energy so that a strong phantom image appears along the side wall. One of the things that all speakers do is 'couple' to themselves based on the distance thy are apart from each other. There can be as much as an 8dB reinforcement of the energy in the 80-250Hz region if the speakers are very close to one another. By manipulating the distance between your front stereo speakers you can vary the amount of mid-bass in the room (further apart less mid-bass - closer together more mid-bass). So with the CLX's your trying to maximize the power range between 80 and 300Hz as well as optimize the image placement and soundstage size as you play with their position in the room.
The CLX's do not have the intensity in the so-called 'power range' to the same degree as more traditional dynamic speakers. Most panel speakers tend to sound a little 'lean' through this frequency region. The CLX's have less of this thinness than any other electrostatic I have heard. There really is a sense of fullness and body to the sound that helps make the speaker sound much more tonally palatable. If you push the speaker too hard though it starts to loose this balance but if used at reasonable listen levels it is very well controlled indeed.
Where the CLX shines is the dynamic range it is capable of. For an electrostatic it is truly outstanding! They claim the efficiency is 90dB and I believe it. I played some Yello and I could not believe how loud I could play it without feeling like the speaker was being stressed. Don't get me wrong - it's not in the league of a big dynamic or horn speaker but it leaves other electrostatics I am aware of in the dust. If you over do it the speaker will start to sound 2-dimensional with constricted dynamics. Within a reasonable power range though it really does have a 'kick' to it that the Quads can only admire. If your listening tastes flow more towards full range large scale classics, heavy metal or movie sound tracks then the CLX's may not be your cup of tea. If your tastes are more light classics, jazz, folk rock and pop then the CLX's are exceptional. Voices are really superb and there is no sense of hardness to the sound as you turn it up. Strings are excellent and trumpet and sax are to die for. Going from 'soft to loud' is as good as I have heard in most speakers and better than any other electrostatic I am aware of assuming you do not push past their dynamic limits of course.
Subs?:
I tried the CLX's with a pair of powered subs I had available and it was a frustrating experience to say the least. I felt I could 'flesh out' the sound a little on the bottom octaves (below 60Hz) but it seemed to throw off the coherency and speed of the panel on it's own. I ended up scrapping the sub idea and continued listening to the bare panels. Again if your looking at a home theatre setup or high sound pressure levels then the sub(s) will certainly provide a more robust sound then the panels can on their own. To some degree I think 'sub or no sub' will be the salient point for most people when it comes to the CLX's. The ability to use and integrate a subwoofer will be mandatory for some and irrelevant for others. Martin Logan has a sub dedicated to the CLX's so that may be my next move. One of the problems is that even though you insert a sub that helps add body to the very low frequencies (60 to 20Hz) integrating it with the power response of the panel between 60 and 300Hz is a problem not easily solved.
As the CLX's have broken in I have become more and more taken with their ability to sound natural, detailed and dynamic beyond any other electrostatic I have ever owned. They are a great tool for discerning what is going on in the rest of the signal chain and are a real plus for someone like myself that spends countless hours listening and discerning differences between audio components. I am looking forward to discovering more sonic nuances as I continue to listen through them.
James Tanner
Bryston
