Is there a "Martin Logan sound?"

[MtBiker]

I was hoping that some people familiar with Martin Logans could weigh in with their opinions or critique my logic. I have a pair of Martin Logan Clarity's on indefinite loan and am not a fan of their sound. The speakers I have to compare them to measure flat, but they clearly (pun intended) do not have the same detail or low distortion as the ESLs. However, the tonal balance of the ESLs seems to be very, very (VERY) far off. So far off, that even my wife cannot stand to watch TV with the ESLs, because the volume has to be cranked in order to simply understand speech on every channel and in every circumstance.

I have more amplifier power than I need, and there is plenty of breathing room around the speakers in all directions. This leads me to conclude that there is one of two problems here:

1. A high crossover point between a dipole and a monopole just below the baffle step is a bad idea.
2. A short panel that operates as a line array at high frequencies and as a point source just before crossing over is a bad idea.

They may have already employed some clever equalization, but by blending radiation patterns in two stupid ways, the speakers might still only sound good at a specific distance. This could also be related to the fact that when I auditioned a range of Martin Logans years ago, I really only liked their largest ones at the time. It may have been the long line or the lower crossover point, or...

[bolserst]

Originally Posted by MtBiker

... the tonal balance of the ESLs seems to be very, very (VERY) far off. So far off, that even my wife cannot stand to watch TV with the ESLs, because the volume has to be cranked in order to simply understand speech on every channel and in every circumstance.

Two questions:

1) What exactly do you mean by tonal balance being off? Do you mean that the highs coming from the ESL seem to be much quieter than the mids & lows coming from the woofer? If so, perhaps the ESL portion has lost some sensitivity due to loss of coating or leakage in the spacer insulation. I hate to ask, but you do have the AC power cords plugged in and turned on right?

2) What makes it difficult to understand? Is it just quiet? or do the voices sound diffuse and phasey? MLs tend to be quite sensitive, so getting them to play loud shouldn't be a problem. If the voices sound diffuse, perhaps one of the ESLs has been hooked up out of phase with the other? Standing 8-10 feet back from the speakers and midway between them you should get a rock solid tangible image of voices midway between the speakers.

[MtBiker]

Unfortunately, they have gotten moved into a different room with no TV, so I can't compare them to my reference, although I thought I had paid close attention to polarity. And of course, they sound fine playing simple, quite music where they are now. The current room is very live, so anything loud or compressed is painful in there with any speaker, but you need a very full sound in order to pinpoint any holes. So, I will have to get them back downstairs to A/B again with careful attention to polarity.

The problem I experienced before was similar to the first speakers I built, not knowing about the baffle step and wondering why it sounded like someone was playing a joke on me with an EQ. In this case, it sounds forward but without making speech very articulate. I took some near/far-field measurements of the panel, woofer, and port, and tried merging at the (published) 450Hz crossover point. It doesn't look good, but that doesn't mean my technique wasn't fundamentally flawed.

Woofer nearfield and panel at 36"


Panel nearfield, vertically/horizontally centered


Sanity check at 18" centered on panel

[bolserst]

Originally Posted by MtBiker

Unfortunately, they have gotten moved into a different room with no TV, so I can't compare them to my reference, although I thought I had paid close attention to polarity. And of course, they sound fine playing simple, quite music where they are now. The current room is very live, so anything loud or compressed is painful in there with any speaker, but you need a very full sound in order to pinpoint any holes. So, I will have to get them back downstairs to A/B again with careful attention to polarity.

The problem I experienced before was similar to the first speakers I built, not knowing about the baffle step and wondering why it sounded like someone was playing a joke on me with an EQ. In this case, it sounds forward but without making speech very articulate. I took some near/far-field measurements of the panel, woofer, and port, and tried merging at the (published) 450Hz crossover point. It doesn't look good, but that doesn't mean my technique wasn't fundamentally flawed.

Did you do any measurements at 1m - 2m with both woofer and panel playing at the same time to see if they are summing properly at crossover? (Each speaker independently tested over course) It is not unheard of for a manufacturer to accidently have one of the drivers hooked up with incorrect phase. So, instead of the ESL and woofer summing at crossover, you are left with a notch in the frequency response. If the other speaker is summing properly it may be more difficult than you might expect to pinpoint this problem while listening to music in a stereo setup. Our ears are often much more forgiving of frequency response notches.

Other than that, my only thought is perhaps room interaction problems. You mention that in the current room they are in is very live. What about the main listening room? Did it have carpeted floors, curtains etc to damp the room? Panel speakers which project out of phase sound rearward can be more difficult to place in a room. Further away from rear walls and angled in toward the listening area usually helps.

Hopefully someone that is more familiar with the ML products will chime in.

One final thought....do you have a large flat screen TV in between the speakers? Could early reflections off of the large flat surface be affecting the intelligibility of voices more than your box speakers?

[Curly Woods]

Originally Posted by MtBiker

I was hoping that some people familiar with Martin Logans could weigh in with their opinions or critique my logic. I have a pair of Martin Logan Clarity's on indefinite loan and am not a fan of their sound. The speakers I have to compare them to measure flat, but they clearly (pun intended) do not have the same detail or low distortion as the ESLs. However, the tonal balance of the ESLs seems to be very, very (VERY) far off. So far off, that even my wife cannot stand to watch TV with the ESLs, because the volume has to be cranked in order to simply understand speech on every channel and in every circumstance.

Something sounds amiss somewhere. Martin-Logan's should excel with spoken word. They are so transparent in their sound that even the smallest details should shine thru without effort. The tonal balance can sound "thin" sometimes (lack of lower midrange heft to many), but they should be exceptional clear in their sound. Not sure what it is as I nor anyone can hear them in your room, but there must be something serious amiss somewhere in the speaker to be having the problem that you are describing here.

.

[Curly Woods]

What amplifier are you using? It would possibly help :-)

[wirewiggler]

Interesting, I just picked up a pair of Martin Logan Aeoni and have them in the living room with the TV. They are kind of worst case scenario my living room has a pocket for the tv and they set in it next to the walls but they sound remarkably clear. Spoken work is easily discerned. When I pull them out and give them some air there is great improvement on sound stage and image. Some amps do not like the load put on them by ESLs and sometimes an inductor can help this. This is what AMD on Headwise recommended
" Take a length of 16AWG magnet wire and wrap it tightly (single-layer) around a 13mm diameter round rod for about 15 turns, so that the total coiled length is about 20mm. Then scrape off the insulation on each end, insert a 1 ohm 5W metal-oxide resistor into the center and solder it in parallel with the coil. Use one of these in series with each active output. "
Though I have not used it as my amp is happy down to 2 ohms.

Bill

[peranders]

I have a ML SL3 but they are a but wider? I like them although I thought the model above sounded better but wallet had objections.

[Andersonix]

MtBiker: Perhaps you are experiencing the narrow and short sweet spot of these smaller panels? And also perhaps too much toe in or an odd setup? Also in general TV sound is too, um, messed up and inconsistent to make a useful reference.

I also have SL3 and have heard several other MLs. Overall I'd say the ML sound was determined by setup in the room and by how good is the woofer and how low is the XO. Clarity is not a good example of a typical ML, as the panel is too short, but is OK if you're right in the sweet spot.

[bolserst]

Originally Posted by Tosh

MtBiker: Perhaps you are experiencing the narrow and short sweet spot of these smaller panels?

Tosh has a very good point.
I just pulled up the specification for the ML Clarity and noticed that the ESL panel is only 26" tall. Not exactly like the line source I had envisioned based on the few MLs I had seen. This will result in a "short" vertical sweet spot, I'd say you would want to have your ears within 6"-8" of the middle of the panel for best sound. You will need to make sure the panels are angled properly(up & down) so that the middle of the panel points to your ear height when you are seated on the couch listening.

The manual also mentions that ML has tried to address the limited vertical dispersion by something they call NAC(natural ambience compensation) Basically, this is a convetional dome tweeter spraying highs upward and outward from the rear top of the enclosure to try and add some highs to the ambient room response for listeners not in the sweet spot. The manual mentions you can turn it on or off by hitting a button with a pen or pencil.

I wonder if this is the source of your problem....did you try turn on/off the NAC?