Why Do Martin Logan Speakers Lack Dynamic Energy?


Martin Logan speakers have a huge open soundstage, vivid midrange and excellent detail, better than some of the best speakers in the world.

The only thing that most Martin Logan speakers lack in their respective price range is dynamic energy. What I mean by dynamic energy is sonic weight, mid-bass slam and movement of air that only cone drivers seem to produce (unless you're talking about the Martin Logan Statements). Speakers like Wilson, Revel or Aerial Acoustics have great dynamic energy, so why can't Martin Logan build a speaker cheaper than $80,000 that has it too?
mab
Electrostatics, planars and ribbons drivers have much less mass than cone/piston drivers and as a result electrostatics can respond to the input signal much more quickly than piston speakers. In general stats also don't exhibit the same level of dynamic compression as piston drivers. It's actually easy to see how some people might interpret stats' quick transient response and the lack of dynamic compression as a flaw. If you want to add more dynamic punch to a stat then simply add an outboard compressor/limiter to gently squash the signal's transients to mimic the behavoir of a typical cone based speaker.
Several possibilities come to mind that might have a bearing on what you're experiencing.

First, the differing radiation characteristics of point-source woofers and line-source panels means that their integration is somewhat distance-dependent. The sound pressure level from the panels rolls off more slowly with distance than it does for the woofers. So if the room is too large for that particular pair of Martin Logans, the bass and midbass energy will be lacking.

Second, some earlier model Martin Logans had a response dip in the crossover region (ballpark 200-300 Hz) that would result in a lack of lower midrange energy.

Third, electrostats in general are extremely demanding of associated amplification, and the Martin Logans are no exception. From my own experience with Sound Lab electrostats, I can tell you that choice of amplification makes a huge difference in dynamic contrast and liveliness.

Fourth, it is possible that the dynamic compression characteristics of the woofer and panel are very different. The primary source of woofer compression is thermal compression, while the primary source of compression in the panels is probaly transformer saturation, which does not set in until you reach a very high input level. So what may happen is the woofer compresses more than the panel does up until the point where the panel compresses severely. I frankly do not know if this situation applies to the Martin Logans - I'm only mentioning it as a possibility in a dynamic/electrostatic hybrid.

Ahem... also, ah... at the risk of coming across as somewhat self-serving, I can think of at least one large, full-range electrostat that has good weight and body in the midbass region...

Cheers,

Duke
Dynamics is a function of moving air rapidly. Your perception is correct. I too had the same concern--I also own a pair of Monoliths that have been modified (a lot).

First, a large planar such as a monolith can absolutely move a lot of air rapidly, however, you have to look at how it's focused to the listener. Fact is--it's not. The room can be designed to specifically account for this and focus the back wave kinetic energy towards the listener--thereby increasing the dynamics. However, what happens to the bass--nothing in that scenario. This has been one of the main difficulties with hybrids. They have the so called promise of "dynamics of a full dynamic speaker transparency of an electrostatic", but in general don't deliver.

One of the problems is cost. The basic issue can be overcome and has been proven with the Statement--but $80k--well it better do just about everything perfect and paint my house too.

Before I get into methods to overcome, you should probably just consider the very basic issue here first. Dynamics are perceived by kinetic air movement focused at the listener--it's that simple. What focuses energy at the listener best? A horn. What focuses energy the least? A planar, and particularly one that is curvilinear spreading out the energy to all directions.

Let's say both a horn and a planar can deliver the same amount of air movement for 1 watt of power, but the horn is focused, where as the planar is not. Let's say the room has no losses--all energy gets to the listener (eventually). What is the perception--it hasn't changed. The direct energy of the horn is very dynamic. The indirect and more diffuse sound field of the planar is far less dynamic, but to a large degree more etherial. Many of us like this room interaction that gives us a sense of space and imagery. I personally like it, and although I've owned horns--I am willing to sacrifice the dynamics for the transparency and imaging.

Now on to what can be done. ML uses woofers that integrate will with their speakers and don't cost obscene amounts of money. As I said previously--I modified mine. The panel was fabulous--the bass wasn't. It was slow and undefined and did not give me the dynamics I wanted in the lower octaves. So I changed it--it's not so simple. I had to bi-amp with an active cross over that was pretty flexible and bipass the internal cross over. The engineers at ML were kind enough to help me with the loading of the new woofers which were Focal Audiom. The results were spectacular--but as the saying goes "don't try this at home".