@Torq That is a really interesting point and I have to agree with you on that. From a standpoint on scaling down these drivers, when we look at the X and Y dimensions being reduced, we can expect that the stiffness of the membranes increases as the driver becomes smaller. In a sense, the dynamic driver does become like a piston as you have mentioned. However, another aspect which has to be considered is the shape of the dynamic driver, which is normally a “cone” shape. As the stiffness of the membrane increases, the more “cone-like” the driver also becomes, possibly introducing distortion to the sound. In a full sized driver, this cone effect is not as significant, as the membrane is relatively flexible in comparison to the size of the driver. Of course, the membrane can be made thinner in a dynamic driver, but there is a limit to how thin it can go before it starts deforming under its own, or the weight of the coil attached, as there is relatively little tension to the membrane. The sound produced by a cone vibrating would not be the same as that of a planar membrane. Our philosophy is to use a planar membrane without any additional surface geometry in order to produce sound that is as distortion free as possible. However, I would have to admit that we don’t have enough data as of yet to conclusively prove performance superiority and… this is a new driver we are developing as well, so there is still finetuning to be done. Now that you have mentioned this, it will definitely be on my to do list, for a head to head comparison of the existing drivers vs a planar IEM driver.
@Resolve Yes that is a good observation and these “peaks” are one of the challenges which we have faced in the engineering of our own planar IEM driver. Similar as to what I have mentioned above, when scaling down these drivers, the tension across the membrane also increases and the dampening characteristics of the driver also changes. This is because not only the membrane, but the effect of the frame on the membrane is also intensified when the driver is made smaller. Simply put, these drivers will become “over dampened” as compared to their full sized counterparts. What we have observed is that, we are not hearing a 3-5 Khz peak for example, but rather all the other frequencies have been dampened such that the 3-5 Khz region becomes revealed a “peak”. Therefore, in my humble opinion, chasing ways to reduce these peaks is chasing the wrong approach. Rather, the solution is to look into ways to relieve this tensioning and dampening issue… which is the philosophy that I have adopted and I am looking into ways in which to reduce this dampening issue so as to have a sound signature without harsh peaks. I think that planar IEM tech is still in its beginning stages and definitely more can be done to improve it.
@antdroid I am a planar lover myself and I am really happy to hear that there is more interest in this area and more companies throwing their hat into the game. Being located in Singapore, I have heard of Senfer and Toneking (but not yet have the pleasure of testing them). One thing that strikes me is that these designs are still open and semi-open, meaning that there will be an element of outside noise disrupting your listening experience. As a personal preference, I do like closed IEMs more (maybe because Singapore is a really crowded place…) and hope that more closed planar IEMs do get developed. It is for this reason that the IEMs we are developing are also closed planars. Of course, the closed design does bring about many other challenges.