I love my new Eve Audio SC 207 speakers that I’ve had for about six months now. Eve Audio is no stranger to unique technologies. Their bass port and passive radiator design are part of the unique design elements they have developed, and part of what makes their speakers sound as good as they do. I’m still impressed at the low end I get from these 7” woofers!
However, their tweeters are also unusual. They are not like the tweeters we see on most other studio monitors. It seems like tweeter technology has come a very long way from the old days of putting a piece of tissue paper across your old NS 10 tweeters to tame the sharp, high end!
Eve Audio tweeters look different and sound fantastic. I decided to ask EVE Audio CEO Roland Stenz about them. It’s fascinating learning how far the technology in these speakers has come. Following are some of the answers he has offered explaining their unique tweeter technology:
Eli: What is the main difference between your tweeters and all the rest?
Roland: EVE Audio is one of few companies using air motion transformer technology to reproduce high frequencies. We decided to develop a new range of air motion transformers for the entire speaker range of EVE Audio.
Eli: What exactly is an air motion transformer?
Roland: It’s a significant disadvantage of a “normal“ dome tweeter that the voice coil is connected only to the surrounding of the dome tweeter diaphragm. The connection causes a lot of resonances and partial oscillations in the dome tweeter diaphragm. The principle of an air motion transformer is different. A very light folded diaphragm is thinly coated with aluminium where the current of the music signal goes through. We place the folded diaphragm in a powerful magnetic field. In result, the walls of each single fold work against each other and the air between the folds is squeezed in and out in a ratio 1:4 (instead of 1:1 as a regular dome tweeter provides). You can say the diaphragm is the motor itself. This better control leads to more resolution and dynamics in the tweeter section combined with a very low distortion level.
Eli: Do all your speakers use this same air motion transformer system?
Roland: EVE Audio has developed three different types of air motion transformers. They are different in construction and most importantly in frequency range they serve and maximum sound pressure level.
The smallest one we call µAMT is only used in our desktop loudspeaker SC203. As a desktop system, this the smallest speaker in our range and consequently it needed a very compact tweeter design. That’s why we had to re-think the existing Air Motion transformer and come up with a very compact design of all components and parts of that tweeter. The crossover frequency is 4800 Hz, because of the combination with a small 3“ woofer.
Eli: That seems like a pretty high crossover point. What about your larger speakers?
Roland: From our SC204 to SC408 all monitors are equipped with our tweeter RS1, RS2 or RS3. These are the tweeter models EVE Audio developed first.
They house a powerful single magnet and a larger diaphragm to achieve more sound pressure level combined with a broader frequency range. For design and aesthetic reasons, only the surface plate differs size-wise between the different speaker models and is the reason for having RS1, RS2 and RS3 tweeters developed. In combination with 7“ or 8“ woofers those tweeter’s crossover frequencies are lower than the one from our µAMT and are used in our 2-way, 3-way and 4-way monitors.
Also, last but not least our main monitors SC3010 and SC3012 are equipped with the largest Air Motion transformer available we call RS6. In this construction, the magnetic system and size of the diaphragm is very different in comparison to the other Air Motion tweeters. These RS6 tweeters allow a much lower crossover frequency between midrange driver and tweeter. In our case, it is 1800 Hz. That has a very positive impact also on the mid-frequency range – which is very important for voices - for example where we achieve a better resolution with those tweeters. The need for low distortion is also the case for higher sound pressure levels in main monitors and another reason for a larger air motion transformer. These RS6 tweeters are hand made in the Berlin EVE Audio factory.
Eli: So, it seems like a very mature technology; with different sizes optimised for the different models. It’s interesting to take a look behind the curtain and learn a little bit more about how the magic happens. Thank you, Roland, for taking the time to explain how this unique and fantastic sounding technology works!
Roland: You’re welcome, and thank you for asking about this.
Check out the Eve Audio homepage to learn more about their line of studio monitors.