CES 2017: ESS Laboratories AMT422 Headphone with Heil Air Motion Transformer

I always go to the ESS booth. I tend to fing the sounds I hear as just okay, but I'm always impressed by the unusually interesting and innovative approach to designing transducers.

For exampole they showed this Heil designed Transar speaker five years ago at the Newport show. A novel but failed product. None the less, I found its workings quite interesting. You can read more about it and see a video of it in action in my ESS report from that show.

Last year at CES I stopped by their booth and found they had a prototype headphone that used a Heil Air Motion Transformer driver. I didn't report on it at the time as it was pretty poor sounding. This time around, however, they brought a pre-production unit and it was much better. So much so that I asked for a sample when available.

Heil Air Motion Transformers are an unusual transducer. The driver itself looks like a ribbon folded like the pleats of an accordion, which is placed in a magnetic field in such a way that as the audio current is passed through the ribbon, the pleats squeeze together and are pushed apart depending upon the signal applied. It's a little counterintuitive, here's the Wikipedia page to explain.

The new ESS AMT422 (~$550) is a full sized, sealed headphone. It expected to be available in Marcha and will come in a light and dark color scheme.

luvmusik's picture

Posted to please review these in the thread "Review Request" here on IF.

These appear to have wood backs and a single Heil AMT folded ribbon driver. The earlier prototype in 2015 was I think a hybrid arrangement of the same Heil with a dynamic driver, maybe ? Not sure.

ESS did make a Heil headphone, single driver, back in 1976 model called - ESS Mark I Heil Air-Motion Transformer Stereophones (AMT). They either had a 1/4" plug end(fotos I saw)or ran off the back speaker outs of a loudspeaker amplifier (per a different owner), and were rare, but lacked bass. I think they were open-back and noticeably had a large Y-yoke metal piece holding the very large oblong (? plastic ?) cups. I think the frequency response rolled off on both ends. Have only seen fotos of 1 set of these, owned by the Heil family. May not have been just a single prototype, because fotos of the retail box were also shown and are up on head-fi.

Interested to read about the brand new ones, and if closed back, should have good bass just considering frequency response only.

PDC3's picture

I've been a fan of Heil-like tweeters in Adam Audio and particularly Emotiva powered monitors & passive speakers. To me, they climb as high as needed yet avoid a shrillness that I think of as "metallic." Emotiva does this at price points lower than I'd expect for that level of quality, although I doubt that's all due to one transducer. Still, I'm a happy fan. Looking forward to your review.

EdAInWestOC's picture

I remember this because it was a visit to a high end store for the specific purpose of auditioning the original ESS AMT-1 floor standing speaker and this visit led me to my long time love of planar and estat speakers/headphones.

The dealer in question had multiple rooms setup along one wall of the facility. At that time, the ESS AMT-1 were the darling of Stereo Review and there was all kinds of talk about how great the AMT approach was. I was not impressed with the AMT-1 but something in the next room sound caught my attention.

The sound from next door was very transparent, fast and almost lifelike. The speakers were the Infinity 2000A hybrid electrostatic speakers. The ESS AMT-1 was very sad when compared to the Infinity speakers and the 2000As were not exactly perfect speakers.

My memory is a bit foggy but I seem to remember the problem with the AMT driver was the relatively high moving mass due to the multiple folds of the tweeter. I seem to remember someone pointing out the slow transients of the original AMT driver and the problem with the tweeter dealing with complex musical passages.

My impression of the original AMT-1s was not very favorable. I thought they were a vague and muffled sounding speaker. There was no point of doing a detailed comparison of the AMT-1 vs the Infinity 2000A. It was like someone threw a wet towel over the speaker when listening to the AMT-1.

It wasn't a wasted trip because I heard estats for the first time in my life and I always loved seeing lots of black glass face plates with blue meters. The dealer sold many high end brands including McIntosh.

I'm sure that ESS has improved the AMT driver but the AMT starts with one foot in the mud...so to speak. I would love to hear a review of the AMT based cans compared to other cans in the same price range.