METACONVERSATIONS

Asking questions is part of our job. And it’s harder via webcam.

The Editor is always asking questions.

Zoom briefings instead of press launches have been a great success during the past year. Epson recently broke the drought with a proper PR bash to announce its partnership with National Geographic to save the permafrost, and perhaps the world, which on Epson’s side involves ridding it of laser printers. They hosted a launch and a lunch overlooking a sunny Sydney Harbour, and rejoining a physical group was most enjoyable, a reminder that however casual a Zoom chat may try to be, there simply isn’t the natterlevel conversation either with the company or from journos on different beats covering technologies that may you may have missed. It’s so good to share. It’s also easier, in the flesh, after some chit-chat, to ask a serious technical question in a friendly manner.

On Zoom, raising your virtual hand with a serious question tends to look more like you’re causing trouble. Not that it stops me; when there’s something I don’t understand, I ask. It’s how I learn. Recently I was on a Zoom call about a soundbar which was enthusiastically presented as having six drivers, 3D sound, Dolby Atmos and DTS:X, all very exciting. I fear may have rather brought things down by putting up my hand and asking for confirmation that this was really just a stereo bar playing in 2.0, yes? It seemed the only possible configuration given the driver arrangement. And yes it was indeed 2.0, though “with Atmos”, they said, and hey it sounded really great. And maybe it does. I just wanted to clear that up.

The awkward question thing also happened last week in one of many Zoom calls recently organised by EISA, the international body of technical editors of which Sound+Image and Australian Hi-Fi are proud to be Australian members. At this time of year EISA normally hosts a big convention in Belgium, but of course it’s all virtual this year, so we’ve been joining the Zooms from here in the evenings, and I’m very happy to spend the time doing so as most of them are useful and illuminating presentations on new technologies and kit, often with the key players and designers there online, taking questions at the end.

My first question this night was a general one. With the active speakers in our group test this issue, on several occasions there had been problems playing from the optical or HDMI ARC output of the TV we attached, with the sound either glitching or dipping every few seconds — perhaps a handshake or syncing problem between the TV and the DAC. Investigating further, I had found that one of the companies had a specific warning online for some TVs, and I had emailed them about it. This Zoom call was with a different company entirely, but they made similar products, so I asked if they had any knowledge of this being an issue.

As soon as I started my question I saw their engineer nodding, and he said yes, happens all the time, TVs are notoriously wayward in their data delivery, and with his company’s DACs they test compatibility with as many TVs as possible, even taking them to stores to plug them into everything, then they monitor helplines for any other problems, and they issue firmware updates. Their new speakers were, indeed, specially designed to make such regular updates easy, he said.

Well that was a more informative answer than I was hoping for; I was pleased to have the general issue confirmed, and impressed with how they were dealing with it.

Then I meant to ask politely whether anyone had yet raised the question of their use of a metamaterial for a clever innovation in their latest speakers, when it didn’t really seem to meet the normal definition of a metamaterial? This came out sounding rather more abrupt than I had intended, but as I say, I was asking because I didn’t get it.

Some background: a metamaterial is a material which has been engineered to have a property which doesn’t exist in nature. The company itself uses an example from the field of optics: “Metamaterials are probably most familiar in the field of optics, where synthetic materials may be realised that have properties that cannot be found in nature. For example, a base material may be infused with another in varying density such that the refractive index varies throughout the material. Thus things like flat lenses may be constructed that are much easier to produce than grinding glass to a precise shape.” This new ‘changed’ material, then, is the metamaterial — it didn’t previously exist in nature, and it has new properties which its ingredients didn’t have on their own.

But this company’s gadget isn’t like that. It’s a normal material that has been shaped to give it special properties. The material itself isn’t changed in any way. So not really a metamaterial, just shaping an ordinary material.

The guy in the Zoom call said no, it’s still a metamaterial if you change the shape to give it a new ability that the material doesn’t have in nature. They do say this in their white paper: “The term ‘meta’ has since gained the more general description of any material that exhibits characteristics foreign to the solid form. In this case, ABS has been moulded into a shape that is an almost ideal broadband absorber.”

But if anything shaped for a new purpose qualifies as a metamaterial, then my coffee cup would be a metamaterial, because it’s been shaped to contain a liquid. I said this on the Zoom call, waving my coffee cup. Indeed everything ever manufactured would be a metamaterial. A sharpened stick is a metamaterial because now you can stick it in things. A woofer, the voice coil, the basket, the dust cap, they’re all metamaterials — all hi-fi products are stuffed full of metamaterials. And I don’t think that’s quite the product differentiation they were going for.

So I did follow up by email, and the reply from this most friendly and open engineer made an important point — some engineering metamaterials use repeating patterns at a very small scale to give a material new properties without actually changing the material itself. That’s why they’re calling this a metamaterial, even though the scale isn’t that tiny, and theirs doesn’t use repeating structures (which was, he said, a point they had discussed as questionable regarding their use of the word metamaterial).

That’s an honest and open answer, the kind you might get face-to-face. And even if this thing isn’t really 100% strictly a metamaterial, I’m perfectly happy to participate in calling it one for the purposes of describing the speakers. Besides, the important thing is that it seems to work, and to deliver a genuine sonic improvement. And I’m not going to argue with that! Cheers,