Metamaterial Absorber for Loudspeaker Enclosures (2020)
aes.org
aes.org
"A more effective but expensive option is to optimise the impedance match between the driver and the acoustic load. In 1940 Terman [4] patented a sound- absorbing apparatus that absorbs the backside radiation from a loudspeaker using a horn. As depicted in Figure 2, the principle is to continuously adapt the impedance from the back of the driver to the end of the cabinet in order to prevent any reflection. Despite its effectiveness, better than a simple pipe as used in the KEF Carlton, this technology suffers from several drawbacks in addition to the cost and a limited control of the wadding acoustical properties. The most obvious is the size: to work correctly, horns should be very long."
Turned into the Nautaloss:
https://www.diyaudio.com/community/threads/the-nautaloss-ref...
which is small (because the horn is curled up), cheap (because it's made of foamcore board), and really good at absorbing high frequencies (foamcore material properties). Key paragraph from the writeup:
"This speaker can be constructed from exactly 1 sheet of $1 foam core stock and the Vifa driver costs $10. These are not the most efficient drivers but at 85 dB for 2.83V input, they are not bad for near field use. The frequency response flatness, the low THD, the linear phase variations, and the near ideal impulse response make them perhaps one of the best values for a near field "monitor" from 200 Hz to 20 kHz."
And of course, ideas from the 1940s are no longer covered by patents.
Those however are definitely not as cheap!
This is the link to the paper: https://www.aes.org/e-lib/browse.cfm?elib=20758
These are speakers with this: https://uk.kef.com/pages/ls50-meta
And this is the marketing page for the same item as the paper covers: https://uk.kef.com/pages/metamaterial
I listened to these speakers... they are good. But I didn't find them "better" than others I listened to in my room (I home auditioned quite a few speaker pairs), a bit too crisp, cold and surgical. That was likely nothing to do with the metamaterial absorption and probably more to do with the way the electronics inside worked. YMMV, listen to them to find out.
In the end for me, I opted for far more traditional speakers: near field I have some PSI Audio studio monitors ( https://www.psiaudio.swiss/ ), and for the larger room some Tannoy Eatons ( https://www.tannoy.com/product.html?modelCode=P0DEL ). I do have some recent KEFs, but they're for the kitchen radio(!).
I would be far more interested in this material and approach being taken out of loudspeakers and implemented in transport modes that have high background noise, or in baffles in concert halls (or even cafes!).
Ouch, those are expensive. Any small studio monitors (4 or 5 inch woofer) you'd recommend in $500-$600 range (per speaker)? I can't really try many out where I live, unfortunately.
As a vague hand-wavey thing, humans hear 95% of the same thing (women hear more!) and it's the individual 5% difference that matters. Plus the room you place speakers in matters (lots of hard surfaces in a room that is a box makes a messy sound that bounces around, you have to shape the acoustics to avoid making good speakers sound bad and also to make good speakers sound great), and if the room is large small speakers can disappear and sound small. And of course what you listen to also matters.
The PSI Audio are studio monitors... they reveal everything, they're as close to perfect as you can imagine so long as you sit 1m from them (I've been in studios, these sound like being there with the band). But studio monitors reveal all the flaws too. They're not for everyone, in fact they're not far the vast majority of people.
I can't really help based on what you asked... room size, music style, how good your ears are, whether you want active (amp built in) or passive (needs an amp), what your usual music source is... these are all the big parameters.
But for your budget, if you just want "good speakers with no fuss and everything built in"... go look at the KEF LSX https://uk.kef.com/products/lsx . They're not superlative compared to the others I mentioned, but they are superlative compared to a Sonos or equivalent. If you have a huge room they still may disappear and sound weak, but they'll do OK for most family rooms in most countries.
Sorry for not giving more details initially - I am actually looking for studio monitors, powered. I'm going to sit very close to them (they will be on my working desk which is 200x80cm). Small room - around 13 m^2. My ear is pretty unrefined :)
Reason for monitors vs. general purpose speakers is that I do some recording and want to use them when playing guitar through modelers. But since they are going to be on my desk, I'm also going to listen to music through them, mostly on Spotify. I currently have a pair of 8-inch Tannoy Reveal which I got from a friend, but they are pretty terrible for this size of room and distance I'm listening at.
Your LSX recommendation might actually be great for my living room!
My system right now is a Rythmik sub plus vintage Ohm speakers and I replaced the crossovers with a MiniDSP running Dirac room correction.
On the basis of that experience, I'd certainly have the LSX/LS50 on my shortlist if I was looking for speakers in that size.
Once you spend anything but the minimum on speakers then you very quickly find that everything else in the room has a far bigger impact on the sound than the speakers themselves.
The size of room, floor material, wall material, etc all have a huge impact on the sound. Obsession over "fidelity" is fine in an actual recording studio but makes no sense for actual home listening where just moving around the room will change the sound, so who's to say what the "correct" sound is.
I listened once to a wall of different studio monitors in a music shop, and the differences between them were very obvious. And there was no clear "best", at least not in a subjective kind. The objective specs were pretty similar since they were all mid-range price wise.
This still doesn't rule oit that the thing making or breaking your sound could be your acoustics.
Now, as I write this you posted 1 hour ago, and the story submission was 3 hours ago, therefore the file would have been taken down during that two hour window. Curiously, buro9’s comment, which seems to imply that they did look at the document, was 38 minutes ago. Maybe they took a while to read it, and commented some time later? That would put the take-down time to not long before you first reported the 404, assuming buro9 took around half an hour to look at it before commenting.
I doubt they got such an increase in requests that they noticed and somehow decided to take it down.
Does anyone have an idea what could have happened here?
I'd read this before, but knew immediately what it was... saw the archive link and remembered where the original was.
I think their `browse.cfm` has session identifiers implicit in it (or a referrer check), and all that happen is it worked for the person who posted it but no-one else.
Culture ships were all described as ellipsoid were they not? With field management controlling the outer skins.
Fig. 6 looks a lot like I imagined Culture ships. Dense complex ridge-and-channel waveguides.