KEF Meta Absorber

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vinylnvalves
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#1 KEF Meta Absorber

Unread post by vinylnvalves »

I saw this https://www.theabsolutesound.com/articl ... echnology/

Interesting it’s hailed as innovation, yes they patented it on application, but washing machines and cars have had cactus style Helmholtz absorbers for a long time. I was thinking could this be scaled up to cover the midrange. I think it would either be massive or ineffective. Bit like having a small square of a perfect absorber in a speaker cabinet. Yes great for tweeters only in IMHO. Shame as one of the easiest things I could make on the CNC router,
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Nick
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#2 Re: KEF Meta Absorber

Unread post by Nick »

I would have thought that the rear wave of a tweeter would have been easy to absorb and convert into heat with wadding.
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Scottmoose
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#3 Re: KEF Meta Absorber

Unread post by Scottmoose »

It is. Although it can take some careful juggling of the type used, its quantities and location for best results, and if combined with rear decompression chamber[s], it gets a little more complex as there are usually some other effects coming into play (typically in the 2KHz region). Nothing particularly out of sight though and with a few days of testing it should get dialed in. In fairness to KEF, this seems a reasonable alternative though, and may improve production consistency -positioning damping material can be a pain; I've known cases where a misaligned felt pad on the rear of the coil caused roughly a 3dB deviation in the response of that unit, so if you can avoid that by substituting a pre-cast item, potentially no bad thing.
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vinylnvalves
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#4 Re: KEF Meta Absorber

Unread post by vinylnvalves »

It might be a better way of absorbing the rear wave in a compression driver. Which is similar to what kef are going. I was always concerned that the thin layer of foam in my JBL’s wouldn’t do anything below 500Hz.
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Scottmoose
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#5 Re: KEF Meta Absorber

Unread post by Scottmoose »

I'm not sure it would be ideal for those drivers. You don't exactly want to be depressurising a compression unit, and this is likely to be a better solution to slightly larger chambers where eigenmodes can be an issue. Not impossible of course, but I suspect alternative solutions are likely to be more effective, if standing waves are proving to be problematic. The impedance curve is probably the fastest way of establishing that.
'"That'll do," comes the cry of the perfectionist down the ages.' (James May The Reassembler)
Website www.wodendesign.com
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