KEF R11 Meta Tower Speaker Review

[Bghead8che]

I should have been more clear on my situation. I have an ear condition that is very sensitive to certain sounds and frequencies and in my experience all aluminum drivers I have tried sound bright and irritating to my ears. Soft domes, ribbons, and beryllium don't not cause the irritation I hear and feel. I think I am just an anomaly though I have run into a handful of people over the years that share my experience. Sounds like people don't have an "brightness" issue with these speakers, which makes sense for most considering how they measure.

 

[Bghead8che]

That is mostly a myth, if the drivers are used within their proper range

D

'How much impact does driver material actually make?'

Nov 3, 2020

Lots of speaker manufacturers make a big deal about their driver materials (see: Focal's flax and glass sandwich cones, various aramid woofers, silk vs metal tweeters (and within that aluminum, titanium, magnesium, and of course beryllium), and so on) and ribbon tweeters. What I'm curious about is this: how much does the material actually matter to performance? Is there actually any serious advantage to any of the more advanced materials for mid/bass drivers over simple doped paper? And for HF drivers, is there really much of a (dis)advantage for various metal designs or ribbons vs...

• dfuller
• Replies: 212
• Forum: Speaker Reviews, Measurements and Discussion

• 

Interesting read. What would be interesting is to compare an all aluminum/metal driver set and all wood, soft dome driver set in the same speaker and have them measure near identical. Based on my experience there would be a sonic difference but of course you couldn't test this in the real world as you can't have two speakers with two different driver sets measure identically (in the same cabinet, form factor, etc). Like I said I have to avoid certain materials, regardless of how they measure, but I am unique in this regard.

 

[Svend P]

What would be interesting is to compare an all aluminum/metal driver set and all wood, soft dome driver set in the same speaker and have them measure near identical.

This has been done. People could tell no difference in sound.

Post in thread 'Harbeth 30.2 vs kef R3'

Jul 1, 2020

With identical frequency responses and distortions lower than the perception limits drivers from different materials actually sound the same but only if you "switch off" their different radiation pattern, i.e. listening to them in free field conditions, see this research work https://www2.ak.tu-berlin.de/~akgroup/ak_pub/abschlussarbeiten/2010/RotterAndreas_MagA.pdf from which I electronically translated to English the conclusions:

The present paper investigated the widely held opinion that the subjective sound impressions of tweeters are clearly related to the drive principle...

• thewas

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[Frank Dernie]

I should have been more clear on my situation. I have an ear condition that is very sensitive to certain sounds and frequencies and in my experience all aluminum drivers I have tried sound bright and irritating to my ears. Soft domes, ribbons, and beryllium don't not cause the irritation I hear and feel. I think I am just an anomaly though I have run into a handful of people over the years that share my experience. Sounds like people don't have an "brightness" issue with these speakers, which makes sense for most considering how they measure.

Whatever your ear condition there are basically 2 possibilities with dome tweeters, either operating in the pistonic range, ie at a lower frequency than their first resonance (breakup mode) or breaking up a lot in the audible frequency range but heavily damped to give an even response (but you are listening to low-Q resonances all teh time).
If a pistonic driver has a breakup mode you can hear because you are sensitive to super high frequencies it may well be disconcerting and aluminium and titanium domes both have the same specific stiffness so it could be both don't sound good, whereas berillium has a much higher specific stiffness so the first breakup mode will be higher than ally or Ti, although it is not only the material affecting this, the dome shape has a big influence too and, with ally at least, anodising adds a stiff surface layer raising the first breakup mode.
I am old now so have no chance of hearing breakup modes on any tweeter...

 

[Bghead8che]

Whatever your ear condition there are basically 2 possibilities with dome tweeters, either operating in the pistonic range, ie at a lower frequency than their first resonance (breakup mode) or breaking up a lot in the audible frequency range but heavily damped to give an even response (but you are listening to low-Q resonances all teh time).
If a pistonic driver has a breakup mode you can hear because you are sensitive to super high frequencies it may well be disconcerting and aluminium and titanium domes both have the same specific stiffness so it could be both don't sound good, whereas berillium has a much higher specific stiffness so the first breakup mode will be higher than ally or Ti, although it is not only the material affecting this, the dome shape has a big influence too and, with ally at least, anodising adds a stiff surface layer raising the first breakup mode.
I am old now so have no chance of hearing breakup modes on any tweeter...

I think you are spot on and that is exactly what I was thinking after owning beryllium tweeters that don't bother me near as much.