New Paradigm Persona Series - said to block out of phase signal at grill (?)

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pwhinson

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I generally have alot of respect for Paradigm, a well-regarded Canadian speaker manufacturer.  Recently they attempted a "super speaker" design which incorporates a pierced metal grill design on the midrange and tweeter drivers which the manufacturer claims "blocks" "out of phase" signal (their words).  What could possibly be the science behind this?  I'm referring to the Paradigm Persona 9H ($35,000/pair).

FullRangeMan

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Its not rocket science, some expensive mid and tweeters drivers have been using metal grills design since the 90s as physical feature to block peaky response and adittional protection.
https://www.madisoundspeakerstore.com/woofers/accuton-c168-6-990-7-ceramic-cone-mid/bass/

dB Cooper

Looking forward to hearing Paradigm at Capital Audiofest (their first time there AFAIK) but I don't know what they're bringing. Guess I'll find out.

Meta grilles can resonate so it remains to be seen whether this is robbing Peter to pay Paul.

Big Red Machine

My wife really loved the Persona's at Axpona. We went in that room 6 times. I could never get past the sound because I never fell in love with it. It was too analytical to my ears and never drew me in. That stopped me in my tracks from taking the plunge. But they are pretty nice looking and they image decently.

Letitroll98

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I found a review of the speaker in TAS so thought there would be a discussion of the grills, not so much.  When Anthony Cordsman got to that part of the review he stated that question will be answered in the accompanying interview.  Which I couldn't find online after ten minutes of searching their site.  Maybe somebody is better than I at searching and can find it.

Norman Tracy

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I would say it is part science/engineering and part industrial design.

On the engineering side as others have replied this type of phase plug is well known.

Here is a ScanSpeak Illuminator D3004/6040-00 Beryllium dome tweeter.



And a closeup of the Persona tweeter.



It is a bit counter intuitive how these work. At tweeter frequencies the wavelength of the sounds are so small it is a fraction of the done's dimension. Sound from the center of the dome is radiated a little before sound from the edge. This time difference yields what is know as destructive interference. The 'destructive' effect referenced is the out of phase energy from different parts of the dome summing and due to the out of phase property reducing the output. A secondary effect is when the tweeter is operating outside its range of piston motion. Different areas of the dome move at different rates which also leads to out of phase outputs. Years ago it was discovered blocking the center as ScanSpeak does with the little clear disk and the Persona accomplishes with the pattern in the metal forces the radiation from the dome center to take a slight detour and that added length brings that output back in phase with the rest of the dome's output.

A second issue is these are drivers with pure Beryllium diaphragms. The Persona Beryllium midrange is the first I have seen since the iconic Yamaha NS-1000. Beryllium is a toxic metal and these are made from a very thin foil. As a practical matter Beryllium will only be potentially toxic if you work in a factory processing it. However I expect the lawyers at Paradigm wanted the Beryllium covered. As an owner you want it covered because if anyone touches the dome of the tweeter or come of the midrange that will be a sad expensive day. As a granddad who has repaired the dust caps my granddaughter pushed in I like those grills.

Where the engineering issue meets industrial design is what I consider the brilliant sleek styling of the Persona range. The pattern of the grill holes, its shape and integration into the rest of the design.

And then there is the woofers. Look typical enough from the outside. Hidden inside is the motor structure.



Yeah, I want to hear those!



FullRangeMan

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I found a review of the speaker in TAS so thought there would be a discussion of the grills, not so much.  When Anthony Cordsman got to that part of the review he stated that question will be answered in the accompanying interview.  Which I couldn't find online after ten minutes of searching their site.  Maybe somebody is better than I at searching and can find it.
I suspect this interview is only in TAS paper magazine of PDF paid edition.