Any experience or thoughts out there with the new Greatplains Altec 415-8b or the big EMS biflex or any other large wideband woofer that relies on mid-cone suspension to let the highs radiate from only the inner portion? I'm wondering about things like radiation pattern, distortion at the physical crossover and low level finesse. Any other thoughts? Thanks very much!
Kept within Xmax limits (historically ~ a mm) the vintage designs work just fine with the proper polar response match-ups based on octave spreads; IOW the mechanical XO is at the right physical point on the woofer diaphragm.
No clue about distortion measurements other than they didn't sound other than as being huge point sources in my youth and more importantly for some, the females often preferred them to typical woofer/horn combos, but then this was the time of ~FM radio BW limited recordings at best unless one could afford RTR systems, special recorded tapes.
Nowadays I'd want at least an 800 Hz horn + 120 Hz sub system to R&R, etc..
Somewhat current Biflex info........
No clue about distortion measurements other than they didn't sound other than as being huge point sources in my youth and more importantly for some, the females often preferred them to typical woofer/horn combos, but then this was the time of ~FM radio BW limited recordings at best unless one could afford RTR systems, special recorded tapes.
Nowadays I'd want at least an 800 Hz horn + 120 Hz sub system to R&R, etc..
Somewhat current Biflex info........
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Just what I posted from dim memory of the last time me n' some others auditioned them in relatively large 'HIFI' reflex cabs in the mid '60s, though in retrospect recall auditioning one of the newer 15" bi-flex with a nice sounding added super tweeter when ostensibly being there to audition the new Barcelona that I was thoroughly disappointed with except for its fabulous cabinetry...........
Mr Peter Pfleiderer from Germany had a patent on a fullrange loudspeaker with a rubber around the voice coil. Solved some problems typical fullrange driver have. He had also for 20 years a patent on this loudspeaker with EQ that can reproduce square waves. He patented the end result and Philipps tried to fight him before the court because of upcoming digital eq and he was in the way (loudspeaker history 80ies and 90ies). Pfleiderer managed to defend his patent but his patent was not used by licensees a lot.
Biflex helps the fullrange speaker in controlled cone breakup.
You gain less moving mass for voice coil and whizzer cone resulting in faster rise time in the highs.
If the cone has very thin paper this is already realized at the cost of cone stability.
Pfleid FRS20, I own a pair of them.
Biflex helps the fullrange speaker in controlled cone breakup.
You gain less moving mass for voice coil and whizzer cone resulting in faster rise time in the highs.
If the cone has very thin paper this is already realized at the cost of cone stability.
Pfleid FRS20, I own a pair of them.
the Pfleid looks super interestng. Would love to hear it. Thanks for posting. I'm teetering on the verge of pushing go on buying a 15" biflex.
In the 80ies and 90ies (and later) it must have been one of the best speakers around.
Mr. Pfleiderer had the problem that the concurrence was talking bad about the product when customers asked for a listening test. Phasey loudspeakers had a difficult competition with them.
https://www.hifi-wiki.de/index.php/Pfleid
I have an article from a magazine which tested it 1996, I think Stereoplay. Will post it here when I find it.
http://www.hifi-forum.de/viewthread-30-3744.html
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Speaking of "phasey" speakers, any idea what the phase on a biflex looks like across the mechanical crossover?
It is what it is.
There is fun with paper tweeters.
Maybe take it further with steeper filter
slopes. And a cleaner cabinet build.
Either way be fun to have a Santana.
Bass and mids with Biflex then add a tweet
Biflex with tweeter sounds fun.
Could also use a modern metal dome.
I like the phenolic ring tweet look though.
And usually measurements dont look amazing
for paper tweets. But my old pioneers had them.
No fatigue actually , or harshness.
Neo magnets have reduced the form factor of mounting
size of tweeters. So be interesting to also to a modern
take with the tweeter mounted on a bar across the speaker
There is fun with paper tweeters.
Maybe take it further with steeper filter
slopes. And a cleaner cabinet build.
Either way be fun to have a Santana.
Bass and mids with Biflex then add a tweet
Biflex with tweeter sounds fun.
Could also use a modern metal dome.
I like the phenolic ring tweet look though.
And usually measurements dont look amazing
for paper tweets. But my old pioneers had them.
No fatigue actually , or harshness.
Neo magnets have reduced the form factor of mounting
size of tweeters. So be interesting to also to a modern
take with the tweeter mounted on a bar across the speaker