Speaker Oasis...Bionor

ddk

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Gentlemen, I have visited this forum for the first time today and see this interesting topic - registered immediately.

Welcome asb! Sorry for late reply but I just saw your post today.

I am writing from Germany, so sorry for my English or probably low experience with forum habits. Please allow a
few remarks about the speaker. The full name of it is that above.

Post 1: "Bionors, simply the best of transducers that I have heard, hands down, not even close to any other room
that I have been in, next to a real live event".

Post 4: "Simply put David's system has become my new reference. I have never heard sound as good as his any-
where or with any other gear". Thank you for these descriptions. It seems the system is properly set up.

Post 8: "I also agree with you about the sweet spot or lack thereof as the imaging is perfect anywhere in the room".

I do not agree, because the mid/high horns are highly directional. Unless you are in a very large room and at some
serious listening distance, it is better to have the horns at ear level and there certainly is a sweet spot if used in stereo.
See also post 26 for room size and driver integration.

Post 8 also: A large version of cinema horns has the name Euronor, a widely sold smaller speaker is called Eurodyn.

Pictures can be seen on www.klangfilm.org for instance in Bauer Kinotechnisches Taschenbuch book scan. Baffle
size for the Eurodyn as recommended by Siemens is at least 2 x 2 m (post 9). Additional pictures in another thread:
http://www.whatsbestforum.com/showt...My-Step-Beyond&p=329572&viewfull=1#post329572

Post 14 etc. about baffle size: The Bionor horns can be set up without baffle or with a smaller custom made baffle.
In fact in Europe I know some people using these without the wooden frames and stands. If put near a wall or in the
corner the bass extension can be good enough.

Thread went off topic later - did I miss something? See also in addition:
http://www.whatsbestforum.com/showt...My-Step-Beyond&p=328915&viewfull=1#post328915

Thank you for attention.

Your comments regarding installation of Bionor's aren't entirely correct. As far as coherence goes I agree that the more distance from the speaker the better, 13m-15m is ideal but I have no problems even at 5m in my room and seating is currently at 9m from front of baffle and sound is fully integrated. Yes for stereo audiophile style imaging there's a sweet spot but the way the room is energized you can sit or walk around almost anywhere in the room and the sound quality will remain exactly the same as will the level and energy very much like walking around a live venue. Horns might be directional but the Bionors were made for a 700 seat theater so they also have a wide dispersion pattern.

Many people have visited me and no one found integration an issue even at closer distances in my place. I don't know what you've heard for yourself but electronics and setup play a major role in proper integration of any speaker including the Bionors, specially within listening room boundaries. I'm aware of Andreas's installation with the metal horns hung inversely on the inside of woofer horn section but he's also using the lenses on his. I haven't tried them in a large space but I didn't like the lenses in my listening room. The speakers seem slightly more articulate with the lenses on but they beam the sound instead of the wider, unforced large dispersed sound of the horn without them, the lenses are also very directional in a small space I really don't like them nor do any of my clients with Eurodyns or speakers I've made using the same Siemens horns. It's a matter of preference using the lens and hanging the horn upside down changes the balance too much for my taste and you need to start compensating for what's lost.

I've done my experiments making different sized baffles or copying the original and in every case the new wood changed the tonality of the speaker, generally duller, the original wood is part of the sound and one can't mess with it for aesthetics. Contrary to what you think the baffle dimensions are more than bass extension, Bionor is a 4 way speaker you have the two way electronic crossover and 2 ways mechanical being the metal horn and the wood horn with baffle. Speaker height is very much part of the design dropping the speakers to the floor alters the sound balance same as messing with the crossover. Sticking them in the corners or up against the wall has the same affect on the Bionors as any other speaker, boomy & muddy! I've seen pictures of the Russian pair on the floor close to the back of the room and toe'd in and heard various Eurodyns in small short baffles, they don't work properly! Some people are forced to make compromises but in many cases they don't know any better when building their baffles, there's a reason why Siemens engineers spec's them the way they did! The other thing you need to consider is the age of these speakers after all these years they don't all perform at the same level, there are better and worse examples the only way to get it right is having experience with many pairs and knowing how they should sound.

Threads do sometime meander and change course on WBF, just the way things are...:).

david
 

MarcelNL

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sorry for digging up an ancient thread, yet since the Bionor is an ancient speaker I figure it does not matter THAT much ;-)

I'm in the process of building a speaker based on the Bionor design and have been reading up on everything there is on the speaker, came across this thread and started wondering about the reference to a metal horn...is that for the tweeter horn or the mid freq horn section? Everything I found thus far makes me think the mid freq horn was made from bent plywood, which was all in fashion in the fifties, or laminated veneer.

I'm currently in the POC stage, with one makeshift speaker in the living room (no space for the second in this interim house) busy tweaking the tweeter filter. So far I'm impressed by the organic life like nature of the sounc. Previously I was using two Breitstrahlgruppen with a sort of 'd Appolito tweeter arrangement integrated into a wall section of our previous home.


Anyone who has been close up to some original Bionor speakers who can share some information?
 

ddk

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May 18, 2013
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sorry for digging up an ancient thread, yet since the Bionor is an ancient speaker I figure it does not matter THAT much ;-)

I'm in the process of building a speaker based on the Bionor design and have been reading up on everything there is on the speaker, came across this thread and started wondering about the reference to a metal horn...is that for the tweeter horn or the mid freq horn section? Everything I found thus far makes me think the mid freq horn was made from bent plywood, which was all in fashion in the fifties, or laminated veneer.

I'm currently in the POC stage, with one makeshift speaker in the living room (no space for the second in this interim house) busy tweaking the tweeter filter. So far I'm impressed by the organic life like nature of the sounc. Previously I was using two Breitstrahlgruppen with a sort of 'd Appolito tweeter arrangement integrated into a wall section of our previous home.


Anyone who has been close up to some original Bionor speakers who can share some information?
Hi Marcel,

They're my speakers. 500hz and up is handled by one compression driver and the metal horn, bass horn is bent wood.

What do you mean by "Breitstrahlgruppen" is it something like the Lansing 537-500 potato masher horns or just a curved lens with holes?

david
 

MarcelNL

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HI David,

Thanks for confirming they are bent wood! I assumed there would have to be a mixup, I probbaly misread your post!

Breitstrahlgruppen or KL-L501 (https://www.klangfilm.org/index.php?lng=0&music=&type=0&frame=1&item=&title=&dir=&num=)
are the boards with two KL405 mounted on them, each at a slight angle for dispersion in theaters. On Klangfilm.org you can find the diagrams. Basically a board approx 100x50cm with two 14" speakers. For my previous system I made of those two boards, mounted the tweeter in the middle of each and mounted the Breitstrahlgruppen in a 10 cm thick solid wall with a large adjacent (storage) room ending up with infinite baffles.

I'm now using three 13" fullrange units in a slightly higher frontloaded horn (just higher not wider), we've compared various KL405 variants (like the Berlin version best) and concluded that Tesla ARO 835 does a great job with some minus points in midrange clarity but bonus points for low range push and definition..Currently the system is powered with a Klangfilm Cinema backup amp, KL204a using an F2a11 tube.

My fullrange units are unfiltered, the tweeter kicks in around 7-8k (work in progress).
 
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Audiophile Bill

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HI David,

Thanks for confirming they are bent wood! I assumed there would have to be a mixup, I probbaly misread your post!

Breitstrahlgruppen or KL-L501 (https://www.klangfilm.org/index.php?lng=0&music=&type=0&frame=1&item=&title=&dir=&num=)
are the boards with two KL405 mounted on them, each at a slight angle for dispersion in theaters. On Klangfilm.org you can find the diagrams. Basically a board approx 100x50cm with two 14" speakers. For my previous system I made of those two boards, mounted the tweeter in the middle of each and mounted the Breitstrahlgruppen in a 10 cm thick solid wall with a large adjacent (storage) room ending up with infinite baffles.

I'm now using three 13" fullrange units in a slightly higher frontloaded horn (just higher not wider), we've compared various KL405 variants (like the Berlin version best) and concluded that Tesla ARO 835 does a great job with some minus points in midrange clarity but bonus points for low range push and definition..Currently the system is powered with a Klangfilm Cinema backup amp, KL204a using an F2a11 tube.

My fullrange units are unfiltered, the tweeter kicks in around 7-8k (work in progress).

Any photos of your current creations, Marcel. Sounds interesting.
 
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MarcelNL

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it's POC, so aquarelpaper on a wooden frame, picture below is from the final stage of putting the pieces together, currently the tweeter sits in front of the center of the middle full range unit. Last tweaks make me think the system is a keeper.
 

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Audiophile Bill

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Mar 23, 2015
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it's POC, so aquarelpaper on a wooden frame, picture below is from the final stage of putting the pieces together, currently the tweeter sits in front of the center of the middle full range unit. Last tweaks make me think the system is a keeper.

Looks pretty cool. What drivers did you use for this triple flh? What fc is the horn loading to? What drivers do you plan above this and what crossover?
 

MarcelNL

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the drivers are the Tesla ARO 835, a Czech sort-of copy of the KL405, the horn and baffle are a straight copy from the Bionor so 500-ish Hz.
No crossover on the fullranges and a 6db sine cap (hand wound coil, hand made loading resistor) on the tweeter at 7-8k.
Next step is to select the resistor material, gold, platinum, palladium, all with their own character and pros and cons.
 
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ddk

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May 18, 2013
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HI David,

Thanks for confirming they are bent wood! I assumed there would have to be a mixup, I probbaly misread your post!

Breitstrahlgruppen or KL-L501 (https://www.klangfilm.org/index.php?lng=0&music=&type=0&frame=1&item=&title=&dir=&num=)
are the boards with two KL405 mounted on them, each at a slight angle for dispersion in theaters. On Klangfilm.org you can find the diagrams. Basically a board approx 100x50cm with two 14" speakers. For my previous system I made of those two boards, mounted the tweeter in the middle of each and mounted the Breitstrahlgruppen in a 10 cm thick solid wall with a large adjacent (storage) room ending up with infinite baffles.

I'm now using three 13" fullrange units in a slightly higher frontloaded horn (just higher not wider), we've compared various KL405 variants (like the Berlin version best) and concluded that Tesla ARO 835 does a great job with some minus points in midrange clarity but bonus points for low range push and definition..Currently the system is powered with a Klangfilm Cinema backup amp, KL204a using an F2a11 tube.

My fullrange units are unfiltered, the tweeter kicks in around 7-8k (work in progress).
Yes 405 boards are tilted slightly in opposite direction. I had the 501 in a flat baffle, not particularly dynamic but could have been the baffle material too. I think I like the Axion 80's best when it comes to full range speakers.

david
 

Audiophile Bill

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Mar 23, 2015
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the drivers are the Tesla ARO 835, a Czech sort-of copy of the KL405, the horn and baffle are a straight copy from the Bionor so 500-ish Hz.
No crossover on the fullranges and a 6db sine cap (hand wound coil, hand made loading resistor) on the tweeter at 7-8k.
Next step is to select the resistor material, gold, platinum, palladium, all with their own character and pros and cons.

Nice. I know the Tesla drivers. Been amassing them for a few years now lol. Think I have 14 now.

Do you happen to know what the horn fc is on the bionor? No problem if not will look it up.
 

MarcelNL

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Yeah I gobbled up a few on the cheap too...it seems there is a huge supply still, I have a few contacts from those purchases and they have plenty or are able to source them quite easily whereas KL405 is almost unobtanium (especially the Vacuumschmelze Berlin version).

The horn Fc is 500Hz or so, which adds up nicely with the current amp which has a 'built in' +3db until 500Hz.

The two units each side system on infinite baffle was great too, but this is next level. My theory is that higher efficiency, three vs two units, and the horn do wonders lowering distortion and increase dynamics.

When finished the system will become an infinite wall with 'sunk in' horns
 

Audiophile Bill

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Yeah I gobbled up a few on the cheap too...it seems there is a huge supply still, I have a few contacts from those purchases and they have plenty or are able to source them quite easily whereas KL405 is almost unobtanium (especially the Vacuumschmelze Berlin version).

The horn Fc is 500Hz or so, which adds up nicely with the current amp which has a 'built in' +3db until 500Hz.

The two units each side system on infinite baffle was great too, but this is next level. My theory is that higher efficiency, three vs two units, and the horn do wonders lowering distortion and increase dynamics.

When finished the system will become an infinite wall with 'sunk in' horns

Hi Marcel,

Yes I have been able to get the Tesla okay thanks. I got a couple of contacts.

Are you running all 3 Tesla in parallel for a 5 ohms total load therefore getting the spl boost? Makes sense.
 

Audiophile Bill

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I should clarify I have been after the 9415 aro mainly - they are 15ohms load.

I don’t know the 835.
 

MarcelNL

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aha, no now in parallel the resistance dips too low, they are 4 Ohm each...I had them paralleled for a while but running them in series now.
Most measurements of T/S parameters that I found should be taken with a grain of salt as they originate from enthusiasts rather than the company who made them (and that would not make them solid either IME), yet DC resistance is for real.
 
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Audiophile Bill

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aha, no now in parallel the resistance dips too low, they are 4 Ohm each...I had them paralleled for a while but running them in series now.
Most measurements of T/S parameters that I found should be taken with a grain of salt as they originate from enthusiasts rather than the company who made them (and that would not make them solid either IME), yet DC resistance is for real.

Yeah all mine are measuring dc resistance between mid 14s to mid 15 ohms.
 

MarcelNL

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Yes 405 boards are tilted slightly in opposite direction. I had the 501 in a flat baffle, not particularly dynamic but could have been the baffle material too. I think I like the Axion 80's best when it comes to full range speakers.
IME the baffles can either be too thin or too thick, too thick does more damage than too thin.
the Goodman's Axioms you mean, yeah well, sigh...unobtanium and all that.
Next stage is likely a field coil, but that is quite the project...
 

ddk

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IME the baffles can either be too thin or too thick, too thick does more damage than too thin.
the Goodman's Axioms you mean, yeah well, sigh...unobtanium and all that.
Next stage is likely a field coil, but that is quite the project...
I learnt that there’s a lot more to making baffles than meets the eye, there’s an art to it. Didn’t realize that Goodman’s have become unobtainable, good samples weren’t hard to find not so long ago.
david
 
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Audiophile Bill

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I learnt that there’s a lot more to making baffles than meets the eye, there’s an art to it.

david

Hi David,
What did you learn specifically in the baffle building process?

cheers.
 
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MarcelNL

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it depends what you consider unobtanium, let's say that 6000Euro/Dollar the pair is a lot...for me enough to tilt the scale to field coil full range units.
 
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MarcelNL

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Hi David,
What did you learn specifically in the baffle building process?
My take home message is; build it in sections to control vibrations and add strength, the wood type does matter, and thickness of the baffle surface itself matters (greatly) too...3 mm somehow was an optimum for me on large baffles.
Just see how Klangfilm made them, that was not done for transport reasons I reckon....O how I wish to be able to speak with the key designer of those days....
 

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