MBL radialstrahler

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The Polish magazine Audio has just published test and measurements of the flagship 101-Xtreme. I haven't had the opportunity to hear any MBL's. The article is in Polish, but we have Google translate!

MBL 101-Xtreme - Zespoły głośnikowe | Testy w Audio.com.pl

YWRkPTMwMHgzMDB4RkZGRkZGJmJnPTMwMHgzMDA=_src_55631-mbl-101-xtreme-audiocompl-fot2.jpg


Response show considerable interferences above 1kHz, but looks like room response might be adequate. Sad that this concept is extremely difficult to DIY.

55657-mbl-101-xtreme-audiocompl-fot1.jpg


Stereophile has tested and measured an earlier model 101E MkII
MBL Radialstrahler 101E Mk.II loudspeaker | Stereophile.com
 
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Having so many drivers that play full 360 degrees it is hard to measure it well having to do measurements in room with walls. Hole at 2,5kHz could be crossover design frequency between drivers.

As for difficulty in making something like 101's there is at least one person in Poland that can make similar speakers with frequency response as desired. Here is his topic at Polish forum:
Wielki projekt ponad wszystkie. - strona 2 - DIY - Audiostereo.pl

I have listened them, and MBL 101D, and 101E mk2 presence of sound propagating in all dimensions is the same. Frequency response are different, because of different crossovers.
 
Sad that this concept is extremely difficult to DIY.
When I worked in Berlin the chap two doors away was one of the pair of people involved in the first prototypes and named in the original patent from the 70s. He told me that the inability of competitors to produce a similar product without a major financial investment in design and development was a major factor in the chap behind MBL stumping up surprisingly large sums of money to develop the product (I was told the amount but am unsure of my recollection). Over the decades this has proved to be correct and is a very rare example of technical lockout in the low tech area of home audio. The cost to develop similar transducers to compete with MBL is simply too high given the limited size of the market and so MBL get to keep it all to themselves.
 
When I worked in Berlin the chap two doors away was one of the pair of people involved in the first prototypes and named in the original patent from the 70s. He told me that the inability of competitors to produce a similar product without a major financial investment in design and development was a major factor in the chap behind MBL stumping up surprisingly large sums of money to develop the product (I was told the amount but am unsure of my recollection). Over the decades this has proved to be correct and is a very rare example of technical lockout in the low tech area of home audio. The cost to develop similar transducers to compete with MBL is simply too high given the limited size of the market and so MBL get to keep it all to themselves.

While omni in typical listening rooms is a debatable choice, the Radialstrahler is a brilliant driver - a real departure from anything else. One does wonder whether the Radialstrahler principles (eg. squeezing of a curved transducer) can be applied to non-omni curved arrays like the CBT.
 
The 101 Xtreme is basically two 3-way units stacked. It also has double subwoofer towers not shown here. Doubling is mostly to get higher spl without straining (high distortion compression). The inevitable problem with mirrored elements is vertical beaming and interferences. The Stereophile mesuements are mostly average of several spots, but also from a single 3-way system with less intereferences.

I see Radialstrahler as an exotic "tour-de-force" mission to stick on some dogma. Just like a BMR or electrostatic planar membrane. The sub has opposing large cone drivers, which also gives omnipole radiation in low frequencies.

The Xtreme system has some kind of sound processor for the bass tower - it has adjustment for gain and delay with values +8 - -8ms. The article doesn't reveal what kind of crossover circuits the onion-towers have, but obviously passive with adjustable values. Some of the matching problems would obviously get better with modern dsp-xo.

The markings on the panel are funny!
dz01NjAmaD0zMDU=_src_55636-mbl-101-xtreme-audiocompl-fot7.jpg


Bass tower markings look a lot more rational
dz00MDAmaD02MTU=_src_55640-mbl-101-xtreme-audiocompl-fot12.jpg
 
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A few years back at a local hiend meet they had this same setup with the full MBL amps and driven by a custom reel to reel vs digital demo..
(Digital sucked in comparison BTW)

The guy sitting in front of us had a RTA spectrum analyzer going and you could see on every song a seagull dip throughout the midrange on every song they played

Now I dont know if the mirror image petals were cancelling at our listening distance or what,
but these are interesting speakers and for whatever reason every time I have listened to these over the years they always play them way to loud for my tastes.

These are visitors from outer space and the prices are too.

Regards
David
 
I heard their floorstanding version driven with their mono block amps at a show. I walked in with an open mind. I was in awe of what the components looked like - nice and shiny. They had a lot of women handing out brochures in office clothing (all marketing). The sound - not so much. Diffused like an open baffle, but with less resolution. At the time I had the Linkwitz Orion and Gedlee Abbey (still own) for comparison.
 
A few years back at a local hiend meet they had this same setup with the full MBL amps and driven by a custom reel to reel vs digital demo..
(Digital sucked in comparison BTW)

The guy sitting in front of us had a RTA spectrum analyzer going and you could see on every song a seagull dip throughout the midrange on every song they played

Now I dont know if the mirror image petals were cancelling at our listening distance or what,
but these are interesting speakers and for whatever reason every time I have listened to these over the years they always play them way to loud for my tastes.

These are visitors from outer space and the prices are too.

Regards
David

David, I agree, they tend to play them extremely loud at shows.
 
The Polish magazine Audio has just published test and measurements of the flagship 101-Xtreme. I haven't had the opportunity to hear any MBL's. The article is in Polish, but we have Google translate!

MBL 101-Xtreme - Zespoły głośnikowe | Testy w Audio.com.pl

YWRkPTMwMHgzMDB4RkZGRkZGJmJnPTMwMHgzMDA=_src_55631-mbl-101-xtreme-audiocompl-fot2.jpg


Response show considerable interferences above 1kHz, but looks like room response might be adequate. Sad that this concept is extremely difficult to DIY.

55657-mbl-101-xtreme-audiocompl-fot1.jpg


Stereophile has tested and measured an earlier model 101E MkII
MBL Radialstrahler 101E Mk.II loudspeaker | Stereophile.com
Very easy. What you see on the frequency response (peaks) are bending modes (natural frequencies) of the lamellas. In particular 3rd modal shape is set at 600hz then 4th at 1k, 5th at 1.6k and so on (for the midrange) . Torsion modes are not exited and so no peaks on response. I can tell you since I performed a fem modal analysis and I also simulate acoustic response by fem
of the system. I have almost complete my DIY system
 
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Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.