The only problem I see is the combination of a 2x10" woofer with a 2" dome midrange. There can be big problems there. I believe a single frequency range measurement would show just that.
Also, it's hard to imagine that a dome midrange of those dimensions can be cut so low (350-450Hz). Perhaps the upper bass and midrange should be crossed at a higher frequency (800-900Hz), and the lower bass should be cut much lower (250-350Hz) for Baflle Step compensation. I don't believe you can fit both those bass drivers properly with midrange.
Also, it's hard to imagine that a dome midrange of those dimensions can be cut so low (350-450Hz). Perhaps the upper bass and midrange should be crossed at a higher frequency (800-900Hz), and the lower bass should be cut much lower (250-350Hz) for Baflle Step compensation. I don't believe you can fit both those bass drivers properly with midrange.
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Perhaps you are all forgetting why this arrangement was used so much and why it works.
Simple really because they mainly got used on bookshelves or in studios above the big mixing desks in the horizontal.
The big mistakes with these is not being mirror image.
Simple really because they mainly got used on bookshelves or in studios above the big mixing desks in the horizontal.
The big mistakes with these is not being mirror image.
Not necessarily. It could be a 3 1/2 way speaker, the lower woofer parted off with an additional coil.
The crossover point is quite low for a dome midrange, that's true. If it's problemactic depends on the required spl, at a certain level the middle of the soft dome comes to a standstill because it's not stable enough. The excursion is not a problem though, it can do +/- 0,5mm, which is huge for a mid dome.
prescot got the Braun L200, which were definitely not used horizontally in studios, but you are right, other models from Braun were actually used in studios. Having them not as a mirror image is a problem though, that's right. They did special order mirror models for big public broadcast channels and radio, and also active versions, The price of these were through the roof (well, public state broadcast at the time had that kind of money) and were not commercially available.
To mirror the baffle should be no problem for a DIY guy (or gal.. ..or anything in between).
The midrange dome has some kind of protection, I think a light bulb heating up and a fuse. Not sure which model had what. Also, for the large speaker the middome was build differently from the smaller models. They knew the limitations of their products all too well.
I knew all these rich peoples Braun speaker quite well in their time, not one of them impressed me. Not even with some of the strongest Japanese amps of that time.
I still use a modified pair SM1003 for rear speaker (horizontaly, tilted, high at the wall, like often seen in studios). They just lack the kind of life dynamic you get from any well made 1"+6" two way today. You can turn them louder, but they still stay boring, some call it "neutral". To bad their is no neutral music, only test tones are. I try to stay objective, even with things I own or build. Really no desireable speaker, except for the clean design.
These are the Studio version, which are a black. coarse finish. Inside identical to the consumer version. Previously owned by the music director of a German FM station (Radio Bremen).
I knew all these rich peoples Braun speaker quite well in their time, not one of them impressed me. Not even with some of the strongest Japanese amps of that time.
I still use a modified pair SM1003 for rear speaker (horizontaly, tilted, high at the wall, like often seen in studios). They just lack the kind of life dynamic you get from any well made 1"+6" two way today. You can turn them louder, but they still stay boring, some call it "neutral". To bad their is no neutral music, only test tones are. I try to stay objective, even with things I own or build. Really no desireable speaker, except for the clean design.
These are the Studio version, which are a black. coarse finish. Inside identical to the consumer version. Previously owned by the music director of a German FM station (Radio Bremen).
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"you can get the mid driver separation down close to the cross-over frequency wave lengths." what measurement is meant here buy 'driver separation'. Center to center?
C-T-C yes.
1 wavelength at xover fc is too large. Better case is 1/4 to 1/3 if you want close to omni radiation pattern.
1 wavelength at xover fc is too large. Better case is 1/4 to 1/3 if you want close to omni radiation pattern.
Lets say I am cutting from mid to tweeter at 2500 Hz. Wavelenthg would be 137mm. Is the the distance from the center of each midrange to the center of the tweeter? Or Midrange center to midrange center?
If 137mm C to T: Putting a 160mm OD midrange and butt against a 60mm OD tweeter would result in 90mm distance or about 65% of the xf wavelength.
To make it 1/3 requires 45mm distance center to center. Obviously not possible, would result in a 60mm midrange OD and 30mm tweeter OD.
To make it 1/3 requires 45mm distance center to center. Obviously not possible, would result in a 60mm midrange OD and 30mm tweeter OD.
I guess in reality, in a d'Appolito arrangement the only goal is 'as close as possible. Everything else does not seem realistic.
you could use a small fullrange driver as "tweeter", crossed over low. that would allow a max mid-to-mid center spacing of 2/3 crossover wavelength as claimed for an actual d'appolito configuration.
They have their own problems, that is why there are none (few) used. Its like I tell my car guys regarding tires: they are "not good in ANY season" and not "All Season". Same with "full range" drivers: they are bad in all ranges :-(
I found this document revealing https://www.linkwitzlab.com/Horbach-Keele Presentation Part 2 V4.pdf
