serenechaos wrote:

Bret said the BMS …his web site says he modifies them. I didn't know it then, or know to ask what he did to modify them.  I guess they were even worse?

It is lie, he does nothing to BMS driver to address what is important. When you be working with you own driver trying to get specific sound out of it you will understand what I mean. Bret treats his subscribers with fairytale about the driver’s modifications but whatever he does with them is irrelevant. He knows that BMS is pathetic crap but they are the only drivers that commercially available be for him to obtain. So, he uses what he can and mask out realty with BS literature about “extrasensory charging the diaphragms” – thank for him his customers are mostly Morons and can’t not recognize difference anyhow.

Interning that he and I had this conversation a few years ago at his site (all deleted now). I was challenging him that he might do nothing important with BMS that might improve sound. Knowing, something about the BMS drivers, knowing their design and using a few of them (few years before Bret embraced them) I was proposing Bret not to divulge what he supposedly modify (it would be OK to keep it as his proprietary know-how) but to name one-two specific sonic flaw of the default BMS drivers that his driver’s modifications have addressed. His response was very predictable – he banned be from his forum. I did not sleep for two month after this and maxed out my anti-depressant prescription…

Unfortunately it is very emblematic for all those people and therefore I have very limited expectations when I talk about Sound with the people who practice audio professionally.

http://www.romythecat.com/Forums/ShowPost.aspx?PostID=930

It is like going to a whorehouse and looking for love…

CO wrote:

I have tried a BMS driver a while ago and it was really bad. About a year ago i heard Berts setup at his house and it did not impress me... It was also with the coaxial BMS. Not much depth or resolution. Did have alot of power though but was difficult to determine because of his poorly integrated multi-multi driver subwoofer at the wrong side of the room.. His demo room is not arranged to get the best out of his system.

Well, depth or resolution is the least of the BMS driver’s problems, not to mention the “depth” not strictly drives characteristics. The damn BMS are absolutely atonal, juts miserably-gray drivers and there is absolutely nothing that can be done to them. The people, who use BMS driver in DB design speakers juts do not know better, do not understand it and have general challenge to distinguish results. A few years ago when I asked that Bert guy about his “modifications” I was very least concern about his speaker or about his company or about the idiots she surround himself. For year I have my quest for capacity of compression drivers in the Absolute Tone domain and I know that it is fantastically difficulty, close to impossible to make any worthy impact in general tonal aptitude of made driver. Unfortunately Bert took my interest in his “alleged modification” like any other audio idiot would do – with fear and in full battleship gear. So, as the result he was dispatched by me his to the very same direction as many people were dispatched – to screw himself. Thos pure people are so afraid for themselves and for this little spot under sun that they have lost any ability to understand what is going on and what the subject of attention is. The sad and the true story of all this that the stupid idea of use the BMS dual concentric compression, as well as the whole design of Swing is not Bert idea but was given (sold, licensed or whatever) to him a few years back by a guy name Gerner Christensen. Gerner made his sad DIY home speaker with BMS drivers and Bert market them as BD Design commercial product. I might say very high level of confidence that Bert hated everything that Swing with BMS does but it is business – who gives a damn what a product does if there are Morons who pay for it. He also has a “help”. The Gerner (what I read by him indicate that he is absolute idiot) made his duty to cruse internet, found anybody why say anything negative about Swing and to slam the people with Sara Palin’s intelligence. People, just do not know all of those things, and trust me I so not say even a fraction of what I know and what I might say on the subject.

Why I do not? Because to the simpleton’s surprise to attack BD Design is very much not my intention. I have absolutely no interest in BD Design, Berts, Gerners and all “politics” that they surround themselves, not more that I have interest in any other company. My interest in the subject purely sonic and all those industry of semi- industry freaks juts cannot understand or afford it. You want more thoughts about Sound and less conversations about audio cretins who protect own ego instead of serving interest of Sound?  Well, buy the BMS driver and build a speaker around them, any speaker. They you would have your own judgment and would understand why the BD Design’s clan had raised their funny-violent defiance against my “interest” in their speakers. BTW, there are a lot of more problems with Swing then juts use of BMS but there is really no audiences to understand it as the “human factor” in this subject is the subject in my view.

In the end I would like do not continue BD Design topic in this thread. I truly see no BD Design’s swing as not something that “pushy” in term of critical performance and I do not feel that people who group around BD Design are qualified to talk about Sound, at least with me. If somebody might report a successful use of BMS then it might be worth to share but please let the pure BD Design crap to go, at least leave it outside of attention for this site. The chewing upon sonic mediocrity and fear of exposure is not what I hope this sithe is all about, at least it is how I would like it to see.

Ok that was a long road to "stick with vertical alignment, and stay away from BMS." 

Back to compression drivers, and implementation... 

If I were in your shoe I would take make as you wish but wish a slight correction:

65Hz Tractrix from ~80Hz to ~800Hz w/ fane 8" ( or better driver)
250Hz LeCleach from ~800Hz to ~10kHz
JBL 2405 ribbon from 10kHz up 

How did / do you go about choosing crossover points, other than by listening and experimenting? 
(e.g. the 800Hz point). 

I'm trying to wrap my head around the above suggestion--
It seems simpler on one hand, to eliminate one driver and horn and crossover at first,
then just add them in later. 
On the other hand, it seems like it would take more to "voice" the system with having to chase crossover points twice.   
Horns just seem by nature to work better narrow band-width, and good sound would seem easier to come by with not forcing the horn to sing out of it's range. 
Thanks,
Robert

serenechaos wrote:

If I were in your shoe I would take make as you wish but wish a slight correction: 65Hz Tractrix from ~80Hz to ~800Hz w/ fane 8" ( or better driver) 250Hz LeCleach from ~800Hz to ~10kHz JBL 2405 ribbon from 10kHz up  How did / do you go about choosing crossover points, other than by listening and experimenting?  (e.g. the 800Hz point).

Actually I did not choose crossover points in my text above but just arbitrary dropped the numbers to give an idea. There was plenty say about crossover point in past at my site, do some search.

serenechaos wrote:

I'm trying to wrap my head around the above suggestion-- It seems simpler on one hand, to eliminate one driver and horn and crossover at first, then just add them in later.  On the other hand, it seems like it would take more to "voice" the system with having to chase crossover points twice.   Horns just seem by nature to work better narrow band-width, and good sound would seem easier to come by with not forcing the horn to sing out of it's range.