AER MD3 or BMS 4592 ND (BD-Design)
by daiwok 
, Hong Kong, Sunday, February 10, 2008, 00:44 (5922 days ago)
Can anyone highlight the difference between the two drivers ? Anyone here who has listened to both or owned both drivers.
I am looking to upgrade from Lowther PM4a.
thanks !
AER MD3 or BMS 4592 ND
by PeterSt. 
, Netherlands, Sunday, February 10, 2008, 04:43 (5922 days ago) @ daiwok
Hi daiwok,
Can anyone highlight the difference between the two drivers ?
Uhhmm ... too different to be interchangeable ? :wink:
The BMS won't be suitable for operating in the amount of "free air" the AER is suitable for. You must change horns first ... 
Peter
AER MD3 or BMS 4592 ND
Can anyone highlight the difference between the two drivers ? Anyone here
who has listened to both or owned both drivers.I am looking to upgrade from Lowther PM4a.
thanks !
Dear Daiwork
Well...if you already are using PM4a I don't think you will find an exchange to MD3 worthwhile. PM4a is a very nice FR driver. I had both drivers and it takes really something to beat a PM4a given the right circumstances.
I can only guess what kind of cabinet/horn you are using today for your PM4a, but as Peter is also mentioning they are not compatiable just to swap for an Orphean horn with BD-Design modified BMS compression drivers. The Orpheans are in a completely different region and has completely different appeal.
It's easy to achieve a set of Orpheans. All BD-Design intelligence are already built in and the filter too.
If you want to *up-grade* in the FR world I think you can only aim at Feastrex, and better you talk with Bert about that.
To my knowledge he is selling those fantastic full range drivers soon.
I had a session here in Serbia with the Featsrex 9nf http://www.feastrex.com/d9xfamily.html and that showed that if FR lovers want to spoil themselves with the best of the best, this is where you should put your bucks.
These drivers are taking the FR level to a much higher level. And you pay for it.
I'm a user of the Orpeans MKII, and frankly, that has very little to do with the FR world.
The BMS/Orpheans will offer you a much more uncolored, much more detailed and true fidel sound where instruments are sounding exactly like instruments. More music, less driver sound.
They are not fullrangers, but almost. Add a good bass system, such as the compact cabinet and you will find yourself in the 7th heaven. 
GC
AER MD3 or BMS 4592 ND
by Bert , Sunday, February 10, 2008, 17:33 (5922 days ago) @ daiwok
Hi Daiwok,
Can anyone highlight the difference between the two drivers ? Anyone here
who has listened to both or owned both drivers.
As others explained, these are two different systems. How do you use your present PM4A's? In the Oris 150?
Bert
--
BD-Design - Only the Best!
AER MD3 or BMS 4592 ND
Hi daiwok,
I have Oris 150s. I originally drove these horns with Lowther PM4a's and then following advice from Bert changed over to AER MD3s. I found the advice and the driver change to both be very worthwhile. The change was made years ago, and I have a serious memory problem as a result of a head injury so I am not going to pretend to remember specific differences in sonic details.
I do very clearly remember that after thirty-five years of buying, building and later designing and building speaker systems including closed box, aperiodic, ported, planar magnetic, electostatic, etc. always searching for something that sounded "right and truly musical" when I heard the Oris 150s with the AER MD3s instead of the Lowther PM4As I decided that perhaps I could finally just relax and enjoy the music instead of always searching for better sound. I've made changes in electronics. As for speakers, years later I'm still just enjoying the music.
Bye,
Don Reid
AER MD3 or BMS 4592 ND
Oh like you Don.... I actually also have a memory problem. When I used PM4's it was not in Oris horns, but others made of gips, and backloaded too.
And my PM4's were generation 1970. (When the good Lowthers excisted).
Things might or have changed in the meantime.
Now Bert is in the air with Feastrex, well what about giving that a try everyone, in an Oris horn. Ho...hooo :wink:
GC
AER MD3 or BMS 4592 ND
by daiwok , Hong Kong, Tuesday, February 12, 2008, 14:47 (5920 days ago) @ GC
Hi Everyone and thanks for all the responses !
Yes the PM4a is a great driver in its own right, given the fact it was designed decades ago, I think it has earned great respect. In fact AER and Feastrex are generic forms of the lowther design.
I am using a LeCleache profile front horn, similar to the Oris. In fact I did consider having an extension made to my horn so I can accomodate the 2" BMS.
I see there is another thread on "Feasterex or BMS 4592 ND" I think all FR benefit from front horns with reduced colouration which is not the case in cabinets.
I am still courious on the BMS 4592 as I have already had the chance to listen to the AER MD3 which is more refined and balance compared to the PM4a. I think things have to come to a point where "its what do you prefer" rather than "what is better" or am I wrong ?
.........BMS 4592 ? AER ? Feasterex ?
David
AER MD3 or BMS 4592 ND
by Bert , Tuesday, February 12, 2008, 15:14 (5920 days ago) @ daiwok
Hi David,
I am using a LeCleache profile front horn, similar to the Oris. In fact I
did consider having an extension made to my horn so I can accomodate the
2" BMS.
The LeCleache in not similar to the Oris horns and an extension will not work optimal either. The horn will be too long and on top of that, you will not be able to use the filter which is designed for the Orphean.
I see there is another thread on "Feasterex or BMS 4592 ND" I think all FR
benefit from front horns with reduced colouration which is not the case in
cabinets.
That depends on the cabinet design and preferences in sound...
I am still courious on the BMS 4592 as I have already had the chance to
listen to the AER MD3 which is more refined and balance compared to the
PM4a. I think things have to come to a point where "its what do you
prefer" rather than "what is better" or am I wrong ?.........BMS 4592 ? AER ? Feasterex ?
I vote for the modified BMS with dedicated filter as used in the Orphean, I am almost sure that this will flaw in other horns.
Bert
--
BD-Design - Only the Best!
AER MD3 or BMS 4592 ND
by daiwok , Hong Kong, Wednesday, February 13, 2008, 05:55 (5919 days ago) @ Bert
Oris and Lecleache
Similar only in terms of front horn theory not in flare. Sorry for any mis representation on your horns.
I like to understand why the BMS would not work ? the Lecleache flare can work for other 2" compression drivers or any driver size - matter of design. Extension of the throat down to 2" driver is continuation of the flare back - right ?
Filter design may be you are right as its optimised for your flare, but if the cut off is the same then the filter should work right ?
Would love the opportunity to hear the Orphean - anyone has a pair in Hong Kong ?
AER MD3 or BMS 4592 ND
by PeterSt. , Netherlands, Wednesday, February 13, 2008, 09:24 (5919 days ago) @ daiwok
Hi David,
Filter design may be you are right as its optimised for your flare, but if
the cut off is the same then the filter should work right ?
No ... wrong.
I think there are too many "soft" properties like the material of the horn, the stiffness, the resonance, the gradation of angles (including the end of the mouth) to be ever able to use the same filter.
Creating a new one ... my guess : many hundreds of hours.
Peter
AER MD3 or BMS 4592 ND
by Bert , Wednesday, February 13, 2008, 10:06 (5919 days ago) @ daiwok
Hi David,
Filter design may be you are right as its optimised for your flare, but if
the cut off is the same then the filter should work right ?
It will work but the absolute result and balance will not be the same. I would not mind selling you the parts though but without warranty if it does not work out in your own designed horns... :wink:
Would love the opportunity to hear the Orphean - anyone has a pair in Hong
Kong ?
No, not yet in Hong Kong as far as I know but someday soon in Shanghai?
Bert
--
BD-Design - Only the Best!