Would like some help with building a monopole speaker with a BG RD75. I'm not much of a diy speaker builder so any info would be helpful. The monopole will be a center channel that will be sitting in front of and crossed over with a planar sub-woofer. I will likely use a minidsp to crossover between the monopole and sub-woofer. I'd like to crossover as low as possible (200hz?). The sub-woofer goes up to 350Hz.
I've tried to read through the thread on the dipole RD75 which seems to address a lot of the issues with reflection, cancellation, baffle size, and baffle edges. My guess is that a lot of these issues do not impact a monopole. What are the primary issues and secondary issues? I know I will need a notch filter to smooth out the response from reading the BG RD75 spec (I will implement this with the minidsp).
I'd like to build something looks similar to the Wisdom speaker that has a small horizontal footprint. Does anyone know the dimensions of this speaker at the top and base. Should the edges be rounded near the edge of the RD75? What interior volume do I need to get down to 200hz? How important is bracing and fill on the interior. Any suggestions on the construction and design would be much appreciated. Let me know if I need to provide further information.
I just want to thank you ahead of time for any help provided.
Regards,
GWho
I've tried to read through the thread on the dipole RD75 which seems to address a lot of the issues with reflection, cancellation, baffle size, and baffle edges. My guess is that a lot of these issues do not impact a monopole. What are the primary issues and secondary issues? I know I will need a notch filter to smooth out the response from reading the BG RD75 spec (I will implement this with the minidsp).
I'd like to build something looks similar to the Wisdom speaker that has a small horizontal footprint. Does anyone know the dimensions of this speaker at the top and base. Should the edges be rounded near the edge of the RD75? What interior volume do I need to get down to 200hz? How important is bracing and fill on the interior. Any suggestions on the construction and design would be much appreciated. Let me know if I need to provide further information.
I just want to thank you ahead of time for any help provided.
Regards,
GWho
Thanks for the pictures. Is there a minimum volume required. What kind of damping material did you use. What crossover frequency did you use? How does it sound?
GWho
GWho
There is a minimum volume mentioned in the spec sheet and the freq. plot is done with this enclosure. I am using a little bit less volume because I discovered this nice aluminium profiel ( used for advertising boards). Can not tell something about the sound, I am still in the building proces. It will be combined with JBL 2235 15" low drivers and will be powered with 4 Hypex Ncore's and DLCP
Thanks for the additional pictures. That is interesting. I will look into aluminium extrusions and see what is available out here.
StigErik - My main speakers are Dipole but the center channel will be sitting directly in front of a planar dipole speaker. My thought is if I made it a dipole there would be issues with the back wave.
GWho
StigErik - My main speakers are Dipole but the center channel will be sitting directly in front of a planar dipole speaker. My thought is if I made it a dipole there would be issues with the back wave.
GWho
You said this aluminum enclosure is used for advertising boards?
I have seen similiar shapes also for horizontal lighting fixtures.
Looks good and the internal shape benefits from non parallel surfaces.
Regards
David
I have seen similiar shapes also for horizontal lighting fixtures.
Looks good and the internal shape benefits from non parallel surfaces.
Regards
David
I agree. I will look around for an extrusion here in the states or build a box for the rd75.
Regards,
GWho
Regards,
GWho
Has anyone managed to track down this extrusion in North America?
It's quite brilliant that it fits so perfectly!
I've been dreading building a box for my RD75 drivers because I really wanted to do a curved back and that requires more shop time and effort than I have lately.
ds23man:
Can I ask how much you paid for your two extrusions, and if that company was good to deal with? If I can't find anything here in NA then I might follow up with them and see if they are willing to ship.
Also, your two drivers don't look quite the length of an RD75. Are they one of the smaller variants, or is it just a visual illusion?
Cheers,
Owen
It's quite brilliant that it fits so perfectly!
I've been dreading building a box for my RD75 drivers because I really wanted to do a curved back and that requires more shop time and effort than I have lately.
ds23man:
Can I ask how much you paid for your two extrusions, and if that company was good to deal with? If I can't find anything here in NA then I might follow up with them and see if they are willing to ship.
Also, your two drivers don't look quite the length of an RD75. Are they one of the smaller variants, or is it just a visual illusion?
Cheers,
Owen
It are indeed the RD-50's.
It cost me 600 euro's, the extrusions are sold with a minimum lenght of 3 meter and mine are 1,6m high. Price included the top and bottem cover which I do not use and the steel mounting feet.
It cost me 600 euro's, the extrusions are sold with a minimum lenght of 3 meter and mine are 1,6m high. Price included the top and bottem cover which I do not use and the steel mounting feet.
And after all this years you still have them and how does they sound like? I have some rd75 left and i like to build some similar like yours.
In the hopes of resuscitating this thread......
I am planning an enclosure for RD75's and Magneplanar ribbon tweeters.
I am planning an enclosure for RD75's and Magneplanar ribbon tweeters.
And what are your plans? I was hoping for answers and for hints more then a year ago 😱 . Well at the moment I am planning a sealed enclosure for the RD 75 analogous to the attached drawing, about 2 m high. In addition I build one or more subwoofers with isophon PSL 320/400s. All together actively driven with hypex plate amplifier model FA502
