Hello all,
I am starting off on an overlty ambitious project for a novice and 1st time build and would like to ask this community for guidance.
Disclaimer/Constraints: All drivers and components have been purchased and I am out of cash so no component substitutions can be made at this time.
This will be an active 5 way open baffle speaker.
Drivers:
Bass section: 2 SB Audience 15 inch OBO woofers.
Woofer A will handle 20Hz to around 160-250hz
Woofer B will sit closer to the ground and will reinforce 30Hz to 80 Hz.
Mid Bass-Midrange: SB Audience 12 inch woofer 160Hz to around 800Hz.
Midrange: SB Acoustics Satori MD60N, 800Hz to 4500Hz.
Tweeter: Fountek Neo CD2.0, 4500Hz and above.
Crossover management:
Peavey Vsx 48E
Question: Given the number of drivers this is going to be a tall build. Would it be better to have the mid-range and tweeter mounted above the Bass section but below the 12 inch mid bass to mid range driver? I am planning on a minimalist baffle to mount these 2 drivers. I am afraid that mounting the 2 higher frequency drivers above the 12 inch woofer would put them significantly above a seated listening position. The 12 inch woofer would be angled down towards the seating position.
For the Bass module, I would prefer a H or U frame but for this initial build, I plan on keeping things simple and will go with a 24 inch wide baffle 1 inch thick baffle.
THANK YOU FOR YOUR INPUT.
NIK
I am starting off on an overlty ambitious project for a novice and 1st time build and would like to ask this community for guidance.
Disclaimer/Constraints: All drivers and components have been purchased and I am out of cash so no component substitutions can be made at this time.
This will be an active 5 way open baffle speaker.
Drivers:
Bass section: 2 SB Audience 15 inch OBO woofers.
Woofer A will handle 20Hz to around 160-250hz
Woofer B will sit closer to the ground and will reinforce 30Hz to 80 Hz.
Mid Bass-Midrange: SB Audience 12 inch woofer 160Hz to around 800Hz.
Midrange: SB Acoustics Satori MD60N, 800Hz to 4500Hz.
Tweeter: Fountek Neo CD2.0, 4500Hz and above.
Crossover management:
Peavey Vsx 48E
Question: Given the number of drivers this is going to be a tall build. Would it be better to have the mid-range and tweeter mounted above the Bass section but below the 12 inch mid bass to mid range driver? I am planning on a minimalist baffle to mount these 2 drivers. I am afraid that mounting the 2 higher frequency drivers above the 12 inch woofer would put them significantly above a seated listening position. The 12 inch woofer would be angled down towards the seating position.
For the Bass module, I would prefer a H or U frame but for this initial build, I plan on keeping things simple and will go with a 24 inch wide baffle 1 inch thick baffle.
THANK YOU FOR YOUR INPUT.
NIK
Greets!
If too high, then kerf cut the backside of the baffle to angle the top one or two down as required and use a small rubber or similar tube to fill the gap, somewhat decoupling it from the big drivers.
If too high, then kerf cut the backside of the baffle to angle the top one or two down as required and use a small rubber or similar tube to fill the gap, somewhat decoupling it from the big drivers.
Yeah, for MDF or similar, though renders the tubing moot; for box construction I only 'think' using no void plywood.
Mhhm... thinking of a half hexagon base and pyramidal frame. Truncated and with only the baffle for the woofers side. I mean, we're talking OB...
The upper frame will somehow hold the midwoofer ( a 12"!!) and the midrange and the tweeter would benefit a lot from being decoupled.
Rubber strings work well, select the diameter according to the weight, or add weight to the mid-tweeter ( group 'em for simplicity...) assembly. Or make 'em each suspended ...
The upper frame will somehow hold the midwoofer ( a 12"!!) and the midrange and the tweeter would benefit a lot from being decoupled.
Rubber strings work well, select the diameter according to the weight, or add weight to the mid-tweeter ( group 'em for simplicity...) assembly. Or make 'em each suspended ...
So you will have open baffle (acoustic) only up to 800Hz (Satori and Fountek have closed backs)
You can mount 15" woofers side by side or in W-frame to reduce height. Simply unnecessary to divide their bandwidths. Then of course the 12" low mid on top of it.
Open baffle (dipole) bass will roll off rapidly, so lowest bass will benefit the most from doubling woofers. https://www.linkwitzlab.com/LX521/Description.htm
You can mount 15" woofers side by side or in W-frame to reduce height. Simply unnecessary to divide their bandwidths. Then of course the 12" low mid on top of it.
Open baffle (dipole) bass will roll off rapidly, so lowest bass will benefit the most from doubling woofers. https://www.linkwitzlab.com/LX521/Description.htm
I would still put lots of damping stuff behind the drivers. Not sure why one would want the back wave of a vibrating membrane to emit in ambient as it represents the error ( 100 % being anti-phase) signal ...
I have a similar issue regarding my present build in that I wanted to fit two Beta 15as, an 8" midrange, and a Heil AMT on an open baffle. The Heil needs to be at ear level. So what I am building is a slot loaded side by side (cone to magnet) arrangement for the Beta 15s, similar to the XSD speakers. That way I get force cancellation, places the Heils at the top level at 38-40", and the midrange in the middle opening. The main caveat is that the slot manifold design uses much more material then a simple baffle mount. Plan "B' will just use one of the Betas ,mounted directly on the baffle, for bass.
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I think the manifold is a better design choice- force cancellation is really valuable for a OB. I think for such a design it would be pretty much the obvious choice to XO the 8" as low as you can readily EQ it and it sounds good at appropriate levels- In my mind, 150-200 is the right XO but not sure what the manifold will allow, 150 shouldn't be a problem IMO but you never know.
FWIW, the pioneer's way allows up to ~275 Hz, but its Fhm is only ~111 Hz factoring in some thermal power distortion, so anything in-between seems reasonable for the Beta 15a.
Would rubber bushings on the baffle mounting hardware provide the same effect?
For the Bass module, I've decided to be brave and build an h-frame. Once this is out of the way. I can work on different configurations of the other drivers.
One last thought. The choice of the Satori dome midrange was based on efficiency parity with other drivers and to keep beaming to a minimum.
Thanks to everyone else who has provided insight. I will post pictures of my plans soon.
5 way OB as 1st time build...
Will send you good wishes, but your active crossover needs to be of high quality to have any chance of success.
Maybe you can have a look at Ripole for the bass section, it is more compact than a u frame with 2 woofers.
By the way, if I were you, I would realy sit down and just think about the project and check what is your goal. The choice of the md60n is realy strange. Generally peaple try to have all drivers dipole. Some are even adding a rear firing tweeter or take open back AMT to have dipole all the way up. It's probably a good choice for a conventional speaker but here...
Even a little and chip faital 3fe25 or tc9fd18 or something like that may give better overall results and coherency
Moreover, trying matching same efficiency is useless whith active crossovers...
You are going to spend a HUGE amount of time here so swapping drivers should be a possibility even if takes 1 or 2 weeks to sell and buy something else...
By the way, if I were you, I would realy sit down and just think about the project and check what is your goal. The choice of the md60n is realy strange. Generally peaple try to have all drivers dipole. Some are even adding a rear firing tweeter or take open back AMT to have dipole all the way up. It's probably a good choice for a conventional speaker but here...
Even a little and chip faital 3fe25 or tc9fd18 or something like that may give better overall results and coherency
Moreover, trying matching same efficiency is useless whith active crossovers...
You are going to spend a HUGE amount of time here so swapping drivers should be a possibility even if takes 1 or 2 weeks to sell and buy something else...
I completely get this point of view. However, there seem to be multiple designs incorporating horn loaded compression drivers to handle these frequencies. Aren't these drivers unidirectional in their radiation patterns? I am not opposed to adding rear firing drivers at a later stage.
Thanks
It will be a fun and long-time hobby! Expect 1-3 years to study and try different configuratoins.
"Open baffle" loudspeakers typically exhibit dipole behavior up to around 800 Hz max, depending on baffle size and loudspeaker frame geometry. If you aim for a fully dipole system, you'll likely end up with a four- or five-way setup, where each driver has little to no baffle. In my case, my system maintains dipole behavior up to around 1500–1800 Hz, after which it gradually transitions to monopole. In my room, this hybrid approach works better than a fully dipole setup.
Full-range dipole designs can be fantastic, but they are far more sensitive to room placement. For them to perform optimally, you really need to position them 1.5–2 meters away from all walls, which requires a lot of space. I’ve also heard systems where only the midbass range (roughly 100 to 500 Hz) was dipole, and they sounded excellent. This frequency range is where cabinet colorations are most noticeable, regardless of how well the enclosure is designed or damped. It is also the range where a boxed speaker transistions from omnipole to monopole, thus from 360degrees to 180 degrees directivity whereas the dipole loudspeaker will be fairly constant at around 90 degrees which interacts better with the room. If you're accustomed to the clarity of dipole sound, those colorations can stand out even in extremely high-end speakers.
Ultimately, there are no hard-and-fast rules in loudspeaker design. If there were, all speakers would look and sound the same. The way a speaker interacts with your specific room and the placement options you have will always matter more than the design philosophy itself.
Full-range dipole designs can be fantastic, but they are far more sensitive to room placement. For them to perform optimally, you really need to position them 1.5–2 meters away from all walls, which requires a lot of space. I’ve also heard systems where only the midbass range (roughly 100 to 500 Hz) was dipole, and they sounded excellent. This frequency range is where cabinet colorations are most noticeable, regardless of how well the enclosure is designed or damped. It is also the range where a boxed speaker transistions from omnipole to monopole, thus from 360degrees to 180 degrees directivity whereas the dipole loudspeaker will be fairly constant at around 90 degrees which interacts better with the room. If you're accustomed to the clarity of dipole sound, those colorations can stand out even in extremely high-end speakers.
Ultimately, there are no hard-and-fast rules in loudspeaker design. If there were, all speakers would look and sound the same. The way a speaker interacts with your specific room and the placement options you have will always matter more than the design philosophy itself.