Hey all

So, a while back I had the absolute pleasure of hearing the Danley BC215. This was the most hifi, absurdly fast and absolutely physical subwoofer i have ever heard in my life. I was absolutely blown away, especially considering there were only two of these boxes setup outdoors.

The BC subwoofer is another unique subwoofer alignment from Danley Sound Labs. Using woofers that combine into a single exit provides impressive punch and extension out of a single cabinet. Due to the physical size of the BC design’s center exit the boundary exhibits forward directivity which can be increased with multiple enclosures.

I think they are an FLH, with two drivers, with a side exit, (or 4x 15" for the BC415 or 2x18" for the BC218) designed to be used next to each other with the exits coupled.

BC215/415: -3@33hz and -10@28hz. 

BC218: -3@26hz and -10@22hz

I heard these outside, away from any walls, and it was incredible.

https://www.danleysoundlabs.com/products/bc215/" rel="nofollow - BC215

https://www.danleysoundlabs.com/products/bc415/" rel="nofollow - BC415

https://www.danleysoundlabs.com/products/bc218/" rel="nofollow - BC218

Do you have any idea what this design is, or where I can find a plan something similar? I would love to be able to DIY these. Any input would be appreciated!

Also sharing plans for commercial products is not what we do here. So please stop asking for it.

MarjanM wrote: These are commercial products so free plans do not exist. Also sharing plans for commercial products is not what we do here. So please stop asking for it.

Really, I meant I'm interested in anything based on similar concepts. I didnt mean I only was looking for the exact plan

I apologize, I have edited my post to reflect this

Who was it on here that did the bc design ? or was thinking about it. 

I think maybe one of the American forums might be more help. 

Yes labs still deliver just big and Hevey. 

Iirc  recently joined member "kapha sound" started a thread on this..... should be easily found by browsing, i saw the thread the other day, should be on page 1 in one of the main forums (other designs, new projects, etc......) 

Small gaps of a few inches between boxes or the ground won’t affect much loss in directivity gain. 

Ok Sh**t... Wrote a rly long detailed response and reload the page and all is gone...

But happy to tell more this time a bit shorter haha

Dutch based and I build as a hobby a Soundsystem with my friends/crew.

Currently still at a early stage.

Tops: JBL HLA 4895 x4 so currently run 2 pairs in stereo but planning to get more potentially in the future.

Amps are all Crest CA but also a few Crest pro series (old once).

DSP are London soundweb Blu series but also got a Xilica XP4080 and a XTA448 not yet fully decided what to use in the filed but tend towards London soundweb atm.

FOH mixer: Midas U16

System mainly used for electronic music anywhere from slow to very fast (BPM in the hundreds) both low and high distortion music.

Subwoofer section is atm still fully missing which is why I am asking here because I was very happy when I heard the old bDEAP subwoofer Tom designed before the BC series.

The combination of High sensitivity and directivity without the need to use cardiod... Makes me especially intrested into this design besides the fact that I found the sound characteristic the last time I heard them very convincing them being able to play quite high having for my oppinion a nice transient response and "kick/punch" characteristic (ofcause not unique but still). And the distortion characteristics if I remember where also rather nice not being high especially when crossover the subwoofer somewhat higher.

So obviously I can't afford due to it being a hobby besides UNI to buy real BC subs and bDEAPs being not available atall in Europe knowing only a single person who owns them personally.

So because of that I look for plans simmilar to these designs. I like the fact that the Bdeap used 12 inch drivers with the only negative aspect being that they are not designed to be layed on their sides like the BC215. (Because the JBL HLA are quite big so I need a bit base to place them on)

So anyways I hoped that maybe here someone was able to design a subwoofer of simmilar character that he might be willing to share with me because my personal simulation skills in AKABAK... Are still quite limited and I wouldn't know how to model and design subs like these.

Hope this answers some of ya questions if not... please feel free to ask.

Yea I already considered to just build the Bdeap because of the puplic domain. Just currently don't have the exact internal dimensions because the patent paper only includes the layout and ya can figure out the horn length but exact once might be ofcause best.

The only issue with them are that I would need to use for example scaffolding for the tops because the tops are 800mm deep with the Bdeap being quite short in the depth (something like 600mm? Or soemthing like that)

So a modified version which would allow to lay them on the side like the bc115 would be ideal but wouldn't know what's the way to design the modification altho I can imagine there prob some not too complex maybe.

And yea I guess it's the respondse which also goes white high and the amount of air 4 of these stacked once can push in such an small area.

I'm not sure this has been cited in this thread but BDEAP clones were done by members more than a decade ago.

https://forum.speakerplans.com/terminator-horn_topic25407_page1.html" rel="nofollow - https://forum.speakerplans.com/terminator-horn_topic25407_page1.html

Oh haha I never saw that thread normally looked at all of them but yea this one also don't got the messurments but there was one on another forum where they already made a guess but it was too uncertain for me.

But I got outside messurments somehwere I think I will take a look atlest i can share them from the tech sheet already the others are maybe on a hard drive I can't access atm

http://www.best4show.com/files/produkte_2_SPL-Bdeap-32.pdf

Here is the tech sheet  and I just realised I talked totally BS above about the depth... Excuse me.

106x106x46 cm

https://imgur.com/a/1fYwVdm" rel="nofollow - https://imgur.com/a/1fYwVdm

Ah yea true that you would have a bigger chamber altho ya would also have a smaller horn path right needing to make the speaker a bit larger to compensate ?

Yea I can imagine newer drivers with more power handling can be nice with more xmax. The ciare and xeleston def look not bad but the B&C response I found not very nice actually for this subwoofer application maybe I get it wrong but the 12BG fell off super early.

The only thing for me would be that I especially look for sensitivity because I work with the older Crest amps I don't got as much power available as it I would have if using Powersoft& co so I like to find a nice Ballance for that.

Contour wrote: Just start a cad drawing using those dimensions, and see if you can fit LAB 12 drivers in there, just as shown. If that fits, most other dimensions should also be close to reality.

Fitting the driver probably not the issue next month when I got my workstation back running I will probably draw up a example. Just with the exact folding of the horn... I am not quite certain. Managing a working horn is probably not a big issue but getting the horn folding optimised I imagine is a bit more tough. But yea I am not very experienced with that haha

Yes but the loss of this first fold is much less significant in these external boundary designs because your horn path is extending outside the box. 

Also consider that the box is already huge and you’ll only need 2. May as well make them 1220x1220x810 in which case the horn path ends up being something like 3m even more I think. It‘s the least of your worries with this approach. 

I know what you mean with the BG. Do you want to share your input data? You can change that roll off by adjusting the expansion rate of the horn. There’s also some other things worth discussing re how to simulate the inside/outside transition, horn mouth size etc 

Sorry only just read this and other posts. Thanks for sharing. Also, didn’t realise you were using Akabak not horn resp. I haven’t used akabak but would be interested to learn. Can help with horn resp though. 

Cheers

I could email you pictures of my plans. I’m reluctant to put stuff up on here because of those Chinese’s thief’s. 

As I understand it the main point of this approach is that when two boxes are  together with their large side facing forwards (in other words placed on their edge) and the relatively small openings placed together in the centre on the ground, the large outside front face of the combined boxes becomes part of the horn. Therefore it seems appropriate to simulate the arrangement by including this extra section. Effectively the full length from the ground to the top of the box. The effective horn mouth also dramatically increases and imo should be simulated as such. 

In the case of the patent image it’s 1.5m inside the box then the extra 1m for the external boundary. As I suggested building a design that’s 1220x1220x810 (to make efficient use of ply wood dimensions) which is a bigger physical box than the box in the patent, then horn path in this case would extend beyond the 3m mark. 

Cheers, and no sorry I don’t have any evidence to back this claim up but it does seem pretty straight forward tbh. 

Sweet technical flex Fudge, but to me it’s a simple horn. The path is expanding inside the box, the cross sectional area of the combined horn paths transitions into the opening which shares the appropriate cross sectional area for that point in the horn to continue expanding through the opening, then the horn continues to expand with the front face of the boxes and the ground until it hits the edge. Complicate it all you like but to me it’s very straight forward. Or bent, as it were ;) 

For example I couldn’t ever understand why the cross sectional area of the horn paths inside the box just before the opening were bigger than the cross sectional area of the opening. This is probably some super technical aspect of those designs that I obviously don’t understand, or maybe it’s not and it’s just the way they build them because it doesn’t matter much, who knows…

Anyway I became much more interested in designing the layout so the last parts of the horn inside the box both have a cross sectional area equal to that of just under half the size of the opening (which you can see, btw, roborg had also come to that conclusion if you study those pictures). That way it’s all just another fold in the horn. This actually gave space to add more folds inside the box. (As this somewhat contradicts a previous point I was making regarding losing a fold in return for easier driver loading, I should say that I hadn’t realised at the time because I hadn’t looked at the plans for so long but also that my general feeling when working with these ideas was that indeed achieving a suitable horn length is not a problem at all here. Also I was addressing PTSD and I would have got more into those details later on as I did mention briefly. So apologies for somewhat contradicting myself there) 

More importantly, all of these ideas came together in a perfectly reasonable and simulatable (if that’s a word) way and in a box size that was very friendly to a sheet of ply. I’m confident it would work in this arrangement and the sims are stunning. Perhaps it’s not as technically savvy as some may require it to be to meet their standards but that doesn’t worry me at all. As long as the physical model is translated accurately to the simulation software which as far as I can see, it is, then it’s worth building. Call it the non technical external ground guidance sub. lol

If you like I could maybe try to translate it into a cad drawing and prepare it for AKABAK I am also no expert so at some point would also require some help figuring out how to get it fully correct. But in theory I could model in there also the case for 2 or even 4 subwoofers togather.

We could also keep the actual files and drawings by email... If you don't like to have it online untill maybe the plan gets more complete and it makes sense getting more input from the community.

Ofcause I would just take first a look to see if it's something I imagine because for me especially scalability is important.

Would you tho not get a way worse QW step response if it was a quarter wavelength pipe ? Because don't know any quarter wavelength pipe sub that is able to play this high without high distortion  but maybe I am confusing some things atm?

Having now read the patent, rather than just viewing an isolated image, it is now more apparent how the external surface increases the length of the horn; although I would dispute the claimed 1m extra. I couldn’t see a reason given for the reduction in area at the exit of the cabinet, so not an ideal horn.

However, I can’t think of any occasion at live events that I have been involved with, where this setup could have been used. There can be very few occasions where this design can be used to it’s full potential.

With regards to the claim in the patent that existing sound equipment does not take account of its physical surroundings, I can’t believe that they are unaware of Mr Paul Klipsch and his 1945 patent. The idea behind this design is not new.

Some of the technical information appears to have been lifted from Dinsdale’s series of 1974 Wireless World articles. Other claims are misleading and some information is technically incorrect.

Most of the supposed benefits of this design can be obtained with any loudspeaker by placing them against a wall, or in a corner.