A couple of people have asked for plans for my bdeap clone, which i've called the terminator horn.  There are 2d plans on photobucket which are the are the final dimensions i worked with.  I'm not strongly recommending anybody build them, as i've hardly experimented with them myself yet, the compression ratio is the biggest thing i want to play with.  Also i'll modify the design (and retrofit to my exisiting cabs) something to reduce coupling between the pairs of speakers in them (i use 2 amps to power it at the moment so gain imbalances might be stressing the speakers unduly, this would help alleiviate this in the event of 1 amp failing.)

  I've made a google sketchup model that is shared as "terminator horn".  Actually it ended up 18mm too large ) So if u use google sketchup, u can get a useful 3d plan to understand the 2d plans better.

 

The 2d plan:  I think internet explorer cant render this gif, but firefox did.  This could be followed exactly, however alot of the compound mitres are best made by trial & error with a power-plane & belt sander, especially the baffles & mouth reflectors.

http://s128.photobucket.com/albums/p188/rave-roborg/new%20system/plans/?action=view&current=bdeaprtt_12mm_200.gif - http://s128.photobucket.com/albums/p188/rave-roborg/new%20system/plans/?action=view&current=bdeaprtt_12mm_200.gif

 

a video showing the internal 3d layout & intended stacking of two cabinets to form the boundary dependent external air-path (bdeap )

 

big version (72megs): http://www.filefactory.com/file/af8a5df/n/Terminator_Horn_4xCiare12_00SW_3_29_2009_avi - http://www.filefactory.com/file/af8a5df/n/Terminator_Horn_4xCiare12_00SW_3_29_2009_avi

small version (9megs):

http://www.filefactory.com/file/af8a50h/n/Terminator_Horn_4xCiare12_00SW_3_29_2009_divx_avi - http://www.filefactory.com/file/af8a50h/n/Terminator_Horn_4xCiare12_00SW_3_29_2009_divx_avi

they are both divx6 but the first one is very high quality...

 

I hope some1 decides to build more of them (i'll have 4 soon )

 

cheers,

  Rob.

  However, bear in mind it has four 1Kw drivers in it.  The ammount of effort to build four 1 driver cabs of the same power handling would be considerably more (4 punishers is an obvious comparison) and the wood & weight savings are huge.  The final speaker built from void free Russian birch plywood with ceramic magnet drivers weighs less than 100Kg.  With the big handles at either corner it's quite easy for two people to carry up stairs, with four it's easy (its the same size but lighter than a lab-horn.)  The box is held at each corner with the four drivers at the bottom, so the people carrying it all stand upright, so there's less risk of back-injuries when the boxes do have to be moved by hand.

  If 4 neodymium drivers are used the total weight would drop to about 75-80Kg, which for the power handling & size is excellent.

  Also i must say that despite being built out of 12mm plywood, it is totally robust.  There is no panel vibration when it is being driven (not usually the case for 12mm builds)  This is due to every panel having alot of internal bracing, this is something that worked really well with the design.

  The mouth and handle supports are all doubled up 12mm ply too, so they are 1" thick where the cab needs strength.

  The access panels are made of 4mm aluminum alloy & have been crudely bolted on in this design, i'd recommend recessing them (i'm lazy) They are also heatsinks for the drivers, which i think is essential.

  I'll sell the design more & say that at the same output levels, distortion levels will be close to a lab-horn, this is because even though the drivers in this, ciare12.00sw's have a much stiffer suspention, they will be excursing roughly 1/2 as far as the lab-12 in the labhorn.  However, this has five times the power handling of 1 lab-horn + heatsinking, so possibly up to 10x the long term power handling.  This is also a very responsive/fast horn, mainly due to the air-load on each driver being much smaller than in most bass-horns.  In real use there is little benefit to using a kick horn before an MT122(dual 12") style mid range horn (except for higher power handling & lower intermodulation distortion).  I typically cross out of this box at about 120hz.

  Finally, i designed them to be used in pairs, as in the video, in this configuration they look good to go to 30hz half space.

 

cheers,

  Rob.

  The main difference being that my design has 4 drivers rather than 2.  I wanted to get as much power as possible into a manageably sized speaker cabinet.  It's possible to get four of these+2midtops+racks,cabling,decks etc.. into a typical long wheel base van & the whole system (with lightweight amps) could weigh less than 700Kg for 20Kw's worth of speakers!

edit: its soundphysics not servodrive, i think they were the same thing at some point check out http://www.soundphysics.com/SPL-BDEAP32.html - http://www.soundphysics.com/SPL-BDEAP32.html

i'd be really interested to see some SPL measurements .

  Some mobile pix show them here:

 

 

I used two stacked correctly at this party, but never got to turn it up (too loud for the croud , for me it was just getting there )

 

PS the mid-tops are just placed like that, it's not stacked or anything official like that

 

so far they've only been run in pairs indoors with little experimentation time.  The first time i used them in a pair at 90degrees to each other they performed a bass-walk over about an hour & pivoted around until the fronts were level (maybe they auto-adjust for optimal output )

  When i get the system outdoors & fix all the little niggles (which are actually all show-stoppers!) i'll make an honest attempt at quantifying things.  My suspicion is that, with music, there will be little audible effect from 90-180degress.  It'll be interesting to find the best angles for hifi or low output.

  Overall I'm totally satisified with the sub-bass reproduction indoors.  Two together seem to deliver everything thats needed for low extention, but they still sound capable up to 150hz (i need to do some A/B comparisons to make any real claims)  I've yet to run them really hard too, in which case kick is going to be modulated quite a bit by the low output.  I want these boxes to be really good for the first 2 octaves, i dont want to have to convince myself of this!

 

 

It's unlikely i'll attempt a precise spl measurement, i dont have the equipment for a measurement to be comparitively useful (also if it was suprisingly good, no one would believe me )  For me the actual spl value is not important, i just know i want a big hornloaded bass section!

  The design is justified in terms of its intended role: i wanted a system with about 15-25Kw hornloaded bass that could fit entirely in a single van & weigh less than 1000Kg with everything.  It remains to be seen if i can drive these with the power i want (8Kw of amplification per cabinet, so actual power input of 2-3Kw long term with good headroom) and get high reliability.

  So far it looks good.  Even with dust-caps blown off the speaker still produces good output  So far one cabinet has been run with 2 behringer ep2500's for at least 40 hours loud.  One run of about 5 hours was with deliberately fattened-up heavily compressed bass with the two amps combined mains draw hitting 20 amps & a few breaker pop-outs, so I reckon the speaker got about 2-3Kw long term & didn't stop making bass!  I slightly off-coloured (IE almost cooked) two of the ciares voice coils with this run too, they still work tho (one actually burst a damaged dust-cap that i'd reglued back on!)

 

  xover at 100hz sounds really quick. at 130ish it still sounds good, >150hz starts to loose clarity)  theres pix here: http://s128.photobucket.com/albums/p188/rave-roborg/new%20system/build/ - http://s128.photobucket.com/albums/p188/rave-roborg/new%20system/build/  its loaded with 2xsn12-b & beyma cp750ti on a p-audio ph-4230.  The mid, like all dual 12"s sears your ears off when its loud, but this one skewers u with the spikes when its quiet   The phase bungs/spikes fit to within 1cm of the drivers.  When i get round to it/when some substantially better drivers than sn12b are invented, i might mould some fibreglass inserts.  X-over to the driver is usually at about 800-1khz.  I'm still looking for a really nice supertweeter to take over from the driver.

 

cheers,

  Rob

 

what do you think are the main differences with yours and the original bdeap32?  obviously you have double the drivers, and therefor your folding etc will be different.  how does an original bdeap look inside?  i notice you have included further horn shaping at the mouth..  why do you think the original bdeap doesnt have these pieces present at the mouth?

Hey roborg,

I've been doing research on any available DIY Boundary Coupled subwoofer designs and yours was recommended in another old thread. I found your SketchUp model and completely re-drew it in CAD:

Do you mind if I published this new file (together with the original SketchUp model) on my GrabCAD page to make it more available for others to study & run simulations?