15NW100 BC Horn

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   Danley's BC sub horn designs seem to have specs that per cabinet/driver/power out-do pretty much anything else out there right now. Originally after seeing the BC218s I was wondering if the same principle could be applied to some 15inch drivers to lose some weight (BC218s clock in at about 500lbs) size and lose some extension but still remain solid down to 30hz. Since then Danley has released the new BC215 which when used in a stack of 4 has a continuous output rated up to 150db and a +/-3db of 33hz; this is madness. I don't have a need for 150db, but I think I've managed to come up with something that should be able to provide 140db continuous at a reasonably smaller size. The complete horn is designed as 4 cabinets stacked together, here's the attempt simmed in 1pi same as all of Danley's BC measured responses (EDIT Danley’s are measured in 2pi**)

Now I don't have great expertise with horn folding so I'd appreciate some critiques here. This was done in Blender and if there's enough demand I'd be glad to show everyone a walkthrough on how it's done, although I have yet to fully figure out how to export the data for CNCing but it does look like there's a way to do it, and for further context on the mouth and orientation of the horn you can see Citizensc's Akabak sims from an earlier discussion on the topic: https://forum.speakerplans.com/bc-horns-from-standard-flhs_topic105665_page1.html

So some notes; a -3db of about 30.5hz, this max continuous SPL is driven by 1700 watts (that's just 425 watts a driver). Is there any reason that using a fair bit less than the rated power would be a negative? The 15NW is rated 1000 rms, 2000 peak which leaves us quite a bit of headroom for peaks. Displacement however hits xvar of 11mm at 3400 watts which is only 3db of headroom. My question here is what's the risk of hitting 14-16mm of displacement on peaks for 6db of headroom? I'm assuming xmech is substantially above xvar so distortion on peaks if you're really cranking these could be acceptable atleast for a little while. My intention here though is not really to ever run these at max output; 130-137db is probably plenty for my needs (50-500 people max, dub/dubstep/dnb/funk/hip hop/house and pretty much anything else that might use sub around 30hz). Group delay with filters enabled is a bit sub optimal, however this can be reduced to about 35ms at 32hz with LW filters and for most front loaded horns I haven't really seen anything that confidently beats this. Even the new Paraflex designs seem to have similar group delay. Compression ratio is 2.6. Current box dimensions are 46" by 29.8" by 20.5" (I'm really trying to save as much space as possible). Also similar to the BC215 design I'm planning on placing some corner reflectors on the top so I can cut handles directly into the frame. I'm also really hoping these will come in under 150lbs each, but I know this is probably way too optimistic especially with bracing.

SO any thoughts/questions/critiques here? I'm really looking to pull the trigger on buying parts either this week or next. Been learning and planning for about 8 months or so now and would like to have atleast a few of them built before the end of the year, but this is my first ever speaker build project and the last thing I want to do is rush into things and waste about 2-3 gs. Also as just a final note I’ll be cleaning up the precise folding and am curious about the best way to overlap the borders around the bends? Specifically the 180 degree bend you’ll see the sections are a bit sloppy.

Edited by KaphaSound - 23 November 2020 at 10:16pm