BC horns from standard FLHs

The values put for VRC and LRC were largely based on citenzensc's BG horn calculations. I believe LRC is the average length from the driver within the rear chamber of 50 liters. To be honest I haven't folded the horn yet but I have an idea of what I'm going for and will adjust parameters accordingly, but playing around in hornresp changing the VRC/LRC by 10-15 didn't seem to have much of an effect other than in the high frequency resonances. Here's displacement and impedance for now, I'll have a look at simulating the face as well.

Edited by KaphaSound - 09 September 2020 at 3:46pm

Your phone was clipping, you need a good mic to measure at high level, 116 db of bass is nothing to write home about , if you remember it as heavy it was way louder.

A scale versus C scale measurements? Big difference... 

This was A scale rating probably over 20 seconds or so during a "drop" or just when the subs were clearly pumping. I'm not assuming this app or an iphone is a great measuring tool, but the difference from the 108 to 116 felt ludicrous, and the 108 was about as heavy as I'd need. I'm pretty sure at a reasonable distance (maybe 10-15m) from the PK rigs at Shambhala you're seeing low teens RMS and that's one of the nicest full body sound baths you can find imo perfectly balanced but if you want more you can always stick your head inside one of their Gravity 18s lol. I also thought a 20hz highpass is fairly standard considering some subs including the Danley BC218 are supposedly hitting 26hz at -3db but going up 5 more hz even still wouldn't drop the spl by as much as I would've expected. I still would love to know if there's a physics answer to the question of does more surface area of a stack move more air and therefore create a more tactile sensation? If you look at the PK rigs again they've got something like 20-30 double 18s stacked about 6 feet high for maybe 5-8,000 people. Surely 20 subs pushing 110db will be moving much more air than one sub pushing 110 and that's why I think bigger systems can give you a more tactile sensation at lower volumes. The Funktion rig for example was in London at E1 which you'll see is probably way over sized for the space but the sheer size of it means it's pushing a massive wavefront surely (note I was standing at the opposite end of the room measuring 116db but honestly in a warehouse like that I'm sure there's some nodes flying around).

Edited by KaphaSound - 29 January 2025 at 1:42am

Bc218 suggested crossover is 20hz indeed, but 24 dB/octave or 4th order, much steeper than your 6 dB/octave first order.

Ok now here's something seemingly much more interesting. The 18nw100 I believe uses the exact same magnet as the 15nw100 (same xmax/xvar and BL strength). I was inclined to believe that the 15 would outperform the 18 in a horn due to the significantly higher EBP, but not according to this. Would the sound be described as "looser" with a driver with a lower EBP or is there really no way to tell without listening? Also note that the length of this horn is actually smaller than the last with a significantly flatter response. I simmed the full horn this time but you can just quarter VRC/VTC/ATC and cross sectional areas and do multiple speakers for the exact same result. Also still keep in mind it’ll be somewhere between 1 and 2pi so I’d expect atleast some modest extension/sensitivity.

Edited by KaphaSound - 10 September 2020 at 12:57am