The construction of a multicell horn

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#226
I tried to pm Petter Perrson to ask him if it is ok to distribute his spreadsheet etc. My intention is to put the files in Google Drive so that anyone can download them. The problem is now that Petters inbox in overflown so hi is hard to reach. I also don't got the spreadsheet or the pdf.
 
#231
The OP said (post 12) that his horn didn't work as expected, so it was bigger than it needed to be:

Petter Persson said:
I would not cross them lower than 400-500 Hz. this is something that I found out after the horns were built. My intention was to use it from 350-400 Hz. Would be intresting to try them with JBL midrangedriver, because the 2445 is not ment to be used lower than 500 Hz.
Click to expand...
Therefore, if you're a perfectionist like the OP, you shouldn't simply clone the design.*

Hornresp can be used to generate variants of the much-sought spreadsheet. Here's how you'd clone the OP's horn:

(1) enter the values

Flare rate is given in post 1 as 183Hz

Throat size is 20cm^2
- or arbritrary, really, depending on your driver and adapter.
OP used a 2445, so to clone his horn, it ultimately has a 2" diameter or 20cm^2 throat

Total mouth size is roughly 3375cm^2
- One cell is illustrated in post 3** as about 15x15cm per cell (but this is not really critical; 20x20cm would also work). With 3x5 cells, each 15x15cm, mouth is ~45x75cm or 3375cm^2

These three numbers are all Hornresp needs. For me, it spits out:

Horn axial length as 77cm.

(2) Export the horn shape

Calculate the horn, then from the Schematic Diagram window, click
FILE - EXPORT - HORN DATA - RECTANGULAR HORN - EXPORT

(3) Spreadsheet it

Next, copy and paste that data to a spreadsheet. Add a couple more columns to divide the dimensions by however many cells you want in your multicell. Done.

:bullseye:

For a JBL 2445 and a 500Hz crossover, I'd suggest a smaller horn; 12x12cm cells and 50cm length models well for me. My simulation is pictured. The values I used for the 2445 are partly guesswork, and the sensitivity seems too low, but the LF response is about right.

*unless your driver is more robust / goes lower than the JBL 2445

**funny: I have seen this post before, but only just realised what the disc is. I saw them live last year. Good cheesy fun.
 

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