The Skram looks like an interesting design. Sort of a 6th order bandpass. I'm going to be busy for the next few weeks, but might have a look at doing a workbook for it after that.
BOXPLAN-6BPS
Current Version: 0.2 (beta)
This workbook can be used to design a series-tuned 6th order bandpass system. It also includes an additional feature that allows you to import an existing 6th order bandpass Hornresp sim as a target. To use it, you'll need to enter the driver dimensions and the desired box box dimensions. To use a Hornresp sim as a target, select the "Import" button to import the sim, then the "Best Fit" option to size the box dimensions accordingly. Then update the file location and driver parameters at the bottom of the spreadsheet and use the "Export" button to export a file which you can then import into Hornresp for further analysis.
Current Version: 0.2 (beta)
This workbook can be used to design a series-tuned 6th order bandpass system. It also includes an additional feature that allows you to import an existing 6th order bandpass Hornresp sim as a target. To use it, you'll need to enter the driver dimensions and the desired box box dimensions. To use a Hornresp sim as a target, select the "Import" button to import the sim, then the "Best Fit" option to size the box dimensions accordingly. Then update the file location and driver parameters at the bottom of the spreadsheet and use the "Export" button to export a file which you can then import into Hornresp for further analysis.
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Then don't do that, LOL.
Seriously, I'll have a look at it when next I get the opportunity to do so.
Lol! If you can make 1 of the side panels a port, then that's 1 less piece of wood you have to deal with! That why I like the different variations of TH's...7 boards minimum in their simplest form.
Lp1 can't be set to the thickness of the wood (in fact, twice the thickness because it crosses two panels), because that would reduce the width of Vc2, and therefore its volume, to zero.
I chose this specific layout for a series-tuned 6th order BP to ensure that it remained as close as possible to the topology of the Hornresp sim (the further you deviate from the topology, the further the measured results will deviate from the sim), while still resulting in a rectangular box.
The attached images show the topology of the sim and the topology of the worksheet's design.
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This is a very important point that Brian makes, and applies particularly so to band pass type loudspeakers, where the relative positioning of the driver / port tubes in the chambers can have a significant effect on the overall performance of the system.
I've done some updates to the 6BPS workbook. Now it allows you to enter the driver's t/s parameters (e.g. Vas, Qes, Qms) and semi-inductance parameters, and it will automatically generate the parameters used by Hornresp (BL, Cms, Rms, Mmd) and include them in the Hornresp import file if you export it from the workbook. I've also moved the driver settings to a separate spreadsheet, and the Hornresp import file data to a separate spreadsheet as well. The former will possibly allow in the future the ability to update the workbook with a driver database, which of course I'm going to import from Hornresp 
. Maybe I'll include a driver export routine as well, if I find the time.
. Maybe I'll include a driver export routine as well, if I find the time.Attachments
