You'll need to use the BOXPLAN-ROAR workbook for that. It's a fairly old workbook btw, and doesn't include the enhancements that the later workbooks have, like the ability to load/save drivers from the Hornresp database. Still, it is usable.
https://www.diysubwoofers.org/sheets/boxplan-roar.xlsm
If I recall correctly, the original ROAR18 box was reduced by 11% after it was optimized. The sheet in the link is for the optimized ROAR18 not 15. I am looking to have the size of the ROAR15 reduced for the same perfomance.
Mrscy,
You will find good instructions for how to use the spreadsheet at the bottom of Brian's "Horn Folding" page. On my browser I kind of stumbled upon them as you must scroll down some distance to uncover these.
I must have read these 3 times over minimum. The information there finally sunk in and from there I was off optimising to my heart's content.
The really terrific thing about the spreadsheets is that all you need to focus on is the drivers frame measurements (cos the driver must physically fit in the enclosure) and then all you need do is choose the outside dimensions of your enclosure. The boxplan optimise button does the rest. It's quite majical to watch the box be optimised little by little right in front of your eyes.
Want more extension - make your Box larger. What more efficiency - make your Box smaller.
The boxplan spreadsheets are the perfect complement to HornResp.
And the layout "graph" makes transfering the path dimensions to your build a complete breeze.
Boxplan are brilliant!
You will find good instructions for how to use the spreadsheet at the bottom of Brian's "Horn Folding" page. On my browser I kind of stumbled upon them as you must scroll down some distance to uncover these.
I must have read these 3 times over minimum. The information there finally sunk in and from there I was off optimising to my heart's content.
The really terrific thing about the spreadsheets is that all you need to focus on is the drivers frame measurements (cos the driver must physically fit in the enclosure) and then all you need do is choose the outside dimensions of your enclosure. The boxplan optimise button does the rest. It's quite majical to watch the box be optimised little by little right in front of your eyes.
Want more extension - make your Box larger. What more efficiency - make your Box smaller.
The boxplan spreadsheets are the perfect complement to HornResp.
And the layout "graph" makes transfering the path dimensions to your build a complete breeze.
Boxplan are brilliant!
Last edited:
Regarding the optimization of the ROAR designs there are a few things I think could be beneficial to consider.
1. The length of the qw resonator (L45) should be such that it's contribution is centered in the passband as defined by L12 to L23/L34 path length.
2. The area of the qw resonator should be 3xSd or grater depending on the the driver to not act constricting since this has to handle the summed output of the driver.
3. Consider the center brace position in the qw resonator as this may obstruct the driver mounting envelope and/or cause dificulties accessing the driver.
4. In some cases it can be beneficial from a responce and efficiency point of view to reduce the L12 to L23/L34 path length in order to lift the lower resopnse knee and thereby also center the qw contribution it the passband defined by it.
5. Strive for an area ~2/3xSd or grater in the L12 to L23 summed paths to avoid constriction since this is a constant area path.
Best regards / martinsson
1. The length of the qw resonator (L45) should be such that it's contribution is centered in the passband as defined by L12 to L23/L34 path length.
2. The area of the qw resonator should be 3xSd or grater depending on the the driver to not act constricting since this has to handle the summed output of the driver.
3. Consider the center brace position in the qw resonator as this may obstruct the driver mounting envelope and/or cause dificulties accessing the driver.
4. In some cases it can be beneficial from a responce and efficiency point of view to reduce the L12 to L23/L34 path length in order to lift the lower resopnse knee and thereby also center the qw contribution it the passband defined by it.
5. Strive for an area ~2/3xSd or grater in the L12 to L23 summed paths to avoid constriction since this is a constant area path.
Best regards / martinsson
Just experimenting with a different layout for the "Design" spreadsheets in the "Boxplan" workbooks. I've also updated the "SS" Boxplan workbook to allow a "pinch" at S2, just in case anyone wants to experiment with that.
I've been working on the workbook for the past few days and I'm not sure that I've got all the bugs out yet. If you come across any, please let me know.
I've been working on the workbook for the past few days and I'm not sure that I've got all the bugs out yet. If you come across any, please let me know.
Attachments
Brian I think it would be great to have a separate table for driver dimensions like some of the other BP workbooks do. It's great to be able to visually check how much physical space the driver frame and motor takes up in the horn path.
If the reset button does what I think it does this will be great when the folds get messed up by making very large changes to the overall box dimensions.
Having the compression ratio auto calc'ed is a major boon thank you.
If the reset button does what I think it does this will be great when the folds get messed up by making very large changes to the overall box dimensions.
Having the compression ratio auto calc'ed is a major boon thank you.
I've moved all the driver info such as the dimensions to a separate "Driver" sheet, as that information doesn't change very often when you're adjusting a sim. The "Driver" sheet also allows you to store and recall driver information in the Hornresp database, including the dimensions, so you only have to enter them once.
The RESET button actually just resets the target sim data (assuming that you've imported a Hornresp sim), but you've given me an idea - to add an option to store and recall BOXPLAN settings just in case the optimization routine goes awry, which can happen sometimes.
BP-MTH-266 with SWS-15D4
Have been enjoying this system in my HT for a few weeks with the Celestion AD15H loaded.
Just had a chance to install and measure the SWS-15D4 in the 266 litre BP MTH in my garage.
Note I changed the exit to the side so I can stand the enclosure on end and reduce floor space foot print so the horn length is likely a bit shorter than the HR predicted response.
I had the 80hz low pass switched on in the Onkyo TX-NR609 receiver I use for a preamp. Too noisy for the neighbours otherwise. No high pass filter engaged here.
The first graph below shows measured at mouth in Blue, HR predicted in RED (with LP 80hz 12 db applied). At 20v my little Biema W220II was beginning to light the clip indicator. The SWS seemed relaxed at this input voltage.
The second graph shows the HR simmed response in Red compared to Omnimics Pseudo noise in Black and Sine Sweep in Blue measurements - intrigued about the difference there.
Tapped horn fun!
Thanks again Brian.
Have been enjoying this system in my HT for a few weeks with the Celestion AD15H loaded.
Just had a chance to install and measure the SWS-15D4 in the 266 litre BP MTH in my garage.
Note I changed the exit to the side so I can stand the enclosure on end and reduce floor space foot print so the horn length is likely a bit shorter than the HR predicted response.
I had the 80hz low pass switched on in the Onkyo TX-NR609 receiver I use for a preamp. Too noisy for the neighbours otherwise. No high pass filter engaged here.
The first graph below shows measured at mouth in Blue, HR predicted in RED (with LP 80hz 12 db applied). At 20v my little Biema W220II was beginning to light the clip indicator. The SWS seemed relaxed at this input voltage.
The second graph shows the HR simmed response in Red compared to Omnimics Pseudo noise in Black and Sine Sweep in Blue measurements - intrigued about the difference there.
Tapped horn fun!
Thanks again Brian.
Attachments
Last edited:
Newest addition to the BOXPLAN family - "Cubo" type subs.
As usual, the BOXPLAN workbook can be downloaded from my Horn Folding page at The Subwoofer DIY Page - Horn Folding
As usual, the BOXPLAN workbook can be downloaded from my Horn Folding page at The Subwoofer DIY Page - Horn Folding
Attachments
Looking good! I'm still familiarizing myself with using your spreadsheets but I've already found them useful and intuitive. Thank you for providing them and the work you put in to maintain them.
Sincerely,
-LL