Change the dimensions in smaller steps
The regression analysis in those workbooks isn't perfect, and trying to change any dimension in a dramatic fashion could lead to what you experienced. To avoid that from happening, change the dimensions in smaller steps, e.g. 50->60->70->80 rather than 50->80.
Brian, I tried that. But some dimensions need as small as 1 or 0.5, as dimensional increments to avoid messing up in the optimization stage. Probably very sensitive designs, looks like.
The BOXPLAN-MWTH workbook is a bit more complicated than most of the others. It requires the user to adjust five variables for the box layout - the external dimensions and the start and ending CSAs of the horn. I suggest that if you're expanding the external dimensions, expand the values for S1 and S5 by a proportional amount as well. If necessary, turn on the "advanced centerline" and "sample points" graphic options, and manually adjust the lengths of the internal panels until the expansion looks fairly smooth, then use the "Optimize!" feature to complete the job.
Even then, you may find that it's simply not possible to fit an optimized MWTH fold inside the dimensions that you want to use. In your specific case, it might not be possible to fit an optimized one in the dimensions 120x100x75, but I was able to find a solution that fits in 120x80x75
Even then, you may find that it's simply not possible to fit an optimized MWTH fold inside the dimensions that you want to use. In your specific case, it might not be possible to fit an optimized one in the dimensions 120x100x75, but I was able to find a solution that fits in 120x80x75
Attachments
Thank you, Brian. 120x80x75 cm is even better than what I intended to work with (20 cm of extra space!).
But this need for stepping etc. reminds of typical static FEA structural analysis. Most FEA software come with certain basic logic that allows them to adapt the incremental stepping of the load based on certain predefined criterion. Is this possible to implement for this and similarly complex worksheets? I have a very basic knowledge of python...
Remember that BOXPLAN can only find an optimized fold for a particular box. It might not be the best box design for the driver that you want to use. That's where the corresponding Hornresp sim comes in.
All of the BOXPLAN workbooks are at various stages of development. There are checks and balances in some that are not present in the others. Yet
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All of the BOXPLAN workbooks are at various stages of development. There are checks and balances in some that are not present in the others. Yet
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Feature request
Hello Brian,
Since horn subwoofers perform better when placed in corners, I request atleast a few spreadsheets be created to accomodate right angled isosceles triangle shaped subwoofers, that fit right into a room's corner, a space that generally tends to be least utilized in any living space. I think Scott Hinson, Roar and Cyclops designs lend well to such corner designs.
Hello Brian,
Since horn subwoofers perform better when placed in corners, I request atleast a few spreadsheets be created to accomodate right angled isosceles triangle shaped subwoofers, that fit right into a room's corner, a space that generally tends to be least utilized in any living space. I think Scott Hinson, Roar and Cyclops designs lend well to such corner designs.
Paraflex
I reasonably assumed that a higher order design like a paraflex would create a great subwoofer with excellent bandpass characteristics, i.e., with most of the driver energy concentrated within the pass band, but with the impulse response being smeared. But both the templates seem to produce hornresp files that simulate with pretty bad looking FR curves and impulse response.
Quit a few of your more mature sheets feature "optimization" that generally gets quite in the ball park of good performance and some even suggest optimal dimensions. Do you plan any such optimization feature in paraflex spreadsheets too?
I reasonably assumed that a higher order design like a paraflex would create a great subwoofer with excellent bandpass characteristics, i.e., with most of the driver energy concentrated within the pass band, but with the impulse response being smeared. But both the templates seem to produce hornresp files that simulate with pretty bad looking FR curves and impulse response.
Quit a few of your more mature sheets feature "optimization" that generally gets quite in the ball park of good performance and some even suggest optimal dimensions. Do you plan any such optimization feature in paraflex spreadsheets too?
The "Optimization" routine included in many of the BOXPLAN workbooks only optimizes the physical layout of the described alignment in the external box dimensions provided by the user. It doesn't make any attempt to optimize the resulting response curve of the sim - to do that would require a lot more coding and access to an API for Hornresp, which is probably not going to happen in a hurry .
The "paraflex" BOXPLANs, at least the ones that I've done so far, don't need an Optimization routine, as their layout can be easily derived from external dimensions provided by the user. For other types of designs, that derivation isn't so straightforward, hence the Optimization routine, which uses Excel's regression analysis to find the best solution for the internal layout.
If you're not getting good results with a particular BOXPLAN paraflex, try changing the external dimensions of the box in the workbook, export the resulting Hornresp sim and reimport it into Hornresp (pressing F6 in Loudspeaker Wizard). Do this a few times and you'll quickly get an idea of how much you'll need to change the dimensions of the box to achieve the response that you're looking for.
.The "paraflex" BOXPLANs, at least the ones that I've done so far, don't need an Optimization routine, as their layout can be easily derived from external dimensions provided by the user. For other types of designs, that derivation isn't so straightforward, hence the Optimization routine, which uses Excel's regression analysis to find the best solution for the internal layout.
If you're not getting good results with a particular BOXPLAN paraflex, try changing the external dimensions of the box in the workbook, export the resulting Hornresp sim and reimport it into Hornresp (pressing F6 in Loudspeaker Wizard). Do this a few times and you'll quickly get an idea of how much you'll need to change the dimensions of the box to achieve the response that you're looking for.
The "Optimization" routine included in many of the BOXPLAN workbooks only optimizes the physical layout of the described alignment in the external box dimensions provided by the user. It doesn't make any attempt to optimize the resulting response curve of the sim - to do that would require a lot more coding and access to an API for Hornresp, which is probably not going to happen in a hurry
The "paraflex" BOXPLANs, at least the ones that I've done so far, don't need an Optimization routine, as their layout can be easily derived from external dimensions provided by the user. For other types of designs, that derivation isn't so straightforward, hence the Optimization routine, which uses Excel's regression analysis to find the best solution for the internal layout.
If you're not getting good results with a particular BOXPLAN paraflex, try changing the external dimensions of the box in the workbook, export the resulting Hornresp sim and reimport it into Hornresp (pressing F6 in Loudspeaker Wizard). Do this a few times and you'll quickly get an idea of how much you'll need to change the dimensions of the box to achieve the response that you're looking for.
I asked David about command line access to hornresp but turns out, it's a pretty old request and will pretty much never happen
I did figure that Paraflex worksheet is a matter of changing dimensions. But sheets with optimization seem to give good output at the first try itself, without much need for change. eg: Tapped horns and the Scott Hinson designs.
Wondered if it's just a function of the designs themselves or maybe something else going on in the background, in the sheets.
I asked David about command line access to hornresp but turns out, it's a pretty old request and will pretty much never happen
I did figure that Paraflex worksheet is a matter of changing dimensions. But sheets with optimization seem to give good output at the first try itself, without much need for change. eg: Tapped horns and the Scott Hinson designs.
Wondered if it's just a function of the designs themselves or maybe something else going on in the background, in the sheets.
Paraflex wants to look funny in a response. but some of its charm is the rippled and rising or similar?? It would seem and certainly cant deny its delivery of the bass. It a freaking ‘whip’ just behind/ahead/around?) the punch...it even hurts! Lol
. But, I dont know if it wouldnt be fair to just create a ‘dual- triple’ qw pipe version of roar or paraflex that looks fine in the ‘phase’ section of its simmed regardless, and if no voids of cancelation from excess in any direction, theres a generic source of straightened out bass and with plenty of it to tweek ekectronicakky to taste, to dsp as needed to flatten anything unwanted exceess? If so, then its EASY!?. Ive got tangbabd w5 1138s and peerless 6.5s with 6mm of xmax that seem to be just fine, and a bunch of 12” stuff from car audio along with an isobaric paraflex morph(its the reason i refer to a ‘spike/ cleanup) ??
Paraflex wants to look funny in a response. but some of its charm is the rippled and rising or similar?? It would seem and certainly cant deny its delivery of the bass. It a freaking ‘whip’ just behind/ahead/around?) the punch...it even hurts! Lol
But, I dont know if it wouldnt be fair to just create a ‘dual- triple’ qw pipe version of roar or paraflex that looks fine in the ‘phase’ section of its simmed regardless, and if no voids of cancelation from excess in any direction, theres a generic source of straightened out bass and with plenty of it to tweek ekectronicakky to taste, to dsp as needed to flatten anything unwanted exceess? If so, then its EASY!?. Ive got tangbabd w5 1138s and peerless 6.5s with 6mm of xmax that seem to be just fine, and a bunch of 12” stuff from car audio along with an isobaric paraflex morph(its the reason i refer to a ‘spike/ cleanup) ??
Intention of paraflex design is to smoothen out the higher end of a tapped horn's bandpass-like response by coupling another quarter wave resonant tube on the form of a throat chamber, corresponding to the higher end of the band pass. I imagined that I'd achieve a flatter FR at the cost of worse impulse response. But thus far it looks like worse of both the worlds.
Offset horns and tapped horns look better in every sense, thus far.
Spot on. Someone finally looking at it and with a keen interst! , youre like a breath of air in the surrounding toxic waste gases. Thank you!
So, if i can pick your brain for a mombt? Please, if we look at the result of the single qw pipe in each (seperate) from a pump in opposite polarities of its pressure cycle in strokes of 200 cm/second.. And treat the long pipe as the initial reference for a ‘total’, and apply the ‘punp in a ‘pipes’ physics to it, we want to pump from the affective center of the pipe action and thats at the 1/3 from closed end. Then it guarantees the pressure bounces off the closed end 100cm away, and cones back 100 cm to the ‘pump’ and that ‘pressure’ then travels 100 cm and another 100cm to the open end if the pipe. 400total. And with a fundamental of 1200cm, or 900cm? I dunno tet, but
The otherside, it has a pipe, it is end fired and so its not ‘ideal’ and will be out of sync with those 200cm/sec strokes if its the same length but at the closed end .
However, it will have traveled 200cm. And just a wobble in everyother 200cm stroke of the opposite hand polarity piston pump. As a result it spits out half the length at 180 degrees, if at 90 degrees per 100 in cm of 720, and if using 1200cm fundamental.
But the pipes are shunted, and connected at the velocity max for a 200cm cycle.
If we want that to be perfect we need to assume a few distances in length are functional and in polarity as well as phase of the 180 position verses zero and 360.
halfwave in each pipe from the other is pressure offset now by the same 200cm and if summed that ends up 1/3 into the long pipe from each source (and one at a bounce).
If i look at my paraflex, i cant see much of the things i can in other sons, or even the compound horn. But i can remove everything thats not in compound horn and compound horn1 even allows me to see what that pressure wave does as individuals(not Siamesed and shunted so to speak).
this has really helped when designing a paraflex classic, alternate and even the ROAR qw pipes. I dont know if itll be useful to you or even if the analogy fits into the many many functions besides a pumping irrigation type of ? But if you can suggest anything in particular or add more or better, of your own, please do! That thick and multiple layer of mystery isnt gonna clear itself away without many thoughts and perspectives . You often have a keen eye for that it seems.
Search FB group ‘ quarterwave theory’ by Benjermin Dodson if you get a chsnce? if not too serious about anything in particular except fun and less than perfect searches for it in qw. gimme a shout? Its not even established or active really, but its there. Youre already invited and anyone else you might think?
