You just need to change the driver data, not the box data. You can recognize that in the posted spreadsheet or hornresp input screen. Besides you can replace driver model for the same box and get good results for existing plan or already built box, when you are designing, different driver will lead to some box differences, because their specifications are different and you can get the maximum performance for each driver.
Sd, BL, etc.
Sd, BL, etc.
Ask them for the HR input parameters or enclosure dimensions. Those 2 ports are not perfect triangles to divide a square port diagonally.
if all looks ok to you guys, i will start gathering the wood , and hardware ,
the drivers seem to be in stock on the webpage but they are on backorder till late december or start of 2023, gezzzzz ,
in the meantime i will start playing with REW so i can take real life measurements
as Art said, the games begin when you actually build a cabinet and then measure the response of it and compare against the simulated data
the drivers seem to be in stock on the webpage but they are on backorder till late december or start of 2023, gezzzzz ,
in the meantime i will start playing with REW so i can take real life measurements
as Art said, the games begin when you actually build a cabinet and then measure the response of it and compare against the simulated data
I see you posted my, in all modesty, awesome mspaint sketch featuring the infamous squares'n'circles, and the revised cutlist.
Hope it's all good.
Hope it's all good.
lol , indeed since you started designing this i always said that Kaffi was doing all the calculations and stuff.along this thread.
Thanks for all you help Kaffi, i am fiddling with sketchup to coax out some 3d of the box.
Max,
The simulations show that a pair of the dual PRV 15SW2000 2x15" in 330 liter cabinets (four 15", 660 liter total exclusive of plywood volume) you are considering would use about 2812 watts (75volts at 2 ohms) at 12.4mm excursion to produce similar output above 40Hz, and more output below than a single 18 (BC18Sw115-4) 340 liter Keystone at 15mm excursion using about 2352watts (97 volts at 4 ohms).
At present driver cost from Parts Express, the four PRV 15SW2000 cost a a few dollars more than the BC18Sw115-4.
Double the similar size cabinets, more weight, but the additional output at 30Hz may be worth it for some types of music.
Given the same 330L box size (x2) and four PRV 15SW2000, I'd choose a higher Fb, for more upper output, using 83 volts (3444 watts, same Xmax at the same vent velocity) and get a pair of cabinets to +134dB above 40Hz:
There are an endless variety of alignments that can be done for the same net volume.
For bass reflex comparisons in typical aspect ratio boxes using typical ports, Hornresp "Nd" (QL=7) works well, and requires less input.
Art
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wow, did not know that you can bypass all the S1,S2 and stuff info on horn resp with CL=7. where do you change that setting,?
in the other hand since i do not have a big hefty account to get materials i prefer to build one by one and start using them instead of wait till i can get a 750 buck driver, i know there is some individuals who can spend on it and do not break a sweat ,they can get 4 of those 750 bucks or even 1000 bucks drivers on a single buy, i am not in that wagon.
although i wish, but being practical i cant.
so Art if the Fb is raised some more i will gain 3 or so db in the upper bass, but actually i want to hit lower if that will make me feel much better what i experienced with the CW218's , i have observed that many sub designs make much emphasis on hitting 100 or 140 hz,at expense of loosing the 10hz that makes a difference of hitting 30hz instead of 40hz, personally i prefer to hit 30 at expense of loosing high range that on my type of music only make the stuff to sound muddy, the 125hz area it was never my cup of tea, on the LX18's it sounds horrendous, so i always do a bell cut there.
i was able to get a copy of the free discontinued Sketchup 2017 and i a started to fiddle with it, i will start doing the 3d models of the double 15's
if there is anything that you can add like port shape or bracing tips it will be very welcome, i know you are a legend in the DIY community
specially for sub cabinet designs and since you design multi panel horns, bass reflex to you is like 1+1=2
I know that you have much experience on where and how to add bracing to panels to minimize power loss because of the ply deflection phenomena.
in the other hand since i do not have a big hefty account to get materials i prefer to build one by one and start using them instead of wait till i can get a 750 buck driver, i know there is some individuals who can spend on it and do not break a sweat ,they can get 4 of those 750 bucks or even 1000 bucks drivers on a single buy, i am not in that wagon.
although i wish, but being practical i cant.
so Art if the Fb is raised some more i will gain 3 or so db in the upper bass, but actually i want to hit lower if that will make me feel much better what i experienced with the CW218's , i have observed that many sub designs make much emphasis on hitting 100 or 140 hz,at expense of loosing the 10hz that makes a difference of hitting 30hz instead of 40hz, personally i prefer to hit 30 at expense of loosing high range that on my type of music only make the stuff to sound muddy, the 125hz area it was never my cup of tea, on the LX18's it sounds horrendous, so i always do a bell cut there.
i was able to get a copy of the free discontinued Sketchup 2017 and i a started to fiddle with it, i will start doing the 3d models of the double 15's
if there is anything that you can add like port shape or bracing tips it will be very welcome, i know you are a legend in the DIY community
specially for sub cabinet designs and since you design multi panel horns, bass reflex to you is like 1+1=2
I know that you have much experience on where and how to add bracing to panels to minimize power loss because of the ply deflection phenomena.
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I advised against it, my original suggestion was to use smaller boxes with higher fs. OP asked for more 30Hz as cheap as possible, I did say that comes at a cost.
At any rate, you guys have fun.
From the Hornresp Help Manual:
Direct Radiator in a Vented-Box Enclosure
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Select the 'Rear Vented' option from the Chamber Type tool and set S1 to L45 = 0 and Vrc, Lrc, Ap and Lpt > 0.
By default, the combined direct radiator plus port acoustical power output is calculated. The Output tool can be used to determine the direct radiator output or the port output. An inner end correction is added to the Lpt rear chamber port tube length where appropriate. If an end correction is added the Helmholtz resonance frequency of the specified system can be seen in the bottom status bar panel by moving the mouse pointer over the Ap label or text box.
Vented-box enclosure system losses are taken into account using the QL quality factor parameter. The default value is 7 but the value can be adjusted between 1 and 99 by double-clicking on the input parameters window QL or Lossless label in edit mode. The value can also be adjusted using the QL slider control in the Chamber section of the Loudspeaker Wizard. If the Loudspeaker Wizard slider is set to the maximum position, the true lossless model is selected. If the slider QL label is double-clicked, the control is reset to the default value of 7. The QL parameter reverts to the default value of 7 when a different record is selected or a new record is added.
Did you notice that Kaffi and Art model the Vented Box in a different ways?
Kaffi modeled as Offset Drive (OD) while Art modeled as Single Driver (Nd). Sometimes you have many different ways to model the same box with advantages or disadvantages.
worth noting that the built in help for hornresp is very good so would be my first source of info on how to model a box I didn't know how to model.
i tought you mean that the built in help of hornresp was useless, now i know what you mean.
my bad.
my bad.
If anyone is interested: We built both a BR and TH-18 cabinet based on the 18SW115.
The BR was based on B&Cs suggested design.
With the same signal going into each enclosure, speakers 6 meters apart, TH on the left and BR on the right, the BR was not audible compared to the TH.
Yet to actually measure it, but based on the fact that the BR felt like it was not turned on (perceptively) when standing out front in the centre of the two setups, id guess the TH was at least 6db louder. If not more.
The BR was based on B&Cs suggested design.
With the same signal going into each enclosure, speakers 6 meters apart, TH on the left and BR on the right, the BR was not audible compared to the TH.
Yet to actually measure it, but based on the fact that the BR felt like it was not turned on (perceptively) when standing out front in the centre of the two setups, id guess the TH was at least 6db louder. If not more.
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