Box looks fine. Look to the "G" sub for ideas on how to do the internal bracing.
Hi again 
thinking a little bit, i think i made an error calculating the dimensions.
My thought is, for the dimensions, i use the volume Vb were Vb=Vab+Vs, so this means i'm considering the volume Vs (from the driver) then. So i'm not considering the internal volume to dimension and i'm considering the external volume right??!
Or i'm just messing up my head???? Is it good to calculate the dimensions with Vb? or with Vab?
thx again and again and again
thinking a little bit, i think i made an error calculating the dimensions.
My thought is, for the dimensions, i use the volume Vb were Vb=Vab+Vs, so this means i'm considering the volume Vs (from the driver) then. So i'm not considering the internal volume to dimension and i'm considering the external volume right??!
Or i'm just messing up my head???? Is it good to calculate the dimensions with Vb? or with Vab?
thx again and again and again
Hi again
thinking a little bit, i think i made an error calculating the dimensions.
My thought is, for the dimensions, i use the volume Vb were Vb=Vab+Vs, so this means i'm considering the volume Vs (from the driver) then. So i'm not considering the internal volume to dimension and i'm considering the external volume right??!
Or i'm just messing up my head???? Is it good to calculate the dimensions with Vb? or with Vab?
thx again and again and again
The Subwoofer DIY Page - Box-Building FAQ - check 2.02.
Don't worry about measuring Vs - if it's not given, a good guess should get you close enough.
brace like this? please ignore extra lines, i'm still learning sketchup.
hmm nice!!
just one more question, wich program do you advice me to do the draw the design?
I've checked "solid works" but seems pretty complete and difficult to learn easy and fast
any more options???
thx again!!!!
Hi
I have owned a pair of the XB 15" drivers for over 10 years now
There is a cabinet design for the Fane XB 18" on the Fane website,
http://www.faneinternational.com/downloads/Cabinets18inch200Lres.pdf
I suggest that you look at that when deciding what to build.
Main points I would make are suggested volume 200 litres
4 off 100mm dia ports per speaker. Note the suggested length of the ports is quite short at 108mm If you care to reverse engineer the tuning of the cabinet I think that you will find that it is tuned higher than your suggestion
If you can sim your cabinet in Winisd pro note the excursion above and below the tuning frequency. It is also possible to add in a hipass filter.
With a bit of adjustment you can optimise the design to give the best power handling. I really like the XB in a ported cabinet, they are a very robust speaker and have low thermal compression.
Good luck with your design
Regards Martin
I have owned a pair of the XB 15" drivers for over 10 years now
There is a cabinet design for the Fane XB 18" on the Fane website,
http://www.faneinternational.com/downloads/Cabinets18inch200Lres.pdf
I suggest that you look at that when deciding what to build.
Main points I would make are suggested volume 200 litres
4 off 100mm dia ports per speaker. Note the suggested length of the ports is quite short at 108mm If you care to reverse engineer the tuning of the cabinet I think that you will find that it is tuned higher than your suggestion
If you can sim your cabinet in Winisd pro note the excursion above and below the tuning frequency. It is also possible to add in a hipass filter.
With a bit of adjustment you can optimise the design to give the best power handling. I really like the XB in a ported cabinet, they are a very robust speaker and have low thermal compression.
Good luck with your design
Regards Martin
i've read this, The Subwoofer DIY Page - Box-Building FAQ and say
" Place braces asymmetrically across the inner surface of the panels. Don't forget to include the volume occupied by the bracing when determining the design's final volume!"
And i've seen G-sub design, and doesn't seem to place the the braces asymmetrically, does it matter a lot? Don't think so right??
thx again for all
If you check my calculation paper (from the first link) , you can see that my Vab is the Vb that www.diysubwoofers.org uses right? My Vb = Vab+Vs(driver)+"Vbraces" right???
pd : anyone knows a good program to draw the speaker???and make the plan?
Thanks again!!!
This is good. Not a cad program but helps with Vb calculations etc.
Boxnotes - Free Speaker Design Software
Boxnotes - Free Speaker Design Software
Hi,
FWIW having multiple ports does not make tuning the box difficult if you
change the way you are looking at, multiple ports are very flexible.
You tune by closing off or stuffing a port. For six ports stuffing 3 will
drop the tuning frequency to 0.71 x Fvent, two to 0.82, one to 0.91.
Its far better to be able to readily adjust tuning to suit placement
than have Fvent set exactly to some notional ideal frequency.
If the best sounding tuning closes off a few ports, this indicates it
would be best to detune them all, (this I do by lining ports with a
thin layer of porous foam), and using more open ports.
As all vented boxes overload easily below the Fvent frequency
there is a strong argument for vented subwoofers to tune as
low as possible, if you want good very low bass capabilities.
If you tune higher, then to fully exploit the drivers capabilities
you must have matching effective subvent filtering in place.
rgds, sreten.
FWIW having multiple ports does not make tuning the box difficult if you
change the way you are looking at, multiple ports are very flexible.
You tune by closing off or stuffing a port. For six ports stuffing 3 will
drop the tuning frequency to 0.71 x Fvent, two to 0.82, one to 0.91.
Its far better to be able to readily adjust tuning to suit placement
than have Fvent set exactly to some notional ideal frequency.
If the best sounding tuning closes off a few ports, this indicates it
would be best to detune them all, (this I do by lining ports with a
thin layer of porous foam), and using more open ports.
As all vented boxes overload easily below the Fvent frequency
there is a strong argument for vented subwoofers to tune as
low as possible, if you want good very low bass capabilities.
If you tune higher, then to fully exploit the drivers capabilities
you must have matching effective subvent filtering in place.
rgds, sreten.
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Your analysis is off for several reasons:
1. Your suggestion would push Fb downwards. The equations used to predict port lengths have been found to be conservative and will likely result in an Fb that has to be adjusted upwards. Closing off ports will not help here.
2. If this is for pro-audio use, the last thing you want to do is to be closing off vents and as a result likely increasing the impact of nonlinear port compression effects on peak output capability.
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