box modeling request (1 Viewer)

[Seungsoo Hwang]

Hi, I had a small request to make of someone with a nicer box modeling program than WinISD. I need to write a paper on building and testing a low frequency speaker for my class and wanted some modeling done of my sub:

Adire Shiva driver in a 2.5cuft sealed box with 400w going into it (4ohms).
Room size is 12'x12.5'x8.5'

Much appreciated.

 

[Jeff Rosz]

hello,
if you want, email me your address and i'll send you printouts tomorrow.

 

[Janne Ahonen]

Hi Seungsoo,
what graphs are you interested in?
If you want, you can try Adire's own limited version (in sense that you can't use any other drivers with it than Adire's) of LspCAD.
On the free (no limitations) side, WinISD pro, subwoofer simulator or Unibox should fulfill your needs, these are quite capable programs.
If you are familiar with that classic WinISD, then using pro version should be easy.
Subwoofer simulator simulates also effect of voice coil inductance (I see that I have some work still to do).
Unibox is implemented as spreadsheet so it is little sluggish (at least for me, your mileage may vary!).
Here are the relevant links (to the programs):
http://www.adireaudio.com/misc/software.htm
http://www.linearteam.dk/winisdpro.html
http://www.geocities.com/f4ier/subsim.htm
http://www.danbbs.dk/~ko/ubmodel.htm
Hope these help.
Regards,
Janne

 

[Seungsoo Hwang]

thanks for your help

 

[Seungsoo Hwang]

Just a few questions on using the winisd pro...

Air pressure? Should I just leave that alone? Same for humidity (I have no way of measuring both of them).

Series resistance? Is that talkin about the resistance of my configuration or the speaker itself? (I have it wired to present a 4ohm load, do I put 4?)

How do I factor room size/gain into my plots? No such option here (which is why I asked for someone with a program better than this one...).

If anyone out there can still send me the requested that would be great.. (did you receive my email Jeff)?

Thanks

 

[Isaac C]

Seungsoo,
I'll leave winISD-specific questions to Janne but I have a suggestion regarding humidity and pressure. Open your local tv/newspaper's website, hopefully the site has current measurements of atmospheric pressure and humidity.
As for considering room acoustics. The Adire Audio version of LspCAD can do this for you. If you want, you could export the room's transfer function to an FRD file (remember to remove the first line containing "Hz dB deg") which you may use with Sub. Sim. See screenshot for example
hth
Isaac

 

[Jeff Rosz]

yes i did. i have the graphs printed. email me your snailmail(USPS) and i'll send em right out. i promise i wont be showing up on your doorstep looking for food or anything.

 

[Jeff Rosz]

oh,
series resistance would be the Re parameter. the actual DC resistance of the coil/s. it will/should be close to 4 ohms, probably like 3.5 or 5.1 ohms or some such number.

 

[Janne Ahonen]

Oh no.. Series resistance is sum of all external resistances seen by driver, e.g. amplifier output resistance, wires, connectors or anything in path to voice coil. It is set to 0.1 ohms by default (I think it is reasonable default).
Default environmental values should work OK. They affect to speed of sound and air density. You see, most box building programs don't deal with this at all (probably because they would confuse users), and stick with each SW author's "favorite" values..
Sorry, I didn't look your initial post carefully enough.. There is no room gain option :frowning: (yet), just please be patient.. However, it is on our to-do list.. That being the case, you should use Adire's LspCAD. There is an option to enter room dimensions.
BTW, new version of WinISD pro should be released soon, where printing and frequency axis have been added among other things.
Regards,
Janne

 

[Jeff Rosz]

oh i see,
so in winisdpro the resistance is asking for whats external of the driver, omitting the coil/s. gotcha

 

[Jeff Rosz]

seung,
here try this link.
hope it helps

 

[Seungsoo Hwang]

got pretty much everything i need, played around with lspcad a bit.. still need a little more work on that hehe. thanks for your help everyone.