Sub Box Programs

[James J. Goiffon]

Wondering if anyone can point me in the right direction Either the program
MAID or TermPRO for Subwoofer Box Building Programs???


any help would be appreciated
Jamie

[Scott Dorsey]

James J. Goiffon > wrote:
>Wondering if anyone can point me in the right direction Either the program
>MAID or TermPRO for Subwoofer Box Building Programs???

Why?

The math isn't so hard... get a copy of the Loudspeaker Cookbook and a
calculator and plug and chug. Doing it by hand also allows you to work
backwards as well as forwards so you can start out with a box and see
what alignments will work best in it.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Yuri T.]

"James J. Goiffon" > wrote in message >...
> Wondering if anyone can point me in the right direction Either the program
> MAID or TermPRO for Subwoofer Box Building Programs???
>
>
> any help would be appreciated
> Jamie

Cool speaker design freeware at this site. Check out WinISD


http://www.linearteam.dk/default.aspx?download=winisd

[DrBoom]

(Scott Dorsey) wrote in message >...
> James J. Goiffon > wrote:
> >Wondering if anyone can point me in the right direction Either the program
> >MAID or TermPRO for Subwoofer Box Building Programs???
>
> Why?
>
> The math isn't so hard... get a copy of the Loudspeaker Cookbook and a
> calculator and plug and chug. Doing it by hand also allows you to work
> backwards as well as forwards so you can start out with a box and see
> what alignments will work best in it.

I second this, not least because it brings back some memories.
I've had LEAP for eons; it's the next best thing to building a box
for large signal analysis , but I sorta miss those late nights with
a pencil, calculator, and a sheet of log/log paper. Not that I've done
either in years, alas.

Having said that, let me caution the original poster that he should approach
design software with a skeptical eye. There is a lot more to designing a
good speaker than fiddling with numbers and looking at frequency
response graphs -- the trick is in the *interpretation* of the numbers,
something one can only learn through building a lot of speakers.
In my experience, software is best used to eliminate designs that *won't*
work and to steer you in the general direction of something that will.
The good news is that it's a lot of fun.

I haven't kept up with recent design software, but I suspect most of them
are based on the same small signal equations Richard Small published back
in the '70's, IIRC. Those techniques are fine to get in the ballpark, but if
the original poster can find something that does large signal (allows simulation
at arbitrary levels of input power) and time domain analysis (i.e. phase response
& group delay plots) he'll save himself a lot of grief. Frequency response only
tells part of the story.

-DrBoom

[Scott Dorsey]

DrBoom > wrote:
>
>I haven't kept up with recent design software, but I suspect most of them
>are based on the same small signal equations Richard Small published back
>in the '70's, IIRC. Those techniques are fine to get in the ballpark, but if
>the original poster can find something that does large signal (allows simulation
>at arbitrary levels of input power) and time domain analysis (i.e. phase response
>& group delay plots) he'll save himself a lot of grief. Frequency response only
>tells part of the story.

Is there anything out there that really does that? I still haven't seen
any decent mathematical models of speaker systems operating way out in
the nonlinear range yet, and that's some important stuff you really need
to know about. I think Dr. Klippel had a paper a year or so ago on some
simple driver models that you could run into the wall, but I'm not sure how
good they were.

As far as time domain stuff down in the linear range, it's really scary to
see (and hear) how different cabinet alignments behave when they look so
similar on paper.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Arny Krueger]

"James J. Goiffon" > wrote in message
...

> Wondering if anyone can point me in the right direction Either the program
> MAID or TermPRO for Subwoofer Box Building Programs???
>

There's a ton of this stuff on the web. It's all based on pretty much the
same set of equations, so there's no need to stick with a favorite brand.
Just go to goggle and search on

subwoofer box design

[DrBoom]

(Scott Dorsey) wrote in message >...
> DrBoom > wrote:
> >
> >I haven't kept up with recent design software, but I suspect most of them
> >are based on the same small signal equations Richard Small published back
> >in the '70's, IIRC. Those techniques are fine to get in the ballpark, but if
> >the original poster can find something that does large signal (allows simulation
> >at arbitrary levels of input power) and time domain analysis (i.e. phase response
> >& group delay plots) he'll save himself a lot of grief. Frequency response only
> >tells part of the story.
>
> Is there anything out there that really does that? I still haven't seen
> any decent mathematical models of speaker systems operating way out in
> the nonlinear range yet, and that's some important stuff you really need
> to know about. I think Dr. Klippel had a paper a year or so ago on some
> simple driver models that you could run into the wall, but I'm not sure how
> good they were.

LEAP from LinearX ( http://www.linearx.com/products/software/LEAP5/LEAP5_01.htm )
has done large signal simulations for a long time. There are probably others
that do it now, but eight or nine years ago LEAP was pretty much the only
game in town for serious loudspeaker CAE. I used it for years with good results.

> As far as time domain stuff down in the linear range, it's really scary to
> see (and hear) how different cabinet alignments behave when they look so
> similar on paper.

Yup, that's what convinced me to buy LEAP way back when. After building
a bunch of designs worked out through large signal simulations, I got to the
point where I could roughly predict the "sound" of a given design before
I built it.

I was working in car audio, so I didn't bother much with mid & high
frequency analysis -- given the complexity of the environment, you pretty
much have to rely on ears, test equipment (which can also be misleading,
as I'm sure you know), and experience. I got pretty good at getting maximum
performance out of subwoofers, hence my nom de net.

An audio system that can't hit 20Hz in the mid 120dB SPL range isn't really
a full range system in my book. :-)

Cheers,
-john