Use "Impedence" or Re for crossover calculator?

[critofur]

Hi, when using something like this crossover calculator:

http://www.lalena.com/Audio/Calculator/XOver/

In the boxes where it asks for impedance, do I use the "nominal impedance" such as 8 for an "8 ohm" speaker, or the Re?

For instance, I was thinking of using either this:

http://www.partsexpress.com/pe/showd...number=299-818

or this:

http://www.partsexpress.com/pe/pshow...99-164&scqty=4

As a vented low woofer along with this (maybe two in series) as the mid(s):

http://madisound.secureserverdot.com...oducts_id=1757

[Cal Weldon]

Use the actual impedance at the intended XO point.

Calculators are just a starting point for an XO. You also will want to consider zobel, padding, BSC and notches.

You must have lots of extra parts on hand to do some tweaking.

[sreten]

Hi,

Using the resistance or the impedance at c/o point are both wrong.
Zobelling the driver to nominal resistance and using this is "correct"
but still wrong for most case. C/o calculators are the devils spawn.

/sreten.


http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.geocities.com/woove99/Spkrbldg/

http://www.zaphaudio.com/
http://www.rjbaudio.com/projects.html
http://www.troelsgravesen.dk/Diy_Lou...r_Projects.htm
http://www.humblehomemadehifi.com/
http://htguide.com/forum/forumdisplay.php4?f=39

[Svante]

Originally posted by sreten
C/o calculators are the devils spawn.

[Thawach]

but still wrong for most case

steren, it's not wrong. here is "got a chance basic version" it made for beginner. sometime it is good. sometime it's not good. i often see.
but it's not good more than good.

[critofur]

Originally posted by Svante

Off topic question here, but, how is that program Basta! ? Do you like it? How does it compare to Sound Easy/LspCAD/Speaker Workshop in terms of features, and, particularly, ease of use?

Somehow I find speaker CAD software to be particularly difficult, always having some trouble with my sound card, PC, or just the software being un-intuative...

[sreten]

Hi,

I've played around with a demo version of Basta a while back
and it is quite easy to use, though the time limit ran out fairly
quickly. The limitations were well explained in the downloadable
user manual.
There is a new demo version that does not run out so all I can say
is give it a try, but the most useful features are turned off I think.

FWIW you'll need it in designing a 3-way.

/sreten.

[sreten]

Originally posted by Thawach



steren, it's not wrong. here is "got a chance basic version" it made for beginner. sometime it is good. sometime it's not good. i often see.
but it's not good more than good.

Hi,

but it's not good more than good = wrong for most cases = more often wrong than correct

/sreten.

[Svante]

Originally posted by critofur


Off topic question here, but, how is that program Basta! ? Do you like it? How does it compare to Sound Easy/LspCAD/Speaker Workshop in terms of features, and, particularly, ease of use?

Somehow I find speaker CAD software to be particularly difficult, always having some trouble with my sound card, PC, or just the software being un-intuative...

Asking me that? Well, I think it is the best program in the world, but then again I wrote it. Nah...

[sreten]

Originally posted by critofur


Off topic question here, but, how is that program Basta! ? Do you like it? How does it compare to Sound Easy/LspCAD/Speaker Workshop in terms of features, and, particularly, ease of use?

Somehow I find speaker CAD software to be particularly difficult, always having some trouble with my sound card, PC, or just the software being un-intuative...

Hi,

You need to understand Basta is a simulator, not CAD.

http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.geocities.com/woove99/Spkrbldg/

Compared to the above it is very easy to use but it has limitations.
The main one is real driver data (frd + zma files) cannot be used.
Its great for crossover interactions with drivers, though for
tweeters parameters are not often available and for ferrofluid
types would produce misleading results.

Other than that its a great demonstration of the the theory in practise.


/sreten.