Tuning an Enclosure

[squidbait]

What exactly are people talking about when the say "They are 2.5 way tuned to ~38 Hz". Are they talking about tuning the enclosure, or referring to the crossover?

[kingdaddy]

There talking about the enclosure, the Tuning of an enclosure refers to the Port length and diameter which gives you your enclosure Fb.

[Hugo Rodriguez]

2.5 way refers to crossver:

Actually is 2 way: lo + hi

"0.5" means that the low range is reinforced with one more woofer that comes into action parelleled through a series coil in low pass region, also reducing the impedance in the extreme low range.

38 Hz refers to the tuning frequency of the box

[squidbait]

Is there a table or something that gives that information?

[kingdaddy]

WinISD is the easiest way I know of, It's freeware and once you have selected the driver you want to model you select what enclosure volume then the desired port diameter and it will tell you the length for whatever frequency you select. Are you designing a speaker?

[squidbait]

That's easy enough. Thanks!

[GrahamnDodder]

Actually, I was lurking and wondering the same thing. But I am on a Mac platform.

Does anyone know of the good place on the web to learn about and how to calculate these parameters?

Are these the T/S equations?

Thanks in advance.

GnD

[roddyama]

Grahamn,

The T/S "tuning" equations are not trival. It requires some serious abilities in math. I'll try to get Planet10 to chime in here as he is an avid Mac user (and seller) who is also into speaker design.

[squidbait]

Now that I understand what it means, how do the different tuning frequencies go into the final design? In other words, how do the different frequencies affect the final product, and how would I choose what I want?

Does that make sense?

[planet10]

Originally posted by GrahamnDodder
Actually, I was lurking and wondering the same thing. But I am on a Mac platform.

I use MacSpeakerz from http://www.trueaudio.com/ for modeling sealed & BR. He hasn't done an update in many years and it is getting very creaky under OS X, so may not be considered good value for the money. There are also some spreadsheet based calculators that should run fine under Excel -- maybe even in AppleWorks.

diySubwoofers has a lot of the math.

I'm still working thru T/S parameter measurement (i've done it the long slow way successfully, but am trying to get Mac-the-Scope to do it automagically)

dave