Software for simulating sealed/acoustic suspension boxes

[piecor]

I want to start a project with a sealed 12" woofer. This is my first experience with sealed box.

Can you suggest a good software which correctly takes into account stuffing?

I have the impression that most calculators online do not consider stuffing properly, but I see that this is quite essential to get good results.

 

[andy19191]

Where will one get the empirical coefficients for a particular type of stuffing and density to plug into the model/s implemented in the software?

 

[planet10]

Stuffing is always something i just estimate. One tyically needs about 10% less volume in a stuffed box to yield the same Q as an undamped box.

And given the exponential growth in box size, as Q drops below max-flat you have a lot of margin for error.

dave

 

[waxx]

Use winisd, and take 90% of the volume you get there for your alignment and stuff loose the box for 90% and you are good. And sealed is very forgiving for size, so a bit to big or small does not make a big difference. I build dozens of sealed boxes like that.

 

[piecor]

Thanks. I had several MS excel softwares for doing that but they don't work with the current version of MS Excel

OK 10% diefference is not a big issue, I compute the desired volume for achieving a certain F3 and excursion behaviour and I'll go with that. If I don't like to Q after adding stuffing I reduce the volume.

Regarding stuffing. I once read that fiberglass wool is one of the best material. At least my loved AR speakers had that inside. Can you suggest a density for fiberglass wool, should I go with 20Kg/m^3 (Kg per cubic meter), lower, or higher?

 

[hollowboy]

You can just stick "sealed speaker calculator" into a search engine 🙂

HiFi Loudspeaker Design

 

[piecor]

You can just stick "sealed speaker calculator" into a search engine 🙂

HiFi Loudspeaker Design

of course that's the first thing I did.

I was looking for something which approximately takes into account an estimate of the stuffing effects and room gain

thanks anyway

 

[hollowboy]

"I was looking for something which approximately takes into account an estimate of the stuffing effects and room gain"

My bad: you even said as much in the first post. Sorry.

 

[hollowboy]

For stuffing, a good reference is Vance Dickason's book.

I just googled "Vance Dickason stuffing experiment", and the 4th result was a full .pdf of his "Loudspeaker Design Cookbook". Jump to page 39 and you'll see several pages of measurements of a bunch of different stuffing materials.

 

[piecor]

thanks... I think I read that book a long time ago, but I didn't remember he had so much information on stuffing... I'll read it tonight! Tnx

For stuffing, a good reference is Vance Dickason's book.

I just googled "Vance Dickason stuffing experiment", and the 4th result was a full .pdf of his "Loudspeaker Design Cookbook". Jump to page 39 and you'll see several pages of measurements of a bunch of different stuffing materials.

 

[planet10]

I once read that fiberglass wool is one of the best material.

It si. A pain to work with the scratchy stuff, We use the recycled cotton substitute.

dave

 

[planet10]

...and you'll see several pages of measurements of a bunch of different stuffing materials.

Ignore the first bit on Bradbury’s work, it has largely been discredited, but the materials absorption graphs at the bottom are helpful.

Bradbury's Fiber Equations

dave

 

[piecor]

Based on Fig 4.0 seems that below 100Hz wool and fiberglass behaves similarly in terms of attenuation, not very sure how to interpret Fig 4.1.
By the way I am right the from the sealed enclosure perspective Fig 4.0 tells me how much the backwave is attenuated?

Ignore the first bit on Bradbury’s work, it has largely been discredited, but the materials absorption graphs at the bottom are helpful.

Bradbury's Fiber Equations

dave