# 4" Loudspeaker cavity design



## The Mang (Dec 4, 2013)

I am in need of assistance getting started on building a cavity for a Quam 4" speaker (Model #4C3Z8OT) http://www.quamspeakers.com/client-control/documents/techspec/QUAM_0204_GENERALPURPOSE.pdf


This link is the only information I have on the speaker. I called Quam and they had no further data to provide.
For my design, the speaker must be covered front and back with side ports. Wanting to produce 100db. I have looked for box design calculators and they all require much more information than what I currently have. 
Any suggestions for where I could begin???


----------



## Mike P. (Apr 6, 2007)

That is an intercom/public address speaker.

http://www.wheelock-products.com/Surface-Mount-Menu-Board-Speaker-System-By-Quam.aspx

Without knowing the parameters of the driver it is impossible to say what the optimum internal net volume is required.


----------



## The Mang (Dec 4, 2013)

12-15 Watts
100db at 1kHz and 1 meter


----------



## Mike P. (Apr 6, 2007)

It is the T/S parameters that are needed. Fs, Qes, Qts, Qms, BL, Sd, Re, Xmax etc. With those we can create a driver file and model it in a program like WinISD to see what is required.


----------



## Odougbo (Oct 16, 2011)

That would be hard to work with, check this company, they have a lot of speakers, very inexpensive: 
http://www.mcmelectronics.com/browse/Woofers/0000000255


----------



## The Mang (Dec 4, 2013)

Okay, I chose a new speaker that supplied the t/s parameters... most of them. Misco DC4WI
I have downloaded winISD and have gone through the tutorial forum on this website. The parameters I was able to input are: Qts, Qms, Qes, Re, Fs, Re, and Sd, and then the physical dimensions. When I try to use my driver a dialogue box displays "Floating point division by zero". From other blogs I am interpreting that as a mistyped parameter on my part... or not enough data entered. I have triple checked and my input is good. From the winISD tutorial I am assuming I need "BL"? I have been researching how to calculate this parameter and am not coming up with much... suggestions?


----------



## Mike P. (Apr 6, 2007)

Upload the driver file so we can have a look.


----------



## Paulcet (Jun 18, 2013)

I think the real question is: What do you want to do?


----------



## The Mang (Dec 4, 2013)

View attachment Misco Model # DC4WI-2.wdr


Find optimal box dimensions...

Also, when I have my driver selected in the new project window and have "Show driver parameters" box checked, the parameters shown are not the parameters I input..?


----------



## Mike P. (Apr 6, 2007)

Your driver file is corrupt, delete it. 

I'll attempt to make a file. I'll need the Sd and Vas if you have it.


----------

