Query - Zaph SB12.3 cabinet volume

[captJackSparrow]

Hi Everyone,


I need some help with volume calculation, anyone who has built SB12.3 3 Way Speakers.



In MTM section i am able to calculate and match volume to .58 Cubic Feet.


But for the Woofer section i am not able to match volume to 3.78 Cubic Feet as mentioned in PDF.



http://www.zaphaudio.com/SB12.3/SB12.3-enclosure.pdf


My Calculations(All values are in cubic inch)

Volume for woofer section above Upper shelf brace
(6.750-.75)*12.25*17.5 = 1286.25
Area of prism triangle *Height = 36.125*17.5 = 632.1875

Upper shelf brace
27.84375
13.5

Woofer
17.250*12.25*14.5 = 3064.03125 - 81.5625(3 bracings) = 2982.46875

Lower shelf brace
51.65625

Lower Section for woofer
7.5*12.25*14.5 = 1332.1875

 

[6L6]

1728in^3 per Ft^3

Internal dimensions of the entire box are 4.49ft^3 (7771in^3)

The MTM enclosure is .58ft (1002in^3)

7771-1002= 6769 or 3.91ft^3

Subtract a bit for the braces and you get 3.78ft^3

 

[captJackSparrow]

Thankyou.


I was able to get close 3.765245225694 ft^3


What i'll do is finish MTM first and leave remaining volume for woofer section, since i am able to match that volume (.58 ft^3/1009.75in^3).

 

[mordikai]

In a sealed enclosure 10% change in volume either way is pretty negligible.

 

[captJackSparrow]

Thankyou.

That inspires some confidence since this will be my first wood project I plan to do all by myself. Previous one being limited to designing AV cabinet/rack.

 

[badman]

Thankyou.

That inspires some confidence since this will be my first wood project I plan to do all by myself. Previous one being limited to designing AV cabinet/rack.

You're overstressing on numerical resolution- 3.7 and 3.8 ft^3 are barely distinguishable in measurements.

But, with that attention to detail, you'll surely have a very successful project.