Enclosure port size : 70 mm Dia and 190 mm Length

[OMARGS]

Dear Members,

Where can I get the port tube for the speaker box in India, as mentioned below size?

PORT Dia: 70 mm
PORT Length: 190 mm

I tried an online search on Google but the size was not available.

Many thanks for considering my request.




Regards,

 

[Nisbeth]

70mm is quite close to the size of the tubes used as drain pipes (at least here in Europe) so maybe you can find something locally in IN as well?

 

[planet10]

I like plumbing pipe. If you can’t find 70mm…

https://frugal-phile.com/boxlib/Changing-Port-Size.pdf

dave

 

[OMARGS]

Dear @planet10


I did not get your point. Please explain my actual port size ID: 70mm and length: 190mm, Cabinet inner dimensions ( H: 368MM X W: 166 X LENGTH: 231, VOLUME 14 L.).

The port available in my area is ID: 103 mm & LENGTH: 150 mm.
or
The port available in my area is ID: 70 mm & LENGTH: 150 mm.


Please share the calculation as per my project.

Many thanks for considering my request.

 

[planet10]

You can always cut a port shorter. Without doing the math, the 103 needs top be longer.

Closest plumbing pipe here to 70mm is 76 mm (3”), so

L₁/L₂ = A₁/A₂

L₂ = L₁ * A₂/A₁

L₂ = 190 * 1.148 = 218mm

dave

 

[OMARGS]

@planet10 Thankyou..

 

[stv]

Any chance you have access to a 3d printer or a 3d printing service and a 3d cad tool (fusion360 or freecad)?
If so, have a look at an optimized port geometry here:

• Calculator
• More advanced calculator
• 3d model for fusion360
• 3d model for freecad
• Documentation of a port construction

Alternatively you could build a rectangular (slot) port using simple boards and similar length and cross section surface as you defined above.
Don't forget to make roundovers/flanges at both ends.

 

[planet10]

you could build a rectangular (slot) port using simple boards

That is most often what i do. Butn i also use them a bit differently than typical BR. i blame John Greenbank (Tangent designer).

dave

 

[Galu]

Closest plumbing pipe here to 70mm is 76 mm

76 mm will be the outside diameter.

The 76 mm PVC pipe I've seen has an internal diameter of 68 mm, but this depends on wall thickness.

 

[planet10]

true

dave