flowport tube

[hlaari]

I need help to find port tube similar like B&W use (flowtube)
https://www.google.com/searchq=b%26w+flowport&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjSi_GD3N3ZAhXMhqQKHZE5D4cQsAQIMQ&biw=1600&bih=794#imgrc=75Q7DCQYKYPYAM

I see at part express did have similar port tube for sale some time ago but not anymore:(

I don´t like this port tube that are made of thin material, I like to know if someone here could help me:crying:




Ari

[Odd]

Link does not work.

[Don C]

I think that he means dimpled tube like B&W. Like these:
http://theaudiocrafts.com/exclusive-70mm-diameter-dimpled-flared-port-tube-70m-dfpt
Could be that B&W has a patent.

[RMC]

Hi Ari and Don,

Having looked at The Audiocrafts vent I'm not convinced this would be a great idea to use such. Inside that vent at the intersection of cardboard and plastic, it looks to me there's a small "ridge" made by the plastic thickness so air flow would hit a tiny bump before exit which could cause turbulence...

As for the dimples magic effect on the flare, I don't know about that, but I'm skeptical. The flared vents I've seen were smooth all around.

R.H. Small in Vented-box... Part II, section 8 "Vent Requirements" mentions "... provided that the inside of the vent is smooth..." (P. 329) That section 8 is quite easy to understand, contrary to some other Small stuff, and its available free on the Web.

For a more "high-flying" but complete vent analysis you may want to check from Harman guys, Salvatti, Devantier and Button, Maximizing Performance from Loudspeaker Ports, available on Harman's Web site in the technical papers section if I remember correctly. Regards,

Richard

[hlaari]

I have found the (flowport) port tube, so the problem is solved:)




Ari

[Earl K]

Dimpled golf-balls fly further & straighter (https://www.google.ca/search?rlz=1C1CHBF_enCA703CA703&q=why+do+golf+balls+have+dimples+fluid+mechanics&sa=X&ved=0ahUKEwjI_ojGmeDZAhVDaq0KHRSCDskQ1QIIvQEoBA&biw=1261&bih=661) .

:)

[Don C]

Do those golf balls fly at the speed of sound?

[grumpy]

No. SoS ~ 760mph

The highest recorded ball speed is 226 mph by Connor Powers during the Quarterfinals of the 2014 World Long Drive Championship.

I would not immediately discount the effect of dimples making a surface have less drag, but the operating conditions may not necessarily be met for a speaker port, and likely have more to do with standing out in the market. There are aerodynamics papers one can dig up if interested. (I’m not)

Flares are a different story altogether.