Port noise

[DIFORCE]

While building my speakers ( Seas Idunn ) I've noticed how everywhere the precision flared ports are being recommended and used ,The thing I dont understand ( besides the price.. ) is how can you tune the port with a huge flare on both ends , or even if I would use one end ... Its still one big flare , How can precise tuning can be made possible ?

Is there any proven fact that they In face are better at reducing port turbulance ? or is it just some kind of audiophile voodoo like silver wires 'cause I have never heard port noise .... ever , in any speaker ..Is it just a myth ? hehe

Many high end speakers dont use them . and many builders dont use them.

Any reason for me not to use normal PVC tube ?

[richie00boy]

I use normal tube. Flares are a good idea, but you only really need them if you are trying to use a bit too small port area in the first place. Checking their tuning is like any other port, the hard part is knowing how long to make it in the first place because of the changing diameter.

[Robh3606]

Any reason for me not to use normal PVC tube ?

It all depends on the volume of air going through the port. I have been using the flared ports and they work great. Even in a subwoofer application there is no port noise. If you purchase them they have an instruction sheet that tells you how long to make the total port length. You just plug some numbers in the provided formula and your are good to go.

Rob

[DIFORCE]

Thank you but im a numbers man , I dont like "working great" ... Of course they are working great , why shouldn't they ? But are there any reason to use them over PVC tubes ? or is the only reason is to allow more air flow in a tight port without hearing the noise ...

[PeteMcK]

there have been extensive papers written on this - essentially, the flares do make a difference to the air flow, I think you calculate the diameter by taking an average; but -
if you don't play at high volumes, port noise isn't an issue, and, here's why you can't be precise - port tuning changes with the level you play at.....

[DIFORCE]

I would imagine that high volume that would make the air move out of the port so rapidly that it would whistle is .. very high

but then again , If some designs use a flared port ... won't that mean they use it to be able to use a smaller port ? and If i would just use a regular tube it would go against design ?

[PeteMcK]

some light reading for you:
http://www.harman.com/EN-US/OurCompa...ions/11094.pdf

FWIW, I use 5 cm cardboard or PVC without flares & have no problems, but I don't play at super high volumes

[David_Web]

Flare-it - Free Speaker Design Software

Check the rest of the site as well. Lots of more info from the tests that led to the app.

I have seen ports form "smoke rings" but without the actual smoke.
And that was a bookshelf speaker. Although at high volume.

[prickears]

Smoke rings, from ports, without smoke.......?

Clouds appear in front of driver at high spl's......?

wwhhhooooaaahhh!! WTF!!

I get this funny feeling i'm doing something wrong!

Gotta be a climate thing.

I sure hope I will get to see such things when I start paying my carbon emissions tax (He He He).

[prickears]

But seriously, I often think that maybe this port noise is built into speakers so you get that bit more warning that they are being 'overdriven'. A safety mechanism, at least from a commercial point of view. You may find that many flared ports of fixed length, have a 'nominal' diameter, for easier calculations. In which case, why not use them, just to be sure?