Straws in ports?

What no carbon fiber,kevlar or teflon??? ;]

A better way than do resistive damping like putting straws is to go for proven modern aeroport, which has flares in both sides of the lenght of the port . Port noise or chaffing is reduced significantly. A lot of companies have been using these. Notice those curved opening on the ports? exactly like that but on both sides. PNR has the patent to this , i am aware the computation for port length over the conventional one has a slight variation. Check PNR aeroport.

Port noise or "chuffing" comes from increased turbulence within the port. The best solution is to either avoid using a port or to use a port that maintains a more consistent flow velocity and level of turbulence across a wider spl range.

As Goroi mentions and i've discussed in many of my previous posts, the use of a port with radiused ( flares ) on both the inner and outer edges can drastically improve the performance of a conventionally ported speaker. As a general rule, going from a straight port to a port with dual radiuses typically requires additional port length. From what i've seen using identical diameter ports, the "aeroports" ended up being appr 1" longer than the orignal straight port in order to obtain the same tuning. The end result was more more consistent performance from the speaker at low frequencies, regardless of the spl range covered.

While adding straws to a port typically increases low frequency output at reduced spl's, it also reduces maximum port flow too. As such, the tuning of the cabinet actually varies with SPL, which isn't what we want. That is, if one is listening over a wide spl range. If listening at strictly lower levels, adding straws can be somewhat beneficial with the aforementioned caveats being noted. Sean
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