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Old 09-22-2020, 12:49 AM   #5 (permalink)
JulianEdgar
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Quote:
Originally Posted by freebeard View Post
Wut? I can't just use a template?
I understand the (aero) joke but the funny thing is that, yes, in fact people used to design bass reflex ports by just rules of thumb.

Then, in the early 1970s, engineers started to build mathematical models of how speakers in bass reflex enclosures behave.

That was of use only to professional audio engineers, and it took another 15 years or so before those equations became widely available to amateurs.

Then, it took until about the 2000s until PC programs came about that could easily churn out enclosure and port designs, and then until the 2010s before combined hardware / software testing mechanisms were released that make it all very easy (and amazingly accurate) to do these speaker designs.

Unfortunately in amateur car aero we're either still at the rules-of-thumb level (template), or using poor models (amateur cfd). As with speakers, some measurements go a long way!
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