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<blockquote data-quote="Z1NONLY" data-source="post: 7469827" data-attributes="member: 634086">I think you mean &quot;flared&quot; rather than &quot;flush&quot; on your vent question. Flaring your port can help reduce flutter and allow you to get away with a smaller port opening. However the flared portion(s) of the port need to be deducted from the overall length when you are calculating tuning frequencies. (That&#039;s why BB asks you the question)Looking at your graphs, the green plot looks like it&#039;s going to give you a lot of port flutter. (Vent air velocity graph)The gray and yellow plots are close to fluttering too. If you ever want to put more power than your are plotting them at in&nbsp; the graph, you will probably get flutter then too.You can enlarge the port opening to avoid the fluttering problem, but then you will end up with a higher tuning frequency if you don&#039;t lengthen your port.And yes you should care about vent air velocity. When the curve goes &quot;light&quot; like your green plot, BB is telling you that you are going to hear your port making noises you probably don&#039;t want to hear. (flutter)</blockquote>

[QUOTE="Z1NONLY, post: 7469827, member: 634086"] I think you mean "flared" rather than "flush" on your vent question. Flaring your port can help reduce flutter and allow you to get away with a smaller port opening. However the flared portion(s) of the port need to be deducted from the overall length when you are calculating tuning frequencies. (That's why BB asks you the question) Looking at your graphs, the green plot looks like it's going to give you a lot of port flutter. (Vent air velocity graph) The gray and yellow plots are close to fluttering too. If you ever want to put more power than your are plotting them at in the graph, you will probably get flutter then too. You can enlarge the port opening to avoid the fluttering problem, but then you will end up with a higher tuning frequency if you don't lengthen your port. And yes you should care about vent air velocity. When the curve goes "light" like your green plot, BB is telling you that you are going to hear your port making noises you probably don't want to hear. (flutter) [/QUOTE]

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