I know the rule of thumb is to keep the end of the port (inside the box) away from any walls by a distance equal to the diameter of the port.
However, although great in theory, how big of a deal is this in real life in terms of chuffing or other negative effects? Let's say I build a sub similar to this SVS one, having a flared 8" port that runs straight towards the rear without any bends, where the distance from the edge of the end flare is very close to the bottom of the sub (e.g. 10mm) inside the box:
This one would have the port end close to both the botton and side wall:
Perhaps far from ideal but so many commerical designs seem to be built like this:
Also on the outside, the port is very close to the floor - certainly no diameter away from this "obstruction".
As long as you tune the length of the port to account for any resulting boundary effects, why should I not go ahead and just to this? Especially if the only other option available is to mount the port on top facing up?
If I do it, is it better to keep any fill away from the critical distance or would it be better to strategically add some around there to mitigate any turbulence?
Speaking of which, does nobody stuff their boxes any longer, say for 15-80Hz? A friend of mine said that's old school and to go ahead if I like wooly and loose bass....🙄
However, although great in theory, how big of a deal is this in real life in terms of chuffing or other negative effects? Let's say I build a sub similar to this SVS one, having a flared 8" port that runs straight towards the rear without any bends, where the distance from the edge of the end flare is very close to the bottom of the sub (e.g. 10mm) inside the box:
This one would have the port end close to both the botton and side wall:
Perhaps far from ideal but so many commerical designs seem to be built like this:
An externally hosted image should be here but it was not working when we last tested it.
Also on the outside, the port is very close to the floor - certainly no diameter away from this "obstruction".
As long as you tune the length of the port to account for any resulting boundary effects, why should I not go ahead and just to this? Especially if the only other option available is to mount the port on top facing up?
If I do it, is it better to keep any fill away from the critical distance or would it be better to strategically add some around there to mitigate any turbulence?
Speaking of which, does nobody stuff their boxes any longer, say for 15-80Hz? A friend of mine said that's old school and to go ahead if I like wooly and loose bass....🙄
It is no problem to have the port close to a wall as long as the air flow is not impeded. The proximity of a wall just increases the effective port length, making the simplified equation to calculate the port length invalid.
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Thank you. So having two side walls close to the edge of the flare/aeroport on the inside does not constitute an "impediment" in your opinion, as long as it is at least a diameter headroom right in front of (head on) the port? Just a need to manually tune the port post-build to account for boundary effects?
Correct
Yes but it might need more than one diameter.
Correct 🙂
Boxsim contains a tool to estimate the effect of walls on the tuning frequency. Extras --> Auslegung Reflexkanal
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