Does it matter if a port protrudes beyond the outside of a bass reflex cabinet if its internal opening is in an appropriate place and the outer opening is in more or less free space? Is this a practical way to use a relatively long tube/port in a fairly small box for a stand mount where the port faces down through the stand, and is not too close to the legs?
Thanks,
Skip
Thanks,
Skip
Yes, it can be done, but very long tubes may introduce nasty resonances. Passive radiator is a better solution.
It certainly has been done. For a Fostex 4-5” IIRC.
One would have to take care that the design did not transition into a DaLine (nothing wrong with that, just needs to be modeled and damped differently).
dave
Yes it makes a small difference what the tube's ends' are like, flush or protruding....
Some will add a baffle at the normally unbaffled end to balance the loads at each end. Should make no difference whether this is inside or outside but there is likely some “polarity”.
dave
Yep, works fine, just take care of the details of the design same as you would for a fully internal port, ie port length and resonances in the passband and port end terminations and clean flow. Design it really well and no one will even know you've done it this way - you can make it visually invisible if you choose.
Actually, symmetric port ends in theory are beneficial. Asymmetric endings can lead to constant pressure differences inside the box compared to outside, due to flow resistance differences for the air moving in and moving out. And that leads to more or less static cone displacements. This mainly is an issue in pro applications however.