ROOSKIE
Major Contributor
Dense foam will create a sealed box. If it is a good fit. It won't be a controlled leak. Same as a cork in a wine bottle or a foam plug in olive oil. Nothing leaks.It's been suggested that shoving the port round the back minimises interference from the direct sounds from the front, but it appears not to be the case if these upper midrange resonances are screwing with an otherwise well behaved driver. Short of blocking the port either completely or with dense foam, thereby creating a 'controlled leak,' any ideas as to how these comparatively nasty midrange resonances can be better tamed while keepngat least some of the benefit?
These resonances are in the nature of porting the box. Where they are strongest and how strong they are is related to port length, box size and placement on the box.
It might be possible to tame them by adding some material/stuffing to the box as they are high enough in frequency (greater than 900/1000hz) to be reduced this way. Even reducing them by 3-6db would be great and very possible. It is possible that being a budget speaker this cabinet has no or very little/ineffective stuffing. Stuffing/thick lining will lower the tuning to some degree as well. It might also reduce the bass if over used. Try not to block the port with stuffing/thick lining.
If the speaker was well away from the wall the port resonance will be "reduced/delayed psycoacoustically filtered" in its ultimate effect as well - however so will bass reinforcement.
I can see using room absorbtion behind them if they are close to the wall, 900-1300hz can be treated.
Sealing the box will likely lower power handling by significant amounts unless highpassed fairly high (guessing 100-120 or maybe higher to reduce distortion to the minimum). So if you need real loud, then keep that in mind. The box will very likely be larger than optimal for a sealed size (as it was desined for the ported alignment) and thus the woofer will be less controlled than it would be in a smaller box. Plus the port helps the woofer out and mitigates excursion down to and around the tuning frequency, there is even a point where the woofer essentually stops moving in and out (minimum motion). If sealing you can try to remove any stuffing as this makes the box appear larger and you dont want that here since you actually would want a smaller box.
In any case someone would be wise to play around here. Looks awesome with only this port issue.
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