Reflex port moved to the front and tuned for new bass units
new re-positioned port with tuned 30hz frequency
Improved bass - and easier matching to room.
OK, it may only be a hollow plastic tube, but the port of a refex loudspeaker is critical to it's low bass performance, low distortion and drive unit matching.
The new units had a totally different specification (Free Air Resonance) to the old ones and as you may recall, I found that the 765's were now sounding somewhat "fat" in the bass and not up to the quality of the rest of the equipment.
The new SEAS L22 bass units cured a lot of the issues, but the real trick, was to move the port from the front (see main picture at the top of this page) to a new position in the front of the lower baffle. Furthermore, the port length and diameter were re-tuned to give a nice low bass support below where the main drivers begin to roll off.
Ported reflex designs need careful design but after some tuning, the new sound was much improved. The final piece of the overall re-design, was to use the best possible damping. For details see here
OK, it may only be a hollow plastic tube, but the port of a refex loudspeaker is critical to it's low bass performance, low distortion and drive unit matching.
The new units had a totally different specification (Free Air Resonance) to the old ones and as you may recall, I found that the 765's were now sounding somewhat "fat" in the bass and not up to the quality of the rest of the equipment.
The new SEAS L22 bass units cured a lot of the issues, but the real trick, was to move the port from the front (see main picture at the top of this page) to a new position in the front of the lower baffle. Furthermore, the port length and diameter were re-tuned to give a nice low bass support below where the main drivers begin to roll off.
Ported reflex designs need careful design but after some tuning, the new sound was much improved. The final piece of the overall re-design, was to use the best possible damping. For details see here