Loudspeakers

Q Acoustics’ costlier cabinets [HFN Apr ’22] employ three distinct techniques to deal with their drivers’ unwanted kinetic energy (vibration). One is the constrained-layer cabinet – a sandwich construction with a compliant gel filling that damps out higher-frequency cabinet vibrations as heat. That’s simply too costly for the 3050c which employs single-skin 16mm MDF for the cabinet walls and thicker 25mm HDF for the baffle. However, the remaining two energy mitigations are retained in the 3050c. One is Q Acoustics’ point-to-point (P2P) bracing, connecting and stiffening the sidewalls of the cabinet at critical locations rather than use a full-width ‘shelf’ bracing that might bring additional modes into play [see cutaway pic, below].

The second resonance-controlling bullet in the 3050c’s armoury is a Helmholtz Pressure Equaliser (HPE). This long tube, mounted vertically inside the back of the enclosure, is tuned to attenuate the fundamental length resonance by normalising the pressure gradient between the top and bottom spaces of its 42-litre cabinet. A mode was detected at 860Hz during our lab tests but at a full –18dB down, relative to the main port output, this suggests that Q Acoustics’ efforts in scaling down a cost-effective version of HPE – using one rather than two internal tubes – has been successful here. PM