Bass-reflex ports are used to enhance the bass reproduction of loudspeakers. However, at higher output levels, the bass-reflex port nonlinearities, specifically the unsteady separation of the acoustic flow, can lead to blowing sounds and acoustic losses. Calculations and measurements are presented for a number of port geometries. The effect of rounding the port terminations and the effect of converging-diverging ports on the production of blowing sounds are investigated. It appears that the intensity of the unsteady separation of the acoustic flow, as well as the radiation efficiency of the port and the quality factor of the port resonances, altogether determine the level of blowing noise. Maximum reduction of the blowing sounds and acoustic losses is obtained by using a port contour geometry that slowly diverges from the center towards both port ends and is rounded with curvature radii that are not too large at both port terminations.
Click to purchase paper as a non-member or you can login as an AES member to see more options.
No AES members have commented on this paper yet.
To be notified of new comments on this paper you can
subscribe to this RSS feed.
Forum users should login to see additional options.
If you are not yet an AES member and have something important to say about this paper then we urge you to join the AES today and make your voice heard. You can join online today by clicking here.
