In this paper, we propose a beam-forming speaker based on digitally direct driven speaker system (digital-SP); the proposed speaker employs multibit delta-sigma modulation in addition to a line speaker array and a delay circuit. The proposed speaker can be realized only by D flip-flops and digital-SP. Delay elements are introduced between the mismatch shaper and sub-loudspeakers, and beam-forming is realized without degradation of the noise shaping performance of the multibit DSMBy using a small amount of additional hardware, we can easily control the sound direction. If a beam-forming speaker can be driven digitally, all processes can be performed digitally without the use of analog components such as power amplifiers, and a small, light, high-quality speaker system can be realized. The prototype is constructed using an FPGA, CMOS drivers, and a line speaker array. The effectiveness has been confirmed by using measurement data. A gain of 8 dB or more is measured relative to the normal digital speaker system. And an attenuation of 14.7dB for 40° direction is measured.
Authors:
Watanabe, Kyosuke; Yasuda, Akira; Ohtani, Hajime; Suzuki, Ryota; Shinkawa, Naoto; Tsuchiya, Tomohiro; Tsuihiji, Kenzo
Affiliation:
Hosei University, Koganei, Tokyo, Japan
AES Convention:
127 (October 2009)
Paper Number:
7950
Publication Date:
October 1, 2009
Subject:
Arrays
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.