Here are a few key points on how the size of the exciter affects sound quality in DML speakers:
- Larger exciters with more surface area generally provide better bass extension and output capability[1][2]. Small exciters may lack deep bass reproduction.
- Size should be matched to the panel area. Underpowered small exciters struggle to properly drive larger panels, while oversized exciters can overdrive smaller panels[2][3].
- Proper mechanical coupling is easier with larger exciters that have more mounting options and contact area with the panel[4]. Poor coupling reduces efficiency.
- Small exciters tend to beam and have uneven off-axis response at higher frequencies. Larger exciters disperse sound more evenly[3][5].
- Using multiple small exciters can equal one larger exciter in output capability if spaced properly. Allows more placement flexibility[1][4].
- Larger exciters require more amplifier power and may lower the overall system impedance significantly[2][5].
- Overall, follow manufacturer recommendations for exciter size selection based on panel dimensions. Proper mechanical coupling and even excitation across modes is key[1][3].
So in summary, larger exciters benefit bass output and dispersion but require more power and careful impedance management. When designed well, even small exciters can provide quality sound in the right application.
Citations:
[1] https://www.diyaudio.com/community/threads/a-study-of-dmls-as-a-full-range-speaker.272576/page-38
[2] https://www.avsforum.com/threads/dml-build-w-exciters-doesnt-sound-good.3273889/
[3] https://techtalk.parts-express.com/forum/tech-talk-forum/1478691-foam-panel-exciter-speakers-sound-really-bad
[4] https://www.reddit.com/r/diyaudio/comments/q0zbj6/i_created_a_big_dml_system_and_learned_a_lot/
[5] https://www.daytonaudio.com/topic/excitersbuyerguide
[6] https://www.audiocircle.com/index.php?topic=70541.3060