Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5523524 | Double chamber bass reflex box | Markus Woldrich | 1996-06-04 |
| 5402503 | Light-weight conical loudspeaker | — | 1995-03-28 |
| 5287412 | Arrangement for reproducing bass tones in a vehicle | Hubert Etzel, Rudiger Fleischer, Edgar Kirk | 1994-02-15 |
| 5243151 | Conical loudspeaker | — | 1993-09-07 |