| Number | Name | Date | Kind |
|---|---|---|---|
| 4437542 | Yeager et al. | Mar 1984 | A |
| 4702046 | Haugen et al. | Oct 1987 | A |
| 4703597 | Eggemar | Nov 1987 | A |
| 4796397 | Capaul | Jan 1989 | A |
| 4964250 | Nelson | Oct 1990 | A |
| 5009043 | Kurrasch | Apr 1991 | A |
| 5069011 | Jenne | Dec 1991 | A |
| 5111579 | Anderson | May 1992 | A |
| 5327698 | Uhl | Jul 1994 | A |
| 5572847 | Elmore et al. | Nov 1996 | A |
| 5618602 | Nelson | Apr 1997 | A |
| 5622012 | Schijf | Apr 1997 | A |
| 5641950 | Kotter | Jun 1997 | A |
| 5643139 | Stout et al. | Jul 1997 | A |
| 5651405 | Boeddeker et al. | Jul 1997 | A |
| 5896710 | Hoyle | Apr 1999 | A |
| 5940913 | Horowitz | Aug 1999 | A |
| 6007890 | DeBlander | Dec 1999 | A |
| 6085861 | Jines | Jul 2000 | A |
| 6244378 | McGrath | Jun 2001 | B1 |
| Number | Date | Country |
|---|---|---|
| 4002547 | Aug 1991 | DE |
| Entry |
|---|
| Auralex Acoustics 2001—Complete Product Guide, pp. 10-11; p. 15; pp. 18-20. |