| Sg. Indef. | spektrum |
| Sg. Def. | spektrumet; spektret |
| Pl. Indef. | spektrum; spektrer; spektra |
| Pl. Def. | spektrumen; spektrerna; spektra |
| Sg. Indef. | spektrums |
| Sg. Def. | spektrumets; spektrets |
| Pl. Indef. | spektrums; spektrers; spektras |
| Pl. Def. | spektrumens; spektrernas; spektras |