Black Box Mark IV
| Brand | Frazier |
| Manufacturer | International Electronics Corporation |
| Function | Speaker |
| Produced | 1960 |
| Country | United States |
| Form Factor | Bookshelf / Stand Mounted |
| Signal Path | Passive Hardware |
| Dimensions | 60.7 × 30.2 × 40.4 cm (W × H × D) |
| Weight | 48lbs (Shipped) |
| Frequency Response | 40Hz-17kHz |
| Treble | Paper Cone |
| Midrange/Bass | Paper Cone |
| Impedance (Nominal) | 8Ω |
| Power Handling | 15W |
| Power Handling (Peak) | 25W |
| Enclosure Type | Bass Reflex |
| Finish | Black |
| MSRP (1960) | $110 |
| Notes | Utility version of Cortez |