AS-51U
| Brand | Heathkit |
| Manufacturer | Heath Company, Daystrom, Incorporated |
| Function | Speaker (Kit) |
| Produced | 1961 |
| Country | United States |
| Form Factor | Bookshelf / Stand Mounted |
| Signal Path | Passive Hardware |
| Dimensions | 58.4 × 29.2 × 29.8 cm (W × H × D) |
| Weight | 24lbs (Shipped) |
| Frequency Response | 50Hz-12kHz ±5dB |
| Treble | Exponential Horn (Jensen) |
| Midrange/Bass | 8" Paper Cone (Jensen) |
| Impedance (Nominal) | 16Ω |
| Crossover Frequency | 1.6kHz |
| Power Rating (RMS) | 15W |
| Power Rating (Program Material) | 25W |
| Enclosure Type | Bass Reflex |
| Enclosure Construction | Plywood |
| Finish | Unfinished |
| MSRP (1961) | $39.95 |
| Channels | 1 Channel |
| Notes | SS-2 with updated styling |