Reference Standard 4.5
| Brand | Infinity |
| Designer | Arnie Nudell |
| Function | Speaker |
| Produced | 1978-1982 |
| Country | United States |
| Model ID | RS-4.5 |
| Form Factor | Floorstanding |
| Signal Path | Passive Hardware |
| Dimensions | Speaker: 64.5"x26.5"x14.5" Control Unit: 2.2"x14.5"x10.25" (HxWxD) |
| Weight | 117lbs |
| Frequency Response | 24Hz-32kHz ±3dB |
| Tweeter (Front) | EMIT* (x3) (PN 902-0143) |
| Tweeter (Rear) | EMIT* (PN 902-0143) |
| Midrange | EMIM** (x4) (PN 902-0012) |
| Bass | 12" Infinity-Watkins Dual-Drive Polypropylene Cone Woofer (x2) (PN 902-1180) |
| Impedance | 4Ω |
| Crossover Points | 150Hz, 5kHz (150Hz Adjustable with Optional Electronic Crossover Control) |
| Dispersion (20kHz) | -2dB @ 60° |
| Recommended Amplifier Power | 100-300W |
| Finish | Oak |
| MSRP | $4,500 |
| Connections |
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| Controls |
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| Notes | *EMIT (ElectroMagnetic Induction Tweeter) **EMIM (ElectroMagnetic Induction Midrange) |