| HD4405 | |
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Throat diameter 25mm (1in) Rated impedance 8 ohms Minimum impedance 5.3ohms  more |
| HD4406 | |
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Throat diameter 38mm (1.5in) Rated impedance 8 ohms Minimum impedance 5.3ohms @ 4.3kHz more |
| HD4407ND | |
 |
Throat diameter 25.4mm (1in) Rated impedance 8 ohms Minimum impedance 7.3 ohms more |
| HD7501 | |
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Throat diameter 36mm (1.4in) Rated impedance 8 ohms Minimum impedance 8.2ohms more |
| HD7502 | |
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Throat diameter 36mm (1.4in) Rated impedance 8 ohms Minimum impedance 7.8ohms more |
| HD7503ND | |
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Throat diameter 36mm (1.4in) Rated impedance 8 ohms Minimum impedance 8.5ohms more |