Short answer: both are flat on axis; the Genelec 8351B holds its response off axis, while the HEDD Type 20 MK2 has the smoother directivity index. The 8351B’s spinorama is exceptionally flat on and off axis, though deep bass distortion rises at 96dB SPL/1m and suffers below about 100Hz. The HEDD is nicely flat on axis, but its horizontal beamwidth is asymmetric at +60/-80 degrees and narrows above 10kHz.
Buy the Genelec 8351B. It is rated higher for sound quality, and saving $5,102 with the HEDD Type 20 MK2 does not make up for the sound-quality gap.
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Specifications Side By Side
| Genelec 8351B | HEDD Type 20 MK2 | |
|---|---|---|
| Price | $9,900 per pair | $4,798 per pair |
| Ranked | #4 of 119 in Large Size Powered Bookshelf Speakers | #26 of 119 in Large Size Powered Bookshelf Speakers |
| Bass Extension (-10dB) | 28Hz (measured, Audio Science Review) | 26Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 33Hz (measured, Audio Science Review) | 32Hz (measured, Audio Science Review) |
| Dimensions | 17”H x 11.3”W x 10.9”D (431.8 x 287 x 276.9 mm) | 14.1”H x 11”W x 13.3”D (358.1 x 279.4 x 337.8 mm) |
| Inputs | XLR | XLR (Analog/AES) |
| Weight | 31.1 lbs (14.1 kg) each | 34 lbs (15.4 kg) each |
| Drivers | 8.6” woofer, 5” coaxial with tweeter midrange, 0.75” (19mm) coaxial tweeter | 7” honeycomb composite woofer, 4” honeycomb composite midrange, HEDD AMT (Air Motion Transformer) tweeter |
| App | Yes (GLM) | Yes (HEDD CTRL) |
| Bluetooth | No | No |
| DSP | Yes | Yes (96kHz/32-bit) |
| EQ | Yes (via GLM software) | Yes (Desk filter, shelf filters) |
| Frequency Response | 32Hz - 40kHz (±1.5dB) (Manufacturer specified) | 32Hz - 40kHz (Manufacturer specified) |
| Amplifier Power | 550w Per Speaker | 900W (3x300W) |
| Maximum SPL | 113dB @ 1m (manufacturer specified) | 120dB @ 1m (per pair) (manufacturer specified) |
| XLR Input | Yes | Yes |
| RCA Input | No | No |
| TRS Input | No | No |
| Optical Input | No | No |
| Coaxial Input | No | No |
| USB Input | No | No |
| HDMI Input | No | No |
| AES Input | No | Yes |
| Aux Input | No | No |
| Outputs | - | XLR (AES pass-through) |
| Spinorama Preference Score | - | 6.11 |
| Spinorama Preference Score with Perfect Sub | - | 7.69 |
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