Short answer: the Neumann KH420 for the higher ranking, the Genelec 8351B for the lower price. The Neumann KH420 ranks #2 of 20 powered bookshelf speakers at $10500. The Genelec 8351B ranks #4 at $9150, $1350 cheaper.
On the Genelec 8351B side: CEA2034 spinorama shows exceptionally flat response both on- and off-axis. The catch: Deep bass distortion rises substantially at higher output (96dB SPL/1m) - the reviewer notes “deep bass suffers” below about 100Hz.
The case for the Neumann KH420: CEA2034 spinorama shows an extended, flat on-axis response that matches Neumann’s own published measurement to within 0.08dB at its one. The tradeoff: Horizontal beamwidth, while well controlled, is on the narrow side at about ±55 degrees.
Buy the Genelec 8351B if the price matters more than the ranking. Buy the Neumann KH420 if the ranking matters more than the price.
Specifications Side By Side
| Genelec 8351B | Neumann KH420 | |
|---|---|---|
| Price | $9150 | $10500 |
| Ranked | #4 of 20 in Large Size Powered Bookshelf Speakers | #2 of 20 in Large Size Powered Bookshelf Speakers |
| Bass Extension (-10dB) | 28Hz | 24Hz |
| Bass Extension (-3dB) | 33Hz | 32Hz |
| Dimensions | 17"H x 11.3"W x 10.9"D (431.8 x 287 x 276.9 mm) | 25.4"H x 13"W x 17.5"D (645.2 x 330.2 x 444.5 mm) |
| Inputs | XLR | XLR |
| Weight | 31.1 lbs / 14.1 kg each | 77.2 lbs / 35 kg each |
| Drivers | 8.6" woofer, 5" coaxial with tweeter midrange, 0.75" (19mm) coaxial tweeter | 10" woofer, 4" dome midrange, 1" fabric dome tweeter |
| App | Yes (GLM) | Yes (MA 1 alignment) |
| Bluetooth | No | No |
| DSP | Yes | No |
| EQ | Yes (via GLM software) | Yes (Room response controls) |
| Frequency Response | 32Hz - 40kHz (±1.5dB) (Manufacturer specified) | 31Hz - 21kHz (±3dB) (Manufacturer specified) |
| Max SPL | 113dB @ 1m | 124dB @ 1m |
| Output Power | 550w Per Speaker | 555w Per Speaker |
The Two Speakers In Full
Genelec 8351B: $9150 Bhphotovideo
Pros: CEA2034 spinorama shows exceptionally flat response both on- and off-axis. Predicted in-room response is “as good as it gets” - should sound very neutral in nearly any room. Horizontal beamwidth of about ±50 degrees is described by the reviewer as exceptionally smooth, a model example of well-executed directivity control. Vertical directivity is nearly as good as horizontal, a benefit of its coaxial driver design that’s rare among non-coaxial monitors. Distortion at 86dB SPL/1m is remarkably low - the reviewer says it’s “better than many headphones.”
Cons: Deep bass distortion rises substantially at higher output (96dB SPL/1m) - the reviewer notes “deep bass suffers” below about 100Hz. A distortion spike also appears near 8-10kHz at that same higher output level. Cumulative spectral decay (waterfall) measurements show resonances around 1-2kHz. Very expensive.
| App | Yes (GLM) |
|---|---|
| Bass Extension (-10dB) | 28Hz |
| Bass Extension (-3dB) | 33Hz |
| Bluetooth | No |
| DSP | Yes |
| Dimensions | 17"H x 11.3"W x 10.9"D (431.8 x 287 x 276.9 mm) |
| Drivers | 8.6" woofer, 5" coaxial with tweeter midrange, 0.75" (19mm) coaxial tweeter |
| EQ | Yes (via GLM software) |
| Frequency Response | 32Hz - 40kHz (±1.5dB) (Manufacturer specified) |
| Inputs | XLR |
| Max SPL | 113dB @ 1m |
| Output Power | 550w Per Speaker |
| Weight | 31.1 lbs / 14.1 kg each |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Links
Neumann KH420: $10500 Bhphotovideo
Pros: CEA2034 spinorama shows an extended, flat on-axis response that matches Neumann’s own published measurement to within 0.08dB at its one minor dip (around 60Hz), with excellent off-axis behavior. Predicted in-room response is smooth and rated “excellent” by the reviewer. Horizontal beamwidth of about ±55 degrees is very well controlled and stays consistent across frequency. Distortion is low at 86dB SPL/1m. Exceptionally high sustained output capability - the reviewer needed to “hold on for dear life” during extreme-level testing at 7 feet, with bass output described as making the entire house resonate. Reviewer’s overall verdict was “Great,” placing it on the recommended list and calling it a speaker “you could buy and forget about upgrading ever again.”
Cons: Horizontal beamwidth, while well controlled, is on the narrow side at about ±55 degrees. Vertical directivity is more limited than horizontal - the reviewer recommends staying within about ±30 degrees of the reference axis (just below the tweeter waveguide edge). Distortion rises noticeably in the bass region at 96dB SPL/1m, with an unusual 3rd-harmonic uptick appearing near 10kHz at that output level. At 106dB SPL/1m, the tweeter’s protection limiting engages and the clipping indicator activates - a real, measurable output ceiling despite the speaker’s otherwise very high capability. Very expensive.
| App | Yes (MA 1 alignment) |
|---|---|
| Bass Extension (-10dB) | 24Hz |
| Bass Extension (-3dB) | 32Hz |
| Bluetooth | No |
| DSP | No |
| Dimensions | 25.4"H x 13"W x 17.5"D (645.2 x 330.2 x 444.5 mm) |
| Drivers | 10" woofer, 4" dome midrange, 1" fabric dome tweeter |
| EQ | Yes (Room response controls) |
| Frequency Response | 31Hz - 21kHz (±3dB) (Manufacturer specified) |
| Inputs | XLR |
| Max SPL | 124dB @ 1m |
| Output Power | 555w Per Speaker |
| Weight | 77.2 lbs / 35 kg each |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Links
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Product prices and availability were last checked August 9, 2026 at 6:57 AM UTC and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.