Short answer: the Genelec 8351B for better sound quality, the JBL 708P for the lower price. The Genelec 8351B ranks #6 of 40 powered bookshelf speakers at $9150. The JBL 708P ranks #20 at $4000, $5150 cheaper.
On the Genelec 8351B side: CEA2034 spinorama shows exceptionally flat response both on- and off-axis. Set against that: Deep bass distortion rises substantially at higher output (96dB SPL/1m) - the reviewer notes “deep bass suffers” below about 100Hz.
What the JBL 708P offers: CEA2034 spinorama shows extremely good frequency response both on- and off-axis, with excellent horizontal directivity. Watch for: A port resonance creates a mild rise around 600-900Hz.
Buy the Genelec 8351B if sound quality matters more than the price. Buy the JBL 708P if the price matters more than sound quality.
Specifications Side By Side
| Genelec 8351B | JBL 708P | |
|---|---|---|
| Price | $9150 | $4000 |
| Ranked | #6 of 40 in Large Size Powered Bookshelf Speakers | #20 of 40 in Large Size Powered Bookshelf Speakers |
| Bass Extension (-10dB) | 28Hz (measured, Audio Science Review) | 62Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 33Hz (measured, Audio Science Review) | 82Hz (measured, Audio Science Review) |
| Dimensions | 17"H x 11.3"W x 10.9"D (431.8 x 287 x 276.9 mm) | 17.2"H x 9.8"W x 11.5"D (438 x 248 x 292 mm) |
| Inputs | XLR | - |
| Weight | 31.1 lbs / 14.1 kg each | 25.1 lbs / 11.4 kg each |
| Drivers | 8.6" woofer, 5" coaxial with tweeter midrange, 0.75" (19mm) coaxial tweeter | 8" woofer, 2409H 1" compression driver |
| App | Yes (GLM) | No |
| Bluetooth | No | - |
| DSP | Yes | No |
| EQ | Yes (via GLM software) | No |
| Frequency Response | 32Hz - 40kHz (±1.5dB) (Manufacturer specified) | 41Hz - 25kHz (+/-3dB) (Manufacturer specified) |
| Max SPL | 113dB @ 1m | - |
| Output Power | 550w Per Speaker | 500W total (250W woofer, 250W tweeter) |
Related Speaker Comparisons
More useful head-to-heads from the same speaker class:
- Genelec 8361A vs JBL 4305P
- Genelec 8361A vs Genelec 8040B
- Genelec 8361A vs Genelec 8050B
- Genelec 8050B vs Genelec 8351B
- Genelec 8351B vs Neumann KH 310 A
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.
Full Genelec 8351B review and specifications →
| App | Yes (GLM) |
|---|---|
| Bass Extension (-10dB) | 28Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 33Hz (measured, Audio Science Review) |
| 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 |
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JBL 708P: $4000 Bhphotovideo
Pros: CEA2034 spinorama shows extremely good frequency response both on- and off-axis, with excellent horizontal directivity. Bi-amplified 500W design (250W woofer, 250W compression driver) handles an 8” woofer and JBL’s 2409H compression tweeter.
Cons: A port resonance creates a mild rise around 600-900Hz. Vertical dispersion is narrower than horizontal, so staying within a few degrees of the tweeter axis matters. Distortion climbs at 96dB SPL, with the tweeter reaching about 2.5% THD at elevated levels.
Full JBL 708P review and specifications →
| App | No |
|---|---|
| Bass Extension (-10dB) | 62Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 82Hz (measured, Audio Science Review) |
| DSP | No |
| Dimensions | 17.2"H x 9.8"W x 11.5"D (438 x 248 x 292 mm) |
| Drivers | 8" woofer, 2409H 1" compression driver |
| EQ | No |
| Frequency Response | 41Hz - 25kHz (+/-3dB) (Manufacturer specified) |
| Output Power | 500W total (250W woofer, 250W tweeter) |
| Weight | 25.1 lbs / 11.4 kg each |
As an eBay Partner, we may be compensated if you make a purchase.
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons