Short answer: the Genelec 8351B for better sound quality, the JBL 4305P for the lower price. The Genelec 8351B ranks #6 of 40 powered bookshelf speakers at $9150. The JBL 4305P ranks #14 at $2200, $6950 cheaper.
The case for the Genelec 8351B: CEA2034 spinorama shows exceptionally flat response both on- and off-axis. The tradeoff: Deep bass distortion rises substantially at higher output (96dB SPL/1m) - the reviewer notes “deep bass suffers” below about 100Hz.
What the JBL 4305P gets right: Erin measured a 45Hz F3 and heard solid 40–50Hz in-room extension—excellent for a compact 5.25-inch active monitor. The catch: The limiter becomes conspicuous around 96dB: Erin measured about 8dB lost near 50Hz at the highest drive and achieved roughly 93dB unweighted at 2m in-room.
Buy the Genelec 8351B if sound quality matters more than the price. Buy the JBL 4305P if the price matters more than sound quality.
Specifications Side By Side
| Genelec 8351B | JBL 4305P | |
|---|---|---|
| Price | $9150 | $2,200/pair |
| Ranked | #6 of 40 in Large Size Powered Bookshelf Speakers | #14 of 40 in Large Size Powered Bookshelf Speakers |
| Bass Extension (-10dB) | 28Hz (measured, Audio Science Review) | - |
| Bass Extension (-3dB) | 33Hz (measured, Audio Science Review) | 45Hz (measured, Erin’s Audio Corner) |
| Dimensions | 17"H x 11.3"W x 10.9"D (431.8 x 287 x 276.9 mm) | 13.2H x 8.3W x 8.8D inches |
| Inputs | XLR | - |
| Weight | 31.1 lbs / 14.1 kg each | - |
| Drivers | 8.6" woofer, 5" coaxial with tweeter midrange, 0.75" (19mm) coaxial tweeter | 5.25-inch pulp woofer; 1-inch annular compression driver |
| App | Yes (GLM) | - |
| Bluetooth | No | - |
| DSP | Yes | - |
| EQ | Yes (via GLM software) | - |
| Frequency Response | 32Hz - 40kHz (±1.5dB) (Manufacturer specified) | - |
| Max SPL | 113dB @ 1m | - |
| Output Power | 550w Per Speaker | - |
| Sensitivity | - | Not applicable (active DSP loudspeaker) |
| Maximum Output | - | ~93dB at 2m in-room before limiting (measured, Erin’s Audio Corner) |
| Amplification | - | 300W system: 125W LF + 25W HF per speaker |
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- Genelec 8361A vs Focal Alpha 65 EVO
- Genelec 8361A vs Kali Audio LP-6 V2
- Genelec 8351B vs Genelec 8040B
- Neumann KH420 vs JBL 4305P
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 4305P: $2,200/pair Amazon JBL
Pros: Erin measured a 45Hz F3 and heard solid 40–50Hz in-room extension—excellent for a compact 5.25-inch active monitor. Tonality is neutral and non-fatiguing, vocal coloration is absent, imaging is precise, and the HDI horn maintains near-constant horizontal directivity above 2kHz. Each speaker is bi-amplified (125W LF + 25W HF), while USB, optical, balanced analog, AirPlay 2, Chromecast, Bluetooth and 24/192 wired interconnect make this an unusually complete system. Grilles caused no meaningful response penalty.
Cons: The limiter becomes conspicuous around 96dB: Erin measured about 8dB lost near 50Hz at the highest drive and achieved roughly 93dB unweighted at 2m in-room, so this is a near/midfield system rather than a high-output theater speaker. A baffle discontinuity produces a 1–2kHz directivity mismatch that cannot be corrected uniformly in the vertical plane; stay within about +/-5° of tweeter height. Soundstage depth and layering trailed the KEF Reference 1 Meta, and wireless speaker linking caps resolution at 24/96.
Full JBL 4305P review and specifications →
| Amplification | 300W system: 125W LF + 25W HF per speaker |
|---|---|
| Bass Extension (-3dB) | 45Hz (measured, Erin's Audio Corner) |
| Dimensions | 13.2H x 8.3W x 8.8D inches |
| Drivers | 5.25-inch pulp woofer; 1-inch annular compression driver |
| Maximum Output | ~93dB at 2m in-room before limiting (measured, Erin's Audio Corner) |
| Sensitivity | Not applicable (active DSP loudspeaker) |
As an eBay Partner, we may be compensated if you make a purchase.
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons