Short answer: the JBL M2 Master Reference Monitor. It ranks #1 of 40 powered bookshelf speakers by sound quality; the JBL 4305P ranks #14.
What the JBL M2 Master Reference Monitor offers: Flagship quasi-active two-way with a 15-inch 2216Nd woofer and D2 compression driver crossing near 800Hz through a large Image Control Waveguide. Watch for: The required bi-amplification/DSP ecosystem is expensive and complex; Erin’s Crown I-Tech 5000HD had fans loud enough that he moved it to another room for measurements.
The case for the JBL 4305P: Erin measured a 45Hz F3 and heard solid 40–50Hz in-room extension—excellent for a compact 5.25-inch active monitor. The tradeoff: 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 JBL M2 Master Reference Monitor if sound quality matters more than the price. Buy the JBL 4305P if the price matters more than sound quality.
Specifications Side By Side
| JBL M2 Master Reference Monitor | JBL 4305P | |
|---|---|---|
| Price | Contact dealer | $2,200/pair |
| Ranked | #1 of 40 in Large Size Powered Bookshelf Speakers | #14 of 40 in Large Size Powered Bookshelf Speakers |
| Bass Extension (-3dB) | 34Hz (measured, Erin’s Audio Corner) | 45Hz (measured, Erin’s Audio Corner) |
| Sensitivity | Not applicable (externally bi-amplified DSP system) | Not applicable (active DSP loudspeaker) |
| Drivers | 15" 2216Nd woofer; D2 compression driver in Image Control Waveguide | 5.25-inch pulp woofer; 1-inch annular compression driver |
| Crossover | 800Hz active DSP | - |
| Max SPL | 123dB manufacturer specified | - |
| Weight | 130 lb each | - |
| Amplification | External two-channel amplification and JBL DSP tuning required | 300W system: 125W LF + 25W HF per speaker |
| Maximum Output | - | ~93dB at 2m in-room before limiting (measured, Erin’s Audio Corner) |
| Dimensions | - | 13.2H x 8.3W x 8.8D inches |
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The Two Speakers In Full
JBL M2 Master Reference Monitor: Contact dealer JBL Professional Dealer Locator
Pros: Flagship quasi-active two-way with a 15-inch 2216Nd woofer and D2 compression driver crossing near 800Hz through a large Image Control Waveguide. Erin measured F3 at 34Hz, less than 1% THD at 86 and 96dB, and only about 0.25dB compression by 102dB. Radiation stays broadly constant to roughly +/-60 degrees through 8-9kHz, producing excellent direct/reflected-sound agreement and enormous clean dynamic range. External DSP amplification permits precise factory crossover, phase and response correction.
Cons: The required bi-amplification/DSP ecosystem is expensive and complex; Erin’s Crown I-Tech 5000HD had fans loud enough that he moved it to another room for measurements. Midrange resonances remain visible despite the otherwise neutral response, and treble dispersion narrows above roughly 9kHz before beaming above 12kHz. Each 130-pound enclosure is physically imposing. This is an amplified system, so passive impedance and sensitivity figures are not applicable to the complete configured product.
Full JBL M2 Master Reference Monitor review and specifications →
| Amplification | External two-channel amplification and JBL DSP tuning required |
|---|---|
| Bass Extension (-3dB) | 34Hz (measured, Erin's Audio Corner) |
| Crossover | 800Hz active DSP |
| Drivers | 15" 2216Nd woofer; D2 compression driver in Image Control Waveguide |
| Max SPL | 123dB manufacturer specified |
| Sensitivity | Not applicable (externally bi-amplified DSP system) |
| Weight | 130 lb each |
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- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- JBL M2 Master Reference Monitor vs Kii THREE
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- JBL M2 Master Reference Monitor vs Neumann KH420
- JBL M2 Master Reference Monitor vs Genelec 8361A
- JBL M2 Master Reference Monitor vs Genelec 8351B
- JBL M2 Master Reference Monitor vs Genelec 8050B
- JBL M2 Master Reference Monitor vs Genelec 8040B
- JBL M2 Master Reference Monitor vs Kali Audio IN-8
- See all 11 comparisons
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