Short answer: both are discontinued, so this only matters if you are buying used. Used, the JBL Studio 630 is the better pick: it ranks #123 of 203 bookshelf speakers by sound quality (rated 3.6/5), against #171 (rated 3.0/5) for the KEF Q350. If you want one new, the KEF Q3 Meta replaces the KEF Q350 and is rated 3.4/5 at $899.99.
The JBL Studio 630 is the better-sounding, deeper-bass choice. Excellent directivity linearity: harmonics of the same instrument stay collocated in the soundstage instead of drifting between positions, giving precise, stable imaging that holds up well into higher frequencies where many speakers start to beam and narrow. Its bass reaches about 54.2Hz before falling 3dB, against 70Hz for the KEF Q350. The tradeoff: Noticeable mid-range dip/scoop relative to the higher frequencies: not dramatic, but audibly “missing” something by the second or third track.
The KEF Q350 is the more accurate pick. CEA2034 spinorama shows a reasonably flat on-axis response with excellent directivity, aided by the coaxial Uni-Q driver. Its measured preference score, a predictor of how neutral it sounds, is 5.25 against 3.67 for the JBL Studio 630. Watch for: Two resonances at 700Hz and 1.2kHz show up on-axis, alongside an upper-bass boost.
Buy the JBL Studio 630 only if you find one used in good condition; both are discontinued, and it is the better rated of the two. For a new speaker, buy the KEF Q3 Meta, which replaces the KEF Q350.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| JBL Studio 630 | KEF Q350 | |
|---|---|---|
| Price | $699 per pair Discontinued | $699.00 per pair Discontinued |
| Ranked | #123 of 203 in Large Size Bookshelf Speakers | #171 of 203 in Large Size Bookshelf Speakers |
| Drivers | 6.5” PolyPlas cone woofer, 1” compression driver (2414H-1) with waveguide | 25mm tweeter + 165mm woofer |
| Dimensions | 14-13/16”H x 9”W x 11-5/16”D | 14.1”H x 8.3”W x 12”D (358.0 x 210.0 x 306.0 mm) |
| Weight | 19.8 lbs (9 kg) each | 29.5 lbs (13.4 kg) |
| Impedance | 6 ohms nominal, 4.7 ohms minimum (measured, Erin’s Audio Corner) | 4 ohms |
| Sensitivity | 83.2dB (measured, Erin’s Audio Corner; 85dB manufacturer specified) | 86dB (measured, Audio Science Review) |
| Frequency Response | 45Hz - 40,000Hz (manufacturer specified) | - |
| Bass Extension (-3dB) | 54.2Hz (measured, Erin’s Audio Corner) | 70Hz (measured, Audio Science Review) |
| Bass Extension (-10dB) | 37.0Hz (measured, Erin’s Audio Corner) | 38Hz (measured, Audio Science Review) |
| Power Handling | up to 150W | - |
| Spinorama Preference Score | 3.67 | 5.25 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | 5.68 | 7.12 (spinorama.org) |
| DIY Kit | No | No |
| Woofer Cabinet | - | ported, rear |
Related Speaker Comparisons
How JBL Studio 630 compares with other leading options:
- JBL Studio 630 vs AsciLab C6B
- JBL Studio 630 vs KEF R3 Meta
- JBL Studio 630 vs KEF Q Concerto Meta
- AsciLab F6B vs JBL Studio 630
- JBL Studio 630 vs MoFi SourcePoint 8
Prices on this page were last checked October 7, 2026 at 9:25 PM UTC. Product prices and availability are accurate as of that date/time 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.
As an eBay Partner, we may be compensated if you make a purchase.
The Two Speakers In Full
JBL Studio 630: $699 per pair Discontinued eBay
Same family: the JBL Studio 698 (floorstanding, rated 4.3/5).
Pros: Excellent directivity linearity: harmonics of the same instrument stay collocated in the soundstage instead of drifting between positions, giving precise, stable imaging that holds up well into higher frequencies where many speakers start to beam and narrow. Good compression behavior: mid-bass stays taut and controlled from low to high volume without the sound falling apart or distorting as you turn it up. A pleasant, controlled mid-bass bump in the 60-100 Hz range adds punch to kick drums without bleeding into an uncontrolled boom on bass guitar. Horizontal radiation holds steady off-axis (about ±60°), so toe-in isn’t fussy. Compared directly to its predecessor, the JBL Studio 530, the reviewer would pick the 630 (smoother trend line through the upper mids and treble, and likely more dynamic headroom) as long as you’re willing to EQ. Measured bass extension of 54.2Hz (-3dB), with a measured sensitivity of 83.2dB.
Cons: Noticeable mid-range dip/scoop relative to the higher frequencies: not dramatic, but audibly “missing” something by the second or third track. Some tracks read as forward or aggressive around 2 kHz, like the upper frequencies are jumping out at you rather than sitting in stage depth. Needs EQ to bring the mid-range back up to be fully recommendable; without EQ available, the reviewer says he’d look at a different speaker entirely. Measured sensitivity (about 83.2dB) runs noticeably below the 85dB manufacturer spec, likely a byproduct of the mid-range dip skewing the average downward. Discontinued and no longer sold new.
Full JBL Studio 630 review and specifications →
| Bass Extension (-10dB) | 37.0Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 54.2Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 14-13/16”H x 9”W x 11-5/16”D |
| Drivers | 6.5” PolyPlas cone woofer, 1” compression driver (2414H-1) with waveguide |
| Frequency Response | 45Hz - 40,000Hz (manufacturer specified) |
| Impedance | 6 ohms nominal, 4.7 ohms minimum (measured, Erin’s Audio Corner) |
| Power Handling | up to 150W |
| Sensitivity | 83.2dB (measured, Erin’s Audio Corner; 85dB manufacturer specified) |
| Spinorama Preference Score | 3.67 |
| Spinorama Preference Score with Perfect Sub | 5.68 |
| Weight | 19.8 lbs (9 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- JBL Studio 630 vs Behringer B2030P
- JBL Studio 630 vs Dynaudio Emit 20
- JBL Studio 630 vs Klipsch RP-600M II
- JBL Studio 630 vs Infinity IL10
- JBL Studio 630 vs Dynaudio Special Forty
- JBL Studio 630 vs ELAC Debut 2.0 B6.2
- JBL Studio 630 vs SVS Prime Bookshelf
- JBL Studio 630 vs Infinity Reference R162
- See all 38 comparisons
KEF Q350: $699.00 per pair Discontinued Amazon eBay
Newer model: the KEF Q3 Meta, ranked higher, rated 3.4/5.
Same family: the KEF Q150 (smaller bookshelf, rated 3.7/5), the KEF Q250c (smaller center, rated 3.9/5) and the KEF Q650c (larger center, rated 3.7/5).
Pros: CEA2034 spinorama shows a reasonably flat on-axis response with excellent directivity, aided by the coaxial Uni-Q driver. Vertical directivity is better than most non-coaxial two-way speakers, another benefit of the concentric design. Measured bass extension of 70Hz (-3dB), with a measured sensitivity of 86dB.
Cons: Two resonances at 700Hz and 1.2kHz show up on-axis, alongside an upper-bass boost. Predicted in-room response looks a bit boomy as a result. Distortion climbs substantially in the 100Hz-1kHz range at 96dB SPL/1m, with a distinct resonance-driven peak around 900Hz-1kHz at both test levels. Discontinued.
Full KEF Q350 review and specifications →
| Bass Extension (-10dB) | 38Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 70Hz (measured, Audio Science Review) |
| DIY Kit | No |
| Dimensions | 14.1”H x 8.3”W x 12”D (358.0 x 210.0 x 306.0 mm) |
| Drivers | 25mm tweeter + 165mm woofer |
| Impedance | 4 ohms |
| Sensitivity | 86dB (measured, Audio Science Review) |
| Spinorama Preference Score | 5.25 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | 7.12 (spinorama.org) |
| Weight | 29.5 lbs (13.4 kg) |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons