Short answer: the AsciLab F6B. It ranks #12 of 222 bookshelf speakers by sound quality (rated 4.6/5) at $980 and is still sold new; the JBL Studio 630 ranks #135 (rated 3.6/5) and is discontinued, so it is only an option used.
The AsciLab F6B is the more accurate option. Called by the reviewer the best sub-$1000 pair of speakers he’s come across to date. Its measured preference score, a predictor of how neutral it sounds, is 6.32 against 3.67 for the JBL Studio 630. The catch: A mild sibilance-inducing lift around 6-8kHz, most noticeable on female vocals, paired with a shallow dip in the upper midrange: correctable with a simple 3-band EQ the reviewer provided.
Why pick the JBL Studio 630: A bookshelf speaker with a 6.5” woofer and a 1” compression driver on a waveguide, giving excellent directivity linearity and precise, stable imaging. Watch for: Noticeable mid-range dip/scoop relative to the higher frequencies: not dramatic, but audibly “missing” something by the second or third track.
Buy the AsciLab F6B. It is rated higher for sound quality and still sold new, while the JBL Studio 630 is discontinued.
Still deciding? The full Passive Home rankings cover every ranked option.
Called by the reviewer the best sub-$1000 pair of speakers he’s come across to date.
Ascilab $980 eBay
A bookshelf speaker with a 6.5” woofer and a 1” compression driver on a waveguide, giving excellent directivity linearity and precise, stable imaging.
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Specifications Side By Side
| AsciLab F6B | JBL Studio 630 | |
|---|---|---|
| Price | $980 per pair | $699 per pair Discontinued |
| Ranked | #12 of 222 in Large Size Bookshelf Speakers | #135 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 38Hz (measured, Erin’s Audio Corner) | 37.0Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-3dB) | 56Hz (measured, Erin’s Audio Corner) | 54.2Hz (measured, Erin’s Audio Corner) |
| Dimensions | 15.7” x 8” x 10.4” (400 x 203 x 265 mm) | 14-13/16”H x 9”W x 11-5/16”D |
| Impedance | 4 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin’s Audio Corner) | 6 ohms nominal, 4.7 ohms minimum (measured, Erin’s Audio Corner) |
| Sensitivity | 85dB (2.83V/1m, measured by Erin’s Audio Corner) | 83.2dB (measured, Erin’s Audio Corner; 85dB manufacturer specified) |
| Drivers | 1” aluminum dome tweeter, 6” fiber cone woofer | 6.5” PolyPlas cone woofer, 1” compression driver (2414H-1) with waveguide |
| Weight | 16.5 lbs (7.5 kg) each | 19.8 lbs (9 kg) each |
| Woofer Cabinet | Passive radiator loaded | - |
| Crossover Frequency | 1000Hz | - |
| Recommended Power | up to 125W | - |
| Spinorama Preference Score | 6.32 | 3.67 |
| Spinorama Preference Score with Perfect Sub | 8.26 | 5.68 |
| DIY Kit | No | No |
| Frequency Response | - | 45Hz - 40,000Hz (manufacturer specified) |
| Power Handling | - | up to 150W |
Frequency Response Compared
Both speakers’ spinorama measurements, overlaid. A flatter line is more neutral: peaks sound forward or harsh, dips sound recessed. Each curve is shifted so its average from 300 Hz to 3 kHz sits at 0 dB, so loudness differences between the two are removed and only the shape is compared. The two were measured by different sources, so small differences, especially in the bass, can come from the measurement setup rather than the speakers.
Measurement data: AsciLab F6B (measured by Audio Science Review) and JBL Studio 630 (measured by Erin’s Audio Corner), via spinorama.org.
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