Short answer: the AsciLab A6B Passive on measured sound quality, the Klipsch RP-600M II on price. The AsciLab A6B Passive ranks #18 of 130 bookshelf speakers at $3790. The Klipsch RP-600M II ranks #74 at $449.99, $3340.01 cheaper.
What the Klipsch RP-600M II offers: Redesigned waveguide extends flush to the baffle edge, reducing diffraction compared to the original RP-600M. Roughly 10-20° wider horizontal radiation than the original, giving more soundstage envelopment while retaining precise imaging. A major step up in overall tonal neutrality compared to the original RP-600M, largely eliminating that model’s midrange resonance issues. Unusually, sounds better with the grille on - the grille smooths out the elevated treble rather than degrading the sound, a rare trait among speakers the reviewer has tested. More refined back-panel hardware, including anodized binding posts and jumper cables for optional bi-amping. Responds well to EQ correction (verified using measurement software and a miniDSP), letting the on-axis response be made genuinely linear. Watch for: On-axis, the treble runs notably hot - even hotter than the original RP-600M in some respects - and needs about 20° of toe-out or the grille installed to sound balanced. Horizontal dispersion is very slightly less linear across angles than the original RP-600M, a minor trade-off for the wider overall radiation pattern. Klipsch’s marketed sensitivity (about 94.5dB) is, like the original, a half-space rating roughly 9dB above the anechoic reality (closer to 85-86dB). In-room bass rolls off around 60Hz in practice, and a 120Hz boost paired with a midrange scoop gives kick drums their “tambour” without real low-end weight - a subwoofer is still recommended. Vertical listening tolerance is limited to about ±10° from the tweeter axis. Toeing the speaker out for better on-axis tonality (rather than using the grille) introduces slightly more diffuse imaging from added sidewall reflections.
What the AsciLab A6B Passive offers: A Purifi 6.5 inch aluminum cone woofer works with two side mounted passive radiators and a Klippel NFS optimized crossover to reach a measured 41.0Hz extension point with an on axis slope of just -0.10dB per octave, essentially flat. On axis deviation measures 0.071dB average, the tightest figure of any speaker added to this catalog from spinorama.org’s current measurement set. Listening window smoothness (0.60) sits in line with AsciLab’s other highly rated bookshelf models already in this catalog. Watch for: 4 ohm nominal impedance and 82dB sensitivity call for a robust amplifier. AsciLab and its resellers frequently list the A6B as sold out or preorder only, and reported prices vary widely by source and region, from roughly $2,900 to over $3,900 per pair, so confirm the current listing before buying. Tweeter material is described inconsistently between sources (alumina ceramic dome versus an SB Acoustics unit), worth verifying directly with a reseller if that detail matters to you.
Buy the Klipsch RP-600M II if the price matters more than sound quality. Buy the AsciLab A6B Passive if sound quality matters more than the price.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| Klipsch RP-600M II | AsciLab A6B Passive | |
|---|---|---|
| Price | $449.99 per pair | €3,790 per pair |
| Ranked | #74 of 130 in Large Size Bookshelf Speakers | #18 of 130 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 41Hz (measured, Erin's Audio Corner) | 34.7Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 70Hz (measured, Erin's Audio Corner) | 41.0Hz (measured, Audio Science Review) |
| Dimensions | 15.7"H x 8"W x 12.5"D (398.8 x 203.2 x 317.5 mm) | 15.9"H x 8.7"W x 11.8"D (405 x 220 x 300 mm) |
| Impedance | 8 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin's Audio Corner) | 4 ohms nominal |
| Sensitivity | 86dB (measured, Erin's Audio Corner) | 82dB @ 2.83V/1m |
| Drivers | 6.5" Cerametallic cone woofer, 1" titanium LTS vented tweeter with Tractrix horn | 1" dome tweeter, 6.5" Purifi aluminum cone woofer, 2x 6.5" Purifi passive radiators |
| Weight | 13 lbs (5.9 kg) each | 27.1 lbs (12.3 kg) each |
| Woofer Cabinet | ported | - |
| Spinorama Preference Score | 4.75 | 5.84 |
| Spinorama Preference Score with Perfect Sub | 6.88 | 7.57 |
| Enclosure | - | sealed with passive radiators |
| Crossover Frequency | - | 1kHz |
| Warranty | - | 2 years |
| Country | - | South Korea |
| Maximum SPL | - | 102dB full bandwidth, 106dB above 100Hz (manufacturer specified) |
Related Speaker Comparisons
How AsciLab A6B Passive compares with other leading options:
- AsciLab A6B Passive vs Epos ES14N
- ELAC Debut 3.0 DB63 vs AsciLab A6B Passive
- Klipsch RP-600M II vs MoFi SourcePoint 10
- Klipsch RP-600M II vs MoFi SourcePoint 10 Master Edition
- Klipsch RP-600M II vs Epos ES14N
Prices on this page were last checked September 16, 2026 at 12:41 AM 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.
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The Two Speakers In Full
Klipsch RP-600M II: $449.99 per pair Amazon eBay
Pros: Redesigned waveguide extends flush to the baffle edge, reducing diffraction compared to the original RP-600M. Roughly 10-20° wider horizontal radiation than the original, giving more soundstage envelopment while retaining precise imaging. A major step up in overall tonal neutrality compared to the original RP-600M, largely eliminating that model’s midrange resonance issues. Unusually, sounds better with the grille on - the grille smooths out the elevated treble rather than degrading the sound, a rare trait among speakers the reviewer has tested. More refined back-panel hardware, including anodized binding posts and jumper cables for optional bi-amping. Responds well to EQ correction (verified using measurement software and a miniDSP), letting the on-axis response be made genuinely linear. Measured bass extension of 70Hz (-3dB), with a measured sensitivity of 86dB.
Cons: On-axis, the treble runs notably hot - even hotter than the original RP-600M in some respects - and needs about 20° of toe-out or the grille installed to sound balanced. Horizontal dispersion is very slightly less linear across angles than the original RP-600M, a minor trade-off for the wider overall radiation pattern. Klipsch’s marketed sensitivity (about 94.5dB) is, like the original, a half-space rating roughly 9dB above the anechoic reality (closer to 85-86dB). In-room bass rolls off around 60Hz in practice, and a 120Hz boost paired with a midrange scoop gives kick drums their “tambour” without real low-end weight - a subwoofer is still recommended. Vertical listening tolerance is limited to about ±10° from the tweeter axis. Toeing the speaker out for better on-axis tonality (rather than using the grille) introduces slightly more diffuse imaging from added sidewall reflections.
Full Klipsch RP-600M II review and specifications →
| Bass Extension (-10dB) | 41Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 70Hz (measured, Erin's Audio Corner) |
| Dimensions | 15.7"H x 8"W x 12.5"D (398.8 x 203.2 x 317.5 mm) |
| Drivers | 6.5" Cerametallic cone woofer, 1" titanium LTS vented tweeter with Tractrix horn |
| Impedance | 8 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin's Audio Corner) |
| Sensitivity | 86dB (measured, Erin's Audio Corner) |
| Spinorama Preference Score | 4.75 |
| Spinorama Preference Score with Perfect Sub | 6.88 |
| Weight | 13 lbs (5.9 kg) each |
| Woofer Cabinet | ported |
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: The Truth about Klipsch’s “NEW” Sound. RP-600M Update. More from Erin’s Audio Corner →
- Erin’s Audio Corner Website Klipsch RP-600M II
- GR-Research: We Bought The "NEW" RP-600M II Is KLIPSCH Listening?! More from GR-Research →
- Erin’s Audio Corner: 5 AWESOME SPEAKERS Under $1000 You Won’t Regret
- Erin’s Audio Corner Measurements (spinorama.org)
- Head-to-Head Comparisons
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- Klipsch RP-600M II vs JBL Studio 630
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- Klipsch RP-600M II vs Behringer B2030P
- Klipsch RP-600M II vs Theory Audio sb25
- See all 116 comparisons
AsciLab A6B Passive: €3,790 per pair Audiophonics eBay
Pros: A Purifi 6.5 inch aluminum cone woofer works with two side mounted passive radiators and a Klippel NFS optimized crossover to reach a measured 41.0Hz extension point with an on axis slope of just -0.10dB per octave, essentially flat. On axis deviation measures 0.071dB average, the tightest figure of any speaker added to this catalog from spinorama.org’s current measurement set. Listening window smoothness (0.60) sits in line with AsciLab’s other highly rated bookshelf models already in this catalog. Measured bass extension of 41.0Hz (-3dB).
Cons: 4 ohm nominal impedance and 82dB sensitivity call for a robust amplifier. AsciLab and its resellers frequently list the A6B as sold out or preorder only, and reported prices vary widely by source and region, from roughly $2,900 to over $3,900 per pair, so confirm the current listing before buying. Tweeter material is described inconsistently between sources (alumina ceramic dome versus an SB Acoustics unit), worth verifying directly with a reseller if that detail matters to you.
Full AsciLab A6B Passive review and specifications →
| Bass Extension (-10dB) | 34.7Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 41.0Hz (measured, Audio Science Review) |
| Country | South Korea |
| Crossover Frequency | 1kHz |
| Dimensions | 15.9"H x 8.7"W x 11.8"D (405 x 220 x 300 mm) |
| Drivers | 1" dome tweeter, 6.5" Purifi aluminum cone woofer, 2x 6.5" Purifi passive radiators |
| Enclosure | sealed with passive radiators |
| Impedance | 4 ohms nominal |
| Maximum SPL | 102dB full bandwidth, 106dB above 100Hz (manufacturer specified) |
| Sensitivity | 82dB @ 2.83V/1m |
| Spinorama Preference Score | 5.84 |
| Spinorama Preference Score with Perfect Sub | 7.57 |
| Warranty | 2 years |
| Weight | 27.1 lbs (12.3 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons