Short answer: the AsciLab F6B on measured sound quality, the Klipsch RP-600M II on price. The AsciLab F6B ranks #12 of 130 bookshelf speakers at $980. The Klipsch RP-600M II ranks #74 at $449.99, $530.01 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 F6B offers: Called by the reviewer the best sub-$1000 pair of speakers he’s come across to date. Very good on-axis linearity and directivity for the price, with a large waveguide-loaded 1” aluminum dome tweeter that keeps a two-way design well-behaved through the crossover. Nice midbass punch from a slightly undersized enclosure alignment that gives kick drums extra impact. Solid, unfussy tonal balance overall. Watch for: 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. In-room bass extension is only about 50-60Hz despite a 6” woofer, trading some low-end reach for that extra midbass punch. Compression and graininess creep in at higher volumes (upper 80s to low 90s dB at 10ft), and directivity (~50-60 degrees horizontal) is narrower than the reviewer’s other current favorite, the Audio First Cadentia 3.
Buy the Klipsch RP-600M II if the price matters more than sound quality. Buy the AsciLab F6B if sound quality matters more than the price.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| Klipsch RP-600M II | AsciLab F6B | |
|---|---|---|
| Price | $449.99 per pair | $980 per pair |
| Ranked | #74 of 130 in Large Size Bookshelf Speakers | #12 of 130 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 41Hz (measured, Erin's Audio Corner) | 38Hz (measured, Erin's Audio Corner) |
| Bass Extension (-3dB) | 70Hz (measured, Erin's Audio Corner) | 56Hz (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) | 15.7" x 8" x 10.4" (400 x 203 x 265 mm) |
| Impedance | 8 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin's Audio Corner) | 4 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin's Audio Corner) |
| Sensitivity | 86dB (measured, Erin's Audio Corner) | 85dB (2.83V/1m, measured by Erin's Audio Corner) |
| Drivers | 6.5" Cerametallic cone woofer, 1" titanium LTS vented tweeter with Tractrix horn | 1" aluminum dome tweeter, 6" fiber cone woofer |
| Weight | 13 lbs (5.9 kg) each | 16.5 lbs (7.5 kg) each |
| Woofer Cabinet | ported | Passive radiator loaded |
| Spinorama Preference Score | 4.75 | 5.55 |
| Spinorama Preference Score with Perfect Sub | 6.88 | 7.50 |
| Crossover Frequency | - | 1000Hz |
| Recommended Power | - | up to 125W |
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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
- Klipsch RP-600M II vs Dynaudio Emit 20
- Klipsch RP-600M II vs Aoshida Audio Musician Knight I V2
- Klipsch RP-600M II vs Philharmonic BMR Monitor
- Klipsch RP-600M II vs JBL 708i
- Klipsch RP-600M II vs JBL Studio 630
- Klipsch RP-600M II vs PS Audio Aspen FR5
- Klipsch RP-600M II vs Behringer B2030P
- Klipsch RP-600M II vs Theory Audio sb25
- See all 116 comparisons
AsciLab F6B: $980 per pair Ascilab eBay
Pros: Called by the reviewer the best sub-$1000 pair of speakers he’s come across to date. Very good on-axis linearity and directivity for the price, with a large waveguide-loaded 1” aluminum dome tweeter that keeps a two-way design well-behaved through the crossover. Nice midbass punch from a slightly undersized enclosure alignment that gives kick drums extra impact. Solid, unfussy tonal balance overall. Measured bass extension of 56Hz (-3dB), with a measured sensitivity of 85dB.
Cons: 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. In-room bass extension is only about 50-60Hz despite a 6” woofer, trading some low-end reach for that extra midbass punch. Compression and graininess creep in at higher volumes (upper 80s to low 90s dB at 10ft), and directivity (~50-60 degrees horizontal) is narrower than the reviewer’s other current favorite, the Audio First Cadentia 3.
Full AsciLab F6B review and specifications →
| Bass Extension (-10dB) | 38Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 56Hz (measured, Erin's Audio Corner) |
| Crossover Frequency | 1000Hz |
| Dimensions | 15.7" x 8" x 10.4" (400 x 203 x 265 mm) |
| Drivers | 1" aluminum dome tweeter, 6" fiber cone woofer |
| Impedance | 4 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin's Audio Corner) |
| Recommended Power | up to 125W |
| Sensitivity | 85dB (2.83V/1m, measured by Erin's Audio Corner) |
| Spinorama Preference Score | 5.55 |
| Spinorama Preference Score with Perfect Sub | 7.50 |
| Weight | 16.5 lbs (7.5 kg) each |
| Woofer Cabinet | Passive radiator loaded |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons