Short answer: the Ascend Acoustics Sierra-LX if sound quality matters most, the Klipsch RP-600M II if price matters most. The Ascend Acoustics Sierra-LX ranks #33 of 130 bookshelf speakers at $1598. The Klipsch RP-600M II ranks #74 at $449.99, $1148.01 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 Ascend Acoustics Sierra-LX offers: Very neutral, flat frequency response - within about plus or minus 1.5dB ignoring one narrow dip. Bass extension down to about 40Hz in-room despite the compact size. Wide, well-balanced soundstage (~60 degrees). Solid build quality with a laminated bamboo cabinet. Watch for: Very low sensitivity at about 81dB, so it needs a genuinely powerful amplifier to reach normal listening levels. Noticeable midrange distortion becomes audible above about 82-83dB SPL. A narrow dip around 3.5kHz on-axis in larger rooms without sidewall reflections - toeing the speakers out 10-20 degrees fills it in, but adds some brightness to the treble. Sensitive to listening height - sitting even slightly above or below tweeter level noticeably shifts the tonal balance.
Buy the Klipsch RP-600M II if the price matters more than sound quality. Buy the Ascend Acoustics Sierra-LX 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 | Ascend Acoustics Sierra-LX | |
|---|---|---|
| Price | $449.99 per pair | $1598 per pair |
| Ranked | #74 of 130 in Large Size Bookshelf Speakers | #33 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) | 47Hz (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) | 14.3" x 7.5" x 10.5" (362 x 191 x 267 mm) |
| Impedance | 8 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin's Audio Corner) | 8 ohms nominal (5.5 ohms minimum) |
| Sensitivity | 86dB (measured, Erin's Audio Corner) | 81dB (2.83V/1m, measured by Erin's Audio Corner) |
| Drivers | 6.5" Cerametallic cone woofer, 1" titanium LTS vented tweeter with Tractrix horn | 6" aluminum cone woofer, 26mm dome tweeter |
| Weight | 13 lbs (5.9 kg) each | 20.9 lbs (9.5 kg) |
| Woofer Cabinet | ported | Bass reflex, flared rear port |
| Spinorama Preference Score | 4.75 | 5.93 |
| Spinorama Preference Score with Perfect Sub | 6.88 | 7.74 |
| Power Handling | - | 350W continuous, 500W peak |
| Frequency Response | - | 28Hz - 23kHz (in-room, manufacturer specified) |
| Country | - | USA |
Related Speaker Comparisons
More top alternatives to Ascend Acoustics Sierra-LX:
- Ascend Acoustics Sierra-LX vs Perlisten S4b
- Ascend Acoustics Sierra-LX vs KEF Reference 1 Meta
- Ascend Acoustics Sierra-LX vs GR-Research NX-Studio
- AsciLab C6B vs Ascend Acoustics Sierra-LX
- Audio First Cadentia 3 vs Ascend Acoustics Sierra-LX
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.
As an eBay Partner, we may be compensated if you make a purchase.
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
Ascend Acoustics Sierra-LX: $1598 per pair Ascend Acoustics eBay
Pros: Very neutral, flat frequency response - within about plus or minus 1.5dB ignoring one narrow dip. Bass extension down to about 40Hz in-room despite the compact size. Wide, well-balanced soundstage (~60 degrees). Solid build quality with a laminated bamboo cabinet. Measured bass extension of 47Hz (-3dB), with a measured sensitivity of 81dB.
Cons: Very low sensitivity at about 81dB, so it needs a genuinely powerful amplifier to reach normal listening levels. Noticeable midrange distortion becomes audible above about 82-83dB SPL. A narrow dip around 3.5kHz on-axis in larger rooms without sidewall reflections - toeing the speakers out 10-20 degrees fills it in, but adds some brightness to the treble. Sensitive to listening height - sitting even slightly above or below tweeter level noticeably shifts the tonal balance.
Full Ascend Acoustics Sierra-LX review and specifications →
| Bass Extension (-10dB) | 38Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 47Hz (measured, Erin's Audio Corner) |
| Country | USA |
| Dimensions | 14.3" x 7.5" x 10.5" (362 x 191 x 267 mm) |
| Drivers | 6" aluminum cone woofer, 26mm dome tweeter |
| Frequency Response | 28Hz - 23kHz (in-room, manufacturer specified) |
| Impedance | 8 ohms nominal (5.5 ohms minimum) |
| Power Handling | 350W continuous, 500W peak |
| Sensitivity | 81dB (2.83V/1m, measured by Erin's Audio Corner) |
| Spinorama Preference Score | 5.93 |
| Spinorama Preference Score with Perfect Sub | 7.74 |
| Weight | 20.9 lbs (9.5 kg) |
| Woofer Cabinet | Bass reflex, flared rear port |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Ascend Acoustics Sierra-LX vs Wharfedale Linton 85
- Ascend Acoustics Sierra-LX vs Philharmonic BMR (v1)
- Ascend Acoustics Sierra-LX vs Ascend Acoustics Sierra-2EX V2
- Ascend Acoustics Sierra-LX vs Dynaudio Heritage Special
- Ascend Acoustics Sierra-LX vs Radiant Acoustics Clarity 6.2
- Ascend Acoustics Sierra-LX vs Emotiva Airmotiv XB2
- Ascend Acoustics Sierra-LX vs MoFi SourcePoint 10
- Ascend Acoustics Sierra-LX vs ELAC Debut 3.0 DB63
- See all 47 comparisons