Short answer: the HiVi Swans 3.1A Sehlin Sound Solutions mod. It ranks #61 of 130 bookshelf speakers by sound quality at $364.99; the Klipsch RP-600M II ranks #74 and costs $449.99, so there is little reason to consider the other one.
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 HiVi Swans 3.1A Sehlin Sound Solutions mod offers: CEA2034 spinorama shows a mostly smooth on-axis response for a DIY three-way kit. Horizontal beamwidth of about ±70 degrees is wide and consistent. Distortion stays under control down to 40Hz at 96dB SPL/1m, a strong result for a 6.5” woofer in this class. Watch for: Some directivity error appears around 2.1kHz on-axis. Predicted in-room response needs about 1-2dB of correction to fit an ideal target curve. Vertical directivity is just okay, so listening height matters more than with a coincident design. Minimum impedance dips to 3.8 ohms with several peaks, a moderately demanding load. Requires DIY assembly (kit only), with additional Sehlin-mod parts and labor beyond the base kit price.
Buy the HiVi Swans 3.1A Sehlin Sound Solutions mod. It ranks higher for sound quality than the Klipsch RP-600M II and costs less, so there is no real case for the other one.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| Klipsch RP-600M II | HiVi Swans 3.1A Sehlin Sound Solutions mod | |
|---|---|---|
| Price | $449.99 per pair | $364.99 per pair for the kit (assembly required) |
| Ranked | #74 of 130 in Large Size Bookshelf Speakers | #61 of 130 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 41Hz (measured, Erin's Audio Corner) | 38Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 70Hz (measured, Erin's Audio Corner) | 60Hz (measured, Audio Science Review) |
| Dimensions | 15.7"H x 8"W x 12.5"D (398.8 x 203.2 x 317.5 mm) | 16.5"H x 8.5"W x 13"D (420.0 x 215.0 x 330.0 mm) |
| Impedance | 8 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin's Audio Corner) | 4 ohms nominal, 3.8 ohms minimum (measured, Audio Science Review) |
| Sensitivity | 86dB (measured, Erin's Audio Corner) | 86.5dB (measured, Audio Science Review) |
| Drivers | 6.5" Cerametallic cone woofer, 1" titanium LTS vented tweeter with Tractrix horn | 6.5" Kevlar woofer, 2" Dome midrange, 1" Soft Dome tweeter |
| Weight | 13 lbs (5.9 kg) each | 13.7 lbs (6.2 kg) |
| Woofer Cabinet | ported | ported, rear |
| Spinorama Preference Score | 4.75 | - |
| Spinorama Preference Score with Perfect Sub | 6.88 | - |
Related Speaker Comparisons
More worthwhile head-to-heads for HiVi Swans 3.1A Sehlin Sound Solutions mod:
- GR-Research NX-Studio vs HiVi Swans 3.1A Sehlin Sound Solutions mod
- AsciLab C6B vs HiVi Swans 3.1A Sehlin Sound Solutions mod
- HiVi Swans 3.1A Sehlin Sound Solutions mod vs MoFi SourcePoint 10
- ELAC Debut 3.0 DB63 vs HiVi Swans 3.1A Sehlin Sound Solutions mod
- GR-Research X-LS Encore vs HiVi Swans 3.1A Sehlin Sound Solutions mod
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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 Philharmonic BMR Monitor
- Klipsch RP-600M II vs JBL Studio 630
- Klipsch RP-600M II vs Behringer B2030P
- Klipsch RP-600M II vs Ascend CBM-170 SE2
- Klipsch RP-600M II vs Infinity Reference R162
- Klipsch RP-600M II vs GR-Research X-LS Encore
- Klipsch RP-600M II vs Infinity IL10
- See all 72 comparisons
HiVi Swans 3.1A Sehlin Sound Solutions mod: $364.99 per pair for the kit (assembly required) Amazon eBay
Pros: CEA2034 spinorama shows a mostly smooth on-axis response for a DIY three-way kit. Horizontal beamwidth of about ±70 degrees is wide and consistent. Distortion stays under control down to 40Hz at 96dB SPL/1m, a strong result for a 6.5” woofer in this class. Measured bass extension of 60Hz (-3dB), with a measured sensitivity of 86.5dB.
Cons: Some directivity error appears around 2.1kHz on-axis. Predicted in-room response needs about 1-2dB of correction to fit an ideal target curve. Vertical directivity is just okay, so listening height matters more than with a coincident design. Minimum impedance dips to 3.8 ohms with several peaks, a moderately demanding load. Requires DIY assembly (kit only), with additional Sehlin-mod parts and labor beyond the base kit price.
Full HiVi Swans 3.1A Sehlin Sound Solutions mod review and specifications →
| Bass Extension (-10dB) | 38Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 60Hz (measured, Audio Science Review) |
| Dimensions | 16.5"H x 8.5"W x 13"D (420.0 x 215.0 x 330.0 mm) |
| Drivers | 6.5" Kevlar woofer, 2" Dome midrange, 1" Soft Dome tweeter |
| Impedance | 4 ohms nominal, 3.8 ohms minimum (measured, Audio Science Review) |
| Sensitivity | 86.5dB (measured, Audio Science Review) |
| Weight | 13.7 lbs (6.2 kg) |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- HiVi Swans 3.1A Sehlin Sound Solutions mod vs ELAC Debut 3.0 DB63
- HiVi Swans 3.1A Sehlin Sound Solutions mod vs GR-Research X-LS Encore
- HiVi Swans 3.1A Sehlin Sound Solutions mod vs ELAC Debut 2.0 B6.2
- HiVi Swans 3.1A Sehlin Sound Solutions mod vs Polk Monitor XT20
- HiVi Swans 3.1A Sehlin Sound Solutions mod vs MoFi SourcePoint 10
- HiVi Swans 3.1A Sehlin Sound Solutions mod vs AsciLab C6B
- HiVi Swans 3.1A Sehlin Sound Solutions mod vs GR-Research NX-Studio
- HiVi Swans 3.1A Sehlin Sound Solutions mod vs Zu Audio Method