Short answer: the Arendal 1723 Bookshelf S THX on measured sound quality, the Klipsch RP-600M II on price. The Arendal 1723 Bookshelf S THX ranks #42 of 130 bookshelf speakers at $1499. The Klipsch RP-600M II ranks #74 at $449.99, $1049.01 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 Arendal 1723 Bookshelf S THX offers: Exceptionally controlled radiation for a conventional two-way: Erin found the early-reflections directivity index smooth enough for broad-band EQ, while horizontal coverage remains orderly through the 1.5kHz crossover. Midbass attack around 120–160Hz is strong, the response is mostly neutral below the treble shelf, and dynamic compression remains under roughly 1dB even near 102dB/1m above the bass. The waveguided 28mm dome and heavy HDF enclosure support clean, cinema-capable output, and sealed/ported flexibility eases subwoofer integration. Watch for: Erin measured only 81.6dB/2.83V/1m sensitivity, so substantial amplifier voltage is required. Anechoic output rolls off around 80Hz and 3% THD is crossed near 80Hz at 96dB, making an 80Hz subwoofer crossover effectively mandatory. The treble sits a couple dB high on-axis and can sound bright; Erin preferred roughly 20° toe-out or a ~2dB high shelf. A vertical cancellation appears above the tweeter axis, so multi-row installations need careful height/aiming.
Buy the Klipsch RP-600M II if the price is the priority over sound quality, or the Arendal 1723 Bookshelf S THX if sound quality is the priority over the price.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| Klipsch RP-600M II | Arendal 1723 Bookshelf S THX | |
|---|---|---|
| Price | $449.99 per pair | $1,499 per pair |
| Ranked | #74 of 130 in Large Size Bookshelf Speakers | #42 of 130 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 41Hz (measured, Erin's Audio Corner) | 44.6Hz (measured, Erin's Audio Corner) |
| Bass Extension (-3dB) | 70Hz (measured, Erin's Audio Corner) | ~80Hz (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) | - |
| 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) | 81.6dB/2.83V/1m (measured, Erin's Audio Corner) |
| Drivers | 6.5" Cerametallic cone woofer, 1" titanium LTS vented tweeter with Tractrix horn | 6.5-inch woofer; 28mm waveguided soft-dome tweeter |
| Weight | 13 lbs (5.9 kg) each | - |
| Woofer Cabinet | ported | - |
| Spinorama Preference Score | 4.75 | 3.97 |
| Spinorama Preference Score with Perfect Sub | 6.88 | 6.77 |
| Enclosure | - | HDF, sealed/ported |
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How Arendal 1723 Bookshelf S THX compares with other leading options:
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- ELAC Debut 3.0 DB63 vs Arendal 1723 Bookshelf S THX
- Arendal 1723 Bookshelf S THX vs JBL HDI-1600
- Arendal 1723 Bookshelf S THX vs Power Sound Audio MT-110-M
- Klipsch RP-600M II vs Aperion Audio Verus V8B
Prices on this page were last checked September 14, 2026 at 1:47 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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- See all 72 comparisons
Arendal 1723 Bookshelf S THX: $1,499 per pair Arendal Sound eBay
Pros: Exceptionally controlled radiation for a conventional two-way: Erin found the early-reflections directivity index smooth enough for broad-band EQ, while horizontal coverage remains orderly through the 1.5kHz crossover. Midbass attack around 120–160Hz is strong, the response is mostly neutral below the treble shelf, and dynamic compression remains under roughly 1dB even near 102dB/1m above the bass. The waveguided 28mm dome and heavy HDF enclosure support clean, cinema-capable output, and sealed/ported flexibility eases subwoofer integration. Measured bass extension of ~80Hz (-3dB), with a measured sensitivity of 81.6dB.
Cons: Erin measured only 81.6dB/2.83V/1m sensitivity, so substantial amplifier voltage is required. Anechoic output rolls off around 80Hz and 3% THD is crossed near 80Hz at 96dB, making an 80Hz subwoofer crossover effectively mandatory. The treble sits a couple dB high on-axis and can sound bright; Erin preferred roughly 20° toe-out or a ~2dB high shelf. A vertical cancellation appears above the tweeter axis, so multi-row installations need careful height/aiming.
Full Arendal 1723 Bookshelf S THX review and specifications →
| Bass Extension (-10dB) | 44.6Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | ~80Hz (measured, Erin's Audio Corner) |
| Drivers | 6.5-inch woofer; 28mm waveguided soft-dome tweeter |
| Enclosure | HDF, sealed/ported |
| Impedance | 4 ohms nominal |
| Sensitivity | 81.6dB/2.83V/1m (measured, Erin's Audio Corner) |
| Spinorama Preference Score | 3.97 |
| Spinorama Preference Score with Perfect Sub | 6.77 |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons