Short answer: the KEF R3. It ranks #15 of 134 bookshelf speakers by sound quality, rated 4.5/5, at $2,200; the Arendal Sound 1723 Monitor S THX ranks #55, rated 4.1/5, at $2,200. Close enough in price that the sound-quality gap is the deciding factor.
The case for the KEF R3: True three-way stand-mount with a 6.5-inch woofer below KEF’s 5-inch Uni-Q midrange/1-inch tweeter. Watch for: The low-frequency alignment rolls gradually rather than delivering high-output sub-bass; KEF specifies 58Hz +/-3dB and Erin’s high-level data supports using an 80Hz subwoofer crossover.
The case for the Arendal Sound 1723 Monitor S THX: A THX-certified two-way with twin 6.5-inch woofers around a waveguided 28mm tweeter, and port plugs that let you run it sealed, with one vent or two to suit the room. The tradeoff: In the configuration measured, the bass response starts to fall early, about 77Hz at -3dB, though it keeps going to about 50Hz at -6dB and 33Hz at -10dB, so it benefits from a subwoofer or placement near a wall.
Buy the KEF R3. It is rated higher for sound quality than the Arendal Sound 1723 Monitor S THX at the same price, so it is the default pick unless a specific strength of the other one matters more to you.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| KEF R3 | Arendal Sound 1723 Monitor S THX | |
|---|---|---|
| Price | $2,200 per pair | $2,200 per pair |
| Ranked | #15 of 134 in Large Size Bookshelf Speakers | #55 of 134 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | Approximately 58Hz (manufacturer specified; consistent with Erin’s measured roll-off) | 76.9Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-10dB) | 35.2Hz (measured, Audio Science Review) | 32.9Hz (measured, Erin’s Audio Corner) |
| Sensitivity | Approximately 86-87dB/2.83V/1m (measured, Erin’s Audio Corner) | 88.7dB (manufacturer specified, 2.83V/1m) |
| Impedance | 8 ohms nominal; suitable for Erin’s 4/8-ohm-rated amplifier | 4 ohms nominal |
| Drivers | 1” tweeter coaxial with 5” midrange; 6.5” woofer | Two 6.5-inch woofers; 28mm waveguided tweeter |
| Dimensions | 16.6”H x 7.9”W x 13.2”D | 22.4”H x 9.6”W x 12.6”D (569 x 245 x 320 mm) |
| Woofer Cabinet | ported, rear Flexible Port | sealed or ported (port plugs included) |
| Weight | 29.9 lbs (13.55 kg) each | 41.2 lbs (18.7 kg) each |
| Spinorama Preference Score | 6.2 (spinorama.org) | 5.07 |
| Spinorama Preference Score with Perfect Sub | 7.97 (spinorama.org) | 7.08 |
| DIY Kit | No | No |
| Certification | - | THX Ultra |
| Frequency Response | - | 46Hz-20kHz ±3dB with two vents, 66Hz sealed (manufacturer specified) |
Related Speaker Comparisons
More worthwhile head-to-heads for KEF R3:
- TAD Compact Reference One (CR1TX) vs KEF R3
- KEF R3 vs Perlisten S4b
- KEF Reference 1 Meta vs KEF R3
- KEF R3 vs GR-Research NX-Studio
- March Audio Sointuva AWG vs KEF R3
Prices on this page were last checked September 30, 2026 at 2:57 PM 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
KEF R3: $2,200 per pair Amazon eBay
Pros: True three-way stand-mount with a 6.5-inch woofer below KEF’s 5-inch Uni-Q midrange/1-inch tweeter. Erin measured approximately 86-87dB/2.83V/1m sensitivity, exceptionally low sub-1% distortion at 86dB and orderly directivity in both planes. The coaxial geometry maintains image stability across seats, while Flexible Port Technology avoids the strong midrange port resonance common to rear-vented competitors. A 110W Parasound drove it successfully in Erin’s listening. Measured bass extension of 35.2Hz (-10dB), with a measured sensitivity of 87dB.
Cons: The low-frequency alignment rolls gradually rather than delivering high-output sub-bass; KEF specifies 58Hz +/-3dB and Erin’s high-level data supports using an 80Hz subwoofer crossover. Narrow high-frequency features and natural Uni-Q narrowing toward the top octave make toe angle audible, although off-axis tracking remains smooth. Sensitivity is moderate, the cabinet weighs almost 30 lb, and this original R3 lacks the Meta successor’s MAT absorber.
Full KEF R3 review and specifications →
| Bass Extension (-10dB) | 35.2Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | Approximately 58Hz (manufacturer specified; consistent with Erin’s measured roll-off) |
| DIY Kit | No |
| Dimensions | 16.6”H x 7.9”W x 13.2”D |
| Drivers | 1” tweeter coaxial with 5” midrange; 6.5” woofer |
| Impedance | 8 ohms nominal; suitable for Erin’s 4/8-ohm-rated amplifier |
| Sensitivity | Approximately 86-87dB/2.83V/1m (measured, Erin’s Audio Corner) |
| Spinorama Preference Score | 6.2 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | 7.97 (spinorama.org) |
| Weight | 29.9 lbs (13.55 kg) each |
| Woofer Cabinet | ported, rear Flexible Port |
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: KEF R3 Review More from Erin’s Audio Corner →
- Erin’s Audio Corner Website: KEF R3
- Audio Science Review Measurements More from Audio Science Review →
- Audio Science Review Measurements (spinorama.org)
- Erin’s Audio Corner: Which is Better for Home Theater: (3) Kef R3 or (3) Kef R2c Center Channel speakers?
- Erin’s Audio Corner: KEF R3 vs R3 Meta vs Reference 1 Meta. Why such a big price gap?
- Head-to-Head Comparisons
Arendal Sound 1723 Monitor S THX: $2,200 per pair Arendal Sound eBay
Pros: A THX-certified two-way with twin 6.5-inch woofers around a waveguided 28mm tweeter, and port plugs that let you run it sealed, with one vent or two to suit the room. Erin’s Audio Corner measured a listening window within a 2.4dB span from 300Hz to 5kHz, a smooth listening window (0.77) and predicted in-room response (0.71), and a preference score of 5.07 that rises to 7.08 with an ideal subwoofer. Sensitivity is a healthy 88.7dB. Measured bass extension of 76.9Hz (-3dB).
Cons: In the configuration measured, the bass response starts to fall early, about 77Hz at -3dB, though it keeps going to about 50Hz at -6dB and 33Hz at -10dB, so it benefits from a subwoofer or placement near a wall. It is large and heavy for a stand-mount at 56.9cm tall and 18.7kg, presents a 4-ohm load, and is sold direct by Arendal.
Full Arendal Sound 1723 Monitor S THX review and specifications →
| Bass Extension (-10dB) | 32.9Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 76.9Hz (measured, Erin’s Audio Corner) |
| Certification | THX Ultra |
| DIY Kit | No |
| Dimensions | 22.4”H x 9.6”W x 12.6”D (569 x 245 x 320 mm) |
| Drivers | Two 6.5-inch woofers; 28mm waveguided tweeter |
| Frequency Response | 46Hz-20kHz ±3dB with two vents, 66Hz sealed (manufacturer specified) |
| Impedance | 4 ohms nominal |
| Sensitivity | 88.7dB (manufacturer specified, 2.83V/1m) |
| Spinorama Preference Score | 5.07 |
| Spinorama Preference Score with Perfect Sub | 7.08 |
| Weight | 41.2 lbs (18.7 kg) each |
| Woofer Cabinet | sealed or ported (port plugs included) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons