Short answer: the Polk Signature Elite ES20. It ranks #75 of 141 bookshelf speakers by sound quality (rated 3.7/5) at $399 and is still sold new; the KEF Q350 ranks #115 (rated 3.0/5) and is discontinued, so it is only an option used.
The Polk Signature Elite ES20 is the better-sounding, deeper-bass choice. A full-size, efficient 6.5-inch bookshelf pair with unusually deep bass for the price. Its bass reaches about 55.7Hz before falling 3dB, against 70Hz for the KEF Q350. The tradeoff: Predicted in-room smoothness of 0.238 and directivity-index consistency of 3.81 are average rather than class-leading.
The KEF Q350 is the more accurate option. CEA2034 spinorama shows a reasonably flat on-axis response with excellent directivity, aided by the coaxial Uni-Q driver. Its measured preference score, a predictor of how neutral it sounds, is 5.25 against 4.49 for the Polk Signature Elite ES20. The catch: Two resonances at 700Hz and 1.2kHz show up on-axis, alongside an upper-bass boost.
Buy the Polk Signature Elite ES20. It is rated higher for sound quality; the KEF Q350 is no longer sold new.
Looking for alternatives? See the complete Passive Home rankings.
Specifications Side By Side
| Polk Signature Elite ES20 | KEF Q350 | |
|---|---|---|
| Price | $399 per pair | $699.00 per pair Discontinued |
| Ranked | #75 of 141 in Large Size Bookshelf Speakers | #115 of 141 in Large Size Bookshelf Speakers |
| Enclosure | 2-way, Power Port bass-reflex | - |
| Drivers | 1” Terylene dome tweeter, 6.5” polypropylene woofer | 25mm tweeter + 165mm woofer |
| Dimensions | 14.8H x 8.5W x 13.8D in | 14.1”H x 8.3”W x 12”D (358.0 x 210.0 x 306.0 mm) |
| Weight | 17 lbs (7.7 kg) each | 29.5 lbs (13.4 kg) |
| Sensitivity | 86dB | 86dB (measured, Audio Science Review) |
| Impedance | 4/8-ohm compatible | 4 ohms |
| Country | United States (design) | - |
| Spinorama Preference Score | 4.49 | 5.25 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | 6.44 | 7.12 (spinorama.org) |
| Bass Extension (-3dB) | 55.7Hz (measured, ASR via spinorama.org) | 70Hz (measured, Audio Science Review) |
| Bass Extension (-10dB) | 38.6Hz (derived, log-interpolated between spinorama.org -9dB/-12dB points) | 38Hz (measured, Audio Science Review) |
| DIY Kit | No | No |
| Woofer Cabinet | - | ported, rear |
Related Speaker Comparisons
How Polk Signature Elite ES20 compares with other leading options:
- Polk Signature Elite ES20 vs Perlisten S4b
- Polk Signature Elite ES20 vs KEF Reference 1 Meta
- Polk Signature Elite ES20 vs GR-Research NX-Studio
- AsciLab C6B vs Polk Signature Elite ES20
- Audio First Cadentia 3 vs Polk Signature Elite ES20
Prices on this page were last checked October 4, 2026 at 9:58 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.
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The Two Speakers In Full
Polk Signature Elite ES20: $399 per pair B&H Photo Video eBay
Smaller model: the Polk Signature Elite ES15 (rated 3.5/5).
Larger model: the Polk Signature Elite ES60 (rated 3.4/5).
Pros: A full-size, efficient 6.5-inch bookshelf pair with unusually deep bass for the price. ASR measured 41Hz estimated in-room extension, a well-damped Q of 0.66, broad horizontal coverage to roughly +/-60 degrees and a 6.44 preference score with a subwoofer. Measured bass extension of 55.7Hz (-3dB).
Cons: Predicted in-room smoothness of 0.238 and directivity-index consistency of 3.81 are average rather than class-leading. The deep cabinet needs substantial shelf or stand space, and its Power Port still requires rear clearance.
Full Polk Signature Elite ES20 review and specifications →
| Bass Extension (-10dB) | 38.6Hz (derived, log-interpolated between spinorama.org -9dB/-12dB points) |
|---|---|
| Bass Extension (-3dB) | 55.7Hz (measured, ASR via spinorama.org) |
| Country | United States (design) |
| DIY Kit | No |
| Dimensions | 14.8H x 8.5W x 13.8D in |
| Drivers | 1” Terylene dome tweeter, 6.5” polypropylene woofer |
| Enclosure | 2-way, Power Port bass-reflex |
| Impedance | 4/8-ohm compatible |
| Sensitivity | 86dB |
| Spinorama Preference Score | 4.49 |
| Spinorama Preference Score with Perfect Sub | 6.44 |
| Weight | 17 lbs (7.7 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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KEF Q350: $699.00 per pair Discontinued Amazon eBay
Newer model: the KEF Q3 Meta, ranked higher, rated 3.4/5.
Smaller model: the KEF Q150 (rated 3.7/5).
Pros: CEA2034 spinorama shows a reasonably flat on-axis response with excellent directivity, aided by the coaxial Uni-Q driver. Vertical directivity is better than most non-coaxial two-way speakers, another benefit of the concentric design. Measured bass extension of 70Hz (-3dB), with a measured sensitivity of 86dB.
Cons: Two resonances at 700Hz and 1.2kHz show up on-axis, alongside an upper-bass boost. Predicted in-room response looks a bit boomy as a result. Distortion climbs substantially in the 100Hz-1kHz range at 96dB SPL/1m, with a distinct resonance-driven peak around 900Hz-1kHz at both test levels. Discontinued.
Full KEF Q350 review and specifications →
| Bass Extension (-10dB) | 38Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 70Hz (measured, Audio Science Review) |
| DIY Kit | No |
| Dimensions | 14.1”H x 8.3”W x 12”D (358.0 x 210.0 x 306.0 mm) |
| Drivers | 25mm tweeter + 165mm woofer |
| Impedance | 4 ohms |
| Sensitivity | 86dB (measured, Audio Science Review) |
| Spinorama Preference Score | 5.25 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | 7.12 (spinorama.org) |
| Weight | 29.5 lbs (13.4 kg) |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons