Short answer: the KEF Q350 for directivity, the Polk Reserve R100 for the smaller cabinet and lower price. The Q350’s CEA2034 spinorama shows a reasonably flat on-axis response with excellent directivity from its coaxial Uni-Q driver, though resonances at 700Hz and 1.2kHz plus an upper-bass boost appear on-axis. The R100 undercuts it at $699 versus $699 and still has unusually useful bass for its size.
Buy the Polk Reserve R100. It is rated higher for sound quality and still sold new, while the KEF Q350 is discontinued.
Looking for alternatives? See the complete Passive Home rankings.
Specifications Side By Side
| Polk Reserve R100 | KEF Q350 | |
|---|---|---|
| Price | $699.00 per pair | $699.00 per pair Discontinued |
| Ranked | #96 of 134 in Large Size Bookshelf Speakers | #109 of 134 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | 68Hz (measured, Erin’s Audio Corner) | 70Hz (measured, Audio Science Review) |
| Bass Extension (-10dB) | 49Hz (measured, Erin’s Audio Corner) | 38Hz (measured, Audio Science Review) |
| Sensitivity | 85dB/2.83V/1m (measured, Erin’s Audio Corner) | 86dB (measured, Audio Science Review) |
| Impedance | 3.6 ohms minimum (measured, Erin’s Audio Corner) | 4 ohms |
| Drivers | 1” Pinnacle ring-radiator tweeter; 5.25” Turbine Cone midwoofer | 25mm tweeter + 165mm woofer |
| Dimensions | 12.8”H x 6.5”W x 10.2”D | 14.1”H x 8.3”W x 12”D (358.0 x 210.0 x 306.0 mm) |
| Weight | 12.1 lbs (5.5 kg) each | 29.5 lbs (13.4 kg) |
| Woofer Cabinet | ported, rear X-Port | ported, rear |
| Spinorama Preference Score | 5.46 | 5.25 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | 7.93 | 7.12 (spinorama.org) |
| DIY Kit | No | No |
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Prices on this page were last checked October 2, 2026 at 10:18 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 Reserve R100: $699.00 per pair Amazon Polk Audio eBay
Pros: Compact cabinet, unusually useful bass for its size and well-controlled woofer breakup. Erin measured F3/F10 points of 68Hz/49Hz, and the X-Port vent avoids much of the chuffing and pipe resonance common to budget rear ports. The 5.25-inch Turbine Cone woofer and 1-inch Pinnacle ring-radiator tweeter produce good detail at moderate levels, while listening roughly 20° off-axis reduces part of the elevated top octave. Measured bass extension of 68Hz (-3dB), with a measured sensitivity of 85dB.
Cons: Erin measured only about 85dB sensitivity and the impedance reaches 3.6 ohms, so it is neither efficient nor an entirely benign AVR load. The treble runs roughly 3dB above the midrange and becomes aggressive above about 85dB SPL. A directivity discontinuity through the woofer/tweeter crossover means EQ cannot fully repair the power response, and a 400Hz impedance feature plus 500Hz-1kHz response irregularity suggests a cabinet or system resonance. Substantial low-frequency compression at higher playback levels limits clean dynamics.
Full Polk Reserve R100 review and specifications →
| Bass Extension (-10dB) | 49Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 68Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 12.8”H x 6.5”W x 10.2”D |
| Drivers | 1” Pinnacle ring-radiator tweeter; 5.25” Turbine Cone midwoofer |
| Impedance | 3.6 ohms minimum (measured, Erin’s Audio Corner) |
| Sensitivity | 85dB/2.83V/1m (measured, Erin’s Audio Corner) |
| Spinorama Preference Score | 5.46 |
| Spinorama Preference Score with Perfect Sub | 7.93 |
| Weight | 12.1 lbs (5.5 kg) each |
| Woofer Cabinet | ported, rear X-Port |
- Links
- Reviews, Comparisons and Sound Samples
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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.
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