Short answer: the Polk Monitor XT20. It ranks #70 of 105 bookshelf speakers by sound quality at $279; the KEF Q350 ranks #81 and costs $699, so there is not much of a tradeoff to weigh.
What the Polk Monitor XT20 gets right: Two-way bookshelf design with a 1” tweeter and 6.5” woofer, part of Polk’s budget-friendly XT lineup (spanning roughly $200-700 across the series). The catch: Notably bright treble, elevated roughly 1-5dB above the midrange depending on frequency - a characteristic shared across the whole Polk XT lineup, requiring either EQ or toe-out to tame.
The case for the KEF Q350: CEA2034 spinorama shows a reasonably flat on-axis response with excellent directivity, aided by the coaxial Uni-Q driver. Set against that: Two resonances at 700Hz and 1.2kHz show up on-axis, alongside an upper-bass boost.
Buy the Polk Monitor XT20. It ranks higher for sound quality than the KEF Q350 and costs less, so there is no real case for the other one.
If sound quality matters at all to you, skip the KEF Q350. It ranks near the bottom of the 105 bookshelf speakers, so look higher up the list instead.
Specifications Side By Side
| Polk Monitor XT20 | KEF Q350 | |
|---|---|---|
| Price | $279.00 | $699.00 Discontinued |
| Ranked | #70 of 105 in Large Size Bookshelf Speakers | #81 of 105 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 50Hz (measured, Erin’s Audio Corner) | 38Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 75Hz (measured, Erin’s Audio Corner) | 70Hz (measured, Audio Science Review) |
| Dimensions | 13"H x 7.5"W x 11"D (330.2 x 190.5 x 279.4 mm) | 14.1"H x 8.3"W x 12"D (358.0 x 210.0 x 306.0 mm) |
| Impedance | 8 ohms nominal (measured, Erin’s Audio Corner) | 4 ohms |
| Sensitivity | 86dB (measured by Erin’s Audio Corner; 87dB manufacturer specified) | 86dB (measured, Audio Science Review) |
| Drivers | 6.5" bilaminate paper cone woofer, 1" Terylene dome tweeter | 25mm tweeter + 165mm woofer |
| Weight | 11.9 lbs / 5.4 kg each | 29.5 lbs / 13.4 kg |
| Woofer Cabinet | ported | ported, rear |
| Discontinued | - | Yes |
Related Speaker Comparisons
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- Infinity IL10 vs KEF Q3 Meta
- Behringer B2030P vs KEF Q3 Meta
- ELAC Debut 2.0 B6.2 vs KEF Q3 Meta
- JBL Studio 630 vs Polk Monitor XT20
- SVS Prime Bookshelf vs Polk Monitor XT20
The Two Speakers In Full
Polk Monitor XT20: $279.00 Amazon Crutchfield
Pros: Two-way bookshelf design with a 1” tweeter and 6.5” woofer, part of Polk’s budget-friendly XT lineup (spanning roughly $200-700 across the series). Measures more linear and has fewer/smaller cabinet resonances than its smaller sibling, the XT15, making it - by the reviewer’s own assessment - probably the better of the two based on data alone. Reasonably good bass output for the price and size, with an F3 of 63Hz. Horizontal radiation of about ±50° gives a respectable, enjoyable soundstage width. Takes well to EQ correction - the early-reflections directivity trend is decently linear, meaning tonal adjustments can meaningfully improve the sound. Provides usable, respectable volume when paired with a subwoofer crossover, even though it isn’t intended to play extremely loud on its own.
Cons: Notably bright treble, elevated roughly 1-5dB above the midrange depending on frequency - a characteristic shared across the whole Polk XT lineup, requiring either EQ or toe-out to tame. Small resonances appear around 300Hz and 800Hz, with some of that energy leaking from the port area. Vertical listening window is narrow - best kept close to the tweeter axis, with only a couple of degrees of tolerance above or below before the sound changes. Still needs a subwoofer for real low-end extension despite the decent F3. Overall linearity isn’t state-of-the-art flat, and while the reviewer found it pleasant, some artificial brightness remains even after basic EQ correction in the crossover region.
Full Polk Monitor XT20 review and specifications →
| Bass Extension (-10dB) | 50Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 75Hz (measured, Erin's Audio Corner) |
| Dimensions | 13"H x 7.5"W x 11"D (330.2 x 190.5 x 279.4 mm) |
| Drivers | 6.5" bilaminate paper cone woofer, 1" Terylene dome tweeter |
| Impedance | 8 ohms nominal (measured, Erin's Audio Corner) |
| Sensitivity | 86dB (measured by Erin's Audio Corner; 87dB manufacturer specified) |
| Weight | 11.9 lbs / 5.4 kg each |
| Woofer Cabinet | ported |
As an eBay Partner, we may be compensated if you make a purchase.
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: Polk’s new budget XT Speakers. Reviewed!
- Erin’s Audio Corner Website Polk Monitor XT20
- Erin’s Audio Corner: 10 Great (and Terrible) Speakers Under $300!
- Erin’s Audio Corner: Budget Stereo Systems You Will Love
- Erin’s Audio Corner Measurements (spinorama.org)
- Reddit Search for Polk Monitor XT20 Review
- Head-to-Head Comparisons
- Polk Monitor XT20 vs KEF Q3 Meta
- Polk Monitor XT20 vs Sonus Faber Lumina II
- Polk Monitor XT20 vs SVS Prime Bookshelf
- Polk Monitor XT20 vs Focal Aria 906
- Polk Monitor XT20 vs ELAC Debut 2.0 B6.2
- Polk Monitor XT20 vs Revel Performa M22
- Polk Monitor XT20 vs Polk R200
- Polk Monitor XT20 vs Dynaudio Special Forty
- See all 26 comparisons
KEF Q350: $699.00 Discontinued Amazon
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.
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) |
| Dimensions | 14.1"H x 8.3"W x 12"D (358.0 x 210.0 x 306.0 mm) |
| Discontinued | Yes |
| Drivers | 25mm tweeter + 165mm woofer |
| Impedance | 4 ohms |
| Sensitivity | 86dB (measured, Audio Science Review) |
| Weight | 29.5 lbs / 13.4 kg |
| Woofer Cabinet | ported, rear |
As an eBay Partner, we may be compensated if you make a purchase.
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons