Short answer: the Polk Audio XT15. It ranks #28 of 74 bookshelf speakers by sound quality at $179; the KEF Q100 ranks #56 and costs $550, so there is not much of a tradeoff to weigh.
What the KEF Q100 offers: 5.25” Uni-Q coaxial driver keeps the tweeter and woofer point-source aligned for consistent imaging. 86dB sensitivity is reasonably easy to drive. Watch for: CEA2034 spinorama shows broad, audible deviations from flat rather than narrow peaks: a lift from 700Hz-1.5kHz and again from 5kHz up, plus a cancellation notch around 1.4kHz from port/cabinet interaction. Bass sensitivity drops to about 80dB and impedance falls below 4 ohms in the bass, demanding a capable amplifier. The reviewer heard boomy, buzzing bass that improved somewhat with the port plugged, and could not recommend it, calling the famous reputation more about looks than sound.
What the Polk Audio XT15 offers: Very low $179/pair entry price for a Hi-Res Audio Certified 2-way design that’s Dolby Atmos and DTS:X compatible, and works with either 4- or 8-ohm amplifier outputs so it drops into almost any AVR without matching concerns. Directivity spread is reasonably even for the price (directivity_spdi_stddev 3.60). Watch for: Bass rolls off earlier than most of this batch at 77.6Hz (-3dB) / 54.2Hz (-10dB). On-axis deviation is the roughest measured figure here (aad_on_axis 0.449), and listening-window smoothness (0.303) trails the pricier options in this group. Modest 86dB sensitivity wants a reasonably powered amp channel. The 5.25” bi-laminate paper woofer is Polk’s entry-tier driver, not the polypropylene/Turbine cones used in its pricier Signature Elite/Reserve lines.
Buy the Polk Audio XT15. It ranks higher for sound quality than the KEF Q100 and costs less, so there is no real case for the other one.
If sound quality matters at all to you, skip the KEF Q100. It ranks near the bottom of the 74 bookshelf speakers, so look higher up the list instead.
Specifications Side By Side
| KEF Q100 | Polk Audio XT15 | |
|---|---|---|
| Price | $550 Discontinued | $179.00 |
| Ranked | #56 of 74 in Medium Size Bookshelf Speakers | #28 of 74 in Medium Size Bookshelf Speakers |
| Bass Extension (-3dB) | 85Hz (measured, Audio Science Review) | 77.6Hz (measured, spinorama.org) |
| Bass Extension (-10dB) | 65Hz (measured, Audio Science Review) | 54.2Hz (measured, spinorama.org) |
| Discontinued | Yes | - |
| Sensitivity | 85dB (2.83V/1m, measured, Audio Science Review) | 86dB (1W/1m) |
| Impedance | 8 ohms nominal | 4/8-ohm compatible |
| Frequency Response | 49Hz - 40kHz (+/-3dB) (Manufacturer specified) | - |
| Drivers | 5.25" Uni-Q aluminum coaxial driver, 1" aluminum dome tweeter | 1" Terylene dome tweeter, 5.25" bi-laminate paper woofer |
| Weight | 13 lbs / 5.9 kg each | 9 lbs / 4.08 kg (9 lb) each |
| Dimensions | 11.8"H x 7.1"W x 10.7"D (300 x 180 x 272 mm) | 16.51 x 18.24cm (6.5 x 7.18 in), 4.08kg (9 lb) each |
| Woofer Cabinet | ported, rear | Ported |
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The Two Speakers In Full
KEF Q100: $550 Discontinued eBay
Pros: 5.25” Uni-Q coaxial driver keeps the tweeter and woofer point-source aligned for consistent imaging. 86dB sensitivity is reasonably easy to drive.
Cons: CEA2034 spinorama shows broad, audible deviations from flat rather than narrow peaks: a lift from 700Hz-1.5kHz and again from 5kHz up, plus a cancellation notch around 1.4kHz from port/cabinet interaction. Bass sensitivity drops to about 80dB and impedance falls below 4 ohms in the bass, demanding a capable amplifier. The reviewer heard boomy, buzzing bass that improved somewhat with the port plugged, and could not recommend it, calling the famous reputation more about looks than sound. Discontinued.
Full KEF Q100 review and specifications →
| Bass Extension (-10dB) | 65Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 85Hz (measured, Audio Science Review) |
| Dimensions | 11.8"H x 7.1"W x 10.7"D (300 x 180 x 272 mm) |
| Discontinued | Yes |
| Drivers | 5.25" Uni-Q aluminum coaxial driver, 1" aluminum dome tweeter |
| Frequency Response | 49Hz - 40kHz (+/-3dB) (Manufacturer specified) |
| Impedance | 8 ohms nominal |
| Sensitivity | 85dB (2.83V/1m, measured, Audio Science Review) |
| Weight | 13 lbs / 5.9 kg each |
| Woofer Cabinet | ported, rear |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Polk Audio XT15: $179.00 Amazon Bhphotovideo Crutchfield eBay
Pros: Very low $179/pair entry price for a Hi-Res Audio Certified 2-way design that’s Dolby Atmos and DTS:X compatible, and works with either 4- or 8-ohm amplifier outputs so it drops into almost any AVR without matching concerns. Directivity spread is reasonably even for the price (directivity_spdi_stddev 3.60).
Cons: Bass rolls off earlier than most of this batch at 77.6Hz (-3dB) / 54.2Hz (-10dB). On-axis deviation is the roughest measured figure here (aad_on_axis 0.449), and listening-window smoothness (0.303) trails the pricier options in this group. Modest 86dB sensitivity wants a reasonably powered amp channel. The 5.25” bi-laminate paper woofer is Polk’s entry-tier driver, not the polypropylene/Turbine cones used in its pricier Signature Elite/Reserve lines.
Full Polk Audio XT15 review and specifications →
| Bass Extension (-10dB) | 54.2Hz (measured, spinorama.org) |
|---|---|
| Bass Extension (-3dB) | 77.6Hz (measured, spinorama.org) |
| Dimensions | 16.51 x 18.24cm (6.5 x 7.18 in), 4.08kg (9 lb) each |
| Drivers | 1" Terylene dome tweeter, 5.25" bi-laminate paper woofer |
| Impedance | 4/8-ohm compatible |
| Sensitivity | 86dB (1W/1m) |
| Weight | 9 lbs / 4.08 kg (9 lb) each |
| Woofer Cabinet | Ported |
- Links
- Reviews, Comparisons and Sound Samples
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