Short answer: the KEF Q150 for better sound quality, the Definitive Technology ProMonitor 1000 for the lower price. The KEF Q150 ranks #25 of 71 bookshelf speakers at $350. The Definitive Technology ProMonitor 1000 ranks #63 at $249, $101 cheaper.
What the KEF Q150 offers: Two-way coaxial (Uni-Q) design with a 1” dome tweeter and 5.25” mid-range time-aligned in a single driver assembly, available in ported or sealed configuration. Exceptional soundstage depth, a hallmark of KEF’s coaxial designs that the reviewer says few other speakers match. Bass extension reaches into kick-drum territory, respectable for a compact bookshelf speaker. Resonances present in measurements are consistent across on- and off-axis readings, meaning they can be effectively corrected with EQ. Distortion profile is essentially the same whether run sealed or ported, since a subwoofer crossover point sits above where the differences would matter anyway. At its sale price (around $300, sometimes seen at $400), the reviewer considers it a clear step up from his previous budget favorite in this range, the Emotiva B1+, mainly due to the superior soundstage depth. Watch for: A high-frequency lift in the estimated in-room response makes it sound noticeably brighter in an untreated room than in a heavily acoustically-treated one - a real preference factor depending on your room’s furnishings. A mild dip in the 1-2kHz region reduces vocal fullness somewhat. Unexplained resonances appear in measurements and persist in both sealed and ported configurations, pointing to enclosure or panel vibration rather than the port. Horizontal radiation is narrower than the reviewer generally prefers from KEF’s lineup, with directivity that widens somewhat around 1.2kHz (near a resonance) and again above about 5kHz. Compression testing at high output (102dB) shows significant nonlinearity, especially at lower frequencies - noticeably worse than a comparable Arendal bookshelf speaker costing over twice as much, which held up better until 80Hz. Not intended for loud listening without a subwoofer - the woofer will over-exert itself without a high-pass filter, and the reviewer recommends crossing over at 80-120Hz. At full retail price (around $600/pair), the value proposition is far less certain than at sale pricing.
What the Definitive Technology ProMonitor 1000 offers: Bass distortion is well controlled per the measurements, and the slow bass rolloff means it can be pushed fairly hard for its size. Ships with a footer that keeps the small cabinet planted despite its light weight. Watch for: CEA2034 spinorama shows severely reduced bass energy between 40-120Hz, a directivity mismatch between the tweeter and woofer, and a severe resonance/interference issue around 14kHz. Distortion at 96dB SPL was so bad the reviewer limited testing to 86dB. Direct comparison to a $118/pair Pioneer SP-BS22-LR left the reviewer calling the $500/pair ProMonitor 1000 “a bad experiment that should be forgotten” and concluding “there is nothing Pro about it.”
Buy the KEF Q150 if sound quality matters more than the price. Buy the Definitive Technology ProMonitor 1000 if the price matters more than sound quality.
If sound quality matters at all to you, skip the Definitive Technology ProMonitor 1000. It ranks near the bottom of the 71 bookshelf speakers, so look higher up the list instead.
Specifications Side By Side
| KEF Q150 | Definitive Technology ProMonitor 1000 | |
|---|---|---|
| Price | $350 Discontinued | $249.00 |
| Ranked | #25 of 71 in Medium Size Bookshelf Speakers | #63 of 71 in Medium Size Bookshelf Speakers |
| Bass Extension (-10dB) | 44Hz (measured, Erin’s Audio Corner) | 80Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 51Hz (measured, Erin’s Audio Corner) | 95Hz (measured, Audio Science Review) |
| Dimensions | 11.9"H x 7.1"W x 10.9"D (303 x 180 x 278 mm) | 10.88H x 6.25W x 6.5D in |
| Impedance | 8 ohms nominal, about 4.7 ohms minimum (measured, Erin’s Audio Corner) | 8 ohms nominal |
| Sensitivity | ~85dB (300Hz-3kHz on-axis, measured, Erin’s Audio Corner) | 86dB (2.83V/1m, measured, Audio Science Review - reviewer noted this vs. a manufacturer spec of 91dB) |
| Drivers | 130mm (5.25") aluminium Uni-Q woofer, 25mm (1") vented aluminium dome tweeter | 1" aluminum dome tweeter, 5.25" BDSS mid/woofer, 5.25" planar bass radiator |
| Discontinued | Yes | - |
| Weight | 12.3 lbs / 5.6 kg each | 7.3 lbs / 3.29 kg each |
| Woofer Cabinet | ported, rear | passive radiator |
| Frequency Response | - | 47Hz - 30kHz (Manufacturer specified) |
Related Speaker Comparisons
More useful head-to-heads from the same speaker class:
- JBL Studio 530 vs Polk T15
- JBL Stage A130 vs Polk T15
- KEF Q100 vs Polk T15
- KEF Q150 vs Emotiva B1+
- ELAC Debut 2.0 B5.2 vs Definitive Technology ProMonitor 1000
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The Two Speakers In Full
KEF Q150: $350 Discontinued Amazon eBay
Pros: Two-way coaxial (Uni-Q) design with a 1” dome tweeter and 5.25” mid-range time-aligned in a single driver assembly, available in ported or sealed configuration. Exceptional soundstage depth, a hallmark of KEF’s coaxial designs that the reviewer says few other speakers match. Bass extension reaches into kick-drum territory, respectable for a compact bookshelf speaker. Resonances present in measurements are consistent across on- and off-axis readings, meaning they can be effectively corrected with EQ. Distortion profile is essentially the same whether run sealed or ported, since a subwoofer crossover point sits above where the differences would matter anyway. At its sale price (around $300, sometimes seen at $400), the reviewer considers it a clear step up from his previous budget favorite in this range, the Emotiva B1+, mainly due to the superior soundstage depth.
Cons: A high-frequency lift in the estimated in-room response makes it sound noticeably brighter in an untreated room than in a heavily acoustically-treated one - a real preference factor depending on your room’s furnishings. A mild dip in the 1-2kHz region reduces vocal fullness somewhat. Unexplained resonances appear in measurements and persist in both sealed and ported configurations, pointing to enclosure or panel vibration rather than the port. Horizontal radiation is narrower than the reviewer generally prefers from KEF’s lineup, with directivity that widens somewhat around 1.2kHz (near a resonance) and again above about 5kHz. Compression testing at high output (102dB) shows significant nonlinearity, especially at lower frequencies - noticeably worse than a comparable Arendal bookshelf speaker costing over twice as much, which held up better until 80Hz. Not intended for loud listening without a subwoofer - the woofer will over-exert itself without a high-pass filter, and the reviewer recommends crossing over at 80-120Hz. At full retail price (around $600/pair), the value proposition is far less certain than at sale pricing. Discontinued.
Full KEF Q150 review and specifications →
| Bass Extension (-10dB) | 44Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 51Hz (measured, Erin's Audio Corner) |
| Dimensions | 11.9"H x 7.1"W x 10.9"D (303 x 180 x 278 mm) |
| Discontinued | Yes |
| Drivers | 130mm (5.25") aluminium Uni-Q woofer, 25mm (1") vented aluminium dome tweeter |
| Impedance | 8 ohms nominal, about 4.7 ohms minimum (measured, Erin's Audio Corner) |
| Sensitivity | ~85dB (300Hz-3kHz on-axis, measured, Erin's Audio Corner) |
| Weight | 12.3 lbs / 5.6 kg each |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: Kef’s Cheapest Bookshelf. Is the Q150 worth your money? More from Erin’s Audio Corner →
- Erin’s Audio Corner Website KEF Q150
- GR-Research: KEF Q150… can it get any BETTER? More from GR-Research →
- Erin’s Audio Corner: 5 AWESOME SPEAKERS Under $1000 You Won’t Regret
- Erin’s Audio Corner: Budget Stereo Systems You Will Love
- Erin’s Audio Corner Measurements (spinorama.org)
- Reddit Search for KEF Q150 Review
- Head-to-Head Comparisons
Definitive Technology ProMonitor 1000: $249.00 Amazon eBay
Pros: Bass distortion is well controlled per the measurements, and the slow bass rolloff means it can be pushed fairly hard for its size. Ships with a footer that keeps the small cabinet planted despite its light weight.
Cons: CEA2034 spinorama shows severely reduced bass energy between 40-120Hz, a directivity mismatch between the tweeter and woofer, and a severe resonance/interference issue around 14kHz. Distortion at 96dB SPL was so bad the reviewer limited testing to 86dB. Direct comparison to a $118/pair Pioneer SP-BS22-LR left the reviewer calling the $500/pair ProMonitor 1000 “a bad experiment that should be forgotten” and concluding “there is nothing Pro about it.”
Full Definitive Technology ProMonitor 1000 review and specifications →
| Bass Extension (-10dB) | 80Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 95Hz (measured, Audio Science Review) |
| Dimensions | 10.88H x 6.25W x 6.5D in |
| Drivers | 1" aluminum dome tweeter, 5.25" BDSS mid/woofer, 5.25" planar bass radiator |
| Frequency Response | 47Hz - 30kHz (Manufacturer specified) |
| Impedance | 8 ohms nominal |
| Sensitivity | 86dB (2.83V/1m, measured, Audio Science Review - reviewer noted this vs. a manufacturer spec of 91dB) |
| Weight | 7.3 lbs / 3.29 kg each |
| Woofer Cabinet | passive radiator |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Definitive Technology ProMonitor 1000 vs Polk T15
- Definitive Technology ProMonitor 1000 vs Sehlin Helium
- Definitive Technology ProMonitor 1000 vs JBL Control 1 Pro
- Definitive Technology ProMonitor 1000 vs Fluance Signature HFS
- Definitive Technology ProMonitor 1000 vs Pioneer Elite SP-EBS73-LR
- Definitive Technology ProMonitor 1000 vs JBL Stage A130
- Definitive Technology ProMonitor 1000 vs Klipsch R-41M
- Definitive Technology ProMonitor 1000 vs Q Acoustics 5020
- See all 18 comparisons