Short answer: the Sony SS-CS5 M2. It ranks #87 of 160 bookshelf speakers by sound quality, rated 3.2/5, at $153; the Definitive Technology ProMonitor 1000 ranks #149, rated 1.7/5, and costs $398.40, which makes this an easy call rather than a real tradeoff.
The Sony SS-CS5 M2 is the better-sounding, deeper-bass pick. Added internal bracing (corners, sides, front baffle) plus an updated crossover meaningfully reduce the resonance issues that plagued the original SS-CS5, giving a smoother, more neutral character overall. Its bass reaches about 80Hz before falling 3dB, against 95Hz for the Definitive Technology ProMonitor 1000. Watch for: Mild sibilance in the 3-5kHz range stands out on S and T sounds in vocals.
Why pick the Definitive Technology ProMonitor 1000: Bass distortion is well controlled per the measurements, and the slow bass rolloff means it can be pushed fairly hard for its size. 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.
Buy the Sony SS-CS5 M2. It is rated higher for sound quality than the Definitive Technology ProMonitor 1000 and costs less, so only choose the other one for a particular feature it does better.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| Sony SS-CS5 M2 | Definitive Technology ProMonitor 1000 | |
|---|---|---|
| Price | $153.00 per pair | $398.40 per pair |
| Ranked | #87 of 160 in Medium Size Bookshelf Speakers | #149 of 160 in Medium Size Bookshelf Speakers |
| Bass Extension (-10dB) | 54Hz (measured, Erin’s Audio Corner) | 80Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 80Hz (measured, Erin’s Audio Corner) | 95Hz (measured, Audio Science Review) |
| Dimensions | 13.2”H x 7”W x 8.7”D (335 x 178 x 220 mm) | 10.88H x 6.25W x 6.5D in |
| Impedance | 6 ohms | 8 ohms nominal |
| Sensitivity | 82.5dB | 86dB (2.83V/1m, measured, Audio Science Review - reviewer noted this vs. a manufacturer spec of 91dB) |
| Drivers | 5.12” woofer, 0.98 in tweeter; 0.75-inch supertweeter; 0.75-inch supertweeter; 0.75-inch supertweeter; 0.75-inch supertweeter | 1” aluminum dome tweeter, 5.25” BDSS mid/woofer, 5.25” planar bass radiator |
| Weight | 9.5 lbs (4.3 kg) each | 7.3 lbs (3.29 kg) each |
| Woofer Cabinet | ported, rear | passive radiator |
| DIY Kit | No | No |
| Frequency Response | - | 47Hz - 30kHz (Manufacturer specified) |
| Spinorama Preference Score | - | 3.2 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | - | 6.58 (spinorama.org) |
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Prices on this page were last checked October 7, 2026 at 9:25 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
Sony SS-CS5 M2: $153.00 per pair Amazon eBay
Older model: the Sony SS-CS5 (ranked higher, rated 3.5/5).
Same family: the Sony SS-CS3 M2 (floorstanding, estimated 3/5) and the Sony SS-CS8 M2 (center, estimated 2.8/5).
Pros: Added internal bracing (corners, sides, front baffle) plus an updated crossover meaningfully reduce the resonance issues that plagued the original SS-CS5, giving a smoother, more neutral character overall. A modest mid-range dip (about 1-2dB) is present but tolerable, and the reviewer would rather have this dip than a peak in that region. Slightly deeper bass than the previous version, measuring about 2dB more output around 60Hz. Distortion drops noticeably when crossed to a subwoofer around 80-120Hz, meaningfully improving midrange clarity and detail versus running full-range. Easy to drive on a standard AVR: no need for a dedicated high-power amplifier. More modern, understated waveguide look compared to the previous version’s glossy trim. Measured bass extension of 80Hz (-3dB).
Cons: Mild sibilance in the 3-5kHz range stands out on S and T sounds in vocals. Some forwardness in the midrange noticeable on certain vocal recordings. Soundstage and sense of envelopment are comparatively flat and two-dimensional, especially next to reference-quality speakers with strong 3D imaging. Marketed as a “three-way” design mainly due to an added super-tweeter that the reviewer considers largely superfluous: it engages only at very high frequencies and adds complexity without a clearly audible benefit, when that cost might have been better spent on the main crossover. Output-limited: realistic ceiling is around the mid-90s dB SPL at a few meters, with comfortable listening closer to 75-85dB at 3-4 meters before distortion and compression become audible. Bass noticeably compresses/shelves below about 120Hz as volume increases, softening kick-drum impact at higher output. Smaller drivers and a lighter motor structure than rivals like the Polk XT20, which the reviewer generally prefers for its better directivity and higher SPL capability. Still needs a subwoofer for any real bass extension.
Full Sony SS-CS5 M2 review and specifications →
| Bass Extension (-10dB) | 54Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 80Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 13.2”H x 7”W x 8.7”D (335 x 178 x 220 mm) |
| Drivers | 5.12” woofer, 0.98 in tweeter; 0.75-inch supertweeter; 0.75-inch supertweeter; 0.75-inch supertweeter; 0.75-inch supertweeter |
| Impedance | 6 ohms |
| Sensitivity | 82.5dB |
| Weight | 9.5 lbs (4.3 kg) each |
| Woofer Cabinet | ported, rear |
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Definitive Technology ProMonitor 1000: $398.40 per pair 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. Measured bass extension of 95Hz (-3dB), with a measured sensitivity of 86dB.
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 $199/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) |
| DIY Kit | No |
| 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) |
| Spinorama Preference Score | 3.2 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | 6.58 (spinorama.org) |
| Weight | 7.3 lbs (3.29 kg) each |
| Woofer Cabinet | passive radiator |
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