Short answer: the Monoprice Monolith THX Compact Satellite. Both are rated 3.2/5 for sound quality (#98 and #93 of 179 bookshelf speakers), and the Monoprice Monolith THX Compact Satellite costs $249.99 against $278 for the Sony SS-CS5 M2, so with nothing between them on sound quality, price settles it.
The case for the Monoprice Monolith THX Compact Satellite: A compact THX certified sealed satellite with a coaxial driver, wide dispersion and a keyhole slot for wall mounting. Watch for: Bass stops at about 82Hz (-3dB) and 62Hz (-10dB), so it needs a subwoofer for any full-range use, and without one its preference score is only 3.57.
Why pick the Sony SS-CS5 M2: Budget three way bookshelf speakers with a better braced cabinet and an easy load for a standard receiver. The tradeoff: Mild sibilance in the 3-5kHz range stands out on S and T sounds in vocals.
Buy the Monoprice Monolith THX Compact Satellite. Both are rated the same for sound quality, and it costs $28.01 less than the Sony SS-CS5 M2.
Want more options? Browse the full Passive Home rankings.
Measured Differences
- Close enough not to matter: bass extension (61.5 Hz vs 54 Hz, 10 dB down).
Prices on this page were last checked November 14, 2026 at 6:17 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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Specifications Side By Side
| Monoprice Monolith THX Compact Satellite | Sony SS-CS5 M2 | |
|---|---|---|
| Price | $249.99 per pair | $278.00 per pair |
| Ranked | #98 of 179 in Medium Size Bookshelf Speakers | #93 of 179 in Medium Size Bookshelf Speakers |
| Sensitivity | 81dB (manufacturer specified) | 82.5dB |
| Drivers | 4.5” polypropylene woofer with coaxial 20mm silk-dome tweeter | 5.12” woofer, 0.98 in tweeter; 0.75-inch supertweeter; 0.75-inch supertweeter; 0.75-inch supertweeter; 0.75-inch supertweeter |
| Impedance | 4 ohms nominal (manufacturer specified) | 6 ohms |
| Frequency Response | 80Hz-20kHz ±3dB (manufacturer specified) | - |
| Bass Extension (-3dB) | 82Hz (measured, Erin’s Audio Corner) | 80Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-10dB) | 61.5Hz (measured, Erin’s Audio Corner) | 54Hz (measured, Erin’s Audio Corner) |
| Dimensions | 6.3”H x 6”W x 5.9”D (160 x 153 x 150 mm) | 13.2”H x 7”W x 8.7”D (335 x 178 x 220 mm) |
| Weight | 4.2 lbs (1.9 kg) each | 9.5 lbs (4.3 kg) each |
| Woofer Cabinet | sealed | ported, rear |
| Spinorama Preference Score | 3.57 | - |
| Spinorama Preference Score with Perfect Sub | 6.56 | - |
| DIY Kit | No | No |
Where the Ratings Come From
- Monoprice Monolith THX Compact Satellite: Spinorama.org measurements and reviews by Erin’s Audio Corner.
- Sony SS-CS5 M2: reviews by Erin’s Audio Corner.
This comparison is generated from the ratings, specifications and measurements on each product’s own page, and it updates when that data changes. How we rank explains how each rating is decided.
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