Short answer: the RSL CG23M for better sound quality, the Parts Express Copperhead Desktop Kit for the lower price, though neither ranks well in its class. The RSL CG23M ranks #131 of 168 bookshelf speakers, rated 2.6/5, at $298. The Parts Express Copperhead Desktop Kit ranks #132, rated 2.5/5, at $119.98, $178.02 cheaper. Both are rated below 3.0/5 among the 168 bookshelf speakers, and the Ascend Acoustics HTM-200SE2, ranked #7 at $368, is a better place to start if sound quality matters.
Why pick the RSL CG23M: RSL’s current MTM monitor, two 4” mineral-filled aramid woofers around a 1” silk dome tweeter in a Compression Guide cabinet, rated at 89dB so it is easy to drive. The catch: No independent measurements yet, so its tonal balance and directivity can’t be compared with ranked speakers.
The case for the Parts Express Copperhead Desktop Kit: Inexpensive, beginner-friendly CNC flat-pack kit with a compact 8 x 5-inch desktop footprint and only one 3.5-inch full-range driver per channel. The catch: Despite the ‘full-range’ label, output rolls off around 120-150Hz and a subwoofer with an unusually high 100-200Hz crossover is effectively mandatory.
Buy the RSL CG23M if sound quality matters more than the price. Buy the Parts Express Copperhead Desktop Kit if the price matters more than sound quality.
About the ratings: the RSL CG23M’s rating is estimated from measured siblings and predecessors rather than its own measurements, with a likely range of 2.2 to 3.0, so this verdict could change once it is measured.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| RSL CG23M | Parts Express Copperhead Desktop Kit | |
|---|---|---|
| Price | $298 per pair | $119.98 per pair |
| Ranked | #131 of 168 in Medium Size Bookshelf Speakers Estimated | #132 of 168 in Medium Size Bookshelf Speakers |
| Bass Extension (-3dB) | 80Hz (manufacturer specified) | 98.1Hz (measured, Erin’s Audio Corner) |
| Drivers | 2x 4” mineral-filled woven aramid fiber woofers, 1x 1” silk dome tweeter | 3.5” Dayton Audio PS95-8 full-range driver |
| Frequency Response | 80Hz - 20kHz (±3dB, manufacturer specified) | 120Hz-20kHz +/-3dB (manufacturer specified) |
| Impedance | 4 ohms nominal (manufacturer specified) | 8 ohms (manufacturer specified) |
| Sensitivity | 89dB (manufacturer specified) | 81dB @ 1W/1m (measured by Erin’s Audio Corner and manufacturer specified) |
| Crossover Frequency | 2,800Hz | - |
| Recommended Power | 40W - 150W | - |
| Enclosure | Compression Guide | - |
| Weight | 9.9 lbs (4.5 kg) | - |
| Dimensions | 16”H x 6”W x 6.5”D (406 x 152 x 165 mm) | 8”H x 5”W x 6.5”D (203 x 127 x 165 mm) |
| Bass Extension (-10dB) | - | 69.3Hz (measured, Erin’s Audio Corner) |
| Power Handling | - | 10W RMS / 20W maximum; 25W RMS with 50Hz high-pass |
| Woofer Cabinet | - | ported, bottom |
| Spinorama Preference Score | - | 2.11 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | - | 5.35 (spinorama.org) |
| DIY Kit | - | Yes |
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More worthwhile head-to-heads for RSL CG23M:
- RSL CG23M vs Cambridge Audio Minx Min 22
- RSL CG23M vs Micca RB42
- Parts Express Copperhead Desktop Kit vs JBL Stage A120
- KEF Q150 vs Parts Express Copperhead Desktop Kit
- JBL Studio 530 vs Parts Express Copperhead Desktop Kit
Prices on this page were last checked October 11, 2026 at 4:59 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
RSL CG23M: $298 per pair Estimated RSL eBay
Older model: the RSL CG23 (estimated 2.4/5). See every RSL CG generation.
Same family: the RSL CG3M (smaller bookshelf, ranked lower, estimated 2.4/5).
Pros: RSL’s current MTM monitor, two 4” mineral-filled aramid woofers around a 1” silk dome tweeter in a Compression Guide cabinet, rated at 89dB so it is easy to drive. It replaced the CG23 and works upright as a main or surround speaker or on its side as a center.
Cons: No independent measurements yet, so its tonal balance and directivity can’t be compared with ranked speakers. Rated only from 80Hz, so it needs a subwoofer, and its 4 ohm load suits receivers set to 6 or 8 ohms as RSL recommends.
Full RSL CG23M review and specifications →
| Released | Oct 2022 (4 years ago) |
|---|---|
| Bass Extension (-3dB) | 80Hz (manufacturer specified) |
| Crossover Frequency | 2,800Hz |
| Dimensions | 16”H x 6”W x 6.5”D (406 x 152 x 165 mm) |
| Drivers | 2x 4” mineral-filled woven aramid fiber woofers, 1x 1” silk dome tweeter |
| Enclosure | Compression Guide |
| Frequency Response | 80Hz - 20kHz (±3dB, manufacturer specified) |
| Impedance | 4 ohms nominal (manufacturer specified) |
| Recommended Power | 40W - 150W |
| Sensitivity | 89dB (manufacturer specified) |
| Weight | 9.9 lbs (4.5 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- No independent measurement review is linked for this model; it is ranked from hands-on listening and comparison against similarly priced speakers.
- Head-to-Head Comparisons
Parts Express Copperhead Desktop Kit: $119.98 per pair Parts Express eBay
Pros: Inexpensive, beginner-friendly CNC flat-pack kit with a compact 8 x 5-inch desktop footprint and only one 3.5-inch full-range driver per channel. The point-source layout avoids a conventional woofer/tweeter crossover and, when listened to around 20 degrees above the driver as intended, can produce precise near-field imaging. Erin measured roughly 81dB sensitivity, consistent with Parts Express’s specification. The included baffle-step network improves lower-midrange balance, while the optional series inductor reduces the driver’s rising top end; Erin recommends retaining it. Several remaining narrow peaks can be corrected with desktop software EQ. Bottom porting conserves desk space, and unfinished MDF invites custom finishing. Measured bass extension of 98.1Hz (-3dB), with a measured sensitivity of 81dB.
Cons: Despite the ‘full-range’ label, output rolls off around 120-150Hz and a subwoofer with an unusually high 100-200Hz crossover is effectively mandatory. Native response has resonances near roughly 2.1kHz and 8kHz plus a broad 14-20kHz rise of 5-8dB, so it is not smooth without the supplied network and additional EQ. Distortion already exceeds 3% in places at 86dB/1m and becomes extreme at 96dB. Erin’s multitone test approached -10dB distortion (roughly 30%) full-range at the highest level, accompanied by 3-4dB compression; even a 200Hz high-pass leaves roughly 3-5% distortion and 2-3dB compression. The angled cabinet demands a specific near-field ear height, and its very low sensitivity plus 10W RMS power rating leave almost no clean-output headroom for room listening.
Full Parts Express Copperhead Desktop Kit review and specifications →
| Bass Extension (-10dB) | 69.3Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 98.1Hz (measured, Erin’s Audio Corner) |
| DIY Kit | Yes |
| Dimensions | 8”H x 5”W x 6.5”D (203 x 127 x 165 mm) |
| Drivers | 3.5” Dayton Audio PS95-8 full-range driver |
| Frequency Response | 120Hz-20kHz +/-3dB (manufacturer specified) |
| Impedance | 8 ohms (manufacturer specified) |
| Power Handling | 10W RMS / 20W maximum; 25W RMS with 50Hz high-pass |
| Sensitivity | 81dB @ 1W/1m (measured by Erin’s Audio Corner and manufacturer specified) |
| Spinorama Preference Score | 2.11 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | 5.35 (spinorama.org) |
| Woofer Cabinet | ported, bottom |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Parts Express Copperhead Desktop Kit vs JBL Stage A120
- Parts Express Copperhead Desktop Kit vs RSL CG3M
- Parts Express Copperhead Desktop Kit vs Pioneer SP-BS22-LR (Philharmonic AAM Mod)
- Parts Express Copperhead Desktop Kit vs Jamo S 803
- Parts Express Copperhead Desktop Kit vs JBL Studio 530
- Parts Express Copperhead Desktop Kit vs KEF Q150
- Parts Express Copperhead Desktop Kit vs Neumi BS5
- Parts Express Copperhead Desktop Kit vs Arendal 1961 Monitor
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