Short answer: the Parts Express Copperhead Desktop Kit, though neither ranks well in its class. It ranks #132 of 168 bookshelf speakers by sound quality, rated 2.5/5, at $119.98; the RSL CG3M ranks #141, rated 2.4/5, and costs $210, which makes this an easy call rather than a real tradeoff. Both are rated below 3.0/5 among the 168 bookshelf speakers, so if sound quality matters, consider the Neumi BS5 instead, ranked #38 at $139.99.
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. Watch for: Despite the ‘full-range’ label, output rolls off around 120-150Hz and a subwoofer with an unusually high 100-200Hz crossover is effectively mandatory.
What the RSL CG3M does well: The current version of the RSL CG3, a compact monitor with a 4” mineral-filled aramid woofer and a 1” silk dome tweeter in RSL’s Compression Guide cabinet, with a keyhole for wall mounting. The tradeoff: No independent measurements yet, so its tonal balance and directivity can’t be compared with ranked speakers.
Buy the Parts Express Copperhead Desktop Kit. It is rated higher for sound quality than the RSL CG3M and costs less, which makes it the one to get unless you need something the other one does better.
About the ratings: the RSL CG3M’s rating is estimated from measured siblings and predecessors rather than its own measurements, with a likely range of 2.0 to 2.8, so this verdict could change once it is measured.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| Parts Express Copperhead Desktop Kit | RSL CG3M | |
|---|---|---|
| Price | $119.98 per pair | $210 per pair |
| Ranked | #132 of 168 in Medium Size Bookshelf Speakers | #141 of 168 in Medium Size Bookshelf Speakers Estimated |
| Frequency Response | 120Hz-20kHz +/-3dB (manufacturer specified) | 90Hz - 20kHz (±3dB, manufacturer specified) |
| Bass Extension (-3dB) | 98.1Hz (measured, Erin’s Audio Corner) | 90Hz (manufacturer specified) |
| Bass Extension (-10dB) | 69.3Hz (measured, Erin’s Audio Corner) | - |
| Dimensions | 8”H x 5”W x 6.5”D (203 x 127 x 165 mm) | 9.5”H x 5.2”W x 6.5”D (241 x 132 x 164 mm) |
| Impedance | 8 ohms (manufacturer specified) | 4 ohms nominal (manufacturer specified) |
| Sensitivity | 81dB @ 1W/1m (measured by Erin’s Audio Corner and manufacturer specified) | 86.5dB (manufacturer specified) |
| Drivers | 3.5” Dayton Audio PS95-8 full-range driver | 1x 4” mineral-filled woven aramid fiber woofer, 1x 1” silk dome tweeter |
| 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 | - |
| Crossover Frequency | - | 2,800Hz |
| Recommended Power | - | 25W - 125W |
| Enclosure | - | Compression Guide |
| Weight | - | 6 lbs (2.7 kg) |
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More top alternatives to Parts Express Copperhead Desktop Kit:
- KEF LS50 Meta vs Parts Express Copperhead Desktop Kit
- Arendal 1961 Monitor vs Parts Express Copperhead Desktop Kit
- Neumi BS5 vs Parts Express Copperhead Desktop Kit
- 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
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 CG23M
- 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
- See all 9 comparisons
RSL CG3M: $210 per pair Estimated RSL eBay
Older model: the RSL CG3 (ranked lower, estimated 2.2/5). See every RSL CG generation.
Same family: the RSL CG23M (larger bookshelf, ranked higher, estimated 2.6/5).
Pros: The current version of the RSL CG3, a compact monitor with a 4” mineral-filled aramid woofer and a 1” silk dome tweeter in RSL’s Compression Guide cabinet, with a keyhole for wall mounting. It is the smaller partner of the RSL CG23M.
Cons: No independent measurements yet, so its tonal balance and directivity can’t be compared with ranked speakers. Rated only from 90Hz at 86.5dB, so it needs a subwoofer and a little more amplifier power than its size suggests.
Full RSL CG3M review and specifications →
| Released | Oct 2022 (4 years ago) |
|---|---|
| Bass Extension (-3dB) | 90Hz (manufacturer specified) |
| Crossover Frequency | 2,800Hz |
| Dimensions | 9.5”H x 5.2”W x 6.5”D (241 x 132 x 164 mm) |
| Drivers | 1x 4” mineral-filled woven aramid fiber woofer, 1x 1” silk dome tweeter |
| Enclosure | Compression Guide |
| Frequency Response | 90Hz - 20kHz (±3dB, manufacturer specified) |
| Impedance | 4 ohms nominal (manufacturer specified) |
| Recommended Power | 25W - 125W |
| Sensitivity | 86.5dB (manufacturer specified) |
| Weight | 6 lbs (2.7 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