Short answer: the TAD Compact Reference One (CR1TX). It ranks #1 of 134 bookshelf speakers by sound quality (rated 4.9/5); the Buchardt Audio S400 ranks #29 (rated 4.4/5).
The case for the TAD Compact Reference One (CR1TX): A 3-way stand-mount design built around a coaxial tweeter-and-6.5” midrange assembly plus an 8” woofer, crossed over at 250Hz and 2kHz, rated for 200W and 86dB sensitivity (measured at about 85.2dB, 2.83V/1m). The catch: Extraordinarily expensive at $87500 per pair.
The case for the Buchardt Audio S400: Compact passive design with a 6-inch aluminum woofer, rear passive radiator and waveguided 0.74-inch tweeter positioned below the woofer. Watch for: The impedance reaches 3.7 ohms (Erin), so a genuinely four-ohm-stable separate amplifier is recommended rather than a basic AVR.
Worth knowing: the Buchardt Audio S400 is discontinued, though it still ranks #29 of 134 bookshelf speakers by sound quality, so a used unit beats most of what is still sold new.
Buy the TAD Compact Reference One (CR1TX). It is rated higher for sound quality than the Buchardt Audio S400.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| TAD Compact Reference One (CR1TX) | Buchardt Audio S400 | |
|---|---|---|
| Price | $87,500.00 per pair | €1,800 per pair Discontinued |
| Ranked | #1 of 134 in Large Size Bookshelf Speakers | #29 of 134 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 38Hz (measured, Erin’s Audio Corner) | 38Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-3dB) | 69Hz (measured, Erin’s Audio Corner) | 53Hz (measured, Erin’s Audio Corner) |
| Drivers | Coaxial 1.38” tweeter + 6.5” midrange, 8” woofer | 0.74” waveguided tweeter; 6” aluminum woofer |
| Weight | 101 lbs (45.8 kg) each | 16.1 lbs (7.30 kg) each |
| Sensitivity | 85.5dB (measured average 300Hz-3kHz @ 2.83V/1m, Erin’s Audio Corner) | Approximately 86dB/2.83V/1m (measured, Erin’s Audio Corner) |
| Power Handling | 200W max | - |
| Crossover Frequency | 250Hz, 2kHz | - |
| Dimensions | 24.7”H x 13.4”W x 17.6”D (628 x 341 x 446 mm) | 14.8”H x 7.1”W x 9.6”D (375 x 180 x 245 mm) |
| Impedance | 4 ohms nominal, 3.7 ohms minimum (measured above 80Hz, Erin’s Audio Corner) | 3.7 ohms minimum (measured, Erin’s Audio Corner) |
| Frequency Response | 32Hz - 100kHz (manufacturer specified) | - |
| Country | Japan | - |
| Spinorama Preference Score | 5.45 | 5.23 |
| Spinorama Preference Score with Perfect Sub | 7.79 | 7.43 |
| DIY Kit | No | No |
| Woofer Cabinet | - | sealed with rear passive radiator |
Related Speaker Comparisons
More top alternatives to TAD Compact Reference One (CR1TX):
- TAD Compact Reference One (CR1TX) vs Revel M106
- TAD Compact Reference One (CR1TX) vs KEF R3 Meta
- TAD Compact Reference One (CR1TX) vs KEF Q Concerto Meta
- TAD Compact Reference One (CR1TX) vs KEF R3
- ELAC Debut 3.0 DB63 vs TAD Compact Reference One (CR1TX)
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The Two Speakers In Full
TAD Compact Reference One (CR1TX): $87,500.00 per pair eBay
Pros: A 3-way stand-mount design built around a coaxial tweeter-and-6.5” midrange assembly plus an 8” woofer, crossed over at 250Hz and 2kHz, rated for 200W and 86dB sensitivity (measured at about 85.2dB, 2.83V/1m). On-axis linearity holds within about ±3dB down to its F3 of 69Hz (F10 38Hz). The coaxial layout gives it exceptionally wide, consistent tonality moving around the room (both horizontally and vertically) since the tweeter and midrange radiate from the same point, unlike a conventional offset tweeter-over-woofer layout that narrows vertically much sooner. Harmonic and multitone distortion measured the lowest the reviewer has recorded to date, beating even the KEF Blade Two Meta and PS Audio Aspen FR10, previously his two lowest-distortion references. Compression is minimal: only about 0.5dB of low-frequency loss between 76dB and 102dB output (26dB of usable dynamic range), with softening only appearing at the very top end at 102dB. At 101 lbs each, the massive, heavily braced cabinet is completely inert: no audible panel resonance even driven hard with full-range bass. CTA-2034 sound power is excellent, and a mild dip in the lower treble/upper midrange shows up with smooth, consistent directivity through that region, indicating it’s a deliberate voicing choice rather than a crossover flaw. Measured bass extension of 69Hz (-3dB), with a measured sensitivity of 85.5dB.
Cons: Extraordinarily expensive at $87500 per pair. Despite the manual recommending the speakers be placed close to a wall (about 1-2 feet) and aimed directly at the listener, the reviewer found direct on-axis aiming made the treble read a bit hot, and preferred toeing them out about 20-30° for a smoother top end: worth experimenting with in your own room. The mid-base-to-midrange transition region is deliberately sloped down in anechoic measurement, meaning it’s designed to be reinforced by nearby wall boundary gain rather than played free-standing well out into the room. At 101 lbs each, the speakers are genuinely difficult to move or set up alone.
Full TAD Compact Reference One (CR1TX) review and specifications →
| Bass Extension (-10dB) | 38Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 69Hz (measured, Erin’s Audio Corner) |
| Country | Japan |
| Crossover Frequency | 250Hz, 2kHz |
| DIY Kit | No |
| Dimensions | 24.7”H x 13.4”W x 17.6”D (628 x 341 x 446 mm) |
| Drivers | Coaxial 1.38” tweeter + 6.5” midrange, 8” woofer |
| Frequency Response | 32Hz - 100kHz (manufacturer specified) |
| Impedance | 4 ohms nominal, 3.7 ohms minimum (measured above 80Hz, Erin’s Audio Corner) |
| Power Handling | 200W max |
| Sensitivity | 85.5dB (measured average 300Hz-3kHz @ 2.83V/1m, Erin’s Audio Corner) |
| Spinorama Preference Score | 5.45 |
| Spinorama Preference Score with Perfect Sub | 7.79 |
| Weight | 101 lbs (45.8 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- TAD Compact Reference One (CR1TX) vs Revel M106
- TAD Compact Reference One (CR1TX) vs KEF R3 Meta
- TAD Compact Reference One (CR1TX) vs KEF Q Concerto Meta
- TAD Compact Reference One (CR1TX) vs KEF R3
- TAD Compact Reference One (CR1TX) vs ELAC Debut 3.0 DB63
- TAD Compact Reference One (CR1TX) vs Klipsch RP-600M II
Buchardt Audio S400: €1,800 per pair Discontinued eBay
Newer model: the Buchardt S400 MK3. It’s likely to perform similarly, though we can’t confirm that yet.
Pros: Compact passive design with a 6-inch aluminum woofer, rear passive radiator and waveguided 0.74-inch tweeter positioned below the woofer. Erin measured F3/F10 at 53Hz/38Hz, approximately 86dB/2.83V/1m sensitivity and smooth, broad horizontal directivity. The waveguide controls crossover handoff effectively, the passive radiator avoids port chuffing, and Erin heard no objectionable narrow-band distortion despite excellent extension for the enclosure volume. Measured bass extension of 53Hz (-3dB), with a measured sensitivity of 86dB.
Cons: The impedance reaches 3.7 ohms (Erin), so a genuinely four-ohm-stable separate amplifier is recommended rather than a basic AVR. Low-frequency distortion naturally rises at high output and the compact woofer cannot supply theater-level deep bass; crossing to a subwoofer protects headroom. Erin measured narrow distortion features above 8-9kHz and vertical lobing outside the intended axis. This is the original S400, distinct from the S400 MKII already ranked. Discontinued.
Full Buchardt Audio S400 review and specifications →
| Bass Extension (-10dB) | 38Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 53Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 14.8”H x 7.1”W x 9.6”D (375 x 180 x 245 mm) |
| Drivers | 0.74” waveguided tweeter; 6” aluminum woofer |
| Impedance | 3.7 ohms minimum (measured, Erin’s Audio Corner) |
| Sensitivity | Approximately 86dB/2.83V/1m (measured, Erin’s Audio Corner) |
| Spinorama Preference Score | 5.23 |
| Spinorama Preference Score with Perfect Sub | 7.43 |
| Weight | 16.1 lbs (7.30 kg) each |
| Woofer Cabinet | sealed with rear passive radiator |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons