Short answer: both are discontinued, so this only matters if you are buying used. Used, the DIYSG HTM-12 v2 is the better pick: it ranks #14 of 222 bookshelf speakers by sound quality (rated 4.5/5), against #30 (rated 4.4/5) for the Buchardt Audio S400. If you want one new, the Buchardt S400 MK3 replaces the Buchardt Audio S400 and is rated 4.0/5 at $2,300.
The case for the DIYSG HTM-12 v2: A high output home theater kit with a 12 inch woofer and horn tweeter, very low distortion, and an easy load for most receivers. The tradeoff: Erin measured F3 at approximately 67Hz, the normal efficiency/bass-extension tradeoff of a high-sensitivity 12-inch design, so a subwoofer is mandatory.
The Buchardt Audio S400 is the more accurate, deeper-bass option. A compact bookshelf speaker with impressively deep bass for its size and smooth, broad dispersion, now discontinued but worth buying used. Its measured preference score, a predictor of how neutral it sounds, is 5.23 against 3.26 for the DIYSG HTM-12 v2. Its bass reaches about 53Hz before falling 3dB, against 67Hz for the DIYSG HTM-12 v2. Watch for: The impedance reaches 3.7 ohms (Erin), so a genuinely four-ohm-stable separate amplifier is recommended rather than a basic AVR.
Buy the DIYSG HTM-12 v2 only if you find one used in good condition; both are discontinued, and it is the better rated of the two. For a new speaker, buy the Buchardt S400 MK3, which replaces the Buchardt Audio S400.
Still deciding? The full Passive Home rankings cover every ranked option.
Measured Differences
- Bass depth: the Buchardt Audio S400 reaches 38 Hz (10 dB down) against 45 Hz for the DIYSG HTM-12 v2, about half an octave deeper. You hear more of the lowest bass notes and kick drums.
- Tonal accuracy above the bass: with a subwoofer taking the low end, the Buchardt Audio S400 scores 7.4 against 5.9 for the DIYSG HTM-12 v2 on the Spinorama preference scale. Its frequency response and off-axis sound are smoother, so voices and instruments sound closer to the recording.
- Efficiency: the DIYSG HTM-12 v2 is rated at 91 dB sensitivity against 86 dB for the Buchardt Audio S400, so it plays as loud with roughly a third of the amplifier power.
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Specifications Side By Side
| DIYSG HTM-12 v2 | Buchardt Audio S400 | |
|---|---|---|
| Price | $920 per pair per kit, Discontinued | €1,800 per pair Discontinued |
| Ranked | #14 of 222 in Large Size Bookshelf Speakers | #30 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 45Hz (measured, Erin’s Audio Corner) | 38Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-3dB) | 67Hz (measured, Erin’s Audio Corner) | 53Hz (measured, Erin’s Audio Corner) |
| Sensitivity | 91dB/2.83V/1m (measured, Erin’s Audio Corner) | Approximately 86dB/2.83V/1m (measured, Erin’s Audio Corner) |
| Impedance | AVR-compatible impedance profile (measured, Erin’s Audio Corner) | 3.7 ohms minimum (measured, Erin’s Audio Corner) |
| Drivers | 12” woofer; compression driver in SEOS waveguide | 0.74” waveguided tweeter; 6” aluminum woofer |
| Woofer Cabinet | ported | sealed with rear passive radiator |
| Spinorama Preference Score | 3.26 | 5.23 |
| Spinorama Preference Score with Perfect Sub | 5.88 | 7.43 |
| Dimensions | 25”H x 18”W x 9.5”D (635 x 457.2 x 241.3 mm) | 14.8”H x 7.1”W x 9.6”D (375 x 180 x 245 mm) |
| Weight | 39.9 lbs (18.1 kg) assembled | 16.1 lbs (7.30 kg) each |
| DIY Kit | Yes | No |
Where the Ratings Come From
- DIYSG HTM-12 v2: Spinorama.org measurements and reviews by Erin’s Audio Corner.
- Buchardt Audio S400: Spinorama.org measurements and 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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