ELAC Debut 3.0 DB63 vs Buchardt Audio S400

Last updated: August 25, 2026

Short answer: the Buchardt Audio S400. It ranks #29 of 131 bookshelf speakers by sound quality; the ELAC Debut 3.0 DB63 ranks #41.

What the ELAC Debut 3.0 DB63 offers: 1” aluminum dome tweeter with a distinctive partial-lens waveguide design paired with a 6.5” third-generation aramid fiber cone woofer, in a robustly built cabinet for the price. Shallow bass rolloff (F3 76Hz, F10 40Hz) allows placement close to a wall without excessive boominess, useful for smaller living rooms. Solid measured performance for the price: on-axis linearity within about 2.5dB, impedance dipping only to about 4.4 ohms (easily AVR-driven), and roughly 20-26dB of usable dynamic range. A clear improvement over its sibling ELAC DB62, which has a sibilance issue tied to the crossover that can’t be fixed with EQ. Wide horizontal radiation of about ±60°, giving a spacious soundstage. Distortion looks good at a moderate 86dB and still reasonable at 96dB. Takes well to EQ correction - the reviewer provides a specific filter set (a low-shelf boost at 650Hz plus peaking cuts/boosts at 550Hz, 660Hz, and 3kHz) that meaningfully smooths out its known deviations. Watch for: A dip in the lower midrange (300-600Hz, about 1.5dB) reduces vocal warmth and can make voices sound slightly hollow. A high-Q resonance around 650-750Hz shows up clearly in measurements, though the reviewer couldn’t reliably hear it in his own A/B testing. A dip around 2-3kHz (roughly 1-2dB) slightly reduces speech intelligibility and attack in the upper midrange. Directivity droops above about 2kHz as the midwoofer narrows toward its beaming frequency while the tweeter’s pattern behaves differently - an inherent trade-off of physically separated drivers that can’t be fully corrected without introducing other issues. Multitone distortion crosses the reviewer’s 3% threshold in the 200Hz-1kHz range, and adding a subwoofer at an 80Hz crossover only modestly reduces it. Toeing the speaker away from the listener loses noticeable top-end air and cymbal energy, giving a softer upper register. Practical loudness ceiling is around 90dB at typical listening distance before midrange distortion and bass attack begin to degrade. Still needs a subwoofer for extension below about 40Hz.

What the Buchardt Audio S400 offers: 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. Watch for: 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.

Buy the ELAC Debut 3.0 DB63 if the price matters more than sound quality. Buy the Buchardt Audio S400 if sound quality matters more than the price.

ELAC Debut 3.0 DB63 vs Buchardt Audio S400

Specifications Side By Side

ELAC Debut 3.0 DB63 Buchardt Audio S400
Price$499.00€1,800 Discontinued
Ranked#41 of 131 in Large Size Bookshelf Speakers#29 of 131 in Large Size Bookshelf Speakers
Bass Extension (-10dB)40Hz (measured, Erin’s Audio Corner)38Hz (measured, Erin’s Audio Corner)
Bass Extension (-3dB)76Hz (measured, Erin’s Audio Corner)53Hz (measured, Erin’s Audio Corner)
Dimensions13.3"H x 7.7"W x 11.7"D (337.8 x 195.6 x 297.2 mm)-
Impedance6 ohms nominal (4.4 ohms minimum, measured, Erin’s Audio Corner)3.7 ohms minimum (measured, Erin’s Audio Corner)
Sensitivity86.2dB (measured, Erin’s Audio Corner)Approximately 86dB/2.83V/1m (measured, Erin’s Audio Corner)
Drivers6.5" Aramid Fiber woofer, 1" soft dome tweeter0.74" waveguided tweeter; 6" aluminum woofer
Weight17.2 lbs / 7.8 kg each-
Woofer Cabinetported, rearsealed with rear passive radiator
Discontinued-Yes

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The Two Speakers In Full

ELAC Debut 3.0 DB63: $499.00 Amazon Crutchfield eBay

ELAC Debut 3.0 DB63 ranking card

Pros: 1” aluminum dome tweeter with a distinctive partial-lens waveguide design paired with a 6.5” third-generation aramid fiber cone woofer, in a robustly built cabinet for the price. Shallow bass rolloff (F3 76Hz, F10 40Hz) allows placement close to a wall without excessive boominess, useful for smaller living rooms. Solid measured performance for the price: on-axis linearity within about 2.5dB, impedance dipping only to about 4.4 ohms (easily AVR-driven), and roughly 20-26dB of usable dynamic range. A clear improvement over its sibling ELAC DB62, which has a sibilance issue tied to the crossover that can’t be fixed with EQ. Wide horizontal radiation of about ±60°, giving a spacious soundstage. Distortion looks good at a moderate 86dB and still reasonable at 96dB. Takes well to EQ correction - the reviewer provides a specific filter set (a low-shelf boost at 650Hz plus peaking cuts/boosts at 550Hz, 660Hz, and 3kHz) that meaningfully smooths out its known deviations.

Cons: A dip in the lower midrange (300-600Hz, about 1.5dB) reduces vocal warmth and can make voices sound slightly hollow. A high-Q resonance around 650-750Hz shows up clearly in measurements, though the reviewer couldn’t reliably hear it in his own A/B testing. A dip around 2-3kHz (roughly 1-2dB) slightly reduces speech intelligibility and attack in the upper midrange. Directivity droops above about 2kHz as the midwoofer narrows toward its beaming frequency while the tweeter’s pattern behaves differently - an inherent trade-off of physically separated drivers that can’t be fully corrected without introducing other issues. Multitone distortion crosses the reviewer’s 3% threshold in the 200Hz-1kHz range, and adding a subwoofer at an 80Hz crossover only modestly reduces it. Toeing the speaker away from the listener loses noticeable top-end air and cymbal energy, giving a softer upper register. Practical loudness ceiling is around 90dB at typical listening distance before midrange distortion and bass attack begin to degrade. Still needs a subwoofer for extension below about 40Hz.

Bass Extension (-10dB)40Hz (measured, Erin's Audio Corner)
Bass Extension (-3dB)76Hz (measured, Erin's Audio Corner)
Dimensions13.3"H x 7.7"W x 11.7"D (337.8 x 195.6 x 297.2 mm)
Drivers6.5" Aramid Fiber woofer, 1" soft dome tweeter
Impedance6 ohms nominal (4.4 ohms minimum, measured, Erin's Audio Corner)
Sensitivity86.2dB (measured, Erin's Audio Corner)
Weight17.2 lbs / 7.8 kg each
Woofer Cabinetported, rear

Buchardt Audio S400: €1,800 Discontinued Buchardt Audio eBay

Buchardt Audio S400 ranking card

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.

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.

Bass Extension (-10dB)38Hz (measured, Erin's Audio Corner)
Bass Extension (-3dB)53Hz (measured, Erin's Audio Corner)
DiscontinuedYes
Drivers0.74" waveguided tweeter; 6" aluminum woofer
Impedance3.7 ohms minimum (measured, Erin's Audio Corner)
SensitivityApproximately 86dB/2.83V/1m (measured, Erin's Audio Corner)
Woofer Cabinetsealed with rear passive radiator