Short answer: the AsciLab C8C for the deepest bass here, the GGNTKT M1 for cleaner on-axis behavior. The C8C’s dual opposed 8 inch side-firing subwoofers deliver cardioid bass control and the deepest bass extension in this batch, measured to 23.4Hz at -6dB, but its bass alignment Q of 2.13 is on the peaky side. The GGNTKT M1’s front and two rear firing 6.5 inch woofers also cancel rearward radiation, yet its 0.475dB average on-axis deviation is rough.
What the AsciLab C8C gets right: Dual opposed 8 inch side firing subwoofers deliver true cardioid bass control and the deepest low frequency extension of any speaker in this batch, measured to just 23.4Hz at -6dB with a listening window smoothness score of 0.75, both near the top of everything on spinorama.org. Set against that: The measured Q of the bass alignment (2.13) is on the peaky side, suggesting some boominess near the port tuning frequency without EQ correction.
The case for the GGNTKT M1: One front and two rear firing 6.5 inch aluminum woofers cancel each other’s rearward radiation for genuine cardioid bass control, confirmed by a sound power directivity index that climbs steadily through the midrange rather than the erratic pattern typical of non cardioid designs. The tradeoff: On axis deviation measures a comparatively rough 0.475dB average despite the excellent listening window smoothness, meaning a listener sitting dead center may notice more unevenness than the off axis figures suggest.
Buy the AsciLab C8C. It is rated higher for sound quality than the GGNTKT M1.
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Specifications Side By Side
| AsciLab C8C | GGNTKT M1 | |
|---|---|---|
| Price | €5799 per pair | £7,500 per pair |
| Ranked | #1 of 68 in Large Size Powered Bookshelf Speakers | #16 of 68 in Large Size Powered Bookshelf Speakers |
| Enclosure | sealed | sealed |
| Drivers | 1” alumina ceramic dome tweeter with waveguide, 2x 6” alumina ceramic midrange/woofers, 2x 8” side mounted opposed cardioid subwoofers | 1.75” titanium ring diaphragm compression tweeter with waveguide, 3x 6.5” aluminum cone woofers (1 front, 2 rear firing, cardioid) |
| Dimensions | 22”H x 10”W x 13.8”D (560 x 254 x 350 mm) | 12.6”H x 15.9”W x 5.5”D (319 x 405 x 140 mm) |
| Weight | 60.6 lbs (27.5 kg) each | 24.3 lbs (11.0 kg) each |
| Amplifier Power | 600W total (100W tweeter, 250W midrange, 250W subwoofer) | 560W total (70W tweeter, 210W woofers per channel, Class D) |
| Bass Extension (-6dB) | 23.4Hz (measured, Audio Science Review) | - |
| Bass Extension (-3dB) | 30.8Hz (measured, Audio Science Review) | 33.8Hz (measured, spinorama.org vendor data) |
| Bass Extension (-10dB) | 20.5Hz (measured, Audio Science Review) | 28.2Hz (measured, spinorama.org vendor data) |
| Crossover Frequency | 150Hz, 1.2kHz | - |
| Warranty | 2 years | 3 years (with registration) |
| Country | South Korea | Germany |
| Spinorama Preference Score | 7.70 | - |
| Spinorama Preference Score with Perfect Sub | 8.48 | - |
| Inputs | XLR, RCA, AES/EBU, Coaxial, Optical | XLR (balanced analog), XLR AES/EBU (digital), USB (calibration/control only, not an audio input) |
| XLR Input | Yes | Yes |
| RCA Input | Yes | No |
| TRS Input | No | No |
| Optical Input | Yes | No |
| Coaxial Input | Yes | No |
| USB Input | No | No |
| HDMI Input | No | No |
| AES Input | Yes | Yes |
| Aux Input | No | No |
| Bluetooth | No | No |
| Frequency Response | 30Hz - 20kHz (±1.5dB) (Manufacturer specified) | 36Hz-20kHz -3dB |
| Maximum SPL | - | 112.8dB @ 1m (manufacturer specified) |
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Prices on this page were last checked October 3, 2026 at 10:26 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
AsciLab C8C: €5799 per pair Audiophonics eBay
Pros: ASR’s revised measurement combines an 8.48 ideal-subwoofer preference score with a 1.7dB response span from 300Hz to 5kHz, supporting highly even vocal and instrumental balance. Bass reaches 30.8Hz at -3dB and 23.4Hz at -6dB, giving substantial low-end reach without an added subwoofer. Measured bass extension of 30.8Hz (-3dB).
Cons: The result applies to the revised measured configuration; confirm that the speaker’s tuning matches it. Each cabinet weighs about 27.5kg and needs a substantial stand. Deep extension and excellent tonality do not guarantee unlimited bass output or eliminate the need to adjust placement. The fitted bass-alignment Q of 2.13 is on the peaky side, so bass may sound boomy near the tuning frequency without EQ.
Full AsciLab C8C review and specifications →
| AES Input | Yes |
|---|---|
| Amplifier Power | 600W total (100W tweeter, 250W midrange, 250W subwoofer) |
| Aux Input | No |
| Bass Extension (-10dB) | 20.5Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 30.8Hz (measured, Audio Science Review) |
| Bass Extension (-6dB) | 23.4Hz (measured, Audio Science Review) |
| Bluetooth | No |
| Coaxial Input | Yes |
| Country | South Korea |
| Crossover Frequency | 150Hz, 1.2kHz |
| Dimensions | 22”H x 10”W x 13.8”D (560 x 254 x 350 mm) |
| Drivers | 1” alumina ceramic dome tweeter with waveguide, 2x 6” alumina ceramic midrange/woofers, 2x 8” side mounted opposed cardioid subwoofers |
| Enclosure | sealed |
| Frequency Response | 30Hz - 20kHz (±1.5dB) (Manufacturer specified) |
| HDMI Input | No |
| Inputs | XLR, RCA, AES/EBU, Coaxial, Optical |
| Optical Input | Yes |
| RCA Input | Yes |
| Spinorama Preference Score | 7.70 |
| Spinorama Preference Score with Perfect Sub | 8.48 |
| TRS Input | No |
| USB Input | No |
| Warranty | 2 years |
| Weight | 60.6 lbs (27.5 kg) each |
| XLR Input | Yes |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
GGNTKT M1: £7,500 per pair Purite Audio (UK) eBay
Pros: The manufacturer-supplied monopole measurement shows a 1.6dB response span from 300Hz to 5kHz, 33.8Hz -3dB extension and a 7.03 ideal-subwoofer score. Those results support even midrange balance and useful bass from a relatively shallow cabinet. Measured bass extension of 33.8Hz (-3dB).
Cons: The cited measurement is specifically monopole, so it cannot substantiate claims about cardioid-mode performance. Outboard electronics add cabling and installation complexity; confirm the complete system configuration before purchase. On-axis narrow-band deviation of 0.475dB is rougher than its listening-window smoothness, so a listener dead center may hear more unevenness than the off-axis figures suggest.
Full GGNTKT M1 review and specifications →
| AES Input | Yes |
|---|---|
| Amplifier Power | 560W total (70W tweeter, 210W woofers per channel, Class D) |
| Aux Input | No |
| Bass Extension (-10dB) | 28.2Hz (measured, spinorama.org vendor data) |
| Bass Extension (-3dB) | 33.8Hz (measured, spinorama.org vendor data) |
| Bluetooth | No |
| Coaxial Input | No |
| Country | Germany |
| Dimensions | 12.6”H x 15.9”W x 5.5”D (319 x 405 x 140 mm) |
| Drivers | 1.75” titanium ring diaphragm compression tweeter with waveguide, 3x 6.5” aluminum cone woofers (1 front, 2 rear firing, cardioid) |
| Enclosure | sealed |
| Frequency Response | 36Hz-20kHz -3dB |
| HDMI Input | No |
| Inputs | XLR (balanced analog), XLR AES/EBU (digital), USB (calibration/control only, not an audio input) |
| Maximum SPL | 112.8dB @ 1m (manufacturer specified) |
| Optical Input | No |
| RCA Input | No |
| TRS Input | No |
| USB Input | No |
| Warranty | 3 years (with registration) |
| Weight | 24.3 lbs (11.0 kg) each |
| XLR Input | Yes |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons