HYDRO-8 // 300 Watt RMS 8 Inch Shallow Mount Subwoofer
CT Sounds is proud to introduce the hydro shallow mount subwoofer series after completing a rigorous R&D process spanning 2 years! Our goal was to engineer a 300-watt 8” shallow-mount subwoofer with a mounting depth below 3.5” that was suitable for both sealed & ported enclosures. To achieve this, we focused on the EBP (Efficiency Bandwidth Product). As a general rule, EBP < 50, is used only for sealed enclosures, EBP 50 - 100, is used for both, and EBP > 100, is used only for ported enclosures. EBP = FS/QES.
| Quick Facts: | |
| RMS Power: | 300 Watts |
| MAX Power: | 600 Watts |
| Voice Coil Configuration: | Dual 2 Ohm |
| Use Cases: | Sealed & Ported Enclosures |
Our 1st prototype utilized a 50.8 mm voice coil & 30 oz magnet resulting in a high QES rating of 1.05 and low EBP of 44.1. The 2nd prototype utilized a 44.7 mm voice coil & 30 oz magnet resulting in a slightly lower QES rating of 0.843 and a slightly higher EBP of 54.8. After the 1st and 2nd prototypes, we determined a larger motor assembly was needed to provide a more controlled electrical system (lower QES). This led us to invest in a custom-tooled basket (used in the final prototype) to keep the mounting depth below 3.5”.
The 3rd and final prototype uses a 44.7 mm voice coil & 40 oz magnet resulting in a reduced QES rating of 0.577 and a balanced EBP of 80.07. In testing, we ran into mechanical noise due to the larger motor assembly and voice coil in a confined space. Therefore, we invested in a custom-tooled cone to maximize the excursion capability by creating an equal distance between the cone, spider, and bottom plate. The result is an 8” shallow-mount subwoofer that is extremely responsive in both sealed & ported enclosures.
| General Specifications: | |
| Product Type: | Car Subwoofer |
| Subwoofer Size: | 8" |
| Voice Coil Configuration: | Dual 2 Ohm |
| RMS Power: | 300 Watts |
| MAX Power: | 600 Watts |
| Voice Coil Type: | 1.75 Inch - 4 Layer High-Temperature Copper Voice Coil |
| Magnet Type: | Y35 |
| Bottom Plate Type: | Low Carbon Iron |
| Surround Type: | Dual White Stitched Competition Mega Foam Surround |
| Cone Type: | Composite Paper with 3% Carbon Fiber Reinforcement |
| Tinsel Lead Type: | Single Braided Flat Copper Tinsel Leads |
| Terminal Type: | 12 Gauge Push Terminals |
| Basket Type: | Stamped Steel |
| Spider Material: | Poly-Cotton Blend |
| T/S Parameters: | |
| Qes: | 0.577 |
| Qms: | 6.549 |
| Qts: | 0.531 |
| Fs: | 46.20 Hz |
| Vas: | 10.298 L |
| Mms: | 82.895 g |
| Cms: | 0.143 m/N |
| Re: | 3.9 Ω |
| Bl: | 12.751 Tm |
| Le: | / |
| Sd: | 227 cm² |
| Xmax - Single Way (mm): | 8 mm |
| Xmax - Single Way (cm): | 0.8 cm |
| Vd (Sd*Xmax): | 181.6 cm² |
| SPL: | 84.48 dB |
| Subwoofer Measurements: | |
| Cutout diameter | 7.51" |
| Overall diameter | 8.77" |
| Mounting depth | 3.26" |
| Box Specifications: | |
| Displacement | 0.02 ft3 |
| Box Recommendations: | |
| Sealed | 0.35 ft3 |
| Ported | 0.875 ft3 |
| Tuning Frequency | 36 Hz |
| Port Area | 14 in2 |
*Enclosure recommendations do not account for subwoofer, bracing, and port displacement.
CT Sounds is proud to introduce the hydro shallow mount subwoofer series after completing a rigorous R&D process spanning 2 years! Our goal was to engineer a 300-watt 8” shallow-mount subwoofer with a mounting depth below 3.5” that was suitable for both sealed & ported enclosures. To achieve this, we focused on the EBP (Efficiency Bandwidth Product). As a general rule, EBP < 50, is used only for sealed enclosures, EBP 50 - 100, is used for both, and EBP > 100, is used only for ported enclosures. EBP = FS/QES.
| Quick Facts: | |
| RMS Power: | 300 Watts |
| MAX Power: | 600 Watts |
| Coil Configuration: | Dual 4 Ohm |
| Use Cases: | Sealed & Ported Enclosures |
Our 1st prototype utilized a 50.8 mm voice coil & 30 oz magnet resulting in a high QES rating of 1.21 and low EBP of 39.23. The 2nd prototype utilized a 44.7 mm voice coil & 30 oz magnet resulting in a slightly lower QES rating of 0.976 and a slightly higher EBP of 48.64. After the 1st and 2nd prototypes, we determined a larger motor assembly was needed to provide a more controlled electrical system (lower QES). This led us to invest in a custom-tooled basket (used in the final prototype) to keep the mounting depth below 3.5”.
The 3rd and final prototype uses a 44.7 mm voice coil & 40 oz magnet resulting in a reduced QES rating of 0.668 and a balanced EBP of 71.06. In testing, we ran into mechanical noise due to the larger motor assembly and voice coil in a confined space. Therefore, we invested in a custom-tooled cone to maximize the excursion capability by creating an equal distance between the cone, spider, and bottom plate. The result is an 8” shallow-mount subwoofer that is extremely responsive in both sealed & ported enclosures.
| General Specifications: | |
| Product Type: | Car Subwoofer |
| Subwoofer Size: | 8" |
| Voice Coil Configuration: | Dual 4 Ohm |
| RMS Power: | 300 Watts |
| MAX Power: | 600 Watts |
| Voice Coil Type: | 1.75 Inch - 4 Layer High-Temperature Copper Voice Coil |
| Magnet Type: | Y35 |
| Bottom Plate Type: | Low Carbon Iron |
| Surround Type: | Dual White Stitched Competition Mega Foam Surround |
| Cone Type: | Composite Paper with 3% Carbon Fiber Reinforcement |
| Tinsel Lead Type: | Single Braided Flat Copper Tinsel Leads |
| Terminal Type: | 12 Gauge Push Terminals |
| Basket Type: | Stamped Steel |
| Spider Material: | Poly-Cotton Blend |
| T/S Parameters: | |
| Qes: | 0.668 |
| Qms: | 6.083 |
| Qts: | 0.602 |
| Fs: | 47.47 Hz |
| Vas: | 10.427 L |
| Mms: | 77.535 g |
| Cms: | 0.145 m/N |
| Re: | 6.4 Ω |
| Bl: | 14.880 Tm |
| Le: | / |
| Sd: | 227 cm² |
| Xmax - Single Way (mm): | 8 mm |
| Xmax - Single Way (cm): | 0.8 cm |
| Vd (Sd*Xmax): | 181.6 cm² |
| SPL: | 84.48 dB |
| Subwoofer Measurements: | |
| Cutout diameter | 7.51" |
| Overall diameter | 8.77" |
| Mounting depth | 3.26" |
| Box Specifications: | |
| Displacement | 0.02 ft3 |
| Box Recommendations: | |
| Sealed | 0.35 ft3 |
| Ported | 0.875 ft3 |
| Tuning Frequency | 36 Hz |
| Port Area | 14 in2 |
*Enclosure recommendations do not account for subwoofer, bracing, and port displacement.






















