About: CT Sounds HYDRO-12 12" 500W RMS 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 500-watt 12” shallow-mount subwoofer with a mounting depth below 4.5” 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.

Our 1st prototype utilized a 61.1 mm voice coil & 75 oz magnet resulting in a high QES rating of 0.89 and low EBP of 37.87. The 2nd prototype utilized a 50.8 mm voice coil & 75 oz magnet resulting in a slightly lower QES rating of 0.716 and a slightly higher EBP of 47.07. 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 4.5”.

The 3rd and final prototype uses a 61.1 mm voice coil & 92 oz magnet resulting in a reduced QES rating of 0.490 and a balanced EBP of 70.73. 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 a 12” shallow-mount subwoofer that is extremely responsive in both sealed & ported enclosures.

Product Highlights:  

• RMS Power: 500 Watts
• MAX Power: 1000 Watts
• Voice Coil Configuration: Dual 2 Ohm (D2) or Dual 4 Ohm (D4)
• Use Cases: Sealed & Ported Enclosures 

Specifications:  

• Product Type: Car Subwoofer
• Subwoofer Size: 12"
• Voice Coil Configuration: Dual 2 Ohm (D2) or Dual 4 Ohm (D4)
• RMS Power: 500 Watts
• MAX Power: 1000 Watts
• Voice Coil Type: 2.40 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

Thiele/Small Parameters: 

• Qes: 0.490 (D2) | 0.526 (D4) 
• Qms: 5.850 (D2) | 5.444 (D4) 
• Qts: 0.453 (D2) | 0.480 (D4) 
• Fs: 34.66 Hz (D2) | 36.84 (D4) 
• Vas: 38.150 L (D2) | 36.150 L (D4) 
• Mms: 204.701 g (D2) | 191.187 g (D4)
• Cms: 0.103 m/N (D2) | 0.097 m/N (D4)
• Re: 3.9 Ω (D2) | 6.4 Ω (D4) 
• Bl: 18.820 Tm (D2) | 22.215 Tm (D4) 
• Le:/
• Sd: 510.7 cm²
• Xmax - Single Way (mm): 11 mm
• Xmax - Single Way (cm): 1.1 cm
• Vd (Sd*Xmax): 561.77 cm²
• SPL: 87.14 dB (D2) | 87.40 dB (D4) 

Subwoofer Measurements:

• Cutout Diameter: 11.10"
• Overall Diameter: 12.79"
• Mounting Depth: 4.52"

Box Specifications:

• Displacement: 0.065 ft3

Box Recommendations:

• Sealed: 0.75 ft3
• Ported: 1.5 ft3
• Tuning Frequency: 32 Hz
• Port Area: 24 in2

*Enclosure recommendations do not account for subwoofer, bracing, and port displacement.