Introduction
This manual provides essential information for the proper installation, operation, and maintenance of your DD Audio 718d-D2 18" Dual 2-Ohm 3600W Subwoofer. Please read this manual thoroughly before use to ensure optimal performance and longevity of the product.
Features
The DD Audio 718d-D2 subwoofer incorporates advanced design elements for high-performance audio reproduction:
- EROM surround
- High-temp, 3.0" voice coil
- Triple Layer Deep bass, high excursion spider system
- Unique glass fiber and natural pulp cone
- Back plate coil gap venting
- Extended pole piece
- DD cast basket
This image displays the front view of the DD Audio 718d-D2 18-inch subwoofer, highlighting its large cone and EROM surround. The DD Audio logo is visible on the dust cap.
An angled perspective of the 718d-D2 subwoofer, showcasing the robust EROM surround and the deep, textured cone. The cast basket structure is partially visible from this angle.
This image provides another angled view, emphasizing the wide EROM surround and the durable cone material. The overall sturdy construction of the subwoofer is apparent.
A rear view of the 718d-D2 subwoofer, clearly showing the large motor structure, the DD cast basket, and the speaker terminals for wiring connections. The extended pole piece is also visible.
This side profile image illustrates the mounting depth and the robust design of the subwoofer's frame and motor assembly. The triple-layer spider system is partially visible.
A detailed side view highlighting the depth of the subwoofer and the construction of the cast basket. The voice coil former and spider assembly are visible through the basket spokes.
Setup and Installation
Proper installation is crucial for the performance and safety of your subwoofer. It is recommended that installation be performed by a qualified professional.
Enclosure Requirements
The 718d-D2 subwoofer is designed for optimal performance in a ported enclosure. Refer to the specifications for recommended enclosure volumes.
- Ported Enclosure Volume: 6.8 - 8.0 CuFt
- Woofer Displacement: 0.25 CuFt
Wiring Configurations
The 718d-D2 features dual 2-Ohm voice coils, allowing for various wiring options to match your amplifier's impedance requirements.
- Parallel Wiring (1 Ohm): Connect positive terminals of both voice coils together, and negative terminals of both voice coils together. Connect the combined positive to the amplifier's positive output and combined negative to the amplifier's negative output. This results in a 1-Ohm load.
- Series Wiring (4 Ohms): Connect the positive terminal of one voice coil to the negative terminal of the other voice coil. Connect the remaining positive terminal to the amplifier's positive output and the remaining negative terminal to the amplifier's negative output. This results in a 4-Ohm load.
Always ensure your amplifier is stable at the chosen impedance.
Operating Guidelines
To ensure the longevity and optimal performance of your subwoofer, adhere to the following operating guidelines:
- Break-in Period: Allow a break-in period of approximately 20-30 hours of moderate use before operating the subwoofer at high power levels. This allows the suspension components to loosen and perform optimally.
- Power Handling: The 718d-D2 has a recommended RMS power range of 600 - 1200 Watts and a peak power handling of 3600 Watts. Do not exceed these ratings to prevent damage.
- Clipping: Avoid amplifier clipping, which can cause severe damage to the voice coil. If you hear distortion, reduce the volume immediately.
- Gain Setting: Properly set your amplifier's gain to match the output voltage of your head unit. Consult your amplifier's manual for proper gain setting procedures.
Maintenance
The DD Audio 718d-D2 subwoofer requires minimal maintenance. Keep the cone and surround free from dust and debris. Avoid exposing the subwoofer to extreme temperatures or moisture.
- Regularly inspect the speaker terminals and wiring for secure connections.
- Clean the exterior with a soft, dry cloth. Do not use harsh chemicals or abrasive cleaners.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No Sound | Loose wiring connection; Amplifier off/faulty; Head unit issue; Subwoofer damaged. | Check all wiring connections; Verify amplifier power and status; Test head unit with other speakers; Inspect subwoofer for visible damage. |
| Distorted Sound | Amplifier clipping; Improper gain setting; Damaged voice coil; Incorrect enclosure. | Reduce volume; Re-adjust amplifier gain; Inspect voice coil for burning/rubbing; Verify enclosure specifications. |
| Subwoofer Overheating | Excessive power; Prolonged high volume; Insufficient ventilation. | Reduce power/volume; Ensure adequate airflow around the subwoofer and amplifier. |
Specifications
Detailed technical specifications for the DD Audio 718d-D2 18" Subwoofer:
| Parameter | Value |
|---|---|
| Speaker Size | 18 Inches |
| Watts RMS | 600 - 1200 |
| Watts Peak | 3600 |
| Impedance | D2 / D4 (Dual 2-Ohm / Dual 4-Ohm) |
| VCD (Voice Coil Diameter) | 3.0 Inches |
| Piston Diameter | 15 1/2 Inches |
| Fs (Resonance Frequency) | 26.92 Hz |
| Qms (Mechanical Q) | 6.79 |
| Qes (Electrical Q) | 0.567 |
| Qts (Total Q) | 0.523 |
| Vas (Equivalent Volume) | 170.4 Liters |
| Xmech (Mechanical Excursion) | 80 MM |
| Xmax (Linear Excursion) | 16 MM |
| Frame OD (Outer Diameter) | 18 3/8 Inches |
| Frame OD w/Gasket | 18 1/2 Inches |
| Mounting Diameter | 16 5/8 Inches |
| Mounting Depth | 10 1/2 Inches |
| Motor Diameter | 7 3/4 Inches |
| Motor Depth | 3 1/2 Inches |
| Woofer Displacement | 0.25 CuFt |
| Ported Enclosure (Recommended) | 6.8 - 8.0 CuFt |
Warranty Information
This product comes with a Limited Warranty. For specific details regarding warranty coverage, duration, and claims procedures, please refer to the official DD Audio website or contact their customer support directly. Keep your proof of purchase for warranty validation.
Support and Contact
For technical assistance, troubleshooting beyond this manual, or general inquiries, please contact DD Audio customer support:
- Website: ddaudio.com
- Email: Refer to the website for contact email.
- Phone: Refer to the website for contact phone number.