SoundQubed SQ-HDC-1HDP-8 4.5" Horn Diffuser + 1" Phenolic Driver (each)

SoundQubed SQ-HDC-1HDP-8 — 4.5" Horn Diffuser + 1" Phenolic VC Driver | Neodymium Magnet | 108 dB | 8Ω | Sold Single

The SoundQubed SQ-HDC-1HDP-8 is a high-output 4.5" horn diffuser and 1" phenolic compression driver system engineered for competition car audio, pro audio front stage builds, and any application where maximum high-frequency output and pattern control are the priority. Featuring a phenolic diaphragm, CCAW winding on a Kapton former, a neodymium magnet (0.96" x 0.19" / 24.5x5mm), an aluminum driver body, and a 4.5" ABS horn with 35° rounded sound coverage, the SQ-HDC-1HDP-8 delivers 60W continuous / 120W RMS / 240W max at a staggering 108 dB sensitivity with horn and a frequency response of 1.5 kHz–18 kHz at 8Ω. Sold as a single unit.

The SQ-HDC-1HDP-8’s phenolic diaphragm is a classic pro audio compression driver material — known for its warm, smooth high-frequency character, excellent power handling, and long-term durability under sustained high-power use. The 4.5" ABS horn with 35° rounded coverage pattern and 1" / 25.4mm throat diameter focuses the driver’s output for maximum SPL and pattern control — delivering 108 dB sensitivity that makes this one of the highest-output horn driver systems available for car audio applications. At 8Ω, the SQ-HDC-1HDP-8 is ideal for multi-driver parallel wiring configurations or pro audio amplifiers rated at 8Ω.

Whether you’re building a competition SPL or SQL system, a high-output demo build, or a multi-driver pro audio front stage, the SQ-HDC-1HDP-8 delivers the output, pattern control, and durability to compete at the highest level.

Why Choose the SoundQubed SQ-HDC-1HDP-8?

• 108 dB Sensitivity (1W/1m) With Horn — One of the highest-output horn driver systems available for car audio — delivers massive high-frequency SPL with minimal amplification.
• 60W Continuous / 120W RMS / 240W MAX @ 8Ω — Pro-grade power handling for a compression horn driver — handles sustained high-power use in competition builds.
• Phenolic Diaphragm — Classic pro audio compression driver material — warm, smooth high-frequency character with excellent power handling and long-term durability.
• 4.5" ABS Horn with 35° Rounded Coverage — Focused sound pattern for maximum SPL and controlled dispersion — ideal for competition and demo build applications.
• Neodymium Magnet — High-flux, compact neodymium motor for maximum sensitivity and output in a compact driver package.
• CCAW Voice Coil on Kapton Former — Lightweight, thermally efficient winding on a rigid former — handles sustained high-power use without thermal compression.
• Aluminum Driver Body — Rigid, thermally efficient housing for long-term high-power performance.
• 8Ω Impedance — Wire two in parallel for a 4Ω load, or use individually with a pro audio amplifier rated at 8Ω.

Installation & Pairing Recommendations

Crossover Configuration: The SQ-HDC-1HDP-8 is a dedicated high-frequency driver — always use a high-pass crossover set at 2 kHz minimum to protect the driver and keep it operating in its optimal range. For competition and high-output builds, use an active crossover or DSP to set a precise HPF at 2 kHz. Never run the SQ-HDC-1HDP-8 full-range.

Amplifier Pairing: The SQ-HDC-1HDP-8 handles 120W RMS at 8Ω and is rated at 108 dB sensitivity — it will be dramatically louder than most woofers and midranges at the same power level. Use a DSP or active crossover with per-channel level control to balance system output. Verify your amplifier’s 8Ω power rating before purchasing.

Impedance & Wiring: The SQ-HDC-1HDP-8 is an 8Ω driver. Two units wired in parallel present a 4Ω load to your amplifier — ideal for high-output stereo builds using a single amplifier channel per side. Verify your amplifier’s minimum impedance rating before wiring multiple drivers in parallel.

Mounting: The SQ-HDC-1HDP-8 requires a 3.7" / 94mm mounting hole diameter with a 4 x 3.4" / 4 x 86.5mm bolt pattern and 3" / 78mm mounting depth. Overall dimensions are 4.5" x 4.5" / 114.7 x 114.7mm, overall depth is 3.65" / 92.8mm. Verify your mounting location provides adequate depth and bolt pattern clearance before purchasing.

Full Specifications

General

Driver (Motor) Specifications

Horn Specifications

Measurements

Frequently Asked Questions

Q: Is the SQ-HDC-1HDP-8 a complete system or do I need to buy the horn and driver separately?
A: The SQ-HDC-1HDP-8 is a complete system — the 4.5" ABS horn diffuser and 1" phenolic compression driver are included together as a single unit. No additional horn or driver purchase required.

Q: Why is the sensitivity rated “with horn”?
A: The 108 dB sensitivity is measured with the horn attached — the horn focuses and amplifies the driver’s output, significantly increasing sensitivity compared to the driver alone. This is standard practice for horn driver systems and reflects real-world installed performance.

Q: Why is the SQ-HDC-1HDP-8 rated at 8Ω instead of 4Ω?
A: The SQ-HDC-1HDP-8 uses an 8Ω voice coil — standard for pro audio compression drivers. Two units wired in parallel present a 4Ω load to your amplifier. Verify your amplifier’s minimum impedance rating before wiring multiple drivers in parallel.

Q: Is this sold as a pair or single?
A: The SQ-HDC-1HDP-8 is sold as a single unit. Order quantity two for a stereo pair.