SoundQubed HDX Series 3.5" Midrange Speakers (pair)
Description
Description
SoundQubed HDX Series 3.5" Midrange Speaker — Glass Fiber Cone | 1-Way | Pair
The SoundQubed HDX Series 3.5" Midrange is a dedicated midrange driver built for enthusiasts who want precise, high-output midrange reproduction in their car audio system. Featuring a glass fiber cone, rubber surround, a 310g barium ferrite magnet, and a 1" / 25.5mm KSV voice coil, the HDX 3.5" delivers 40W RMS / 120W max at 86 dB sensitivity with a frequency response of 120 Hz–20 kHz. Designed for use with a high-pass crossover at 140 Hz, it’s the ideal midrange driver for 3-way component builds, A-pillar installs, and any application where a dedicated midrange is needed to fill the gap between your tweeters and woofers. Sold as a pair. No grill included.
The HDX 3.5" is a 1-way driver — meaning it’s a pure midrange with no integrated tweeter. It’s designed to be crossed over at 140 Hz high-pass and paired with a dedicated tweeter (such as the SoundQubed HDX Series 2.2" Titanium Dome Tweeter) for a complete front stage. The glass fiber cone and rubber surround deliver accurate, detailed midrange reproduction with controlled resonance, while the 310g barium ferrite magnet provides a solid motor for clean, punchy output at real amplifier power levels.
The T/S parameters reflect a driver purpose-built for midrange duty: Fs of 140 Hz, Xmax of 1.4mm, Vas of 0.55L, and a cone area (Sd) of 32cm². Small, focused, and efficient — exactly what a dedicated midrange should be.
Why Choose the SoundQubed HDX Series 3.5" Midrange?
- 40W RMS / 120W MAX @ 4Ω — Handles real amplifier power for a 3.5" midrange — pairs well with any SoundQubed 4-channel amplifier running bandpass or HPF.
- 86 dB Sensitivity (1W/1m) — Efficient output for a dedicated midrange driver — keeps up with your tweeters and woofers without excessive power.
- Glass Fiber Cone + Rubber Surround — Stiff, lightweight cone material delivers accurate, detailed midrange with controlled resonance and long-term durability.
- 310g Barium Ferrite Magnet — Solid motor for a 3.5" driver — clean, punchy midrange output at real power levels.
- 120 Hz–20 kHz Frequency Response — Purpose-built midrange range — covers vocals, instruments, and upper harmonics with clarity.
- Recommended HPF at 140 Hz — Cross over at 140 Hz to protect the driver and keep it operating in its optimal range.
- Compact 3.5" / 89mm Footprint — 2.80" / 71mm baffle cutout fits A-pillar pods, dash locations, and custom midrange mounts with ease.
- Sold as a Pair — Two drivers included for a balanced, symmetrical front-stage midrange image.
Installation & Pairing Recommendations
3-Way Component Build: The HDX 3.5" midrange is designed for use in a 3-way component system. Pair it with the SoundQubed HDX Series 2.2" Titanium Dome Tweeter (crossed over at 3.8 kHz HPF) and a dedicated 6.5" or 6x9" woofer (crossed over at 80–100 Hz LPF) for a complete, high-output front stage. Use an active crossover or DSP to manage the three-way crossover points precisely.
Amplifier Pairing: The HDX 3.5" handles 40W RMS / 120W max at 4Ω. Run it on a dedicated channel of any SoundQubed 4-channel amplifier with the HPF set at 140 Hz. The Q4-150ABv2, Q4-2000, or Q4-3200 are all excellent choices for a 3-way active front stage build.
Mounting: The HDX 3.5" requires a 2.80" / 71mm baffle cutout and 1.52" / 38.7mm mounting depth. Overall diameter is 3.50" / 89mm, overall depth is 1.65" / 42mm. No grill is included — plan your mounting location accordingly. A-pillar pods and custom fiberglass mounts are the most common install locations for this driver.
Full Specifications
General
| Specification | Value |
|---|---|
| Nominal Diameter | 3.5" / 89mm |
| Nominal Impedance | 4 Ohms |
| RMS Power Handling | 40W |
| MAX Power Handling | 120W |
| Sensitivity (1W/1m) | 86 dB |
| Frequency Response | 120 Hz – 20 kHz |
| Recommended Hi-Pass Crossover | 140 Hz |
| Number of Ways | 1-Way |
| Sold In | Pair |
| Grill Included | No |
Driver Specifications
| Specification | Value |
|---|---|
| Voice Coil Diameter | 1" / 25.5mm |
| Voice Coil Former Material | KSV |
| Winding Material | EISV |
| Cone Material | Glass Fiber |
| Surround Material | Rubber |
| Basket Material | Steel |
| Basket Color/Finish | Black Matte |
| Magnet Material | Barium Ferrite |
| Magnet Weight | 310g |
Thiele & Small Parameters
| Parameter | Value |
|---|---|
| Equivalent Volume (Vas) | 0.55L / 0.019ft³ |
| Excursion One Way (Xmax) | 1.4mm |
| Free Air Resonance (Fs) | 140 Hz |
| Mechanical Factor (Qms) | 7.08 |
| Electrical Factor (Qes) | 1.37 |
| Total Factor (Qts) | 1.15 |
| Mechanical Mass (Mms) | 3.2g |
| Mechanical Compliance (Cms) | 402mm/N |
| BL Factor (BL) | 2.938 |
| Voice Coil Inductance (Le) | 0.169mH |
| Cone Area (Sd) | 32cm² |
| DC Resistance (Re) | 4.20 Ohms |
| Mechanical Mass w/o Air (Mmd) | 3g |
Speaker Measurements
| Dimension | Value |
|---|---|
| Overall Diameter | 3.50" / 89mm |
| Overall Depth | 1.65" / 42mm |
| Front Mount Baffle Cutout | 2.80" / 71mm |
| Mounting Depth | 1.52" / 38.7mm |
| Motor Diameter | 2.36" / 60mm |
Frequently Asked Questions
Q: Is the HDX 3.5" a full-range speaker or a dedicated midrange?
A: It’s a dedicated 1-way midrange driver — not a full-range speaker. It’s designed to be crossed over at 140 Hz HPF and paired with a dedicated tweeter for a complete front stage. Do not use it without a high-pass crossover.
Q: What tweeter pairs best with the HDX 3.5" midrange?
A: The SoundQubed HDX Series 2.2" Titanium Dome Tweeter is the natural companion — cross it over at 3.8 kHz HPF and the HDX 3.5" at 140 Hz HPF for a seamless 2-way or 3-way front stage within the HDX ecosystem.
Q: Does the HDX 3.5" come with a grill?
A: No — the HDX 3.5" midrange does not include a grill. Plan your mounting location and pod/baffle design accordingly.
Q: What amplifier channel should I use for the HDX 3.5" midrange?
A: Run it on a dedicated channel of any SoundQubed 4-channel amplifier with the HPF set at 140 Hz. For a 3-way active build, use a DSP to manage the crossover points between your tweeter, midrange, and woofer channels precisely.
