Efillooc 3 Inch Full Range Speaker Unit (Round) – Model SQ305 Yellow

The Efillooc 3 inch full range speaker round (Model SQ305) is a highly capable audio driver designed to deliver neutral, clear, and highly accurate sound across its operating range. Driven by a Y35 Aerospace Magnet and a natural pulp sound cone, the SQ305 handles 20W typical RMS (40W peak) with an impressive 89dB ± 3dB sensitivity.

Its technical performance highlights an exceptionally flat and smooth frequency response from approximately 100 Hz all the way up to 20 kHz, ensuring that midrange vocals and high-frequency details remain natural without unwanted harshness or emphasis. With a 4 Ohm nominal impedance and a free-air resonant frequency (fs) of approximately 100 Hz, this driver provides excellent efficiency and stability for desktop audio, custom enclosure builds, or multi-way setups.

Key Features

• Flat & Neutral Acoustic Response: Delivers a remarkably smooth output from 113 Hz to 20 kHz to keep music balanced and distortion-free.
• Natural Pulp Sound Cone: Utilizes a lightweight pulp cone for warm, accurate tonal quality and clear vocal reproduction.
• Y35 Aerospace Magnet & 20-Core Voice Coil: Provides strong motor structure control, reliable heat handling, and a high sensitivity rating of 89dB ± 3dB.
• Versatile 4 Ohm Driver: Easily driven by standard digital desktop amplifiers, head units, and custom audio modules.
• Optimized Enclosure Design: Tuned for a recommended box volume of 4L, making it ideal for compact bookshelf or desktop speakers.

Detailed Description

The Efillooc SQ305 is built for audio enthusiasts and DIY builders who demand accurate tone and consistent electrical performance from a compact driver.

Acoustic Performance (SPL vs Frequency)

When analyzing the Sound Pressure Level (SPL) across frequency (Hz), the SQ305 displays an impressively flat and smooth response from 100 Hz up to 20 kHz. The vertical axis measures output loudness in decibels (dB), while the horizontal axis tracks pitch from deep bass to high treble. Because the curve remains stable throughout the midrange and upper frequencies, the speaker does not overemphasize or hide particular notes. Below 100 Hz, the acoustic output naturally rolls off, making it best paired with a properly tuned 4L enclosure or an added subwoofer to achieve deep, rumbling bass.

Electrical Characteristics (Impedance vs Frequency)

The impedance graph illustrates the electrical load this driver places on an amplifier. Starting from low frequencies, the curve shows a distinct resonance spike reaching near 40 Ohms around 100 Hz, representing the speaker’s free-air resonant frequency (fs). Past this peak, the impedance drops and flattens around 4 Ohms between 200 Hz and 1 kHz, establishing its rated nominal 4 Ohm impedance. Above 2 kHz, a subtle upward rise in resistance occurs due to natural voice coil inductance, ensuring smooth amp stability.

Technical Specifications

Applications

• Full-Range Desktop Enclosures: Combine two SQ305 drivers in 4 L enclosures for high-fidelity personal listening setups.
• Midrange Driver in Multi-Way Systems: Use as a dedicated midrange component in 3-way or 2.1 speaker projects due to its flat 100 Hz – 20 kHz output.
• Subwoofer-Assisted Satellite Speakers: Pair with an active subwoofer crossing over around 120 Hz – 150 Hz for a complete, full-range room system.
• Custom DIY Audio Builds: Great for boomboxes, compact radio retrofits, and custom soundbars requiring efficient 4 Ohm drivers.

Frequently Asked Questions (Q&A)

Q: What power amplifier should I use with the Efillooc SQ305?

A: A 4 Ohm-compatible amplifier rated between 15W and 40W per channel RMS will cleanly power this driver without distortion or clipping.

Q: Does this speaker require a separate tweeter?

A: No. Because the SQ305 plays smoothly all the way up to 20 kHz, it functions as a single full-range driver without needing an additional tweeter.

Q: What type of box works best for this driver?

A: A 4 L cabinet volume is recommended by the manufacturer. A 4 L ported enclosure (tuned near 100 Hz) provides extended bass output down to around 85-90 Hz, while a 4 L sealed box offers tight, controlled mid-bass suitable for use with a subwoofer.

Q: Does this speaker produce deep bass on its own?

A: The acoustic response begins to roll off below 100 Hz, which is standard for a 3-inch cone. For music with heavy sub-bass, pairing the driver with a separate subwoofer is recommended.