Sony 4" Woofer 1-544-237-21
Update 9 January 2024

by AudioPhil™
Audio Enthusiast & Vintage Gear Aficionado | Exploring the Past, Present & Future of Sound | #AudioTech #VintageAudio | Tap-tapping on the MPC One 🎧✨
Introduction
Immerse yourself in the intricacies of the Sony 4" Woofer, a marvel of engineering, born in the mass-manufacturing facilities of Singapore. Boasting a 6Ω impedance and a resonant frequency (f(s)) of 77Hz, this woofer represents the pinnacle of audio design. Originally integrated into the renowned Sony 2-way loudspeaker model SS-H311, it stands as a testament to Sony's commitment to quality sound.
Our analysis ventures into the realm of acoustic possibilities, revealing that when housed in a finely-tuned vented box, this woofer could potentially deliver rich, deep tones as low as 50Hz. Yet, in real-world applications, its practical frequency sweet spot spans from 100Hz to 1,500Hz. Such a range makes it an ideal candidate for integration into compact, mass-produced midi-HiFi systems, where space is at a premium but sound quality cannot be compromised.
In our laboratory, where the pursuit of sonic perfection knows no bounds, we often experiment with woofers of various profiles to push the limits of audio technology. While the Sony 4" Woofer holds its own in standard applications, our experimental loudspeakers frequently explore alternative designs to achieve unparalleled acoustic experiences.



From its origins in the Sony SS-H311 loudspeaker, a notable 2-way ported design, emerges the Sony 4" Woofer, a key player in the realm of superior sound. This particular woofer, identified as the Sony model 1-544-237-21, has been carefully extracted from its original setting in the boombox speaker to be examined in greater detail. The SS-H311, known for its 6Ω impedance, intriguingly does not specify a power rating, adding an element of mystery to its specifications.
This woofer, with its 4-inch diameter, pairs elegantly with what appears to be a 1" wide-range tweeter, creating a harmonious balance between low and high frequencies. The crossover point in this system is believed to be around 1.5kHz, a strategic choice that likely plays a significant role in defining the acoustic characteristics of the SS-H311. In this focused examination, the Sony 4" Woofer stands out as a component of interest, not just for its functional role, but also for the acoustic possibilities it represents in the broader landscape of sound technology.



Woofer Measurements
Note: The measurements provided for this woofer were obtained using the DATS driver measurement system in a non-professional setting. Additionally, these measurements were conducted on an older loudspeaker, which might differ from other units of the same model. Therefore, we cannot guarantee the accuracy or reliability of these measurements or any comments made on this page. This information should be used as a general guide rather than a definitive assessment of the woofer's performance.
Parameter | Estimate | Units |
---|---|---|
Qts | 0.641 | |
Qms | 4.343 | |
Vas | 4.06 | l |
Qes | 0.752 | |
Fs | 77.40 | Hz |
SPL | 86.02 | dB |
Re | 6.00 | Ω |
Pe | not measured | W |
Le | 0.68 | mH |
BL | 23.777362 | |
Xmax | not measured | mm |
Dd | 20.00 | cm |
Z | 6 | Ω |
Sd | 314 | cm |
Discussion
The parameters provided for the woofer offer valuable insights into its performance characteristics and suitability for various audio applications:
- Qts (Total Q Factor) - 0.641: This value, which is a measure of the woofer's overall damping (electrical and mechanical), indicates a moderately low level of damping. A Qts in this range suggests that the woofer is versatile and can be used in different types of enclosures, such as sealed or ported, but it might be more optimal in ported designs.
- Qms (Mechanical Q Factor) - 4.343: This is a measure of mechanical damping of the woofer (independent of electrical factors). A higher Qms value like this indicates lower mechanical damping, which can lead to a more resonant and potentially 'boomier' bass response.
- Vas (Equivalent Compliance) - 4.06 liters: This parameter represents the volume of air that has the same compliance as the woofer's suspension. A smaller Vas value like this suggests the woofer is suitable for smaller enclosures, making it a good choice for compact speaker designs.
- Qes (Electrical Q Factor) - 0.752: This measures the electrical damping of the woofer. A value around this range indicates a moderate level of electrical damping, which influences how well the woofer can control its movement at its resonant frequency.
- Fs (Resonant Frequency) - 77.40 Hz: This is the frequency at which the woofer naturally wants to vibrate. A lower Fs usually indicates a woofer capable of producing deeper bass. 77.40 Hz is relatively high, suggesting this woofer is better for mid-bass rather than deep bass reproduction.
- SPL (Sound Pressure Level) - 86.02 dB: This indicates the efficiency of the woofer. An SPL of 86.02 dB means the woofer can produce a reasonable sound level with a given amount of power, though it's not exceptionally efficient.
- Re (Voice Coil Resistance) - 6.00 Ω: This is the DC resistance of the woofer's voice coil. It confirms the impedance rating (6Ω) and is important for matching with amplifiers for optimal performance.
- Le (Voice Coil Inductance) - 0.68 mH: This measures the inductance of the voice coil. Higher inductance can affect the woofer's response at higher frequencies, but 0.68 mH is reasonably low, which is good for reducing distortion.
- BL (Motor Strength) - 23.777362: This parameter reflects the strength of the magnetic field and the voice coil's effectiveness within it. A higher BL can indicate a more powerful and controlled woofer movement.
- Dd (Diameter of Diaphragm) - 20.00 cm: This is the effective diameter of the woofer. It helps in determining the Sd (surface area of the diaphragm).
- Z (Impedance) - 6 Ω: This confirms the woofer's impedance, which is crucial for matching with the right amplifier.
- Sd (Diaphragm Surface Area) - 314 cm²: Larger surface area can move more air, which is beneficial for bass reproduction. This area is typical for a 4" woofer.
Overall, these parameters suggest a woofer that is best suited for mid-bass reproduction in small to medium-sized enclosures, with a relatively efficient, controlled response, but not designed for very deep bass.
DIY Loudspeaker Suggestions
Using the Sony 4" Woofer with the estimated parameters in a DIY loudspeaker project, you should consider the following recommendations to optimize its performance:
- Enclosure Type: Given the Qts value (0.641), this woofer is versatile enough for both sealed and ported enclosures. However, its smaller Vas (4.06 liters) suggests it's more suited to a compact design. A ported (bass reflex) enclosure might be more beneficial if you're seeking a bit more extension in the lower frequencies, albeit the woofer's Fs (77.40 Hz) indicates it won't produce very deep bass.
- Enclosure Size: The woofer's small Vas value implies that it doesn't require a large enclosure to perform optimally. Use a speaker box design software or calculator to determine the ideal volume and port dimensions (if you choose a ported design) based on the Vas, Qts, and Fs values.
- Crossover Design: The woofer's expected usable frequency range is likely between 100Hz and 1,500Hz. Design a crossover network that transitions smoothly from this woofer to your chosen tweeter around 1,500Hz, which is in line with the suspected crossover point in the original Sony SS-H311 loudspeaker.
- Tweeter Selection: Pair the woofer with a high-quality tweeter that performs well starting from around 1,500Hz. A 1" dome tweeter could be a good match, similar to the original Sony configuration.
- Power Handling and Amplification: Although the power rating (Pe) is not measured, be mindful of the woofer’s limitations when choosing an amplifier. The woofer's Re (6 Ω) should be matched with an amplifier capable of driving 6Ω loads. Avoid overdriving the woofer to prevent distortion and potential damage.
- Damping Material: Use appropriate damping material inside the enclosure to minimize internal standing waves and absorb unwanted resonances. This can improve the overall sound quality, especially given the woofer's higher Qms, which suggests lower mechanical damping.
- Experiment with Tuning: If you opt for a ported design, experiment with different port lengths and diameters to find the best balance between bass extension and tightness. The goal is to enhance the bass response without making it sound boomy or uncontrolled.
- Aesthetic and Practical Design Considerations: Consider the overall size, shape, and aesthetics of your DIY speaker. Ensure the enclosure is sturdy and well-braced to minimize vibrations.
- Testing and Fine-tuning: Once built, test the speaker with various types of music and in different room positions. Small adjustments in crossover values, speaker placement, and room acoustics can significantly affect the overall sound.
Remember, DIY loudspeaker building is as much an art as it is a science. It involves a bit of trial and error, and personal preference plays a significant role in the final sound. Enjoy the process of creating something unique!