STX W.15.160.16.FCX 16 Ohm Midwoofer Specs and 12L Bass-Reflex Enclosure

User question

STX W.15.160.16.FCX

Artificial Intelligence Response

Direct answer to the question

STX W.15.160.16.FCX is a 15 cm-class / 5-inch hi-fi midwoofer driver, not a power supply. The official STX product page identifies it as a “Midwoofer cone driver” intended for 2-way speaker applications. Its main headline parameters are 16 Ω nominal impedance, 160 W program power, 100 W AES power handling, 89 dB sensitivity, and a recommended 12 L bass-reflex enclosure tuned to 40 Hz. (stx.pl)

Key points

• Type: midwoofer / low-mid loudspeaker driver for speaker cabinets. (stx.pl)
• Nominal impedance: 16 Ω. (stx.pl)
• Power: 160 W program, 100 W AES. (stx.pl)
• Sensitivity: 89 dB at 4.00 V / 1 m. (stx.pl)
• Resonance frequency \(F_s\): 38 Hz. (stx.pl)
• Recommended box: Bass-reflex, 12 L @ 40 Hz. (stx.pl)

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Detailed problem analysis

For clarity, the first offline sample answer is a misidentification. The official STX documentation shows that W.15.160.16.FCX is a speaker driver, specifically a midwoofer, not an SL Power STX-series AC-DC supply. (stx.pl)

What the part number means in practice

The STX naming convention here is consistent with a loudspeaker driver:

• W = woofer / midwoofer family
• 15 = 15 cm class
• 160 = power class
• 16 = 16 Ω version
• FCX = STX’s higher-performance family with carbon-fiber diaphragm and advanced motor linearization elements. This interpretation matches the official feature list, which includes fiber carbon diaphragm, aluminium basket, copper/aluminium demodulation and symmetry rings, and a copper Faraday cup. (stx.pl)

Official technical data

Below is the most useful engineering summary from the official STX page:

Parameter	Official value
Driver type	Midwoofer cone driver
Intended use	Optimal for 2-way application
Nominal impedance	16 Ω
Program power	160 W
AES power handling	100 W
Sensitivity	89 dB @ 4.00 V / 1 m
Resonance frequency \(F_s\)	38 Hz
\(R_e\)	11.3 Ω
\(Q_{ms}\)	3.30
\(Q_{es}\)	0.38
\(Q_{ts}\)	0.36
\(V_{as}\)	25 L
\(M_{ms}\)	9.5 g
\(B!L\)	8.1 T·m
\(L_e\) at 1 kHz	0.28 mH
Effective piston area \(S_d\)	0.0095 m²
Voice-coil diameter	25 mm
Max linear excursion	10.5 mm p-p
Mechanical displacement range	18 mm p-p
Overall diameter	156 mm
Cutout diameter	121 mm
Mounting depth	76 mm
Magnet	Ferrite
Basket	Aluminium
Diaphragm	Fiber carbon
Recommended enclosure	Bass-reflex 12 L @ 40 Hz

(stx.pl)

Engineering interpretation of the specifications

1. 16 Ω nominal impedance
This is the defining electrical characteristic. A 16 Ω driver draws less current than an 8 Ω driver for the same amplifier voltage. In practical loudspeaker design, this often makes the unit attractive for:

• pairing two drivers in parallel to obtain an approximately 8 Ω nominal load,
• series/parallel array topologies,
• tube amplifiers or systems where current demand should remain moderate.

That is an engineering inference from the official 16 Ω rating, not a direct manufacturer usage claim. (stx.pl)

2. Enclosure suitability
The combination of \(F_s = 38\text{ Hz}\), \(Q_{ts} = 0.36\), and \(V_{as} = 25\text{ L}\) is consistent with a driver that can work well in a small vented enclosure. STX explicitly recommends 12 L bass-reflex tuned to 40 Hz, which is a very useful starting point if you are building a compact 2-way speaker. (stx.pl)

3. Cone and motor design
The official page highlights:

• fiber-carbon diaphragm,
• aluminium basket,
• copper/aluminium demodulation rings,
• copper Faraday cup,
• vented magnetic system / coil cooling.
  These features are associated with lower modulation distortion, better inductance linearity, improved thermal behavior, and cleaner midrange performance than a simpler ferrite/steel/basic-cone design. (stx.pl)

4. Sensitivity notation
The manufacturer gives 89 dB at 4.00 V / 1 m. For a 16 Ω nominal driver, 4 V corresponds to about 1 W ideally, since \[ P=\frac{V^2}{R}=\frac{4^2}{16}=1\text{ W}. \] So this rating is effectively comparable to a 1 W / 1 m sensitivity figure. The real value varies slightly because the DC resistance is listed as 11.3 Ω, while “16 Ω” is nominal impedance over frequency, not pure resistance. (stx.pl)

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Current information and trends

As of the currently indexed official STX product page, this exact model is shown as out of stock / unavailable, with a listed price on the English page of €58.52 and on the Polish page 252.00 zł at crawl time. Availability is inherently time-sensitive and may change. (stx.pl)

From a broader loudspeaker-engineering perspective, this driver reflects current mainstream hi-fi midwoofer design trends:

• stiff composite diaphragms for reduced cone flex,
• shorting/demodulation rings to lower distortion,
• vented voice-coil systems for lower power compression,
• rigid cast or aluminium baskets for better mechanical stability.
  Those trends are directly reflected in the official feature set of this STX unit. (stx.pl)

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Supporting explanations and details

Practical application areas

The official product positioning is 2-way loudspeaker use. In practice, that means it is suitable for:

• bookshelf loudspeakers,
• compact towers using one or two units,
• center speakers,
• replacement / upgrade of existing 15 cm-class low-mid drivers,
• DIY hi-fi systems where a 16 Ω driver is desired. (stx.pl)

What the dimensions imply

There is often confusion between:

• nominal size: 5-inch / 15 cm class,
• overall frame diameter: 156 mm,
• cutout diameter: 121 mm.
  This is normal in loudspeaker practice. The nominal “5-inch” label is a market class, not the actual outer basket diameter. (stx.pl)

Crossover considerations

STX does not specify a crossover point on the product page, so any exact crossover recommendation is a design decision, not an official value. As an engineering guideline for a driver of this type:

• use real measurements before finalizing crossover,
• expect it to be used as a woofer/midwoofer, not as a full-range unit,
• pair it with a tweeter that can comfortably cross in the typical low-kHz region,
• verify the breakup behavior and off-axis response before choosing the final acoustic slope.

Those are general loudspeaker-design best practices rather than STX-published values.

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Ethical and legal aspects

For a speaker driver, the main practical ethical and legal issues are:

• hearing safety: even a compact system can produce hazardous SPL if overdriven,
• thermal safety: amplifier clipping can overheat the voice coil despite nominal power ratings,
• product warranty / authenticity: use genuine replacement parts and avoid relying on reseller listings that may paraphrase or mistranslate specifications,
• electrical compatibility: ensure the final system impedance is safe for the amplifier.

The most reliable source for this specific driver remains the official STX specification page. (stx.pl)

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Practical guidelines

If your intent was to buy, replace, or design with the STX W.15.160.16.FCX, these are the practical engineering steps:

1. Confirm the electrical target

   • If replacing an existing unit, verify the original speaker was also 16 Ω.
   • If designing new, decide whether you want a single 16 Ω driver or two in parallel for approximately 8 Ω system impedance.

2. Use the official box recommendation as the starting point

   • Begin with 12 L net internal volume.
   • Tune the vent to 40 Hz.
   • Then refine in simulation and by measurement. (stx.pl)

3. Respect the real power rating

   • Treat 100 W AES as the more meaningful continuous-power figure.
   • Treat 160 W program as a higher, less conservative rating. (stx.pl)

4. Check fit before ordering

   • Cutout: 121 mm
   • Outer diameter: 156 mm
   • Depth: 76 mm (stx.pl)

5. Measure the final build

   • impedance sweep,
   • near-field woofer and port response,
   • gated frequency response,
   • distortion at intended SPL,
   • thermal compression after several minutes of drive.

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Possible disclaimers or additional notes

• STX explicitly states that it reserves the right to change technical data, so production revisions are possible. (stx.pl)
• Reseller pages may mix program power, RMS, and AES terminology incorrectly; the official STX page is preferable. (stx.pl)
• The official page gives max linear excursion as 10.5 mm p-p. Interpreting that as approximately ±5.25 mm one-way is a reasonable inference, but it is still an inference from the published peak-to-peak number. (stx.pl)

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Suggestions for further research

If you are designing a cabinet around this driver, the next useful items to determine are:

• intended box alignment: sealed vs bass-reflex,
• crossover target and tweeter choice,
• whether the 16 Ω version is required or whether the 8 Ω version would be more practical,
• on-axis and off-axis response measurements in your actual baffle,
• distortion performance at the intended listening level.

If you want, I can next help you with one of these specific tasks:

1. box design for this driver,
2. bass-reflex port calculation for 12 L / 40 Hz,
3. crossover starting values, or
4. comparison with the 8 Ω version.

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Brief summary

STX W.15.160.16.FCX is a 16 Ω, 5-inch / 15 cm-class STX midwoofer for 2-way loudspeakers, with 100 W AES, 160 W program power, 89 dB sensitivity, 38 Hz resonance frequency, and a manufacturer-recommended 12 L bass-reflex enclosure tuned to 40 Hz. The power-supply interpretation is incorrect; the official STX source clearly identifies it as a loudspeaker driver. (stx.pl)

If you want, I can now provide a complete enclosure design or a crossover starting point for this exact driver.

Disclaimer: The responses provided by artificial intelligence (language model) may be inaccurate and misleading. Elektroda is not responsible for the accuracy, reliability, or completeness of the presented information. All responses should be verified by the user.