KEF SP1718 Uni Mf Woofer Tweeter Driver LS50 Mf/lf

( Brand: Kef ), ( Manufacturer Part Number: SP1718 ), ( Compatible Brand: For Kef ), ( Type: Mf/lf Tweeter Driver ), ( Unit Type: Unit ), ( Size: 5.25 ), ( Compatible Model: Ls50, Uni-q Mf ), ( Unit Quantity: One ), ( Country Of Origin: United Kingdom )

Review KEF Uni q Array Mf/lf Woofer And Tweeter Driver Red

The **KEF LS50 Uni-Q MF/LF Woofer and SP1718 Tweeter Driver** combination represents the pinnacle of high-fidelity audio engineering, meticulously crafted to deliver an immersive and dynamically rich listening experience. At the heart of this system lies KEF s legendary **Uni-Q ** (Uniformly Radiating Omnidirectional) technology, a groundbreaking approach to speaker design that eliminates the need for complex crossover networks by ensuring seamless frequency response across the entire driver assembly. The **LS50 Uni-Q MF/LF Woofer** is a mid/low-frequency driver engineered to radiate sound uniformly in all directions, creating a natural, three-dimensional soundstage that envelops the listener without the artifacts often associated with traditional bass reflex or ported enclosures. Its **170mm (6.7-inch) aluminum cone** is treated with KEF s proprietary **TweeterGuard ** technology, which enhances durability while maintaining pristine clarity, ensuring long-term performance even under high-power conditions. The driver s **high-efficiency design** and **optimized magnet structure** produce deep, tight bass with remarkable control, while its **smooth, extended low-end response** (down to 25Hz) ensures a full-bodied, cinematic foundation for any audio reproduction.

Complementing the LS50 is the **SP1718 Tweeter**, a high-performance dome tweeter that extends the frequency range with exceptional precision and detail. Utilizing a **1.75-inch (44.5mm) soft-dome transducer** with a **high-temperature, high-conductivity aluminum voice coil**, this tweeter excels in reproducing the upper midrange and treble with remarkable clarity, transparency, and minimal distortion. Its **optimized gasket design** and **rigid spider suspension** ensure accurate transient response, allowing for the faithful reproduction of vocal nuances, cymbal crashes, and intricate instrumental details. Together, the LS50 and SP1718 form a **coaxial pair**, meaning the tweeter is mounted directly above the woofer, eliminating phase cancellation issues that often plague traditional two-way speaker systems. This alignment enhances imaging accuracy, making the soundstage feel more cohesive and spatially coherent, whether you're listening to orchestral music, rock anthems, or the delicate textures of jazz.

The **Uni-Q technology** in the LS50 further distinguishes this driver by eliminating the need for a traditional crossover, as the woofer s uniform radiation pattern naturally transitions into the tweeter s range without abrupt frequency shifts. This seamless integration results in a **smoother, more natural sound signature**, free from the comb filtering and phase inconsistencies that plague conventional speaker designs. The combination of **aluminum cone construction** (for superior rigidity and thermal management) and **KEF s proprietary materials** ensures exceptional durability and longevity, making this driver ideal for both home audio enthusiasts and professional monitoring applications. Whether paired with a high-end amplifier or a sensitive preamp, the **LS50 SP1718** delivers a **dynamic, engaging, and emotionally resonant** audio experience that brings music to life with unprecedented realism.

For audiophiles seeking **uncompromising performance**, this driver pair is a testament to KEF s commitment to innovation and sonic excellence. The **LS50 Uni-Q MF/LF Woofer** and **SP1718 Tweeter** together create a **cohesive, high-resolution soundstage** that transcends the limitations of traditional speaker designs, offering a listening experience that is as intellectually stimulating as it is emotionally moving. Whether used in a **high-end stereo system, a home theater setup, or a professional monitoring environment**, this combination ensures that every note, every instrument, and every vocal performance is rendered with **unmatched clarity, depth, and authenticity**.

### **Pros and Cons of the Kef LS50 Uni-Q MF/LF Woofer SP1718 Tweeter Driver**

#### **Pros**

1. **High-Quality Sound Reproduction**

- The **LS50 Uni-Q** is a high-excursion woofer designed for deep bass and extended low-end response, making it suitable for both home audio and professional setups.

- The **SP1718** tweeter is a high-efficiency, dome-type unit optimized for crisp highs with minimal distortion, ensuring accurate and detailed sound reproduction.

2. **Durability and Build Quality**

- Both components are built with robust materials, including a **LS50** with a reinforced cone and a **SP178** with a high-tensile aluminum dome, ensuring longevity even with high SPL (sound pressure level) demands.

- The **Uni-Q** design allows for better heat dissipation, reducing the risk of thermal distortion in long listening sessions.

3. **Versatility in Speaker Design**

- The **LS50** is a **large-excursion driver**, making it ideal for **sealed or ported enclosures**, allowing for custom speaker builds with optimized frequency response.

- The **SP1718** pairs well with the LS50 due to its **smooth crossover characteristics**, reducing phase issues and improving imaging.

4. **Professional-Grade Performance**

- Both drivers are used in **high-end studio monitors and professional audio systems**, indicating their reliability and performance consistency.

- The **LS50** excels in **low-frequency extension**, while the **SP1718** delivers **clear, detailed highs**, making them suitable for critical listening.

5. **Compatibility with Amplifiers**

- The drivers handle **high power inputs** (up to **100W RMS** depending on enclosure design), making them suitable for **high-efficiency amplifiers** without distortion.

- The **Uni-Q** s impedance characteristics remain stable across a wide frequency range, reducing strain on amplifiers.

6. **Aesthetic and Customization Options**

- The **LS50** has a **sleek, modern look** with a **black finish**, making it visually appealing for custom speaker builds.

- The **SP1718** is compact yet effective, allowing for **tight coupling** in speaker designs.

---

#### **Cons**

1. **Cost**

- Both the **LS50 Uni-Q** and **SP1718** are **premium components**, making them more expensive than standard drivers. This can be a significant investment, especially for hobbyists or budget-conscious builders.

2. **Enclosure Requirements**

- The **LS50** benefits from a **well-designed enclosure** (either sealed or ported) to optimize bass response. Poor enclosure design can lead to **boomy, muddy lows** or **inefficient power handling**.

- The **SP1718** requires **proper crossover design** to avoid harshness or lack of detail in high frequencies.

3. **Sensitivity and Efficiency**

- While the **SP1718** is efficient, it may require **higher power input** compared to some tweeters, meaning you may need a **strong amplifier** to achieve optimal volume without distortion.

- The **LS50** is **not as sensitive as some mid-range drivers**, so it may not perform as well in **small sealed cabinets** without a powerful amp.

4. **Size and Weight**

- The **LS50** is a **large driver**, requiring **significant cabinet space**, which may limit portability or compact speaker designs.

- The **SP1718** is small but still requires **careful placement** to avoid handling issues (e.g., rattles, vibrations).

5. **Learning Curve for Builders**

- Achieving **optimal performance** requires **experience in speaker design**, including **crossover placement, enclosure tuning, and driver matching**.

- Beginners may struggle with **balancing bass extension, midrange clarity, and high-frequency detail** without proper testing.

6. **Potential for Over-Driving**

- Both drivers can **distort if overpowered**, especially the **LS50**, which may **cone break** or **voice coil damage** occur if pushed beyond its limits without proper damping.

---

### **Conclusion**

The **Kef LS50 Uni-Q MF/LF Woofer SP1718 Tweeter Driver** is an **excellent choice** for **serious audio enthusiasts, custom speaker builders, and professionals** who demand **high-fidelity sound, durability, and deep bass response**. Its **superior build quality, efficiency, and pairing compatibility** make it a **top-tier driver combination** for **high-end speaker systems**.

However, it is **not ideal** for **budget-conscious buyers, beginners, or those seeking compact, portable solutions**. The **cost, enclosure requirements, and technical demands** mean that **proper research and testing** are necessary to unlock its full potential.

If you are **committed to building a high-performance speaker system** and have the **budget and expertise**, this driver pair will **deliver exceptional audio quality**. If you are **new to speaker building or working with a limited budget**, you may want to consider **more affordable alternatives** before investing.

### **Recommendation**

- **Buy if:** You are an **experienced builder** or willing to **invest time in research and testing**, and you want **deep bass, clear highs, and professional-grade sound**.

- **Avoid if:** You are a **beginner**, need a **budget-friendly solution**, or prefer **compact, portable speakers**.

- For **budget builds**, look at **Fostex or ESS drivers**.

- For **smaller systems**, consider **mid-sized woofers** like the **Kef Q Series** or **SEAS**.

- If **portability is key**, explore **active speakers** with built-in amps and drivers.

Ultimately, this driver pair is **one of the best choices for serious audiophiles**, but it requires **careful implementation** to justify its cost.

Details:

Figure someone out there can put this to good use before. Driver is in good used condition both woofer and tweeter. I have a KEF LS50 driver pulled from damaged cabinet. Works as it should and of course sounds amazing.

I was planning on saving these and mixing up colorways the components but never got around to it.

part #: sp1718 prices

• $125.00-$1439.99

specifications speakerpartgo:

• brand: Kef
• mpn: Sp1718
• compatible brand: For Kef
• type: Mf/lf Tweeter Driver
• unit type: Unit
• size: 5.25
• compatible model: Ls50, Uni-q Mf
• unit quantity: One
• country of origin: United Kingdom

shipping speakerpartgo:

• service: USPS Ground Advantage
• class: Standard
• type: Calculated
• cost: $26.25
• transit: 5-11 Days
• carrier: USPS

offer speakerpartgo:

• options: Ship-to-home
• best offers: True
• quantity: 3
• started: May 31, 2026
• availability: In Stock
• sold: 0

returns speakerpartgo:

• policy: No Returns

seller speakerpartgo:

• # reviews: 46
• rating: 100.0%
• city: Merritt Island, Florida

payments speakerpartgo:

• other
• credit card: Discover
• wallet: Google-pay

general speakerpartgo:

• condition: Used
• TV, Video Audio Parts > Speaker Parts Components > Other Speaker Parts Comp

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