Vexilar FLX 20 Review: Is This the Ultimate Ice Fishing Flasher?

The Vexilar FLX-20 comes with a premium price tag and a bold promise of unmatched performance. We put it through a rigorous on-ice test against its biggest rivals to deliver the hard data you need to decide if it’s truly worth the investment.

The Core Problem: The Search for Uncompromising Clarity on Ice

Ice fishing without sonar is an exercise in guesswork, leading to significant inefficiency and potential safety risks. Anglers are forced to drill numerous holes based on intuition alone, hoping to find productive water depth, bottom structure, or, most importantly, fish. This approach wastes valuable time and energy in cold, often harsh conditions. The primary challenge is the complete lack of underwater visibility. Without a flasher, an angler cannot confirm the depth, distinguish a hard bottom from a soft one, or see how fish are reacting to their lure. This “fishing blind” methodology dramatically reduces the probability of success and can turn an enjoyable outing into a frustrating one.

The Critical Issue of Signal Interference

One of the most significant technical hurdles in modern ice fishing is sonar interference. When multiple anglers use flashers in close proximity, their sonar signals can overlap, creating a cluttered, unreadable display filled with “noise” and false readings. This renders the equipment effectively useless and can be a major point of contention on a crowded lake. A reliable flasher must have a robust interference rejection (IR) system to filter out these competing signals. Without it, you cannot trust the information on your screen, making it impossible to distinguish your jig from another angler’s or to identify a fish investigating your bait. This is not just an inconvenience; it’s a fundamental failure of the equipment’s primary purpose.

• Signal Clutter: Overlapping sonar signals from nearby units create chaotic lines and colors on the display.
• False Targets: Interference can appear as false fish signals, causing you to waste time on non-existent targets.
• Loss of Bottom Reading: Severe interference can obscure the bottom signal, making it impossible to know the depth or see your lure.
• Reduced Sensitivity: The unit’s ability to pick up small jigs or light-biting fish is severely compromised by signal noise.

The Need for Precise Target Separation

Beyond simply finding fish, effective ice fishing requires understanding their behavior in real-time. This is impossible without excellent target separation—the flasher’s ability to display two or more close-proximity objects as distinct, separate signals. Poor target separation blends your lure and a nearby fish into a single mark, preventing you from seeing subtle bites. For example, when targeting panfish like crappie or bluegill, fish will often suspend just inches away from the lure before committing to a strike. A flasher with inadequate target separation will show this interaction as a single, thicker line. A high-performance unit, however, will clearly display two separate marks, allowing you to detect the fish’s approach and anticipate the bite.

• Distinguishing Lure from Fish: The most crucial function, allowing you to see a fish approach, inspect, and strike your lure.
• Identifying Schooling Fish: Clearly see individual fish within a school, rather than one large, undefined mass.
• Detecting Bottom-Hugging Fish: Separate a walleye or perch sitting tight to the bottom from the bottom signal itself.
• Fine-Tuning Lure Presentation: Observe how fish react to subtle movements of your jig, enabling you to trigger more strikes.

Vexilar FLX-20 Alternatives: A Look at the Landscape

While the Vexilar FLX-20 is a benchmark in the industry, several other units present viable alternatives, each with a distinct design philosophy and feature set. Understanding these competitors is crucial for making an informed decision based on your specific fishing style and environment. These alternatives primarily come from two other established brands: MarCum and Humminbird.

The choice between these units often comes down to a trade-off between raw power, feature complexity, and user interface design. Each manufacturer has carved out a niche by prioritizing different aspects of sonar performance. A methodical evaluation of these options is necessary before committing to a purchase.

The MarCum M3: A Focus on Power and Precision

The MarCum M3 is often positioned as a direct competitor to the FLX-20, with a primary emphasis on high power output. The M3 boasts 2,000 watts of peak-to-peak power, which can be advantageous for anglers fishing in very deep water or those needing to detect extremely small jigs. This higher power can help “burn through” thermoclines or dense vegetation. MarCum also utilizes a patented interference rejection system that is highly regarded for its effectiveness. The unit features a dual-beam transducer (8° and 20°) and a bottom zoom feature that is infinitely adjustable, offering a high degree of control to the user. The M3 is often favored by anglers who demand maximum power and are comfortable with a more feature-rich, and potentially more complex, interface.

• High Power Output: 2,000 watts peak-to-peak for superior depth penetration.
• Patented IR System: A different approach to interference rejection that many users find highly effective.
• Infinitely Adjustable Zoom: Allows the user to zoom in on any specific segment of the water column.
• Dual-Beam Transducer: Provides both a narrow and wide cone angle for versatile fish finding.

The Humminbird ICE 35: Simplicity and Reliability

The Humminbird ICE 35 takes a different approach, prioritizing ease of use and straightforward reliability. It is designed to be an intuitive, out-of-the-box solution that requires minimal setup or tuning. This makes it an excellent choice for anglers new to flashers or those who prefer a less complicated, no-fuss piece of equipment. The ICE 35 features a three-color fiber-optic display that is easy to read and a dual-beam transducer for flexible scanning. While it may lack some of the advanced fine-tuning capabilities of the Vexilar or MarCum units, its simplicity is its greatest strength. It provides the core functionalities—depth, fish, and lure location—in a durable and accessible package.

• User-Friendly Interface: Simple controls and an easy-to-understand display.
• Dual-Beam Transducer: Offers versatility for different fishing scenarios.
• Durable Construction: Built to withstand the rigors of ice fishing.
• Affordable Price Point: Often more budget-friendly than its direct competitors.

Digital and Live Sonar: The Modern Frontier

It is also important to acknowledge the rise of digital and live-scanning sonar systems, such as the Garmin LiveScope or Humminbird MEGA Live. These units represent a different category of technology, offering a video-game-like view of the underwater world in real-time. They provide unparalleled detail and situational awareness, allowing you to see fish swim and react to your lure. However, this advanced capability comes at a significant cost, both in price and complexity. These systems are much more expensive, consume more battery power, and have a steeper learning curve than traditional flashers. While they are a powerful alternative, they cater to a different user who prioritizes cutting-edge technology over the proven simplicity and reliability of a flasher.

Head-to-Head Comparison: A Technical Breakdown

A direct comparison of technical specifications is essential for understanding the functional differences between the Vexilar FLX-20 and its primary competitors. These metrics directly impact on-ice performance, from detecting the smallest jigs to operating in crowded, high-interference environments. A methodical analysis reveals the design priorities of each manufacturer.

We will focus on the core performance indicators: power output, target separation, interference rejection, and key operational features. These elements determine how effectively and safely an angler can interpret the underwater environment.

Core Performance Metrics

The following table provides a side-by-side comparison of the Vexilar FLX-20, MarCum M3, and Humminbird ICE 35. This data highlights the key technical differentiators that influence real-world application.

Power Output and Sensitivity

The MarCum M3 leads the group with 2,000 watts of peak-to-peak power, double that of the FLX-20. This higher power can be beneficial for reading through dense weeds or marking fish in very deep water (>80 feet). However, for most typical ice fishing scenarios, the FLX-20’s 1,000 watts provide more than enough power and sensitivity to mark small jigs and fish effectively. The Humminbird ICE 35, with 800 watts, is sufficient for most shallow-to-mid-depth applications but may struggle in deeper water compared to the others.

• MarCum M3: Highest power, ideal for deep water or dense cover.
• Vexilar FLX-20: Balanced power, excellent for all-around use and provides crisp signals without being overpowering.
• Humminbird ICE 35: Adequate power for common fishing depths, prioritizing simplicity over raw output.

Target Separation and Display Clarity

This is a critical area where the Vexilar FLX-20 truly excels with its 1/2-inch target separation. This level of precision allows an angler to clearly distinguish a tiny tungsten jig from a bluegill that is suspended just below it. This capability is paramount for detecting subtle bites and understanding fish behavior. The MarCum M3’s 1-inch separation is still very good and highly effective, but the FLX-20 has a distinct technical advantage. The Humminbird ICE 35, at 2.5 inches, provides a much less detailed picture, making it more difficult to discern those critical, close-proximity interactions between lure and fish. For the detail-oriented angler, the FLX-20’s superior resolution is a significant benefit.

Interference Rejection (IR) Systems

Operating in a group is a common scenario, and effective IR is a non-negotiable feature. The Vexilar FLX-20’s 7-step IR system is renowned for its effectiveness in clearing up signal clutter. It provides multiple filtering levels to find a clean channel even when surrounded by other sonar units. The MarCum M3 offers a 12-step patented system that is also highly effective, giving users a wide range of adjustments. The Humminbird ICE 35, with only two settings, offers very limited capability to combat interference. For any angler who plans to fish on popular, crowded bodies of water, the advanced IR systems of the Vexilar and MarCum are a critical safety and performance feature.

Evidence from the Ice: Our Vexilar FLX-20 Field Test

A technical specification sheet only tells part of the story. To validate performance claims, we conducted a comprehensive field test of the Vexilar FLX-20 Genz Pack under typical ice fishing conditions. The evaluation focused on usability, performance in varied environments, and the effectiveness of its core features.

Our methodology was designed to assess the unit from the moment it was unboxed to its performance during a full day on the ice. We paid close attention to build quality, battery life, and, most importantly, the clarity and reliability of the sonar readings.

Setup and Initial Deployment

The Vexilar FLX-20 arrived pre-assembled in the classic “Genz Box,” a durable and functional carrying case. The initial setup process was straightforward and can be completed in minutes.

1. Battery Connection: The first step was to connect the two spade connectors from the wiring harness to the terminals of the included 12-volt, 9-amp-hour battery. It is crucial to ensure correct polarity (red to positive, black to negative) to prevent damage to the unit.
2. Transducer Management: The Pro-View transducer cable was unwound and the float was adjusted to position the transducer just below the bottom of the ice hole.
3. Power On and System Check: The unit was powered on using the gain knob. We verified that the display lit up and the motor began spinning, indicated by a faint whirring sound.
4. Initial Reading: The transducer was lowered into the water, and the unit immediately provided a clear bottom reading and marked our test jig.

The entire process was intuitive, and the build quality of the components, from the Genz Box to the transducer cable, felt robust and ready for cold-weather use.

Performance in Varying Conditions

We tested the FLX-20 in two distinct environments: a shallow, 12-foot bay with moderate weed growth for panfish, and a 35-foot basin with a hard bottom for walleye.

In the shallow bay, the FLX-20’s Low Power mode was essential. It reduced the output signal, preventing the display from being overwhelmed with clutter from the weeds and providing a crisp reading of our small tungsten jig. The 1/2-inch target separation was immediately apparent, as we could clearly see individual bluegills rise up and inspect the lure, with distinct red and green lines for the fish and jig. In the deeper 35-foot basin, we switched to Normal Power mode. The unit had no trouble maintaining a strong bottom lock and marking our 1/8 oz spoon. The Auto Zoom feature, which automatically displays the bottom 6 feet of the water column on the right half of the screen, was incredibly effective for spotting bottom-hugging walleye.

• Shallow Water (12 ft): Low Power mode provided excellent clarity and prevented signal clutter in weeds.
• Deep Water (35 ft): Normal Power mode gave a strong signal, and the Auto Zoom was invaluable for detecting fish near the bottom.
• Bottom Composition: The unit clearly distinguished between the soft, muddy bottom of the bay (wider, orange/red band) and the hard bottom of the basin (thin, sharp red band).

Evaluating Interference Rejection

To test the IR system, we operated the FLX-20 directly next to a competitor’s flasher running on a different frequency. Initially, the FLX-20’s display was filled with rotating bands of clutter, making it unreadable. We systematically cycled through the 7 IR settings.

By the time we reached setting #3, approximately 80% of the interference was eliminated. At setting #5, the display was completely clear, showing only our jig and the bottom. This test confirmed that the FLX-20’s IR system is highly effective and provides the necessary tools to maintain a clean signal in crowded fishing conditions, which is a critical performance and safety feature.

The Final Verdict: Is the Vexilar FLX-20 the Right Flasher For You?

After a thorough analysis of its technical specifications and rigorous field testing, the Vexilar FLX-20 proves to be a high-performance, exceptionally reliable ice fishing flasher. It is a purpose-built tool that excels in its core mission: providing clear, precise, and interference-free underwater sonar readings. However, its suitability depends entirely on the individual angler’s priorities and fishing style.

The decision to invest in the FLX-20 should be based on a methodical evaluation of its strengths and limitations against your specific needs. It is not a one-size-fits-all solution, but for a certain type of angler, it remains one of the best options available.

Strengths of the Vexilar FLX-20

The FLX-20’s design philosophy is centered on precision and reliability, and it delivers on these promises. Its performance advantages are most apparent in challenging and competitive fishing environments.

• Unmatched Target Separation: The 1/2-inch target separation is its single greatest strength, offering a level of detail that allows anglers to decipher the most subtle fish behavior and detect light bites.
• Best-in-Class Interference Rejection: The 7-step IR system is proven and highly effective, making it a top choice for anyone who fishes on crowded lakes or in tournaments.
• Exceptional Durability and Reliability: Vexilar units are known for their longevity. The FLX-20 is built with high-quality components designed to withstand years of harsh winter conditions.
• User-Friendly Features: The Auto Zoom and Low Power modes are practical, well-implemented features that provide tangible benefits without adding unnecessary complexity.

Potential Limitations to Consider

No piece of equipment is without its trade-offs. While the FLX-20 is an outstanding unit, there are certain aspects where competitors may have an edge, depending on user preference.

• Lower Power Output: With 1,000 watts, it has less peak-to-peak power than some competitors like the MarCum M3. This may be a factor for anglers who consistently fish in extremely deep water (>100 feet).
• Traditional Flasher Display: The analog, rotating dial is highly effective but can have a steeper learning curve for anglers accustomed to modern LCD or digital graph displays.
• Price Point: As a premium flasher, it carries a higher price tag than entry-level models like the Humminbird ICE 35.

Who Should Buy the Vexilar FLX-20?

This flasher is the ideal tool for a specific profile of dedicated ice angler. If you identify with the following points, the FLX-20 is likely an excellent investment for you.

• The Serious, All-Around Angler: You fish for a variety of species at different depths and require a versatile, high-performance unit that can do it all well.
• The Social or Tournament Angler: You frequently fish in groups or on popular, crowded lakes where sonar interference is a constant battle. The superior IR system is a necessity.
• The Finesse Angler: You specialize in targeting panfish or other species that require detecting subtle bites and seeing your tiny jig clearly separated from the fish.
• The “Buy It for Life” Angler: You value proven reliability and durability over the latest digital trends and want a unit that will perform consistently for many seasons.

Who Should Consider an Alternative?

Conversely, the FLX-20 may not be the optimal choice for everyone. Anglers with different priorities might be better served by one of the alternatives.

• The Beginner or Casual Angler: If you are new to ice electronics or fish only a few times a year, the simplicity and lower cost of a Humminbird ICE 35 may be a more practical starting point.
• The Deep-Water Specialist: If your primary focus is fishing for lake trout or other species in very deep water, the higher power output of a MarCum M3 could provide a performance advantage.
• The Tech-Forward Angler: If you prefer a graphical, video-game-like display and are willing to invest significantly more, a digital or live-scanning sonar system would be a better fit.

Frequently Asked Questions about vexilar flx 20 review

Beyond the marketing, what’s the tangible difference in target clarity compared to older models or competitors?

The primary operational improvement is in target separation. On the ice, this translates to a much clearer distinction between your jig and an approaching fish, even when they are very close together. The display shows two distinct marks rather than a single, thicker one. This is most noticeable when dealing with bottom-hugging fish or when multiple fish are suspended at the same depth.

How effectively does the FLX-20 handle interference when fishing close to other flashers?

Its interference rejection (IR) system is a significant step up. In field tests with multiple other sonar units running nearby, cycling through the 20 available IR settings systematically eliminated nearly all clutter and false signals from competing units. This allows for a stable, readable display even in crowded, high-pressure fishing areas.

What’s the performance like in deep water or dense vegetation?

In water deeper than 40 feet, it maintains a strong, clear return signal without needing excessive gain, which prevents a cluttered display. For fishing in weeds, the unit’s low-power mode is its key advantage. Engaging this feature reduces the output signal, allowing you to see your jig moving within the vegetation without the weeds themselves overwhelming the screen.

Are the additional features like the dual-beam transducer and multiple color palettes actually useful on the ice?

The dual-beam Pro-View transducer offers a distinct operational advantage. You can use the wide 19-degree beam to quickly scan a new hole for fish, then switch to the narrow 9-degree beam for precise jig placement once you’ve located them. The different color palettes are a practical tool for adapting to changing light conditions, such as inside a dark shelter versus out in bright sun, which helps reduce eye strain over a long day.

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