Reviewed: New Radar Detectors from Cobra and Whistler

Last updated 2023

Until a few years ago, except for a few models from Escort and Beltronics, plus the Valentine One, nobody was offering solid protection against Ka-band radar.

This poses a special challenge for radar detectors. U.S.-spec radar guns operate on three narrow slices inside this phenomenally wide radar band. The hard-working radar detector must scan the entire spectrum in search of signals. This takes time, reducing sensitivity (radar-detection range) and occasionally it leads to missed signals.

Fortunately for the driving public, radar detectors appear to benefit from a type of Moore's Law: As component costs have fallen, performance against Ka-band radar has gone up. After tests this year it's clear that acceptable Ka-band sensitivity has finally arrived.

Here's a look at how some of these performed, with reviews of each model.

Cobra XRS 9955

We have a more detailed review of the Cobra XRS 9955. If you need additional information, this model is identical to the Cobra XRS 9950, also reviewed.

One very useful feature on the XRS 9955 is Ka-band signal identification. An alert in reaction to police radar is depicted numerically by either 33.8, 34.7 or 35.5. Off-frequency Ka-band signals from non-police sources are displayed generically as "Ka band", along with their signal strength.

Okay, so why is Ka frequency ID a big deal? Simple: it tells at a glance if you're in the presence of a radar gun, an automatic door opener or another radar detector. (Drivers with no interest in this distinction should properly consider themselves to be future prey.)

Cobra XRS 9945

This Cobra differs from the pricier Cobra XRS 9955 primarily by its smaller OLED display. That's not necessarily a drawback in our opinion, just less of a visual distraction. Otherwise, the list of features is similar. Like its sibling, the XRS 9945 accepts the Cobra GPSL module ($129). With that addition the Cobra becomes a red light camera detector as well.

If there's a downside to this model it's the chrome trim adorning its upper housing and controls. This makes for a stylish product on the display rack, but it reflects noticeably in sunlight and the resulting windshield glare can be a distraction. Performance, though, particularly on K and Ka bands, is much improved over previous models and the best yet from Cobra at this price point.

Cobra XRS 9845

The Cobra XRS 9845 has most of the features found in the step-up model, the Cobra XRS 9945, and shares its case. (Be advised that the upper housing, an artful blend of contrasting hues and textures, employs far more brightwork than the Cobra XRS 9945, generating a dazzling mirror image of itself in the windshield glass.)

Cobra XRS 9745

The Cobra XRS 9745 is one of two models in the current XRS-series lineup (the other is the XRS 9955) with a darker, less-reflective upper housing. That makes it less visually intrusive on sunny days and some may prefer the more muted appearance.

This Cobra text-display model began life as the 12-band XRS 9730 a few years ago. During the interim it has apparently gained an ability to detect three additional bands of radar and laser signals, now offering no fewer than 15. If you've no idea what all this means, you're not alone, unless maybe you're a radar detector salesman. After reading more about this somewhat puzzling claim, you may be inclined to focus on more important attributes, like Ka-band sensitivity, for instance.

On that score, the Cobra XRS 9745 does well, trailing some of its more expensive stablemates but still honorably acquitting itself.

Cobra XRS 9645

This Cobra is an electronic twin of the XRS 9745, distinguishable by slightly different colors -- plus some chrome -- on the upper housing. On the road, the two behave nearly identically and their performance is very similar.

The alphanumeric text display can be dimmed at night and during daytime is usually readable except in direct sunlight.

Like all of the Cobra radar detectors in this group, the XRS 9645 sports an audio jack, a useful feature and unusual to find at this price point.

Whistler Pro 78SE

When it was tested in another review , the Whistler Pro 78SE turned in terrific scores. Its replacement, the CR85, has equal performance and even more features.

One feature that gives this and similar Whistlers a competitive edge over the competition is Ka RSID, Whistler-speak for Ka-band radar signal identification. Ka band radar alerts are far more likely to be police radar than are X- and K-band alerts. Those two bands are shared by a host of devices that pose no threat--mostly radar-controlled automatic door openers--but while Ka band isn't similarly afflicted, it has its own problems.

Ka band's extraordinary width makes it home to plenty of signals generated by other radar detectors, particularly low-cost Korean imports.

But Ka RSID will tell you whether you're listening to an alert generated by an old Cobra radar detector—or, say, a traffic-monitoring radar next to the freeway.

Ka RSID is also found on the Whistler XTR-695SE and XTR-690SE. Both receive the same electronic upgrades as the Pro 78SE and are worth a look by those shopping for upscale features with the same stellar performance.

Whistler XTR-695SE

The Whistler XTR-695SE is the range-topping model and has a wider range of user-selectable menu options. This one uses an LCD display that's fashionably backlit by the user's choice of color. Intense sun makes some of the combinations tougher to read, however.

Fortunately, the XTR-695SE is saved from potential banishment to a closet by virtue of its alert system. A pair of dazzling blue LEDs flashes during an alert, making it impossible to ignore. The user can also create a more contrasting display by careful manipulation of background and foreground colors.

Fortunately, its voice alerts and audible tones proved eminently capble of conveying necessary information, making the display more of a non-issue to most.

Alone among the high-end Whistlers, the XTR-695SE has a 2.5mm audio jack. This allows the XTR-695SE to power a remote speaker or, for motorcycle riders, a helmet headset.

Whistler XTR-690SE

Consider this Whistler the alternative to the Pro 78SE, identical save for the color of its display. While the Pro 78SE has a trendy blue LED screen, the XTR-690SE's is red.

Choosing between the two display colors is partly left up to one's fashion sense, although each color has its advantages. Many prefer a red display at night, citing aircraft cockpit instruments of that color as proof of superior legibility. Others feel that blue is more visible under a wider variety of lighting conditions. Regardless, the two radar detectors are comparable in price and perform identically.

With attributes shared with its siblings, the Whistler XTR-690SE rounds out the trio of new offerings, all equally imbued with performance, utility and valuable features including Ka RSID. Unlike the competing Cobras, all three Whistlers weigh in with remarkably consistent radar-detection performance, even under difficult circumstances.