Tested: Cobra XRS 9930 vs. Whistler Pro 78

Best New Radar Detector Under $150

By Craig Peterson
3/6/2008

Cobra XRS-9930 and Whistler Pro 78: Can they run with the big dogs?

For years I've written that nearly all radar detectors priced under $200 have lousy Ka-band performance. And since the majority of new radar guns operates on this band, cutting corners on sensitivity can easily lead to trouble.

But radar detector customers are a notoriously price-sensitive bunch and most want models retailing below $150. This begs the question: Has the industry finally produced a moderately-priced radar detector with high performance?

To find out, I gathered up for review the eligible candidates from mass-marketers Cobra Electronics and Whistler.

The Cobra XRS 9930 ($230 MSRP, street-priced about $145) will remain on sale until inventory in the retail pipeline is gone, having recently been superseded by models we've also tested: the XRS 9940 ($230 MSRP) and XRS 9950 ($260).

Whistler's entry is the Pro 78 ($230 MSRP, about $150 street). A similarly priced electronic twin, the XTR-695, shares this platform and differs mainly in features, giving it similar performance.

The two competitors were tested at our remote desert site. Then I spent one month logging street miles with each unit. Here's what I found, the results listed alphabetically.

Cobra XRS 9930

The XRS 9930 uses a bright, multi-colored graphic display to show operating mode and compass cardinal points, plus radar and laser alerts. The display's daytime legibility is very good even in harsh sunlight. At night, it's too bright on dark highways, even fully dimmed. A solution is to run it in full-dark mode or mount it out of one's line of sight to lessen the visual distraction.

Audible alerts arrive via either voice or tones. The latter are reasonably distinct and also loud enough for most cockpits.

The Cobra XRS 9930 has an extensive menu of user-selectable preferences but I'd recommend against altering the factory-default settings. The XRS 9930 ships with Ku band, POP mode, VG-2 and Spectre 1 RDD detection all shut off.

Most won't need these. POP mode is a feature used by a very tiny number of radar guns, Ku band is not used in the U.S. and the Spectre Mk I radar detector detector hasn't been around for years. (The current Spectre Mk IV RDD model, called Stalcar outside North America, can spot this detector from 1,264 feet away, making it a poor choice if you drive in Virginia or Washington, D.C., or other places where detector use is illegal and RDDs are used to spot them.)

On the highway, the Cobra frequently issues K- and Ka-band alerts in reaction to the local oscillators of nearby radar detectors. In town, most falses are X- and K-band automatic door openers. Selecting the City X+K setting increases filtering on both bands and helps reduce these falses. In congested, slow-speed city traffic the IntelliMute feature further reduces false alarms.

The Cobra XRS-9930 offers 10 user menu options to let you tailor its operation to your preferences. Once dialed-in, it's an easy piece to live with. But does it perform? We'd have to find out.

For reference purposes a Valentine One ($399) was included. Having tested the V1 several times at these two sites, I knew that like other high-end models (BEL RX65, BEL Vector 995, Escort 8500 X50 and Escort 9500ix, among others), the V1 can spot all three types of radar at the maximum distance allowed by the 5.3-mile-long Straightaway site.

At that location the XRS 9930 proved that Cobra has at least partially closed the performance gap. On Ka band it delivered an impressive 90 percent of the detection range of the Whistler Pro 78 and V1. But it fared less well on the other bands, trailing the Whistler Pro 78 on X and K bands.

The performance differential between the two radar detectors widened noticeably at the far more difficult Curve test site. Here the detection-range issue is complicated by a hiccup I've noticed in this and other Cobra radar detectors, a reluctance to alert to radar coming from an off-angle. At this site the radar gun is aimed nearly 35 degrees away from the target vehicle's path. It's also aimed uphill some 15 degrees, shooting into space.

The off-axis and very weak radar beam taxes the detector's signal-processing software. With nothing to deflect the microwave signal toward a detector's antenna, there's an agonizingly slow increase in signal strength until the target car is almost squarely in the radar beam. This is precisely the type of scenario where traditionally, only a high-dollar detector could save you.

Compared to the Whistler Pro 78, here the Cobra XRS 9930 gave 24 percent less range on K band and 52 percent less range on X band. On the first two X-band passes it gave plenty of warning. Yet on the next two it didn't detect the radar before our speed had already been locked-in. (These scores were averaged for the test results chart.)

The iffy X-band performance would make it a poor choice for the admittedly slim number of drivers who need protection from the few X-band guns still in service. Its K-band sensitivity, while not class-leading, was respectable. And this Cobra is much more adept at detecting Ka-band police radar than previous Cobras I've tested.

REVIEW SUMMARY

Pro

Extensive feature set
Cool graphic display
Excellent Ka-band range

Con

Uneven X- and K-band performance
A bit noisy in town

Verdict

Best performance yet from a Cobra at this price point

Whistler Pro 78

A high-visibility blue text display conveys operating mode and alerts. A pair of laser-bright blue LEDs atop the case also blinks to get one's attention during alerts.

Display illumination adjusts automatically, toggling between full-bright and dim in reaction to ambient light. It can also be manually adjusted in three steps. This is the first instance in memory where Auto Dim has been offered on a radar detector at this price point. Features like this traditionally have been reserved for models costing upward of $299 and is unavailable on some, the $399 Valentine One and the $249 Rocky Mountain Radar RMR-C450, among others.

There's a choice of voice alerts or three different sets of audio tones. Whistler has offered the latter for years as a way of optimizing the audio for users with varying levels of auditory acuity. Considering our rising national median age, this feature will likely appeal to an increasingly large audience of drivers.

This new Whistler platform caught the Spectre (Stalcar) radar detector detector by surprise. When I tested the latest Spectre Mk IV and Mk IV+ RDDs last year, neither could detect the Pro 78. After some hurried software tweaks by its maker, the Spectre now can ferret out this Whistler, but at limited range, some two-thirds less than with the Cobra.

At the Straightaway test site the Whistler Pro 78 turned in surprisingly good scores. It delivered a whopping 85 percent more X-band range than the Cobra and 61 percent greater K-band range. On Ka band the Whistler showed a nominal 9 percent increase in range.

More importantly, the Whistler Pro 78 equaled the V1's range on both X and Ka bands, an achievement of some significance for a detector with a price one third as much. (Note: If we could get some kinks out of this road to lengthen it, premium-priced models like the V1 would display even greater detection range, widening the gap with less-pricey units like these.)

At the Curve test site the Whistler again showed a clear performance edge over the Cobra where it trounced the XRS 9930 on X and K bands. On Ka band the Whistler eked out a slim lead over the XRS 9930 and, significantly, came within 6 percent of equaling the leading Valentine One's detection range.

After crunching the numbers it's clear that the Whistler Pro 78 can handily dispatch its competition from Cobra and is easily the best-performing Whistler I've tested. Its stellar showing compared to the $399 Valentine One is a testament to the fact that for the first time, a value-priced model can just about run with the big dogs when conditions are favorable.

REVIEW SUMMARY

Pro