June, 2015

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Cobra SPX 7800BT Review





Our forum has not embarked on officially reviewing a Cobra radar detector until this year, mainly because the vast majority of detectors from this company in the past few years have simply been poor performers, placing them as a “better than nothing” type of detector. Most of these detectors are widely popular, however, their popularity is due to their cost differential over their competitors, and not due to their performance.  Toward the end of fiscal year 2014 and into the spring of 2015, Cobra Electronics Corporation introduced some new radar detectors with price ranges above the traditional $100 to $150 range. These new detectors, categorized in the SPX and XRS lineup, separate themselves from the company’s conventional detectors by offering features like Bluetooth capability, “Xtreme Range Superheterodyne® Technology,” and multi-colored OLED displays. Given the addition of these new features and technology, we wanted to review the best radar detector from this lineup by thoroughly assessing its design, its detection range against radar sources, its accuracy to alerts, and its functions.  Our forum Moderator, Vortex, who has been testing and reviewing many radar detectors and laser jammers since 2012, conducted the following series of tests on the Cobra SPX 7800BT radar detector in order to provide enthusiasts in this community and prospective buyers accurate information on this radar detector’s performance.




Radar and LIDAR (laser) Detection

    • X-band
    • K-band
    • Ka-band
    • Laser

Radar Receiver Type : Superheterodyne antenna (Xtreme Range Superheterodyne® Technology)

LIDAR Infrared Receiver Type : LaserEye® (unknown number of diodes)

Global Positioning System (GPS) Receiver : No built-in GPS receiver; position is determined when connected to a smartphone

Spectre Undetectable : Immune to Spectre I radar detector-detectors


    • Length : 3.71″
    • Width : 2.43″
    • Height : 1.54″

Power Requirement

    • Hardwire (ie. connecting the detector to the fusebox) : 12V DC with a negative (-) ground
    • Dash accessory outlet : Straight power cord with auxiliary USB charge port (included)



Display : Multi-color Organic Light-emitting diode (OLED)

    • Alert Screen
      • Radar : signal strength (5 bars), signal type, and signal frequency
      • LIDAR : pulse rate
      • iRadar Community Alerts: photo-enforced areas, speed trap areas, caution areas
    • Standby Screen
      • compass heading*, vehicle speed*, City/Highway indicator, vehicle battery voltage, IntelliMute indicator; * indicates smartphone required

User Preference Settings

    • City / Highway filtering : 4 City Modes (X, X + K, X + K + Ka, Max), Highway
    • Auto Mute
    • Tone / Voice
    • Color theme : Multi-color, Red, Blue, Orange, White, and Green
    • Display Timer
    • Smart Power
    • Factory Default


Included Accessories

Cobra accessory dash cord with USB port

Cobra accessory dash cord with USB port

Cobra hardwire cord with built-in fuse

Cobra hardwire cord with built-in fuse

Cobra universal windshield suction cup mount

Cobra universal windshield suction cup mount


Overview of the Cobra SPX 7800BT

The Cobra SPX 7800BT is Cobra Electronics Corporation’s top radar detector, equipped with the latest technologies like Bluetooth capability for GPS information and app functionality (iRadar), Xtreme Range Superheterodyne radar antenna technology, and ultra-low-noise, signal amplifiers. With all this premium technology, our reviewer thoroughly tested the SPX 7800BT in real world scenarios, such as driving in town where sources of K-band are common as well as driving on busy freeways, and also subjecting the detector to simulated scenarios involving Instant On radar, which the company states is defended by the radar detector. By utilizing all the available features on this detector, our reviewer observed and recorded the key performance levels like range detection and sensitivity on video as shown below in the different segments:

Size and Accessory Power Plug – A Comparison

Left To Right - Cobra 7800BT, Valentine One, Escort Redline, Escort Passport Max 2

Left To Right – Cobra 7800BT, Valentine One, Escort Redline, Escort Passport Max 2

Left To Right - Valentine One Plug, Escort Plug, Cobra Plug

Left To Right – Valentine One Plug, Escort Plug, Cobra Plug

Left To Right - Passport Max 2, Redline, Valentine One, Cobra 7800BT

Left To Right – Passport Max 2, Redline, Valentine One, Cobra 7800BT

 The new Cobra 7800BT is definitely much smaller in size when compared to the other premium radar detectors.  For some users, the small size allows for concealed installations near the roof liner, or on the corners of the windshield.  The accessory power plug, included with the purchase, is a traditional 12V DC power supply, however, it does distinguish itself from the other two plugs pictured (Valentine One and Escort SmartCord) by incorporating a built-in USB port.  This port provides drivers the option to use it for charging small devices like smartphones or small tablets.

Radar Detection Performance 

The bottom line up front about this radar detector’s performance for detecting radar and alerting the driver in a sufficient period of time is abysmal. Our reviewer found the detection so poor even when the scenarios employed a radar source that was constantly On (C/O), which is the easiest radar source to detect.

The video shows the poor detection range, and compares it against the detection range of the other competing radar detectors. The second and third order effects of this observation against Constant On detection is drivers can expect almost little to no alerts for speed traps where police turn their radar guns On and Off depending on traffic flow. This On and Off technique is called Instant On (I/O).

When our reviewer compared the detection range of the Cobra 7800BT against other radar detectors, he found that this detector had very bad detection range against common Ka-band radar guns operating at 34.7 GHz. In the test below, which simulates a common scenario of a police car using radar against oncoming traffic around a curve, the Cobra 7800BT clearly demonstrated very poor detection range almost to the point where the driver has no reaction time to slow down safely and not draw attention. 

Our reviewer also tested the Cobra 7800BT against the infamous “POP” test.  POP is a radar gun function used by MPH Industries that bursts radar signals for milliseconds in order to prevent potential radar detectors in an area from detecting the radar. Although POP results cannot be used to issue citations, usage of it implies speed enforcement. Cobra Electronics Corporation states that the Cobra 7800BT can detect POP, so our reviewer wanted to determine how well it detects:

The results show the Cobra 7800BT detects POP less than 50% of the time. Clearly, this detector, as the reviewer states, “is one of the worst performers ever tested, … besting only the RMR C495,” which in itself is a scam as posted in our reviews earlier in 2014.

False Alert Mitigation ★

All premium radar detectors currently available have a feature that minimizes the number of false alerts. They use a combination of built-in filtering mechanisms and user inputs, such as manually locking-out a known location for false alerts.  Although none of the detectors score perfectly in this category, due to many environmental factors and circumstances, such as Blind Spot Alert sources found on certain vehicles, the Cobra 7800BT’s filtering mechanism seems to make false alerting worse rather than better. When the Cobra 7800BT detects a false alert source, it recognizes it incorrectly as Ka-band source. See the video below for a demonstration of this fault:

According to our reviewer, “…it does this with a LOT of K-band signals. More than 50% of them in my experience. So what happens is that in practice, the thing incorrectly alerts to Ka-band ALL THE TIME! As I’m learning the tones for the Cobra, I’m actually learning to associate the Ka beeps with a false alert. That’s not good… Sometimes it actually goes back and forth between K and Ka, even rapidly changing what it displays on the screen.”

Lastly, like all radar detectors, the Cobra 7800BT has a City mode that allows drivers to use when they are driving in town where there is a high occurrence of false signal sources, like automatic doors at stores. However, City mode on this detector has a large, negative impact on the detection performance. Basically, the Cobra 7800BT is very quiet until the driver is in the target zone of a speed trap:

Our reviewer sums the above video with: “Sure, we could say that a detector would ideally filter out these non-threatening sources, but the radar coming from that sign would be virtually identical as what would come from a police radar gun. Other detectors has far less of a hit and still alerted with plenty of time, even with TMF/TSR on. So yeah the Cobra does have some K band filtering options available which is great and needed these days, but it comes at the cost of a huge hit in (already lackluster) performance.”

Laser Detection Performance ★★★

Our reviewer sums up the laser detection performance of the Cobra 7800BT with: “Stripping away the nonsensical marketing speak, what guns can the Cobra actually detect? Well it can detect the standard lidar guns like the ProLaser2, ProLaser3, Applied Concepts LZ1, and Laser Technology Inc. Ultralyte LRB. It detects the Laser Atlanta, but not when the gun is put into Stealth Mode, a very simple technique they use to defeat laser jammers. It also doesn’t alert to some of the more complicated VPR guns like the TraffiPatrol XR, Laser Ally, or Dragoneye Compact.” In a nutshell, this detector has very basic laser gun detection capabilities and can only alert to a few of the most popular laser guns in use throughout the United States.

Smartphone App : iRadar 

Like the competition, the Cobra 7800BT offers users similar integration capabilities between the radar detector and a smartphone via an app called iRadar. This app, which is available for Apple and Android phones for free on iTunes or GooglePlay, uses the Cobra’s built-in bluetooth module to establish a wireless connection to a smartphone in order to alert the driver of surrounding threats in the area, or allow the driver to report his or her threats to the iRadar cloud. We gave this app two out of five stars because for the most part it is not legitimately helpful, yet it has a navigation feature which earned it some kudos.

In the video above, we compared the iRadar against similar apps like Escort Live and Waze in order to provide readers an overview of other available apps and how their usability and functionality influence our standard of scoring. Our reviewer learned during the testing that the iRadar has a serious fault with user inputs related to reporting received alerts. The Cobra iRadar does not accept a user’s choice during reporting, and ALWAYS reports alerts to the cloud. This means that if you encounter an alert from an unknown source, like a false alert from an automatic door opener at CVS or Walgreens, the iRadar app WILL report the alert to the cloud despite you telling it specifically NOT to report it.

Escort Live - example of alert on iPhone

Escort Live – example of alert on iPhone

Cobra iRadar - example of alert on iPhone

Cobra iRadar – example of alert on iPhone

Lastly, this app has another annoying feature when you have it turned On and decide to leave your car parked in an area where the detector recently detected a false alert, such as a shopping center or grocery store. In this scenario, since “Not Sure” inputs are still reported to the cloud, the false alerts encountered at the store, will make their way to the cloud, and the app will in turn continue alerting you to those false alerts on your phone as you walk-around the store, unless you turn the app off.


The new Cobra 7800BT is a technical addition to the Cobra radar detector lineup, offering an array of new features not seen in previous generations. This emergence of this new technology in detectors like the 7800BT is due mostly to the company trying to remain competitive amongst the other rival brands like Valentine One and Escort Incorporated. As always, our reviewer, Vortex, tested this latest model to demonstrate the strengths and shortfalls quantitatively and qualitatively. Tests like this one were very important, because we had never done such a thorough test on a Cobra radar detector in order to show readers the full face value of these radar detectors.  Now, readers can actually view for themselves the pros and cons in Cobras. In this review, our reviewer’s tests showed poor radar detection performance, in various scenarios and settings, and the less than average performance of the iRadar app. Despite the significant cost difference between the Cobra 7800BT and the traditional sub-$100 Cobra radar detectors, the higher-priced Cobras still share the same below average radar detection performance. Our reviewer noted earlier in the testing that most of the main components in the new Cobra 7800BT are the same ones used in the lowest priced radar detectors from Cobra. Therefore, this explains why the performance is sub-par across in terms of radar detection.




– Special thanks go to our forum Moderator, Vortex, for taking the time to do a great review of the Cobra SPX 7800BT.

– Additional discussion on the Cobra SPX 7800BT can be found here:

– Forum members may purchase the Cobra SPX 7800BT from the following trusted sources: