Cobra SPX 7800BT Radar Detector Review

So how good are the inexpensive Cobra radar detectors? Why don’t we do a top of the line Cobra SPX 7800BT review and see what Cobra’s latest and greatest radar detector is capable of?

Personally I’m generally a fan of the higher end radar detectors. My point of view is that while you can save $200 or whatever by going for a lower end radar detector, if you get owned because you were using a lower end RD, the costs of the ticket, lawyer fees, court costs, insurance hikes, time and headache of dealing with the ticket, etc. far outweigh the money you saved by going with a lower tier RD. In a sense, this is a pay to play game.

That said, people keep asking about the more affordable radar detectors. Plus, after a while, I get tired of talking about and testing the usual contenders like the Redline, V1, and Max2. At one point I saw a comment online about how forum members think that the only acceptable choices are the Redline or V1 and how everything else must suck. Reading this, I started wondering just how good some of the less expensive detectors really are. Sure they’re not going to give the same performance as the higher end detectors and we should expect that, but will they still ultimately save us from tickets in the majority of situations? At the end of the day, isn’t that what really matters? Heck, even with the best detector money can buy, you can STILL get owned.

For the sake of understanding more of the big picture both for myself and for others, I’ve been spending time playing with some of the more affordable radar detectors lately. The Uniden LRD950 (now DFR7) has been showing a lot of promise so I’ve been spending time running that to get a better feel of it. This weekend it decided to commit seppuku so it’s currently in the mail heading back to home base to get repaired. Now that my attention is focusing back to the other options out there, I figured I’d start sharing with you guys some of my experiences while I play with a high end Cobra.

I’ve currently got a brand new retail Cobra SPX 7800BT that I’m testing thanks to @BestRadarDetectors. (A HUGE HUGE thank you to everyone who’s loaning me detectors to test!!! The community at RDF is utterly amazing and I’m truly honored to have a chance to work alongside you all. 🙂 )

When it comes to testing, I like to remain objective and unbiased as possible. Sure I’ve heard the typical “Cobras suck!” and “Cobras leak!” comments too, but I haven’t had any first hand experience. Having run this Cobra for a little while now, I gotta say that it’s opening my eyes to what’s possible. Seriously. Some of the things it is doing is just blowing my mind. It’s sucking in ways I didn’t even know was possible.  😯 Sure it costs less than the other options, but OMG…

As I play with it, I figured I’d go ahead and share my impressions with you.

So with that said, what’s the Cobra SPX 7800BT all about?

Cobra SPX 7800BT Review


cobra spx 7800bt radar detector stock photo

The SPX 7800BT is Cobra’s high end detector that features their best performing and longest range radar platform, has bluetooth to pair with your phone, RLC alerts, a fancy OLED display, and so on. Think Cobra’s competitor to the Max2 but without GPS lockouts. It retails for $280 but you can find it online for less…

The SPX series detectors all share the same radar platform. (The 7800BT shares the same platform as the SPX 5300 which retails for $110 and can be found for $54 shipped on Amazon.) All SPX series Cobras have the same horn and performance, but they have different features added around it and a different case… So this detector we’re talking about will give you the same performance as one you can find online for $54 brand new. That should tell you something…


Let’s start with some of the good things about the SPX 7800BT. First off, this detector is TINY!

Cobra SPX 7800BT review size comparison with V1, Redline, and Max2

Power Cable

The power cable also has a USB port which is actually really handy, especially considering most people are going to use the cable and not hardwire it. You can charge a phone off that (it puts out plenty of power which is great) and I also used it to keep my GoPro charged while testing this unit. 🙂

Cobra SPX 7800BT review power cables

Range and Performance

Additionally, it also actually *CAN* detect radar in such a way that it’ll actually protect you in real world encounters, particularly in easier encounters. I did some testing with a bunch of other affordable detectors and this Cobra was the worst detector tested.

After a followup test, it looks like the Cobra may no longer be the worst performing radar detector I’ve tested yet. When it comes to range, it can actually perform better than the Whistler CR85.

I found that while it can actually detect radar and save you in relatively easy conditions, in more challenging conditions, even this top end Cobra can get owned by C/O. In my mind, that’s completely unacceptable.

Sometimes it may give you plenty of time to slow down, it’s true. That’s definitely not always the case though, and even less so compared to other detectors. So while you will hear stories of how cheaper detectors can lead to saves, and this is true that it can, if you start getting into less than ideal circumstances where things like traffic, hills, curves, or trees get involved and start reducing your detection range, those are the situations where the higher end detectors will really start to set themselves apart from the Cobras. This is something really key to understand.

Even in tougher situations where it may not give you the all out range of some of the higher end detectors, sometimes in the tougher situations, if you slam on the brakes as soon as it alerts, you may have just enough time to slow down. (Sometimes not even that, but sometimes you may get only a few seconds.)

False Alert Filtering

The thing is, slamming on your brakes every time you get an alert may not be a good idea because it also likes to report K band blind spot falses as 35.5 Ka alerts.

In fact 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 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 screen.

In addition to 35.5 (the most common false alert frequency by far), sometimes it reports to other wacky frequencies like 34.9.


The screen itself also has some issues. Every time it updates the screen as it’s displaying your changing speed or direction, it momentarily blacks out the screen while it’s refreshing. As you’re accelerating or braking, it’s constantly updating your screen and so it looks like the screen is flickering. It looks like this happens only when the speed or direction is changing, not actually when something on the screen is changing at any point. To give you an example, here’s an encounter with a K band speed sign.

The screen itself does show a bunch of useful information such as speed and direction. It’s a newer, fancier screen. It uses an OLED display like the Max2 and LRD950 so it has the same benefits and compromises. It can display more information, has better resolution, and can display multiple colors whereas you won’t see that with LED screens like the one on the V1 and Redline. However, it’s also very difficult to see in direct sunlight. This is a property of OLED screens and isn’t something Cobra specific. The Max2 and Uniden have this issue as well.

Cobra SPX 7800BT review display comparison with Max2, Redline, and V1


Cobras are known for being leaky and causing problems for other RD users. Here’s an example of it making my V1 go nuts.

and here’s an example in the real world of a Cobra making my V1 throw 8 (!!) false Ka alerts in the 33.8xx range, a frequency range where police radar is actively in use here.

Radar Detector Detector Immunity

Due to their leakiness, they’re very easy to pick up with a radar detector detector. He’s an example of me hunting down a leaky Cobra using an ancient VG-2. I don’t know which Cobra model this was, and I don’t have an RDD at the moment to test out the SPX 7800BT and see if the frequencies it emits would be detectable by a VG-2 or one of the Spectres, but here’s what they generally are known for being like.

Ku Band False Alerts

Speaking of false alerts, I mentioned that they like to alert to K band as 35.5 so you get lots of false alerts on Ka. Well, you’ll get other false alerts too in addition to Ka. For example, I’ve seen it false to Ku just sitting in my driveway. Ku isn’t used here so I turned it off after doing a little testing like this…

Safety Alert System

Cobra’s version of SWS is called their Safety Alert system. It alerts you to things like construction zones, emergency vehicles, and other things that people can set up beacons for. SWS was originally designed to warn RD users of things coming ahead, but it never really took off and so it’s more like an extra checkbox on a features list rather than something actually useful. Some manufacturers like Escort are actually starting to remove SWS from their products altogether due to lack of use and the fact that it reduces performance. Cobra has it in their products and you guessed it.. false alerts! Here’s my Cobra alerting to a train in the area even though there’s no trains here.

Strobe Alert

They also have another similar feature called a Strobe Alert. Emergency vehicles have IR transmitters on their light bars that change traffic lights to make it easier to get through. I actually found an ambulance that triggered my Cobra and alerted me to an oncoming emergency vehicle. Pretty cool to see it in action, but of limited real world value considering they’d be running their IR transmitters when they’re actually busy and trying to get somewhere, not when they’re trying to hunt down those evil speeders. 😀

Cobra’s Radar “Bands”

For those of you who’re wondering about that whole “15 band” thing that Cobras can detect, that’s all gobbldeygook.

Basically it’s claiming every unique thing it can detect as a “band,” whether it’s X, K, Ka, Ku, SWS, a different pulse rate of lidar (125 pps, 200 pps, etc.), or whatever else. In fact having multiple bands is a registered Cobra trademark and so not only is it misleading as if a detector that can detect 15 bands is better than one that can detect 9 or 12, but one of the reasons that no one else discusses that is that that’s a Cobra trademark and legally they can’t. It’s more than just the fact that it’s nonsense.

This is something that got me back before I was into RD’s. I remember being at Best Buy and figured the most expensive Cobra that could detect the most bands was the best. Here’s a more comprehensive talk on the Cobra 15 bands bit for those of you guys who are curious about that.

Stripping away the nonsensical marketing speak, what guns can the Cobra actually detect? Well it can detect the standard lidar guns like the PL2, PL3, LZ1, and 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.

POP Radar Detection

This Cobra can detect POP. It catches less than half of the 67 ms Ka POP shots that I shot it with though. This was one of the worst performers I’ve ever tested, besting only the RMR C495 which claims to detect 100% of POP shots and actually catches 0%. So at least the Cobra can do something.

The thing is though, POP detection actually doesn’t matter in the real world. It’s always recommended to turn POP off. Not only isn’t used much at all in the real world, but it slows down performance everywhere else and you’ll get false alerts to POP. I noticed that with the Cobra, I actually get a LOT of POP falses, more than with most other detectors. So yeah its POP detection is subpar, but it doesn’t matter because you’ll wanna turn it off anyways.


To quiet down false alerts in town, rather than do something based on speed like savvy, savvy emulation, cruise alert, or whatever else, the Cobra attempts to mute your low speed signals based on your vehicle’s RPM’s.

I did a little research into this and it actually can work. When your ignition coil triggers a spark plug to fire, every time it does, it causes a disturbance in your vehicle’s electrical system and by being tapped into that, you can actually monitor the engine’s RPM. Based on that, you can manually set a certain RPM where your RD actually shuts down its detection circuitry so that it mutes (and also becomes undetectable by RDD’s… their counter to not having stealth technology like the M3’s) when you’re driving around at low speeds.

This doesn’t work with hybrids, diesels, electric vehicles, and some other cars too, but it should work with some. It didn’t work on my Miata, but it did work alright on my brother’s Santa Fe. That said, this is a really bad way to mute signals in my experience. Engine RPM and vehicle speed might be somewhat correlated, but not directly, so there’s times when you’ll want it muted and it won’t be, and vice versa. I wouldn’t count on it.

Here’s a clip of me setting the RPM threshold at a higher RPM, the Cobra not recognizing that I’m now at a much lower RPM, and then when I hit it with radar, it alerts anyways.

City Modes

Cobra has some City modes to help quiet down X and K band falses in town. Think Auto and TSR mode. It also helps with blind spot falses. Enabling this filter actually has a pretty huge negative impact on performance. It already doesn’t have the greatest performance ever. I did a test with a bunch of detectors with filters on and off against a K band speed sign and with the filter on, the Cobra dropped to alerting to just 1 second before my speed was registered.

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.

iRadar App

This Cobra has bluetooth and pairs with Cobra’s version of Escort Live. They call it iRadar. It can function as a display for your detector, make it easier to change settings, and give you alerts to and from the cloud. Yay! How well does it work?

Alert Reporting

Well, it actually does work. It reports you alerts to the cloud. It also tells you about other people’s alerts. Escort Live does the same thing, but there are some key differences here. Namely, Escort Live lets you decide when you see a potential alert whether or not you want to report it (for X or K band, Ka and Laser are reported automatically) or if you want to lock it out.

Escort Live alert

With iRadar, when you get an alert, you get the choice to report it as a “Live Police” or “Not Sure.”

Cobra iRadar alert

Alerts vs. Lockouts

Either way, no matter which button you choose, I’ve found that it always reports *EVERY* alert you get to the cloud. What that means is that every time your detector goes off, whether false or legit, it’s going to report that to the cloud and everyone else in the area has to deal with not only their false alerts, but everyone else’s false alerts too!!

You’ve got to be ******* kidding me…


With Escort, if you know you’re dealing with a stationary false alert, you press “lockout” so that it learns this alert and never alerts you to it again. With Cobra, you press “Not Sure” (even if you’re totally sure), it alerts everyone in the area, and now everyone’s RD’s are also going off. Awesome…


Now the app also knows when you’re parked. (You stop moving and your RD shuts off.) When that happens, iRadar saves your parking spot for future reference which is pretty cool. However, if you pull into a shopping center (where K band falses are prevalent) and leave your car, the app stays running in the background and endlessly alerts you to being in a threat area. No joke. You can walk around in the grocery store or wherever and your phone will keep alerting you to a radar threat area, your own false alert that you can’t lock out, you can’t tell quit alerting you and everyone else in the area, and it keeps notifying you even when it knows you’re parked and no longer driving.


The app does have some strong suits though. For example, it has turn-by-turn navigation built in, something people have been asking Escort to do with Live for quite some time. It’s not perfect and it has some quirks like it sometimes forgets that it’s navigating, stops, and then doesn’t save any sort of user history for you to access while driving, so you have to manually retype in your address or location while driving, but at least it has the feature built in.


It also can automatically launch the app when your phone detects your RD via bluetooth. This is automatic and pretty cool.

You can mimic this ability with Escort Live, but it requires a jailbroken phone and manually configuring the app Activator.

Cobra SPX 7800BT Highlighted Features

Here’s the highlighted features for the SPX 7800BT online:

  • Ultra-low-noise, signal amplifiers that once were affordable only to military systems
  • Low-microwave-loss circuitry utilizing gold-plated circuit boards
  • Use of flip-chip Mixer/Multiplier diodes in packages that were once unattainable
  • First Local Oscillator Transistor (Super-low-noise, high-mobility J-FET) that has been chosen to optimize signal gain, output power, and low noise characteristics over its frequency range
  • Powerful CPU that enables sweeping of the entire police radar band spectrum in less than 240 milliseconds

What a load of nonsense. It looks like they’re basically just using a bunch of fancy sounding but pointless words to dance around the fact that they have poorly designed products. That stuff all sounds great, but it doesn’t mean anything, and it doesn’t translate into well performing radar detectors.

“If you can’t dazzle ’em with brilliance, baffle ’em with bullshit.”

Cobra SPX 7800BT Review Conclusion

I’m not anti-Cobra. I WANT their products to be good. I want people to have more options for awesome radar detectors. Competition is great for the consumer.

That said, I’m also a fan of well-engineered products. I like it when things work well. Unfortunately, this isn’t the case with this Cobra.

Now that I’ve had a chance to run a Cobra, would I recommend it? I think the answer is pretty obvious. If someone wants to do so anyways, more power to you. That said, there’s certainly better options out there. From a purely selfish standpoint, I’d would really rather you didn’t. It causes problems for other RD users out there.

Looking forward, I have high hopes for Cobra. Monomoy, the investment company that purchased Escort/Beltronics also recently purchased Cobra so they all share the same umbrella company. I can only hope that some of the R&D that Escort has done goes into Cobra’s products to make the inexpensive products perform better and false other RD’s less. It’s good for everyone if Cobras perform better and quit leaking, and I really hope that Monomoy/Escort/Bel does something about it. Will they? Maybe, maybe not. They have an opportunity here and while I don’t see a good reason to run or recommend a Cobra product at this time, I really do hope things improve in the future.

All that said, if someone is looking for a good quality radar detector, I definitely can’t recommend the Cobra. There are much better options out there, some expensive and some affordable, but either way, it doesn’t take much to be better than a Cobra.

For recommendations on a really good radar detector, take a look through my Radar Detector Buyer’s Guide and choose from one of the good quality options. You’ll wind up with a much better experience, and fellow radar detector users around you will thank you too. 😉

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Review Date
Reviewed Item
Cobra SPX 7800BT
Author Rating
Product Name
Cobra SPX 7800BT
USD 280
Product Availability
Out of Stock

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    • youngdae woo on June 9, 2021 at 6:04 am
    • Reply

    I know what whislers intl version means but why do others dont? Is it an outdated concept?

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