Uniden R4 Review: An R3 on Steroids

The brand new Uniden R4 ($449) is now available for pre-order. It builds upon the R4 offering even longer range, improved false alert filtering, a refreshed design, and a bunch of useful new features. You can think of it as an R3 on steroids.

Uniden R4

I’m a fan of this new R4. Let’s take a look at its improvements over the R3.

Note: Due to supply chain issues, there will be a very limited number of R4’s available initially and I expect them to sell out quickly at launch, just like the R3 and DS1 did. Pre-order the Uniden R4 here.

Disclosure: This is not a paid or sponsored review. Uniden sent me an R4 earlier for test and review. It’s a pilot production sample (same hardware as retail copies) and I’ve tested with both beta and public firmware. I make a percentage when you purchase using the affiliate links in this article. It supports me and allows me to continue doing tests and reviews like this for you.

Here is my complete Uniden R4 review video if you prefer watching instead. 🙂

Uniden R4 Improvements over the R3

The Uniden R3 is a legend at this point and the R4 builds upon it. Here are the improvements the R4 brings:

Refreshed Design

Uniden has refreshed the detector’s design with a more angular design and larger top buttons.

Uniden R3 and R4

Uniden R3 and R4 side by side alerting to Ka band

However, it’s what’s under the hood that is most impressive.

Upgraded Radar Detection Platform

The R4 adds not one, but two LNA’s (low noise amplifiers) to help boost the sensitivity and thus range of the detector. There’s one LNA for X/K band and a second LNA specifically for Ka band.

With this improvement, the initial test results are very impressive.

Long Range Test Results

First up, here’s some testing at my standard red barn test course:

Uniden R4 red barn testing on 35.5R4 33.8 test results at the red barn courseR4 34.7 test results at the red barn courseR4 35.5 test results at the red barn courseI’ve done some additional testing on a second difficult test course with a bunch of detectors vs. 34.7 around a bend.Vortex's Around the Bend, Forest Test Course with Uniden R4 34.7 (8-1-21)

The R4 consistently turns out top tier results, besting even more expensive radar detectors.

Results will vary between tests, as always, and I’ll share more test results in my full review once they’re available, but so far the R4 with its dual LNA design is looking extremely impressive.

To put this improvement into context, here’s a side-by-side comparing both the R3 and the R4 on the same test course. What a difference…

In practice I’ve seen some impressive detections too. Here’s a quick 35.5 encounter with an officer shooting 90 degrees off-axis relative to me. Usually I get extremely short detections in this situation, but this was a surprisingly long detection, especially considering trees were blocking the signal the entire time. (Audio muted because we were all chit chatting in the car, lol.)

@hiddencam on RDF has been doing a bunch of testing as well and he’s also finding the R4 to be a strong performer. As always, results will vary from one test to another, so let’s look at even more test results so we can get a better sense of the big picture.

Here’s the test results from his first test with the R4.

hiddencam 34.7 R4 RF test results 1

hiddencam 35.5 R4 FF test results 1

So the R4 is consistently one of the top performers.

Here are the test results from his second R4 test.

hiddencam 34.7 R4 RF test results 2

Depending on conditions, sometimes the detectors will give comparable advanced warning, especially when things are terrain limited.

However, when conditions allow, the R4 is capable of giving you longer distance alerts than previous R series detectors.

hiddencam 34.7 R4 FF test results 2

Bonus: After I finished writing this review, he also published test results on K band. The R4 did excellent there too if you’d like to check it out.

So with the addition of the LNA, it is definitely looking like the R4 is the best performing Uniden detector yet.

We still need to do a lot more testing to get a full sense of the big picture, and that will come in time once people start receiving their units and doing some more testing, but so far so good!

Purchase the Uniden R4 here.

Improved False Alert Filtering

The R4 adds several new false alert filtering capabilities.

Auto Lockouts

The biggest change is that autolockouts are now available. Instead of having to double press the mute button every time you pass a speed sign or an automatic door opener, the R4 (like the R7) can automatically learn stationary false alerts after several passes and then mute them for you.Uniden R4 Auto Mute Mem On

The R3 has limited memory so it can’t get this feature. People driving in cities have also reported running out of manual lockouts on the R3 and so with the extra memory, we should have enough manual and automatic lockouts now with the R4.

That said, I’ve had some shopping center door openers get auto locked out twice and yet I still get alerted on subsequent passes. For this reason, I think that Uniden still has some work to do with their lockouts to get them to reliably stick, similar to the R7.

Auto Mode

The R4 adds a new sensitivity mode called Auto Mode that varies the detector’s sensitivity based on your speed. In the city it can dial back its sensitivity to cut back on false alerts. On the highway it can run at full sensitivity for maximum range.

Uniden R4 Auto City Sensitivity

More K Blocks

The R3 has a K Block feature for 24.199 +/- 5 MHz to help filter out BSM falses from nearby Honda and Acuras. The R4 adds a second K Block for 24.168 +/- 2 MHz to help cut out additional BSM falses.

Uniden R4 K Block 2 Weak

According to Uniden’s website, “The R4 also has the best K Band filter on the market, offering the least amount of false alerts from blind spot monitors and K Band sensors in other vehicles.” Unfortunately though, that hasn’t been my experience.

The K Blocks do help knock out many BSM falses, but I still get false from Hondas and Acuras outside the K Block ranges, I get falses from Jeeps, Buicks, Mazdas, etc.

I’ve spent the past month driving with the Escort MaxCam 360c (which has BSM filtering comparable to the Redline 360c), and that detector is much quieter in terms of BSM filtering. The R4 does address some Hondas and Acuras, some GMC’s, etc., but I do find that other detectors offer more effective K band filters.

K Band & Photo Radar Changes

The R4 adds a wider K band scanning range, particularly below 24.050, to help you detect lower end K band, especially with photo radar.

The R4 can detect the MRCD and MRCT like the R3, but the R4 adds support for the Gatso RT3 and RT4 photo radar systems as well.

Uniden R4 Gatso RT3 and RT4 On

In my early testing, I find that I get quite a few Gatso falses. (I don’t have any Gatso in my area.) Once the detector launches and people start testing it, we’ll see how well it detects.

Display Updates

We now have two different display modes to customize how alerts show up.

Uniden R4 Alert Display Modes 1 & 2

Personally I prefer Alert Display #2 for the larger display, plus it’s more similar to how the R3 looks.

Additionally the R4 adds an ambient light sensor so the display can automatically get brighter or darker, day or night. (No more needing to rely on adjusting based on time.)

RDD Immunity

Uniden advertises the R4 as being undetectable by the Spectre Elite. I’ve done some testing with multiple R3’s against the Spectre III and Spectre Elite and found that the R3 is stealth to the newer Spectre Elite and detectable by the older Spectre III. I was hoping that the new LNA’s would help improve the stealthiness of the R4, but results look comparable with the R3.

In my testing, results varied and sometimes the Spectre III wouldn’t alert at all, but most of the time I could pick up the R4 quite easily when driving by. Additionally I could also pick up the R4 when pulling up behind it, similar to an officer pulling up behind your car at a red light, despite the lack of a rear antenna in the R4.

I haven’t tested against the Spectre Elite, but against the Spectre III, the R4 I’m using continues to be detectable.

Laser Gun Detection

In terms of laser detection, no radar detector is ever a reliable layer of protection against laser. That’s what laser jammers are for. Laser sensitivity is unchanged with the R4 (aka, not super great), but what’s new is that the R4 can now tell you which gun (brand or model) you’re being shot with, a first for a radar detector.

Uniden R4 Laser Gun ID

(Whistler radar detectors can tell you the pulse rate, but the R4 translates that into a laser gun.)

Physical Design

Coming back to the physical design changes, there are some functional improvements as well.

Uniden R4 side ports

The power cable has been moved to the right side of the detector. I prefer this location when running the RD hardwired above my RVM.

Note: If you already have a power cable for your R3, you can use the existing cable for your R4. (The same mounts are compatible too.)

The headphone jack has been moved to the right side as well.

The MiniUSB port has been changed to a MicroUSB port so you will need a new USB cable for firmware updates. (You can use this cable if you don’t have one already.)

Minor Updates

There’s also little things like now you can mute signals in the middle of a voice announcement.

Uniden has also recently released new update software which makes it easier to update their detectors. It’s compatible with the R3 too, but now firmware updates are even easier.

What a difference...

Advantages of the R3 over the R4

Running both detectors, overall I greatly prefer the R4. However, the R3 does have some advantages over the newer R4.

First, the R3’s mute button sticks out, making it very easy to press. The R4’s mute button is flush with the face of the detector, plus there’s a little lip under the button that can get in the way when you try and press the button. It’s not a huge deal, but it is a minor annoyance.

Second, the R3 retails for just $299, or $150 less than the R4.

According to Uniden, the R3 is not being discontinued. They’re going to continue selling it to slot into the lower price point.

Future Improvements

Finally there are plans for future add-ons to the R4, but all of these things are planned for sometime after launch. (There is no current ETA.)

First up, you’ll notice a port on the left side of the detector. Uniden is working on their own laser jammers and once they’re released, you’ll be able to plug them in to the side of your R4 and get an integrated radar and laser package. (We’ll have to see how effective their upcoming jammers are.)

Uniden R4 side laser jammer port

Next, there will be a wired remote control that will plug into the new port on the side of the cig. lighter power cable. It’s backlit and glows at night. This cable duplicates all the functions already available on the R4 itself so I find it largely redundant, but it can be nice in case you have your R4 mounted out of reach and want a secondary controller to change settings or mute your detector.

Uniden R4 with remote keypad


Bluetooth is also built into the R4. The app is still in development and will be released after launch. No word on when it’ll be released or what features it’ll offer, but I’d expect at least the ability to change settings from your phone.

I’m not sure if there’s plans for an Open API, but I sure hope so!

Should You Upgrade?

Overall I’m very happy with the R4. It’s a top notch performer and easily one of the best non-arrow detectors on the market.

I think it’s a great upgrade over the Uniden R3. If you own an R3, should you upgrade? Here are the main reasons to do so:

  • Longer range
  • Better false alert filtering
  • Autolockouts
  • Automatic speed-based sensitivity adjustments
  • More K blocks for additional BSM filtering
  • Additional photo radar detection

To me, it’s a solid upgrade. That said, the R3 is still a great choice and I think it’s the best detector under $300. You can purchase the Uniden R3 here. That said, if you want longer range and improved false alert filtering, you can step up to the R4.

If you want one, you can pre-order the Uniden R4 now. Quantities are limited due to supply chain issues and I expect these to sell out quick.

Thank you for reading!

This website contains affiliate links and I sometimes make commissions on purchases. All opinions are my own. I don’t do paid or sponsored reviews.

Click here to read my affiliate disclosure.

Permanent link to this article: https://www.vortexradar.com/2021/11/uniden-r4-review/


Skip to comment form

    • DAVID Scott on November 3, 2021 at 3:40 pm
    • Reply

    Excellent review 👏

    • Thomas Jalbert on November 3, 2021 at 5:48 pm
    • Reply

    Is there any word on if Uniden is going to do the same treatment to the R7? …perhaps they’d call the new model the R8 to keep the naming conventions similar.

  1. I wonder the permance about MRCD. This function is extremely terriable in Alberta. R7 almost never work. I hope R4 could be better.

    • John on November 4, 2021 at 8:25 am
    • Reply

    Excellent review. I read the included graphs. I would be curious to read a similar in-depth review of the R4 vs R7.

    R7 is my first detector with directional arrows. Now I can’t live without this feature. It tells me when I pass the source so I know where it was coming from. And it lets me know if a cop is creeping up on me from behind. Saved me several times.

    • Hill on November 7, 2021 at 6:55 am
    • Reply

    Always appreciate your posts Vortex, this one no exception. I’ve been using the R3 since 2017, and it has been a Godsend. I just ordered the R4 using your link and your review sealed it for me. The potential photo radar detection and longer range made me choose the R4 over the R7 upgrade, as whether I had arrows or not, ultimately I slow down regardless, when the detector alerts. Personally, I think Uniden is seperating needed features between the R4 and R7. I guess they didn’t make an R4 with arrows cause it would cannibalize sale of existing R7’s potentially. Just sucks for the consumer as now i wanna run the R4 and 7 simoultaneously to get it all, but as Dana Carvey said-“not gonna do it.” I think a new model combing all features, into one unit sized between the R4/7, would be a home run. Thanks again Vortex!

    • John M Kurilla on November 19, 2021 at 3:04 pm
    • Reply

    Received R4 this week and found out Red Light cameras in Toledo,Ohio are not alerting. GPS and Red light camera are turned on. Preformed a factory rest.. Help.

    • Justin on December 10, 2021 at 8:40 pm
    • Reply

    I wanna see the uniden r4 vs the Radenso ds1 but who am I ? Lol

    • Tom on February 18, 2022 at 2:34 am
    • Reply

    Did the 1.59 firmware update for the R3 put it’s false alert filtering on par with the R4?

    • Tom on February 19, 2022 at 10:36 pm
    • Reply

    How is it that you say the R4 has Bluetooth when Uniden’s own website and manual does not mention Bluetooth?

    • Chris on November 15, 2023 at 12:59 pm
    • Reply

    Amazing that it beats the muck touted R7. I love it every time Uniden comes out with a new model, it makes replacing my R3 that much cheaper. I’ll prolly upgrade to the R4, mostly for the improved range. The other features are just bonuses. Auto dim would be nice.

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