Which model has the best VOX feature?

I’m looking for the model that has the best VOX
feature? I’ve heard some are not that sensitive even on the highest
setting. Which model has the best sensitivity setting?

I want a VOX that can pick up noise without having to put your
mouth right up against the mic.

That is not an easy question to answer because it is somewhat ambiguous. What type of radio are you searching for? Is it a business radio, FRS/GMRS, amateur (ham), MURS, or something else? Will you be using a VOX compatible headset to communicate or just the radio itself? Will you be using the radio(s) in a noisy environment or in an area that is quiet?

Your environment and mode of operation (handheld or headset) together are going to affect VOX communication more than the VOX circuitry alone. Yes, some radios operate with VOX better than others, but there is more to it than that.

Your success with VOX with any radio equipped with the feature is going to depend a lot on how you use it, what you use it with and where it is used.

Thanks for the reply. I’m using it for FRS/GPRS. No headset. Mainly a quiet area in a small rural town. Only obstruction might be a couple small business stores – it’s not a straight line of sight but I will only require about 1,000 to 2,000 feet of distance range. The reason for using the VOX feature is to actually place one in my car and keep the other one with me (wherever I go, or in my home). Then if my car alarm goes off, hopefully it will be able to transmit the sound to me. (If it’s not loud enough from inside the car…do you think I could use a headset/microphone and extend outside underneath my
car where the actual car alarm speaker is located and place it right next to it?).

It’s basically like a baby monitor. When the baby cries, I want to be able to hear the crying so that I can know attention is required.


For example, what do you think of the BaoFeng UV-3R model for what I need? I saw the UV-5R models too but i think those are even more useless for me if the VOX is exactly the same as the UV-3R. I don’t want to spend more money if it has other features and better features, but the same VOX feature. I’d only spend more if the VOX feature is actually better on the UV-5R than it is on UV-3R, but I’m guessing they are probably the same.

I saw that they have VOX and sensitivity levels 1 to 9, but not sure how well it works for transmitting something like a car alarm noise? Does it only recognize voice and block out other sounds or will it pick up something like a car alarm or anything loud and transmit it?

I don’t know enough about 2 way radios to make decision. I feel that since I pretty much just need the VOX/baby monitor function, everything else on the 2 way radio to me is irrelevant. I won’t be using it to do anything else other than to serve as a full-time noise monitor for me.

Could I make a better choice with another brand? Actual baby monitors are not good for me as they are too limited in range.

It seems that I have to use a 2-way radio for this even though I don’t actually need any other function…so I’m paying just so that I can use the VOX/baby monitor function. That’s why I hope to find the best possible one since that’s all my money is banking on.

All things considered, a VOX enabled two way radio may not be the most practical solution for you.

If you are in the US, the Baofeng UV-3R and UV-5R are primarily sold as ham radios and are not approved for use on FRS or GMRS. At the least, they require an amateur license to operate in the US. Also, the radio in the vehicle will need to be powered on at all times, which means you will need a constant source of power, which makes operating from batteries impractical, and not all handheld radios allow operation while plugged into or charging from a vehicle.

In addition, VOX will not be able to distinguish between an alarm sound and other extraneous or unwanted noises, such as traffic from passersby, which means that the radio would likely “key” up and transmit every sound it detects, constantly bombarding the frequency or channel with noise. Since the frequencies on amateur, FRS, GMRS, CB, and MURS are shared with other two way radio users of those services, this could become disruptive very quickly and potentially create unwanted attention from the FCC (or its equivalent agency in other countries).

Fortunately, there are much simpler and more practical solutions available. Vehicle alarm systems and cell phone apps exist that do almost exactly what you need, and they are specifically designed for that purpose. They are not uncommon and if you search the Internet you will find a lot of them. They may not necessarily be the cheapest route, but they would be much more effective for your needs, and at the end of the day, the costs may well be worth avoiding the pain and hassle of trying to hobble together a home-grown solution that may or may not even work the way you want. I hope that helps.

Thanks so much for your response. It’s very helpful the advice you gave. Sorry, if the BaoFeng isn’t a good example to use, maybe another kind of 2 way radio?

I still have a couple more questions. First, I’m currently working overseas in Korea and I was told that walkie talkies here (probably FRS?) didn’t require any license to use. I’m parked in a quiet place so I’m not worried about “other” noise that might keep the VOX transmitting all the time. Also, when you said that if the radio on VOX keeps transmitting via other constant noises, that seems to indicate that you are saying the VOX sensitivity is REALLY sensitive if it can indeed pick up and transmit a car passing by or even some people walking by talking. I was led to believe that VOX are usually not sensitive enough that nothing would get picked up unless you spoke DIRECTLY into the unit. So I’m not sure now who is right. Is VOX really that sensitive? (It’d be great if it is as sensitive as you seemed to indicate). Also, aren’t there plenty of channels or PRIVATE channels I could use so that even if I was transmitting a lot, nobody would be disturbed and constantly alerted via my VOX transmissions and cause some unwanted attention by authorities?

I contacted another business and they told me that VOX radios that transmit over FRS can only output .5 watts so that means the range might be much more limited than I thought. I’m expecting at least 1 to 2km but if VOX can only output .5W at FRS, how much range do you think that would give me with very little obstruction?

Last but not least, I was made aware about car alarms that now also work with smartphone apps where you can remotely arm and disarm, start engine, lock/unlock, and even be alerted if alarm is triggered via smartphone app no matter where you are or how far you are. This sounds really great, except for one thing, I’m not a smartphone user (yet). Plus, I already have an alarm system setup in my car.

If I were to go this route, I’m guessing it would cost me an enormous amount because I’d have to buy everything from scratch just for the sake of using it as a car alerter/notifier.

I’m assuming these would be new expenses:

  • buy a new car alarm that works with smartphone apps ($400-$600?)
  • buy a new smartphone w a data contract ($0 to $500)
  • pay monthly for my new smartphone bills + data ($50-$100?)

That’s like over 1k I’d have to invest in. Right now I only pay $15 bucks a month for my regular flip phone since I sparingly use it. I only require it for some texting and few minutes of calls per month. Does it make sense for me to have to get a smartphone + contract + data plan just so that I can use the car alarm app?

It still seems to me that going the walkie talkie route is much cheaper for me even if it’s not as good as the smartphone car alarm combo. $100 vs $1000.
That’s what I’m thinking. Correct me if I’m wrong. Plus, as I’m only here temporarily, investing in the smartphone + car alarm doesn’t seem like a great idea for me also if I’m only going to need it for another year or 2. The walkie talkie or some sort of VOX device seems much simpler to get and to get rid of when I don’t need it anymore.

Please advise once more. Might you know of any other option where I can use some sort of proximity sensor device that can notify me via pager/text/key fob alerter etc. if 2 way radios REALLY isn’t going to work for me?

I don’t know what the rules and laws are governing the use of radios in Korea, so I can’t really comment on that. However, FRS radios do not have “private” channels. You may be referring to privacy codes. They are used to eliminate unwanted conversations from other users on the same frequency or channel, but they do not make channels private.

This thread explains what Privacy Codes are and what they do and don’t do.

As for the VOX sensitivity, it varies depending on the radio, environment, whether you are using the mic in the handheld or the headset, and what sensitivity setting you use. This video may help.
Radio 101 - Using VOX on two way radios

FRS radios are limited to 500mW (1/2 watt). Many FRS radios max out below that, so the actual wattage of the radio will depend on the specific make and model. Your range will vary based on the actual wattage of the radio, but more importantly, what is around you, such as buildings, other vehicles, terrain and even weather conditions. If the radio is outdoors, your range will be affected by all of these. If it is inside the vehicle, it will limit range further due to the steel, glass and other elements of the vehicle itself. The only way to know your actual range is to test it inside the vehicle at the location.

Once again, you are attempting to use a radio in an application for which it wasn’t really designed to be used. That’s not to say that it couldn’t work, but the results may not be what you want or need.

There may be other solutions that are less expensive than the vehicle alarm and smart phone apps and are more suited to your requirements than using handheld FRS radios. I don’t know of any firsthand, but if you search the Internet you may be able to find something better that does what you need.

Thanks again for your input.
It’s really helpful.

Yeah, the only way to really know is for me to test it out. I just dont want spend $100 and then 2 minutes later find out it’s not going to do what I need it for. Then I’m not sure if I can return it or not. That would suck to be out $100 bucks with something I used once and not need anymore.

Yes, I noticed that some radios come with the ear phone and external mic. Do you think that if I use the external mic on the radio in my car and then sort of hang or dangle the external mic outside my car (little opening in my window or something) that the mic would then work better at picking up noise than if I just left it in my car with windows all rolled up? Is that how the mic works? I’m thinking the earpiece w/ mic would come in handy for that as I can just expose it to the outside rather than exposing the entire radio itself outside.

What do you think?

I think it’s messy.

Once again, I don’t know what the rules are regarding the use of FRS radios in Korea. Before you experiment, you may want to check with the agency governing their airwaves regarding the approved uses of radios on those frequencies, such as transmission of vehicle alarms and other incidental sounds. You never know who may be listening.

I was able to go to a Costco and test out the only radio they had on display for sale (a Motorola brand). Luckily it had power so I was able to play around with it for a while. I set both of them to VOX on the same channel and sensitivity levels were only 1 to 3 (3 being most sensitive).

Speaking directly into one radio did come through automatically on the other radio no problems. Then I tried putting it away from my mouth and it was a bit harder as I’d have to speak up or make noise louder for it to pick up. I even did an imitation of a siren or alarm with my voice without looking like an idiot around the people and it picked up my voice making that alarm noise!

So this leads me to believe that if I do what I’m planning on doing, it will pick up my car alarm noise and transmit it to me.

I’ve gone ahead and ordered a pair online and will test it out when it arrives. I’ll post back here to let you know how it went (pass or fail).

I’ve decided that the best way is to use the external mic/earphone set that comes with it. The wire is pretty lengthy (looks to be around 1.5 to 2m). I’ve found the little grommet in my car where I can easily slide the external mic through the hole and into my engine bay where the actual car alarm is also located so it should be plenty loud enough for it to be picked up by my radio. The length of the wire allows me to simply leave the radio on my car dash or even hang it on the side wall or ceiling if I want so I wouldn’t need to constantly put in and remove the mic from the car firewall each time…I only need to plug in the mic or plug it out when not in use.

I think it’s going to work just fine. The only issue might be the 0.5 watts and the slight building obstruction, but as I said, I don’t have many obstructions at all, and it’s only about 1,000 feet away. The box indicates that in open country range, the range is about 5km (FRS on .5 watts) and if you are in the city it would be limited to about 1 km range. Since I’m not even in the city but a small town with very little buildings in the way, I’m thinking even 1 km is plenty good enough for me as I only need about 1,000 feet range which is way less than 1 km.

My last question for now is the battery. It comes with a LiPo battery pack, but they said it’s also swappable with using 3 AAs. If I use 3 AA NiMH batteries with 2000 mah capacity each, does that mean I’d have 2,000 mah battery pack essentially? So those should last a lot longer than the LiPo battery pack it comes with which are usually only 650 to 850 mah rating.

I’m not sure if it’s as simple as that but my guess is if I buy a nice set of 2000-2500 mah rechargeable AA batteries, those would last much longer than the 700 mah lithium battery?

I have had good luck using the Axis M10 series of cameras for such remote baby monitoring applications. They work well with SecuritySpy. These cameras have available features such as two way audio, an integrated PIR sensor to detect motion even in total darkness, and a remotely controlled (white) nighttime illuminator, which works pretty well on the area directly in front of the camera.

It will work, but is a really bodgy and unreliable means of keeping track of your vehicle safety. Vox is dreadful for proper communicating, but as alarms are loud, it will work. The real problems are going to be simply keeping the batteries charged (and yes 3 cells in series give the same capacity, just a higher voltage. You could buy a charging cable for a vehicle and just wire in in permanently - when charged the current drops considerably. The real issue is simply that the range can vary so much. You could sit working and if the alarm goes off - you hear it. But move your office chair a foot the left and you’re in a dead spot. Somebody parks a truck outside and the link has gone - and you don’t know.

I’m pleased it works. I’d never use it myself. Just too unreliable for me. Security systems for me to have confidence in them need 100% reliability. Short range radio probably gives you 50% at best, probably even less.

You really did a good job!