Low Quality VOIP

[Rafal Fila 1368578]

Hello everyone, I use Vpilot to connect to Vatsim and have the VHF simulation turned off however the quality of VOIP I receive is really low. Some ATC will also receive me 3 by 3. I know that the audio others receive is a lot better after listening to what my friends hear and others on youtube.

 

As trouble shooting I have calibrated my microphone and increased the network priority of Vpilot and FSX. I know it cant be my audio equipment as I use studio Audio Technica headphones as well as large diaphragm condenser microphone with an amp. I have been looking for the answer to my problem on the forum and youtube for a week and didn't find anything concrete. If anyone can direct me to any links or have any ideas why thats the case, It will be greatly appreciated as using text is no fun

[Jonathan Fong]

Unfortunately, one of the flaws with VATSIM is that the voice codec, frankly, sucks. It's a relic from the days when VATSIM was first formed, and the staff don't seem too keen on changing it, mainly because that would break compatibility with a few of the 'legacy VATSIM clients' that are no longer being updated. Until we get new clients for all current platforms (XP10, FSX and P3D) that are under active development (i.e. are being regularly updated), we won't get a new voice codec. For now, you'll just have to learn how to decipher what's coming through your speakers - VHF simulation can help a bit, and you'll get used to it after a while. Good luck!

[Ernesto Alvarez 818262]

and the staff don't seem too keen on changing it

 

just highlighting this little part, but not exactly true. IMO they have simply chosen the lesser of two evils, until they can work out the issue with the clients. while you only mentioned 3 sims, Xplane, FSX and P3D (which none of the clients are native to, they work because P3D happens to use simconnect), dont forget FS9 is still used on the network as well by plenty of users.

 

the discussion has been going on for years and plenty of users have made promises over the years, dont see any of those around still for one reason or another.

 

until the older clients, being Squawkbox and FSINN, are fully retired when another client comes out that adds support for FS9 along with the others, i dont see the network being able to move forward with the voice issue. unless someone figures out a way for dual VOIP support where the newer clients get routed to the new codec and older clients routed to the old one

[Shrikar Galgali]

I feel controllers and pilots who use USB Microphones have voice just fine and very much like real world RT. I have had "Good Quality Sound" Experiences in Tokyo , Dubai , Qatar , UK , USA and so many other places. Its all about using a decent quality USB Microphone along with keeping sufficient distance between Mouth and Mic. Avoid the AUX

[Simon Kelsey]

I know it cant be my audio equipment as I use studio Audio Technica headphones as well as large diaphragm condenser microphone with an amp.

 

Well, actually, this probably is the problem.

 

I also have a high-quality studio condenser (I do voiceovers), but when I tried using it online once I was unintelligible (on the VATSIM voice codec -- it works fine with other VOIP applications).

 

My guess is that the voice codec is terrible with background noise and the more open pattern of a condenser (which by definition is going to be rather further away from you and pick up more of the room than a headset) doesn't play well.

 

You will get the best results from a decent headset, ideally with a noise-cancelling microphone -- just make sure the levels in to the Windows recording mixer are good and the mic properly positioned (but I'm guessing you know this already ).

 

I'll also reproduce a post I made on the same subject on the VATSIM-UK forums recently, for the benefit of those reading this:

 

The codec, basically, doesn't handle background noise or poor audio very well at all, and when you have people using ultra-cheap desktop mics (or even built-in mics on laptops) or cheap headsets, often with sub-optimal settings for the level of audio going in or out, in noisy rooms etc -- it all gets turned to mush, especially when you throw in a bit of packet loss from a dodgy internet connection somewhere. If you have a decent headset with the microphone correctly positioned, a reasonable internet connection and enough spare oomph in your PC (I suspect a lot of audio breakups are nothing to do with the internet connection and everything to do with pilot clients running on PCs already overtaxed with running FS and probably not giving enough CPU cycles to decoding the incoming audio) you can get very reasonable results, as is the case with most VoIP applications -- unfortunately in the real world there is a huge amount of variability between the equipment each individual uses.

 

The problem is that changing the codec would break existing pilot and controller clients as they would need to be updated to include the new codec. Given that Squawkbox and FSINN, in particular, are no longer supported by their developers, you'd have a lot of people who suddenly found that they couldn't use voice (and FS9 users would be left high and dry as SB and FSINN is all that works with that sim -- I don't know about XSquawkbox but I imagine X-Plane users might be in the same boat). So its not quite as simple as just updating the codec -- all the developers of the different ATC and pilot clients currently in use on the network would have to make changes to their software to support it, and for those pieces of software that are no longer supported by their developer a workaround would have to be found (I imagine a standalone voice client could be developed as an interim measure as was done in the past with AVC, but someone still has to write it/test it/support it etc).

 

Long story short -- it will happen sooner or later, and the general feeling (amongst the BoG as well) seems to be that it should be sooner rather than later, but it's not something that can be achieved without some careful thought and planning to avoid breaking the network for large swathes of users.

 

There are some simple things which people can and should do to maximise their voice quality:

 

- Use a headset, not a desktop mic and make sure it is positioned correctly -- ideally about 1cm to the side of and 1cm below the lips, never touching

 

- Ensure that your Windows recording levels are set appropriately

 

- Reduce the load on your PC as much as possible -- ideally, avoid running any un-needed apps and programmes which will suck CPU cycles from the audio codec and consider upping your pilot/ATC client's priority in terms of CPU time if you are having lots of problems with broken transmissions (also be aware that if you or someone else on your network is sucking bandwidth -- i.e. watching Netflix or downloading/uploading a m[Mod - Happy Thoughts]ive file, for instance, this will knock on to your voice transmission and reception quality). Pilots may wish to consider running their client on a networked machine if possible (provided it has a reasonable amount of grunt) which will both ease the load on your FS machine and hopefully give you a few more FPS as well as possibly reducing the number of broken transmissions by ensuring that the voice client isn't competing with resource-hungry applications like FS for CPU time.

 

- Follow the advice given in CAP413 regarding transmission technique -- make sure the PTT is fully depressed before starting to speak to avoid clipping the start of transmissions, speak SLOWLY (100 words per minute is what CAP413 recommends -- for comparison, the normal rate of conversational speech is about 180wpm, and BBC World Service newsreaders aim for 120wpm, which is noticeably slower than usual: in other words, consciously slow down) and CLEARLY -- no mumbling! Finally, make sure that you have stopped speaking BEFORE you release the PTT to avoid clipping the end of transmissions. A brief pause (hesitation is perhaps a better description) before numbers can also make them easier to understand, and especially slow down if you are aware that the person on the other end is writing down what you are saying! (pilots (and controllers) on Oceanic, take note!).

 

Many people on the network speak far too quickly and/or mumble their words, which coupled with the distortion from the codec makes them quite unreadable. Speak up and enunciate clearly!

[Rafal Fila 1368578]

Thanks everyone for the help! As an experiment I will borrow a shotgun microphone and audio mixer from work and see if I can clean up the sounds coming in and out.

[Johnny Coughlan]

I've a sneaky suspicion this is also causing a rise in new 'txt only' pilots.

 

Yes I know it could be just because they're new and are not comfortable using voice and yes I know maybe because some have a physical disability before people jump on that bandwagon.

 

I'm only throwing the theory out there because I did get feedback from pilots who said they were embarr[Mod - Happy Thoughts]ed in having to keep saying “say again" due to poor audio quality in fear of ATC getting pissy with them.

 

I've had one ATC trainee say recently he is only using voice now because he wants to be an ATC, he found the audio too hard to deal with as a pilot.

[Simon Kelsey]

Thanks everyone for the help! As an experiment I will borrow a shotgun microphone and audio mixer from work and see if I can clean up the sounds coming in and out.

 

I'd try a high-p[Mod - Happy Thoughts] filter as well if you can -- my other suspicion is that b[Mod - Happy Thoughts] response can be a bit of a problem with the codec, and if you concentrate on the main speech frequencies (i.e. about 300Hz - 3kHz) you may get better results (at work when we have dodgy phone lines to deal with we often cut everything below about 300Hz, everything above about 5kHz and put a bit of a peak in at around 2.5kHz, which can help with intelligibility).

[Rafal Fila 1368578]

I've a sneaky suspicion this is also causing a rise in new 'txt only' pilots

 

I have not been on Vatsim long enough to place my opinion however when I was doing a flight today, 3 out of 7 pilots in the airspace were typing. As you said, they could be new or just a coincidence, just my observation.

 

I'd try a high-p[Mod - Happy Thoughts] filter as well if you can -- my other suspicion is that b[Mod - Happy Thoughts] response can be a bit of a problem with the codec, and if you concentrate on the main speech frequencies (i.e. about 300Hz - 3kHz) you may get better results (at work when we have dodgy phone lines to deal with we often cut everything below about 300Hz, everything above about 5kHz and put a bit of a peak in at around 2.5kHz, which can help with intelligibility).

 

Thanks for the heads up, I will fiddle around and try to contact a friend which is doing a sound engineering degree. Ill keep you guys posted if I work something out.

[Rafal Fila 1368578]

Update: Me and my friend managed to improve the general sound however the mids got distorted which made the ATC somewhat understandable. Basically what he said is that the netcode loses lots of the quality to save packets and sometimes if you have a specific voice, there might be more distortion however he has no way to confirm that. The long story short is if you have extra $600-$800 laying around and you want to hear the ATC better than get a mixer and hire someone to adjust it for you, you will get about 20% improvement.

[Matthew Kosmoski 891361]

Some ATC will also receive me 3 by 3.

 

This bugs me more than it should, but the scales folks try to emulate are objective and require some equipment to measure. To come along and try to say that kind of thing is absolutely meaningless since you don't have an s-meter, nor could you for voip. There's no signal strength to be had! Only the clarity portion could you attempt to simulate. And even then, readability 3 isn't something to complain too much about. Plenty of real world pilots and radios will qualify for such a readability when flying low.

 

https://en.wikipedia.org/wiki/Five_by_five

 

https://en.wikipedia.org/wiki/RST_code

 

https://en.wikipedia.org/wiki/S_meter