Start a new topic


Welcome to the PTZOptics forum(s)!

This thread has been created for end users to discuss the topic of the line level audio input when getting started with the PTZOptics cameras.

Please make sure to respect the experience level(s) of all users at all times when posting within our forums or your account may have access removed.

1 person has this question

Hi Ron,

Not a lot of Mics output Line level so we don't have too many to recommend. The ones that do output line level are usually looking for phantom power which the cameras do not provide. Using a mixer is generally the best way to handle something like this. 

Need a recommendation...  I plan to purchase a 30x camera, and will use the camera at the back of a room. I need a microphone at the camera to pick up audio, and will sync audio recorded at the audio board for editing.  

I have looked into small audio mixers to use with a dynamic mic to deliver the line-level signal needed at the camera (I do have 120VAC available for power.) But would love to find a mic/system that delivers the line-level signal needed without the mixer.
Any recommendations on how to accomplish this?  

BTW, I think it would be a great idea to provide a mic on the camera... or provide a mic level input on your cameras. 

Hi Joseph,

You would want to try lowering the value if the signal is too high in OBS.

The range should be something like -97 to 30, so you could try dropping to -10 and go from there. 

Thank you, Colin. The current Input Vol setting is 0 dB. Should the settings be higher or lower to reduce the level coming into OBS? I want to avoid making the adjustment in OBS because I’m not the only operator and I want to discourage making changes within OBS.

Hello Joseph,

Yes, you can adjust the L/R Vol from within the camera's Web Interface under the Audio section. Those changes will affect the audio signal that is being fed into OBS via NDI.

Just be sure to click Apply at the bottom of the Audio Page and then Reboot the camera from the System page for the changes to take effect. 

It may also help to try lowering the output signal coming from the mixer. 

I have audio input to the camera from an Alesis mixer using the 3.5 mm line level input on the camera. The mixer output is +4dBu (1.24 volts). I receive the audio from the camera in OBS via an NDI source. The meter levels in OBS are higher than I see on the mixer meters. OBS clips the sound well before the mixer levels reach their peak. Will changing the Audio Settings for the PTZOPTICS camera (input Vol L/R) allow me to match the meter levels between the mixer and the camera? I know I can change the OBS settings in the audio mixer, but it would be better to match these outside OBS, if possible?

Hi Eric,

That is certainly an odd one.

I could garner guesses but they would be guesses at best :-)

Very glad to hear everything is now working as expected.

If you have any questions in the future don't hesitate to come back.

Hello Matthew,

I apologize for the long response. I did fix the problem. We have our camera mounted under a balcony. The nearest power source is about 7 feet away. The camera's power supply is connected to a 6 strip with a power switch. I read in one of your posts that the camera should be turned off and on again. I was doing this at the power switch of the 6 strip. For some reason that wasn't power cycling the camera so it would reset, but when I used the power switch at the base of the camera it restored audio to the HDMI connector-I had to get a tall ladder to do it but it worked!!

Thanks for all your helpful suggestions


Hi Eric,

It is absolutely my pleasure to try and assist.

If you're getting audio in the network stream that certainly eliminates any WebUI settings as the cause.

And if the OSD Setting for DVIMode is set to HDMI everything should be flowing nicely.

I'm keeping my fingers crossed over here that a simple firmware update will resolve this.

If unresolved by a firmware update definitely get in contact with our support team to take the testing further and possibly RMA the camera.


Thank you so much for replying. I appreciate your helpful suggestions and all the great links.

I'll update the firmware and see if that's the problem. 

I'm getting audio out of the RJ45 jack. I can stream on youtube with audio from that connection just fine, which is why I'm scratching my head as to why the HDMI doesn't have audio. 

If I'm able to fix the problem I'll report back and post my solution, hopefully it will help others. 

thanks again


Hi Eric,

I believe this should be working with your current firmware revision.

That being said there is an updated version of the firmware for your model available.

You can find the latest firmware by visiting the PTZOptics Firmware Finder and supplying your serial number to obtain the proper firmware.

Once you have successfully loaded the latest firmware try the steps again to enable HDMI audio output via the OSD.

Of note the 3.5mm audio input on the camera will only accept a line level signal that does not require any power from the camera to operate.

This can be a cell phone, laptop or PC or a powered mic to name a few examples.

There is one other thing I would check in the cameras WebUI and in the "Audio" section

I would make sure that the "audio switch:" is set for "On"

The other default values would be as follows: Audio Type: AAC, Sample Rate: 48K, Bit Rate: 96k, Input Type: Line In, Input Vol L: 8, Input Vol R: 8, ADTS Options: Off

Once set click the "Apply" button and reboot the camera.

I hope that the update or additional settings to check solves your issue but if it does not please make sure to reach out to the PTZOptics support team by submitting a ticket here:

One of our team members will be happy to assist you in further diagnosing the problem if needed.

If anything above does solve your issue we'd love to hear about it.


My camera doesn't seem to be putting audio on the HDMI output. I have done everything that you mentioned in your post above. Any other ideas? I have the PT20X SDI GY G2 model. 

Is there a new firmware version? Mine is SOC v6 2.40-ARM v6 3.08THI

any help would be appreciated


The PTZOptics camera line features an audio input on the back panels for most models.

The connection is a 3.5mm stereo unbalanced line level input that will not supply any power.

The camera does not feature any amplifier or pre-amplifier capabilities.

The levels of the audio input are set in the audio section of the IP interface

Once properly connected you will find the audio feed available via the following channels

  • IP (RTP / RTSP / RTMP) *AAC Only
  • NDI
  • USB 3.0 B (USB Models only)
  • HDMI

Note if you are unable to get audio to travel via your HDMI output please check the cameras OSD, On Screen Display, using the remote or web interface and navigate to the "Setup" section and make sure that the "DVIMode" is set for "HDMI." note this may require a reboot of the camera to fully commit.

1 person likes this
Login to post a comment