Which external speaker for GXV3610 cam


#1

the specs of the GXV3610 cameras say:
audio output: Line-Out, 600Ω, 0.707 Vrm

what kind of speaker do you use with your camera? any links would be highly appriciated.


#2

this is a line out connection which will require a amplifier/amplified speaker


#3

yes, but what exactly?

my issue is:
I have several GXV3610HD Cameras and several GXV phones, softphone app, etc…
but there is a 1-2 second delay on the speaker output. (I call the GXV3610 with a GXV3240, and then I hear myself talk on the video with a 2 seconds delay).

I used different standard PC speakers but the issues is always there.

I asked the Grandstream Helpdesk what to do and they refered to this:
“audio output: Line-Out, 600Ω, 0.707 Vrm”

600 Ohm ???
a PC speaker has like 1-8 Ohm

so I was wondering if I am using the fundamentally wrong kind of speaker?


#4

As stated, it is a line out connection and the 600 is what one would normally expect from a microphone output. The camera itself does not have enough power to drive a speaker on its own. When I tested for you the other day, I was using a pair of amplified speakers.

“The decibel volt reference voltage is 1 VRMS = 0 dBV.[1] The decibel unloaded reference voltage, 0 dBu, is the AC voltage required to produce 1 mW of power across a 600 Ω impedance (approximately 0.7746 VRMS).[2] This awkward unit is a holdover from the early telephone standards, which used 600 Ω sources and loads, and measured dissipated power in decibel-milliwatts (dBm). Modern audio equipment does not use 600 Ω matched loads, hence dBm unloaded (dBu).”

You really need to try and do a capture to see the issues and what device is causing the latency (hopefully). The only thing I can think of is that there is transcoding taking place.


#5

I dont think I have the tools to capure or trace what and where exactly the latency happens. however:

direct IP video call from GXV3240 to GXV3240 via IP VideoTalk has almost no latency.
calling a GXV3240 via skype from my smartphone has almost no latency.
using the speaker directly with my phone does not have any latency.

thus I assume the latency happens in the camera or between camera and speaker.


#6

Check the 3240 manual as it may indeed have a capture function. Look in Maintenance/debug


#7

so I bought a GXV3611IR (with internal Mic and speaker) on Amazon to do more hands on testing. The result was:

the GXV3610HD can not do Motion Detection and Video Capture to FTP while also doing a live call to a GXV3240 phone.

after several tests I noticed call from the camera to the phone is ok and in real time, almost no latency if motion detection is disabled.
if motion detection is enabled you will have some latency and sometimes audio drops off for a second completely .
if you have motion detection and email sending picture to FTP storage this all is even worse.
and if you have motion detection email sending and picture to FTP storage and video to FTP storage it becomes unbearable. latency will build up during the call and sometimes you have several second drop off of audio and mic on the camera. in a one minute call the latency will be like 5 seconds at the end.

the first couple of seconds the connection will be fine and also in real-time. then the camera will have drops in audio and the latency starts. I usually record 20 second captures (5s pre-motion)