Cell phone high definition call sound decidedly low def

[uptime1]

While quality testing a new deployment, we noticed that 3CX user's voice sounds horrible (very thin, tin can like) when making or receiving high definition calls to a Samsung A52 cell phone. Other Samsung phones don't have the audio quality problem with the older phones sounding the best, perhaps because they're not trying to get all fancy with HD calls.

3CX 18, Flowroute, Grandstream GXP2160, RPi SBC (though no difference LAN VPN vs SBC - we tested to verify)
Quality of 3CX user's voice is really bad as heard by cell phone user.
All devices codec is u.Law on 3CX, SIP trunk and phone.

Anyone else experiencing this?

 

[VasilisV_3CX]

Hi @Uptime,

Does this issue happen when making internal calls as well (mobile client extension to extension)?

 

[Lee Cramman]

I have seen a few complaints online about the general quality of the A52 earpiece speaker, these would probably be more obvious the higher the quality of the call.

I would suggest seeing if you can replicate the problem with the A52 connected to bluetooth.

Either way, it's likely to be a problem with the handsets (hardware or software).

However, it's a pretty common phone so others may be able to weigh in with personal experience.

 

[uptime1]

Lee, thanks for your reply! Bluetooth is a good idea! I'll try it.

 

[VasilisV_3CX]

Keep us posted @uptime1!