Issues connecting via proximity to an SX10

[frank.vassios1]

I have a Dell 7400 2 in 1 laptop.  I have Cisco Proximity 4.0 installed and it works just fine in one office with an SX10 and another office with a Mini setup  When I go into a third office with another SX10 it will not find the system to connect.  The weird part is the SX10 unit in that office where I cannot connect works fine for others who come into the room.  We have compared all settings on the SX10 with the ones in Office 1 where it works from this same laptop.  We even installed another SX10 from storage and it exhibits the same behavior.  It works for all systems connecting via proximity except the Dell 7400.  Yet that same 7400 works in other rooms.  We are open to any thoughts or suggestions as to how to resolve this.  We even went as far as to turn off all peripherals in the room and bluetooth on the 7400.  No luck, yet someone sitting in the room tries on anotehr system and it connects immediately.  

[mneergaa]

That's a very interesting case. Any hypothesis we can make would be guesswork, essentially. The things to check would be a combination of

1. Codec hardware differences; Are both SX10 units SX10N units? The SX10N has a built-in ultrasound speaker. See https://community.cisco.com/legacyfs/online/media/sx10_vs_sx10_n.jpg
2. Settings/drives on the specific unit. There may be some noise cancellation that interacts with the acoustics of the room. Checking for updated audio drivers and trying different microphone settings might make a difference.
3. Acoustic interference in the room. Other ultrasound sources, e.g. ultrasonic buzz from a nearby TV, might cause the codec to reduce output. If changing the acoustics / noise profile of the room isn't possible, I think you can override the output volume from the codec web interface. Search for "Ultrasound" under the config screen.