No you don't.
These headsets are primary for Chating during multi Player, thats why they are headset and not headphones.
If you want Game audio to multi players you never needed these.
You buy Headphones and connect to the headphone socket of the TV.
You use a Headphone splitter cables to link more than one 3.5mm headphones to the TV audio out..
Due to Wireless nosie interference you will not find many multi user wireless headphones set ups as they cost alot to broadcast on seperate channels to multi units...
The Pulse Elite Edition headsets are digital, and process 7.1 surround sound. So, there won't be any interference issues if you are using this model. If two of them won't work via a wireless connection, just plug the additional headsets into your receiver.. The reciever should automatically downmix the surround audio for you - so you'll get perfectly usable sound.
Also, I'm pretty sure SCE does read this forum. They may or may not respond to every single post, but they did create and continue to maintain this forum. It's not like it's a black art, lol, so I wouldn't waste my time suggesting otherwise.
The headsets don't do 7.1 sound there are only 2 speakers. They use a distortion filter to fake 7.1 like HDTVs do with there 2.1 set ups.
Even basic Wifi G is known to Stop these headsets from working correctly. So they are effected by normal every day 2.4GHz signals never mind adding a duplicate product. In the same room...
No. You can only use one PS3 wireless stereo headset at a time on a single PS3. It has nothing to do with the headsets themselves. You could use more than one with a PC if you had the right software. The PS3 has multiple USB ports for the adapters, but the PS3 only allows one device to be specified as the chat audio device; and only allows one headset USB adapter to be used as the audio output device in the Sound Settings. It is a System software limitation. Not a hardware limitation.