Integtate Audio Only Application to Website

We have an operating website that needs the immediate addition of an integrated audio only client / server group chat application. The solution needs to: Provide a service whereby members can audio chat, no texting and no video, in groups of no more than 10 using their choice of platform, although we expect the majority to use mobile platforms we do not wish to exclude laptop, note book or desk top platforms running Windows, Mac/Apple, Linux or Android. The solution must be low latency, directional positioning would be nice but not a must have option. We need admin control of all groups, the ability to record all audio conversations as well as giving members the option of creating their own chat groups. Logging into the chat facility needs to be facilitated via an applet on the main web home page as well as being a downloadable applet targeted mainly at mobile users. Finally, this installation cannot be based on public servers, that's a non-negotiable point.