Rane - HAL EXP7x, with Dante Pro AV Networking by Audinate

The Rane EXP7x Expander for the HAL1x provides eight channels of full-featured, drag and drop Acoustic Echo Cancellation (AEC). Each channel of AEC can be added to any HAL1x system input and route to any Halogen DSP block, including the gain-sharing automixer, manual mixer, regular Room Combine block, or Conference Room Combine block.

The Rane EXP7x Expander for the HAL1x provides eight channels of full-featured, drag and drop Acoustic Echo Cancellation (AEC). Each channel of AEC can be added to any HAL1x system input and route to any Halogen DSP block, including the gain-sharing automixer, manual mixer, regular Room Combine block, or Conference Room Combine block. Chain up to 32 EXP7x units to a HAL1x for 256 assignable AEC channels.

Because EXP7x AEC channels are not associated with a particular hardware input, preset recall can re-assign an AEC resource across inputs / rooms as required. Drag and drop AEC supports the typical one-AEC-per-microphone configuration. With optimum acoustics, mic and loudspeaker placement, or with rarely used mics (such as audience mics) it allows mixing more than one mic into a single AEC channel, significantly reducing cost.

More Details:http://www.rane.com/hal/hal1x.html#p7TP3c6_7