Came across this today
Maybe good for talking or T-21 sound
Its only 1 1/2 "x 1 1/2"
http://www.aliexpress.com/product-fm/451680358-Mini-Digital-Amplifier-Board-10W-10W-Class-D-Digital-Amplifier-DC-12V-090151-wholesalers.html?biz_type=null&url_type=wto_buyer360_pic&biz_type=sitePromo_wto_buyer360_alert&crm_mtn_tracelog_plan_id=528048625&crm_mtn_tracelog_task_id=9087662&crm_mtn_tracelog_log_id=1440400899