Is it possible to use Hibernate Envers another database for audit tables?
You can use another schema / directory. See the configuration properties org.hibernate.envers.default_schema and org.hibernate.envers.default_catalog [1], as well as the schema / catalog assigned to @AuditTable .
org.hibernate.envers.default_schema
org.hibernate.envers.default_catalog
schema
catalog
@AuditTable
[1] http://docs.jboss.org/hibernate/core/4.0/devguide/en-US/html/ch15.html