Hello Ferry,
ASIO drivers are designed to be low-level, specifically so that they can get the highest performance and lowest latency. However, the trade-off is that most only allow a single application (e.g. Hauptwerk or Windows) to stream audio to them at a time, and even those that are 'multi-client' usually require all applications using them to do so at the same sample rate (since high-quality sample rate conversions add some latency and CPU overheads).