MiniDSP vs DCX - most DIYers looking for a good low cost active option will be choosing between these units. Which is the better choice?
In general I would tend to recommend MiniDSP as the first low cost option to try.
It performed slightly better in listening tests than DCX and it's filtering options would tend to give it a further advantage. The digital converters can be easily bypassed where external DACs are used, along with digital input. While DCX supports digital input, it is setup for AES which won't suit consumer equipment. While it can accept SPDIF, the level needs attenuating which negates the advantages of having a digital input.
DCX can be improved with supported modifications, but the cost is considerably more than the unit itself.