In a previous post I mentioned that you can't solve a problem created by a room with DSP. That does not mean that a DSP is not desirable or needed. For those using digital consoles it is tempting to think you don't need a DSP for a small system because you can do everything you need in the console. While technically true, it is not best practice.
A DSP will allow you to create layered EQ settings (Loudspeaker correction, Boundary compensation, and Room curve) and lock them behind a password so that your console eq can be used for making on the fly adjustments without having to worry about ruining the system eq. One hazard of using the console as a system processor is when main eq settings get changed with scene changes. This can create numerous problems up to and including feedback. What if your console breaks down and your immediate fix is to substitute a different one and you can't import your house curve. Below is a the iPad User Control Interface and system schematic page for a QSC system. There are presets for mutes and eq changes when opening and closing air walls as well as facilities to test each driver in the system while walking around so you can hear if there are any problems.
All of this processing power is contained in a single rack space or smaller chassis depending on your needs. This system is running on a QSC Core110f
Sometimes a loudspeaker processor is all that is needed but these have a fixed architecture, while often costing as much or more than a DSP. This is a DBX Zone Pro 640m. It has AGC (most don't) which you really need for a lobby feed. It and others can be a good low cost option for a small system that is not expected to change over time.
Here we see the ZonePro GUI. This is very limiting compared to our modern DSP, but costs much less and is the perfect fit for many applications.
Increased flexibility with signal routing, FIR filtering, AGC, and others are features a modern DSP can offer that are hard to find on traditional loudspeaker processors. The right choice for you will depend on many factors such as: existing system components, audio network connectivity protocol, whether the system is portable or fixed, etc.
Contact me to discuss various DSP options and price points for your application.