The FBQ1502 is a true stereo (2channel) unit. The FBQ800 is also stereo, but it has linked control over the left and right channels. Also, the FBQ1502 features 15 controllable frequency bands, while the FBQ800 has 9 bands. This means the FBQ1502 will have more fine tuned control over the sound. In addition, the FBQ1502 has balanced inputs and outputs, while the FBQ800 has unbalanced RCA connectors only. The FBQ1502 can be used balanced or unbalanced.