I assume it is the Apogee DAX in your system photos. Seeing as from what I have read the crossover is at about 330 hz, I'd say there is a good chance of it being improved upon. That is if your technician knows how to do it properly. All op amps are not created equal. I do not know what it has in there. As for other things, power supplies have always been one of the most important parts of audio equipment. Anything that can be done there will be beneficial. Further more, as usual, any capacitors that have signal through them might ought to be looked at.
You may be better off buying a new one that is better all around... Bryston maybe.
You may be better off buying a new one that is better all around... Bryston maybe.