I did something sort of similar. I took the rear wall out and made a new rear wall to mount 6.5" speakers and an amp to it. The amp then has a press-fit wood and carpet cover that frames it. The press-fit cover used to surround my old amp perfectly (4-way Monitor 1, now long out of production). One of the channels died in it so I had to replace it with a new Zapco that has a bit different dimensions. Eventually I'll make a new cover so it fits better.
Anyway, this way I didn't lose any shelf space but I have a stereo that hits hard.
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