Shielded speakers are a dime a dozen but you don't have to put them near the monitor anyway.
I agree. If you need to put them next to your monitor, shielded is the only way to go.
But if you are looking for high power capabilities, shielded speakers will be much more expensive than stock automotive ones.
Interesting experience:
After first getting my cab together and in place, I noticed some wierd colors in one corner of the screen. Thinking the cheap set of PC speakers I put in the machine was the culprit, I pulled them back out. No change.
On the floor, 5-feet away from the monitor, was one of my vintage Pioneer S-910 speakers. I moved it 6 more inches away from the machine, and the weird colors were gone.
Moral: Never underestimate the effect that a set of speakers might have on your screen. Be sure to test the intended speakers in their intended locations before cutting the holes.

RandyT
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Grammar