I think it is pretty unlikely. If you have a very large room AND listen at very high volumes, you might be able to detect a difference.

I added an XPA-3 to my Onkyo 805 / M60 combination. I have a large room but rarely listen at high volumes. I *like* having the amp, but I cannot tell any qualitative difference.

If you don't have a highly capable sub, I'd certainly spend the money there first.

Nice looking receiver. How do you like it?

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