Seems to me that your wife is not complaining about the size of those beauties...she is complaining about having an "audio room" in "her living room".
Take her up on her word and build your space in the attic with all the attendant functions required. Be sure to consult with an acoustic company and have a builder that understands what's required. This is not just about nail guns and sheetrock.
Just my two cents.
Regards,
barts