A quick google search reveals a couple of links. The first one, from Go Madrid, has this to say about the Hotel Conde Duque:
The Hotel Conde Duque is really a quiet oasis in the bustling city of
Madrid. The hotel is located in the peaceful and landscaped square of
Plaza Conde Valle de Suchil close to the city centre, so instantly has
a more relaxed and inviting atmosphere than many of the other
available vacation spots in the city. It is ideally situated near the
metro so traveling to Madrid's "must see" attractions poses no problem
at all and can easily be done. The rooms here are very clean, with
well-appointed bathrooms, many of which have luxurious marble baths.
Breakfast is served promptly and is substantial, typical of a four
star venue. The setting of the hotel is quaint, overlooking a local
playground and park, which is filled every afternoon with children and
their families, giving the Conde Duque a real traditional, family
Which may fit your needs. of course, you'd still need to check online reviews for this site, but it's a start - if a hotel is specifically listed on a separate list of allegedly quiet hotels.