I understand the challenge of finding quad rooms,having recently returned from 2 weeks in Spain with my family of 4 (including 2 teenagers). We had 8 great days in Madrid staying at Hotel Suite Prado, 2 blocks toward the Prado from Plaza Santa Ana. We were in room 301 which actually consisted of 5 rooms!(large bath w/ 2 sinks, dressing room, large bedroom w/ king bed or 2 twins, living room with pullout sofa bed,another room w/ a rollaway, plus a kitchenette with sink and fridge and cooktop. The airconditioning was super as was the soundproofing. There is an elevator and the staff is very helpful! The webaddress is www.suiteprado.com. For us it was an ideal solution though perhaps a bit pricey--not knowing your budget--it was 174 euros a night--but worth it to us for location,etc.