@minorl And, what level of smoothing are you using? How many speaker systems actually produce sonically accurate bass down to 18 Hz at the listening position? I'll give you a hint. It has a diameter of three mm. There is no such thing as a system that could not benefit from subwoofers if you want a realistic presentation at volumes that will not damage your hearing.
I am a fanatic when it comes to measuring systems. I have been doing it since 1995. However, it helps a bunch if there is something you can do with the measurements, like use them to guide your use of equalization and adjustment of group delays, set up of subwoofers, etc. All this can be done digitally at very high resolution. These tools are so powerful I can make a middling system sound like one 10 times as expensive. There is no other way to integrate subwoofers correctly. Every other method is wishful thinking. Can you take the edge off a bad room? No, not completely as the reflections disturb the imaging. You have to manage the room with the appropriate methods or use speakers with tightly controlled dispersion. Measure away and get yourself a full function digital preamp.
@erik_squires Give me a break. Treating a room makes speakers sound smaller not bigger. Subwoofers can make a system sound bigger if a two way crossover is used, much bigger.