Today I've got something that every audiophile, no matter what side of the subjective/objective scale they hang their philosophical hats on, can enjoy. If you want to noticeably improve the performance of your system all you have to do is make your room less noisy.
Don't believe me? For the readers who, as a matter of course, doubt anything I write, try this. Measure the ambient noise level in your room. Most rooms will be between 39 and 42 dB when measured with a smartphone sound pressure reading app. Lately I've been using "Decibel 10th" for IOS.
In my office, with the window open, I get an average reading of 43 dB. With the window closed I get 3 dB less noise with a 40 dB average reading, and with the blinds pulled down I get 37/38 dB average ambient room noise level from my listening position. My main listening room in the new house is even quieter -- there the average background SPL level is only 35/36 dB.
We all know the power verses SPL equation -- for every 3 dB of added headroom and added high volume capabilities you need to double your amplifier's power rating. Conversely, if you lower the ambient noise level in your room by 3 dB you can listen (with the same signal-to-noise) at a 3 dB lower level. Put another way -- if your room is 3dB quieter you can play music with 3 dB more signal to gain without using any more power.
What are the easy ways to lower your room's ambient noise level? Closing windows and doors, as I demonstrated earlier, are the obvious ones. Curtains, a thicker rug, an added overstuffed chair, and some attention to the seals around doors and windows can lower your noise floor another 3 dB, just like I did in my office using pleated blinds.
A more ambitious ambient noise reduction scheme can involve adding soundproofing to the spaces in your walls and replacing any single-pane windows with double- or even triple-pane glass. These projects can make a substantial difference in a room's ambient noise level.
As with all tweaks, the first thing is to determine if your system needs said tweak -- how quiet is your listening room? Measure it. If you get anything over 42 dB it's high time you tried to quiet your room some.