Full detailed sound at 30 - 40 - 50 dB

I have Ascend Acoustics Sierra 2 speakers, and they sound great at lower volumes. I'm powering them with a Rega Elex-R, and live in a condo, so rarely listen at loud levels. I've had about eight pairs of good quality speakers over the years and these sound the best of any of them at lower volumes. Good luck.

@gdhal

Thank you for your ringing endorsement of Grateful Dead Music to produce a more peaceful and well-balanced child. I don’t have children, but I would recommend Dead for folks with a new puppy. My one-year-old is a jammin’ Deadhead dog, who asked me to buy him a tie-dye bandana for his birthday...(He is also a Jazz fan...) Like father, like son.

@cheapbob

You're welcome.

Cat on a tin roof, dogs in a pile
Nothing left to do but smile, smile, smile 

I recently built a pair of back-loaded horn speakers using full-range single drivers and had a similar challenge as the OP since they are in a system in an upstairs room that I’m gradually converting into a small listening room. So low volume listening levels are important. What I discovered after experimentation using my own (SS) gear and borrowing gears from my friends was that a low powered tube amplifier with a very low damping factor - high output impedance, and using basic speaker cables, produced the best sound quality at low volume. The trade off however is the lower bass gets a little boomy at higher volumes. Ironically, the amplifier that gave the best result was a very moderately priced Chinese unit with only 8.5 wpc. Next best was a Decware integrated. So like everything else in life there’s always a trade off.

“Full detailed sound” can easily be heard at ambient noise + about 20 db. In general ambient noise will be anywhere between 35-50 db, depending on the time of the day and other running equipment in the room like Air Conditioners, Computers or others using cooling fans. Ambient noise of 30 db or lower will only exist in studios or specially treated rooms. Even people may believe that their rooms are as quiet as 30 db or lower usually they don’t have the equipment to support their assumption. To measure such low sound pressure levels your sound level meter should be able to measure as low as 25 db. Now, for all those owning a calibrated sound level meter, not the one on your mobile phone, please check the lowest end of the scale, mostly it’s only able of measuring as low as 30-35 db.

As for waking up the baby, it may happen a few times at first, but after some time the baby will adapt to the sound of music. I remember when my wife was pregnant, I used to play music at ambient + 40 – 50 db levels almost daily, so after the birth of my son we thought it to be better to lower the levels to ambient + 20 – 30 db or so. Now, all babies sometimes have their “crying hour”, including my son, but after some time we found that when we played our favorite music, ambient + 30 – 40 db, he became quiet, relaxed and would fall asleep real quickly. It almost worked as if the music to his ears was as familiar as his mothers’ voice. It came to the point that before sleeping we played Joan Armatrading (popular music 37 years ago when my son was born), he would sleep real quickly. Not surprisingly…. he is now into high end audio…

So, go ahead, enjoy the music, even with the whole family is in the house or in the room. Just remember that the ears of a baby are still much more sensitive than ours, so keep the sound pressure levels between 60 to 70 db at most….. Happy listening.