How loud is loud?

When you start to think its too loud, It only means you're too old. :D

**The cleaner your system is, the less loud it will seem.**

This is because the human ear/brain system uses higher ordered harmonics as cues to determine sound pressure. In this regard the human ear is actually more sensitive to such harmonics than fine test equipment: we can hear harmonic distortion that we have troubles measuring.

If your system sounds loud at 90-95 db at the listening chair then it is an indication that there is excess harmonic content that is not part of the original signal (unless the signal itself has added distortion too). This can come from the electronics, resonances in the playback system or hard surfaces in the room itself.

If you are running an SET and it seems loud at less than these levels its an indication that your speaker is not efficient enough to take advantage of the SET's ability to have low distortion. Instead, it is being driven hard enough that the higher ordered harmonics are showing up on peaks/transients- this causes the amp to sound like its playing louder than it really is and contributes to the sense that it is playing loud.

It is these harmonics (particularly the odd orders, 5th, 7th and 9th) that are why transistor amps tend to sound brighter and harsher than tubes as well, despite these harmonics often being at seemingly vanishingly low levels. But our ears use these harmonics to calculate sound pressure, so even the slightest change in this area can be heard.

An additional complicating issue is that our ears are tuned to birdsong frequencies (Fletcher-Munson). Musicians like to make sounds where the harmonics fall into this very sensitive range as well. Its no easy task that sound systems have to play everything right without contributing in a negative way at these frequencies!

I noticed that in spite of Fletcher-Munson curve some gear still plays lows and highs at low volume while other gear quits and sounds midrangy. Also, room itself plays role. In my room playing soft sounds cleaner with better imaging. I suspect it is reverberation in the room that is causing multiple echos - still audible at higher volume.

Digital audio provides a very good platform for dealing with things like Fletcher-Munson, when needed. Much better than old fashioned analog loudness buttons.

There is an unlimited # of ways audio CAN be processed digitally, many for good reason. Digital sound processing is the ULTIMATE sound quality tweak in terms of possibilities at ones disposal.

My preamp has zero adjustments for anything although I turn my sub up and down in a small range from time to time and that's all it needs. I assume people listen to different levels depending on how they feel (late at night I can easily enjoy listening at lower levels than during the day, regardless of ambient sound)...I simply use the "it feels too loud" adjustment criteria regardless of the content...I listen to a lot of jazz piano trio stuff these days and back the level off when the piano feels unnatural or like its poking me in the brain. When I noodle on my electric guitars (along with a rhythm track of some sort) I think I must play too loud all the time partly due to the "amp grease content factor", but it feels good so I don't stop.