Allow me to cause some controversy.
Bernard, set those bass and treble controls the way you want.
Unless you are living in a room that has
exactly the same acoustics as the mixing room used by the studio's soundtrack engineers
and you are using the exact same monitoring/mixing speakers
and subwoofer
and amplifiers, simply setting your system to a flat state does not guarantee exact duplication of the sounds that those engineers and/or directors wanted you to hear.
Most movies and music seem to be mixed decently but I've had some that had waaaaay too much treble which drove me nuts & had to give my treble knob a twist to mellow it out. As far as music goes there is one CD I have,
Wrecking Ball by Emmylou Harris, where her vocals are recorded with such a horrendous amount of sibilance and "sizzle" the only way for me to listen to this album is to turn the treble down almost all the way (because my Technics' treble midpoint is set at 20kHz to avoid messing with the midrange).
Edit: as far as the bass control/subwoofer question, it is
possible for the bass control on your receiver to change the way the subwoofer sounds but this depends on how the bass control is designed. My Technics' bass control is centered at 50Hz which is quite low compared to many other receivers (probably to make it easier to control excessive bass "thumpiness" on modern pop & rock recordings). So this would definitely change the way the typical subwoofer sounds. But many other receiver's bass controls are centered in the 100hz to 150Hz range--this particular section of the bass region is sometimes called "pseudo bass". This will have little-to-no effect on most subs (remember, tone controls have different amounts of roll-off on either side of their center frequency, in other words, some controls centered at 100Hz will have an effect possibly down to 50Hz and up to 150Hz; others may just get down to 80Hz and up to 120Hz). Some speaker companies purposely design their smaller woofers to exaggerate these frequencies to make the woofer sound more "exciting" and though obviously you can tell it isn't true
low bass it still sounds pretty good (but without causing the woofer or amplifier to strain themselves).
As far as needing the bass control to tame sonic problems, it also has it uses. I have a few CDs that I use mine with. One example is one by Thievery Corporation,
Mirror Conspiracy, that has some upper bass effects that react badly with my specific room/speakers relationship: on several of the tracks this bass becomes very boomy and blurry (it does not do this in my car though). I am certainly not going to move my speakers just for a few songs, so by simply turning the bass control knob I can get rid of most of that boominess.
Also: unless recently things have changed drastically, most speakers' frequency responses are tested in an anechoic chamber. So this means when you put that same speaker in a real-life living room, it is almost guaranteed that the smooth and lovely frequency response you saw on the graph on their website is going to look like it drank a six pack of beer on the way to your house. So personally, I no longer worry about trying to get "perfect sound" in my listening room. And anyway, most good manufacturers listen to and tweak their speakers in rooms set up like the typical living room to make sure their product will sound acceptable once the customer puts it in
their living room.
So once I learned about the actual sound recording process and especially, about room/speaker interactions, I was no longer intimidated by those bass and treble controls.
LJ
