Quote:

Conventional opinion says to calibrate the sub to the same level as the speakers but I'm not convinced that's correct.

Our ears are about 40dB less sensitive to a 20Hz tone than to a 1KHz tone (that's ten thousand times less sensitive) for normal listening levels. Given our ears' decreased sensitivity to lows, we need to turn the bass up. We can't turn it up 40dB because as the frequency increases, our ear becomes more sensitive and the bass would be too hot. This is where a loudness control would be very useful.

I've found 6dB above my speaker levels to be a good compromise for my room. It sounds just right for music and I have earth-shaking LFE during movies.





If it sounds good to you there that's all that matters.

The Fletcher-Munson effect you refer to is well known to recording engineers whose job it is to factor that phenomena into the recording to achieve the "right" tonal balance. Striving for linear response, as the Axiom engineers do so painstakingly in all their products, makes it possible to reproduce the recording as faithfully as the engineer intended. Unfortunetly our listening rooms vary so much that most everyone experiences different unlinear, less accurate response, therefor the need for optimal placement, toe-in, acoustical panels, and multiple subs for HT applications to minimize adverse room acoustics throughout the seats.

Nevertheless many people prefer the increased response in the lower octaves and use equalization to give them a gently rising response in the lower bass. It can sound very good on some soundtracks or recordings.

What works best for me is to know where I can find reference volumes that gets me flat response, then depending on the movie or quality of recording I spice to taste. Most of the time I just leave it at the level where all speakers/sub are flat. The sound is most balanced and most detailed there and the bass doesn't sound "overcooked". I run multiple subs with combined output of 75db most of the time. For action movies though I like it a few db hot but my processor and equalizers are set to return everything to reference levels when they shut down.

I gotta disagree with you on the loudness control. For bad speakers maybe, but with the Axioms it plays havoc with their response characteristics and destroys their great mids. Separate bass, treble, mid-range controls can be useful though depending on the room.

John