music frequency

I should mention I was referring to the fundamental frequencies of the instruments.

My observations include the total music waveform, harmonics and all. We could debate whether a harmonic that is 40 dB down is important, but it is 40 dB down.

Nice links, Thank you.

I look for a speaker that will output down to 40Hz. Thanks for the responses.

Picking 40Hz means you will loose much of the reproduction of the bottom 7 keys on a piano and organ.

Remember that in general, a speaker that goes to 30Hz at 3db down will reproduce 40Hz notes clearer and more realistically than a speaker that goes to 40Hz at 3 db down.

Zargon...My point is that those seven lowest piano keys rarely get played. A speaker that doesn't try for the lowest frequencies may reproduce higher ones better (not worse as you suggest) because it can use a smaller lighter cone driver, which is not being driven in and out to the ends of its excursion range. If one must compromise, skipping low end extension is a reasonable choice. It depends also on the quality of the bass that is present...is the response smooth or lumpy. The Magnepanar MG1.6 speaker (which I use) quits at 40 Hz, but for most music the bass sounds OK because the response is unusually smooth.

I am not saying that very low frequency capability is worthless: rather I am suggesting that a separate LF driver (called a subwoofer) is better. (That's what I use).