frequency range for instrument vs speaker

FWIW, Squeezebox touch has a frequency spectrum display mode that can be switched to by touching the display area where album art is displayed by default I believe. Dunno how accurate, but it appears to be somewhat useful to get an idea of what the frequency content of what is playing is. A nice bonus feature! Also has a VU meter display for those that miss those on our modern gear. Very pretty!

Other points about low frequency extension are that

1) It's not a brick-wall. Extension to 50Hz generally means that output is at least 3dB down at that point with a noticeable 1dB of drop up much higher like at 80Hz.

2) The effects are worse than the numbers would suggest due to the equal loudness curve spacing at low frequencies. Once you get to 50Hz at moderate listening levels 3dB is like 6dB down at 1KHz which is 1/4 the acoustic power and quite significant (a full 10dB gets you a perceptual halving of volume).

3) The -3dB extension does not imply that the speaker is actually flat to that point. Many small speakers have a bump in frequency response (a few dB) which boosts the harmonics of low frequency instruments and can either give the impression the missing frequencies are still there or make the speaker sound boomy depending on what they're trying to reproduce. This design choice is more likely in speakers with less low frequency extension.

Drew: I understood that speaker frequency response is measured in an anechoic chamber so that consistent comparisons can be made with regard to speaker response performance. In the real world, the speaker sits on a hard or soft floor, close to or far from walls and ceilings. These variables, plus furniture, curtains and rugs create colorations in the music and then we must consider the type of amplifier and cables attached to the speakers and how they respond to the impedence characteristics. So speaker designers can create an instrument that looks perfect on paper when operated in an ideal environment, but how it behaves in our homes can be an entirely different matter, right? For example, just placing speakers near corners in a room can reinforce the base or adding curtains on the wall can dampen down the highs. I also learned in the past that too much dampening in the room kills the music. I have my speakers positioned a good distance from any wall. My speakers sit on spikes on a wood floor but I have a good sized rug placed directly in front of them. I haven't made a detail spectrum measurement but I believe I am close to a flat response curve as I could possibly get. Not saying that it is flat, just that I have acheived a satisfactory balance. I think about all of the parameters that speaker designers must consider both acoustically and electronically and then the nearly infinite variables of peoples' listening enviroment, associated cables and electronic gear and I can see why we have so many types and styles of speakers.

Just to be clear, the SB touch frequency spectrum display would indicate the frequency distribution of the signal the touch receives as input. I wonder if it is based on the digital input signal or the analog output of the internal DAC? Dunno.

ANyway, my point is that this is different than the response one would measure with a microphone if one were to do that with another similar device that works with a microphone as input. Furthermore, what the mike would measure would depending on placement location in the room due to room acoustics. The normalized differences between the two at any point if analyzed somehow would tell you the effects of the room acoustics compared to the source music signal.

Probably some good fodder in there for another thread or two on how to quantitatively measure source material quality and/or related system performance. I am not up to date on all the specific devices/programs that can do this but the technology surely exists and could be applied by inquiring minds fairly easily these days I would expect.

I seem to recall that a typical electric bass guitar drops to mid to high 30's on the open low string. For some reason 38 is sticking out in my mind. lots of fronts will do that but the discussion on spl above my explain why the sub helps out.