frequency range for instrument vs speaker

FRogman,

I think we are in agreement save perhaps the technical details.

As I understand it currently from very limited reading on the topic, as long as the recording captures all the real harmonics produced by the instruments accurately, and the system including speakers deliver these up to snuff as well, the lower "difference" tone harmonics can be heard, but they are artifacts most likely produced by our listening senses, not explicitly by the speakers.

We might be saying the same thing, not sure.

Not so sure either. If a recording captures, say, a 25hz tone that is a difference tone produced by two instruments' fundamentals (let's say 90hz and 125hz; just for argument, I am not up to the math right now) interacting acoustically, and the speaker playing back the recording has no output below, say, 30hz, then that 25hz tone is missing in the playback of the music. Now, does the presence in the recording of the two original fundamental tones mean that the acoustic interaction of these two tones in the listener's room produce the 25hz difference tone at the same level and with the same quality as what is heard live? I doubt it.

Moreover, why is it possible to hear the hall's sound in a live recording before a single note of music sounds from the recording; or in the rests in the music. Interesting tuff, no?

I'm no expert but I gather that it is believed most likely the undertones or combination tones, when they exist, are created by our human hearing apparatus. IN that case the speakers do not have to produce the undertone frequency, our ears do that as a result of non linear inter-modulation distortion produced somehow by our ears and the rest of our aural nervous system.

But I gather this process is not really well understood. It could be that the undertones are real and in the recording, though I am not aware of how this could be accounted for scientifically. In that case, the speakers would have to be able to reproduce them in order to be heard.

Its one of those grey areas apparently that most likely is what it is and I personally would not worry about much.

Having said that, ideally, I like my speakers to go flat at lifelike listening volumes down to 20hz or so to the greatest extent possible without sacrificing elsewhere even if just as an insurance policy that I am not likely to miss anything good down there assuming it exists and I am able to hear it.

The reality is though that speakers that can do that and still do all the rest well do not come cheap and are probably the exception and not the rule. I am willing to punt somewhat on that full low end extension if needed in order to get the frequencies above that really matter right. Its a common scenario that applies to many I suspect. One of the many possible practical compromises an audiophile on a budget or with limited space must face. A good sub blended in properly can go a long way to help address the issue for many when needed.

06-21-12: Onhwy61

You can't count on many speakers to make meaningful bass below 50 Hz.

Way too broad a generalization.

Really? I've been in audio for 43 years and worked in retail for awhile. I've listened to countless speakers and read countless speaker reviews that include response curves. In most ported stand-mounted speakers, there is a 5-10 dB hump around 80-100 Hz that drops off rapidly below that. If you reference the bass response to 1000 Hz, it's often down 10-15 dB at 50 Hz. Naturally, the bass response on floorstanders will be better, but for the small footprint towers, not really by that much. Mostly it buys better sensitivity.

Only when you get into the larger and waaay more expensive floorstanders (and bigger stand-mounts like the stand-mounted TAD do you get serious bass below 50 Hz, and that select group IS NOT most speakers. Most speakers include all the junk that passes for hi-fi and the fact that mini-monitors far outnumber floorstanders.

(JohnnyB53)
I'd say just about *any* loudspeaker would benefit from the right pair of subs properly blended.

(Onhwy61)
Benefit to a bass obsessed audiophile - yes. Required or needed for music reproduction - no.

Bass obsession has nothing to do with it. If the subs are properly blended, they won't particularly excite the bass-obsessed. What they *will* do is provide a more linear extension through the musical frequencies to energize the listening area uniformly--more like a live concert--and reproduce very low frequency resonances of the original recording venue. In a symphonic concert hall this spectrum has a profound effect on the crackling excitement of in-room energy, even before the conductor raises his baton. This audible room energy separates listening to live orchestral music from what most people can listen to at home--unless they have sub(s) that go to 20 Hz or below.

If you look around, you'll find reviews of powerful subs with sub-20Hz response that add soundstage and room acoustics to recordings of solo guitar--which by itself reaches only down to 80 Hz.

Hmmm.. I looked into undertone a bit as well as phantom tone etc.
http://en.wikipedia.org/wiki/Undertone_series

It seems that undertone is rather rare unlike overtone which is all over the place. If the article is correct, only wind and string instrument can create undertone.

Piano can create tone lower than fundamental of notes struck through sympathetic vibration of lower strings.

Ecruz, I agree with you. I had similar experience with sub and perceiveds something similar so there is definitely something going on in the sub 40Hz area.