frequency range for instrument vs speaker

****Clearly a sub often if not usually makes a big difference but the existence of lower frequencies in the harmonics is not required to explain it.**** - Mapman

Very true, but it is required when the sub is used in a purely "augment" mode as many (most) subs are used; as opposed to using the sub's internal xover, when the benefits you describe are technically as well a audibly obvious.

Another term for undertone is "difference tone".

Or "combination tone"?

From what I read, it would seem to account for hearing frequencies lower than the fundamental but is believed to be most likely due to non linear inter-modulation distortion associated with how we hear more so than an aspect of actual sound per se, an "illusion" per se, so most likely not something that the speaker would play a role in producing assuming the speaker does in fact deliver the real instrument fundamental frequencies up to snuff.

****so most likely not something that the speaker would play a role in producing assuming the speaker does in fact deliver the real instrument fundamental frequencies up to snuff.****

Some modern composers have exploited these difference tones in their music, and the tones are audible to the listener (audience). When I was in music conservatory we performed an experiment to find out if the remarkably loud difference tones produced by certain combinations of fundamentals heard in the performance of Eugene Bozza flute trios were captured by a recording, and they most certainly were. So I think while some of these effects may occur in the recesses of our hearing mechanisms only, undertones, in the usual sense, can most definitely be captured by the recording process, and hence need to be reproduced by speakers if the complete timbre of instruments is to be reproduced.

The cool thing about all this is that there is so much to this stuff that is still not fully understood.

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?