40hz ratings/speaker response


Hi, as a neophyte to the technical end of this wonderful addiction, I am curious. If a speaker's frequency response capability is rated to say 40hz or above, what happens to that sound that was recorder that falls below that range? Say for instance the lower octaves on an accoustic piano, or a cello, electric bass etc? And again, what happens to a speaker, with the same rating, if the volume is "pushed" to hear and feel music that has a lower range?
Curious
joeb

Showing 4 responses by redwoodgarden

Perhaps the size of the listening room has something to do with the limitation of sound frequency. Assume that sound travels at 1223km/hour at sea level. Then if my conversion table is correct, sound travels at 1,114 feet/second. The sound frequency that we are debating here is 40 cycles per second. The wavelength of sound at 40 cycles per second is about 28 feet. That means that it would take a 28 foot room to fully develop sound at 40 cycles per second. I think that this is size limitation of most listening rooms. Larger rooms will develop lower frequencies of sound. If you want to fully develop sound at 35 cycles per second, you will need a 32 foot room. If you want to fully develop sound at 30 cycles per second, you will need a 37 foot room. If you want to fully develop 25 cycles per second, you will need a 45 foot room, etc., etc. In conclusion, why are we torturing ourselves trying to get speakers of lower frequencies, when we should be considering getting LARGER ROOMS. Let's go for broke, if want to develop a one cycle per second sound wave, you will need a 1114 foot room!!!
Thanks Bob(inpepinnovations) for the clarification. This old dog just learned a new trick.
Joeb, the point that I was trying to make was that sound waves can't be heard if they don't have room to develop at least one full cycle. For simplicity sake, one cycle of sound meanders like the letter S. According to the laws of physics, one full cycle of sound at 40 cycles per second needs 28 feet to develop. That is why I thought 40 cps was the lower limit for a normal listening room. One would have to be rich to have a room large enough to hear deeper tones. However, Bob at inpepinnovations said that only one half of the space required for a full cycle is required in order to hear a low frequency. One half of a full cycle would look like the letter C instead of the letter S. Assuming that the revised theory is correct, 40 cycles per second (hertz) could be heard in a 14 foot room, not a 28 foot room as I first proposed. Also, sound at 25 hertz would only require a 23 foot room, not a 45 foot room. In short, my theory was shot down.

Allow me to propose an anology to explain the limitation of the 40 hertz rated speaker. Imagine a soprano singer trying to sing bass. The vocal cords are too short to develop the lower frequencies, and thus distortion sets in. As you proposed, let's imagine that the soprano singer tries to sing bass even louder on the second try. The distortion would be louder and more pronounced, but the lower octave would never be reached. If the soprano singer continues these attempts, her vocal cords would be destroyed, just as a speaker would be destroyed in the same attempt.
Bear, there is only one full range speaker that I know of that can effectively go down below 40hz...
K-horns. You don't need subwoofers when using K-horns. These full range speakers can easily handle organ notes down to 32hz. Around this point you no longer hear sound, you feel it in your chest. If speakers can handle frequencies below 40hz, you will be able to tell the difference in pitch between each frequency. This can not be done with speakers rated above 40hz.

Some have raved about LaScalas' deep base that can go down to 45hz. I have both pairs of the above speakers in my system. Trust me when I say that the K-horns can run rings around the LaScalas... even though they both use exactly the same 15 inch bass driver. What makes the difference is the folded horns inside the cabinets. You can not fight the laws of physics. Larger horns will create a deeper bass than smaller horns. It is possible to have two smaller 12 inch woofers develop bass notes down into the 20s with the proper horn cabinet (much below the range of the K-horn).
This is the principle of the soon to be released Klipsch Jubilee (home version).

Because of their high efficiency, K-horns only need 100 clean watts to produce 120db of earth shattering 32hz sound. Expensive high wattage amps are not needed to produce deep clean bass.