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May 13, 2018 - 6:03pm
#1
Bandwidth VS Frequency Response ?
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It may be silly to some... but I was taught that it is better to ask than to assume.
My curious mind just wants to know what all this means.
Any input would be appreciated.
Bandwidth and frequency response are essentially the same thing, in audio equipment, but power bandwidth is different because of the specific way it is cited.
The concepts are general, but the way they are cited and specified make each case different. Citing a frequency response/bandwidth must be defined by citing the way the end points are defined, or the whole thing is nebulous and meaningless.
For example, a speaker's bandwith/frequency response is usually specified as some low and high frequency limit MINUS 3DB. This means that the limits are the low (and high) frequencies where, with a constant input voltage to the speaker at all frequencies, the sound power coming out of the speaker drops off to half of what it was across the middle frequencies.
The speaker bandwith is thus defined from the LF 3db frequency to the HF 3db frequency. Sometimes speaker bandwidth is specified without saying how many db down defines the HF and LF end points. In this case the bandwidth given is meaningless, since the basis for the end points is undefined! Sometimes the 6db points are given, but the resulting bandwith will be wider than the 3 db bandwidth, making the speaker seem better than it is to someone who is not looking closely enough at the information (the speaker's power output at the 6db points is only 25% of the midband power).
Any speaker where the 6db bandwith is given by the manufacturer is trying to pad the performance of the speaker in a non-standard manner and this gives me a very negative perception of the speaker and its manufacturer.
Thanks Commsysman. Your explanation actual sunk into my brain, I can see(virtually) an arch on a graph that tapers off at at both ends.
With the specs from my amp being what they are, the 'effective' frequency response being put out appears to lessen as the output power is increased (less at half power output than at 1 watt output) assuming both are with an 8 ohm load. Regardless, I'm OK with 10Hz to 100kHz as the listed specs, still beyond what I can actually hear, and I will probably never run it beyond half power anyway.
Now I will move onto acquiring speakers that will utilize as much of the available frequency response as possible while being as clean and efficient as possible.
Thanks again for your sharing of technical knowledge, in an understandable english language approach!
Steve
Frequency = pitch (think Bass vs Mid vs Treble) [or numbers in Hz as previously mentioned like the sliders on an equalizer]
Bandwidth = allowed power or rate of power allowed (think loudness in decibels)
Think of a parametric equalizer...it employs both strategies at once... ie one can control "how much" pitch with frequency as well as "how much rolloff of loudness" in decibels around each pitch or frequency.
What was said is exactly right...but maybe this makes it more obvious the difference between the two.
Kind Regards,
Ron
ps. In its simplest form, its Hz vs d/dx(dB). or rate of change of dB around any given Hz