| » What
is "Frequency Response"? |
| Frequency response is the measure of
any system's response at the output to a signal of varying
frequency (but... |
| » What
is Amplifier? |
| A component that increases the gain or
level of an audio signal. |
| » What
is Bass? |
| Low frequencies; those below approximately
200 Hz. |
| » What
is Bi-Wiring? |
| A method of connecting an amplifier or
receiver to a speaker in which separate wires are run
between the amp and the... |
| » What
is Coaxial? |
| A speaker typically with one driver in
the middle of, and on the same axis as, another driver.An
audio or video cable... |
| » What
is Decibel (dB)? |
| A logarithmic measurement unit that describes
a sound's relative loudness, though it can also be used
to describe the... |
| » What
is Impedance? |
| A measure of the impediment to the flow
of alternating current, measured in "ohms" at a given
frequency.... |
| » What
is Sensitivity? |
| A measurement (in dB) of the sound-pressure
level over a specified frequency range created by a speaker
driven by 1... |
|
| What is "Frequency Response"? |
Frequency response is the measure of any system's response
at the output to a signal of varying frequency (but constant
amplitude) at its input. It is usually referred to in
connection with electronic amplifiers and similar systems.
The frequency response is typically characterized by the
magnitude of the system's response, measured in dB, versus
frequency. The frequency response of a system can be measured
by:
- Applying an impulse to the system and measuring
its response (see impulse response)
- Sweeping a constant-amplitude pure tone through
the bandwidth of interest and measuring the output
level
- Applying a maximum length sequence
Once a frequency response has been measured (e.g., as
an impulse response), providing the system is linear and
time-invariant, its characteristic can be approximated
with arbitrary accuracy by a digital filter. Similarly,
if a system is demonstrated to have a poor frequency response,
a digital or analog filter can be applied to the signals
prior to their reproduction to compensate for these deficiencies.
Frequency responses curves are often used to indicate
the accuracy of amplifiers and speakers for reproducing
audio. As an example, a high fidelity amplifier may be
said to have a frequency response of 20 Hz - 20,000 Hz
+/- 1dB. This means that the system amplifies all frequencies
within that range within the limits quoted. "Good
frequency response" therefore does not guarantee
a specific fidelity, but only indicates that a piece of
equipment meets the basic frequency response requirements.
Human beings are capable of hearing between 20Hz to 20kHz.
Frequencies at or even above and below this may be relevant
(sub bass, high harmonics).
|
| What is Amplifier? |
| A component that increases the gain or level of an audio
signal. |
| What is Bass? |
| Low frequencies; those below approximately 200 Hz. |
| What is Bi-Wiring? |
| A method of connecting an amplifier or receiver to a
speaker in which separate wires are run between the amp
and the woofer and the amp and the tweeter. |
| What is Coaxial? |
1. A speaker typically with one driver in the middle
of, and on the same axis as, another driver.
2 . An audio or video cable with a single center pin that
acts as the hot lead and an outer shield that acts as
a ground. |
| What is Decibel (dB)? |
| A logarithmic measurement unit that describes a sound's
relative loudness, though it can also be used to describe
the relative difference between two power levels. A decibel
is one tenth of a Bel. In sound, decibels generally measure
a scale from 0 (the threshold of hearing) to 120-140 dB
(the threshold of pain). A 3dB difference equates to a
doubling of power. A 10dB difference is required to double
the subjective volume. A 1dB difference over a broad frequency
range is noticeable to most people, while a 0.2dB difference
can affect the subjective impression of a sound. |
| What is Impedance? |
| A measure of the impediment to the flow of alternating
current, measured in "ohms" at a given frequency.
Larger numbers mean higher resistance to current flow. |
| What is Sensitivity? |
| A measurement (in dB) of the sound-pressure level over
a specified frequency range created by a speaker driven
by 1 watt (2.83V at 8 ohms) of power with a microphone
placed 1 meter away. |
