How large a subwoofer should I choose?
This is a common question. The size and quantity of subwoofers is
related to the size of the audio system, but most importantly, the size
of the room. Subwoofers need to be treated differently as bass
frequencies react to the room in a very different manner than midrange
and treble frequencies. Bass travels in all directions, and escapes
into other rooms through doorways and openings. The ultimate choice for
subwoofer size depends on your listening room. The larger the room, the
larger the subwoofer needed to energize the room, or multiple smaller
subwoofers can be an option.
What are passive speakers?
A passive speaker is a unit without an internal amplifier. This
speaker, with speaker level binding posts on the rear, is designed to
be connected to an amplifier or receiver, via speaker wire.
Choosing speaker wire:
The choice of speaker wire is extremely personal. There are many brands
on the market that make excellent, high quality speaker wire, which may
or may not impact sound quality. The choice of speaker wire is that of
the consumer. It is critical that speaker wire be used, and typically
the thicker the gauge (AWG), the better.
SPEAKER GLOSSARY
Cone
The radiating area of the speaker, which moves the air, causing sound.
Voice Coil
Copper winding which amplifier current flows through, in tern causing a reaction with the magnet.
Impedance
There are two major types of impedance, nominal and minimum. Unlike a
resistor, a speaker does not have a constant "resistance", the
impedance is always fluctuating as the speaker operates. The nominal
impedance is the "resistance" that the speaker shows to the amplifier
while the speaker is not moving. The minimum impedance is the lowest
impedance that a speaker will exhibit, as it operates through its
frequency range.
Magnet
The magnet creates a magnetic field, which is constantly charged.
Crossover
A complex series of resistors, capacitors and inductors, which is
designed to separate the signals being sent to the speaker and send
them to the appropriate driver. This protects the speakers from playing
frequencies they are not capable of.
Tweeter
A small driver, which plays the highest of frequencies. Its size limits
the amount of power it can handle, as well as how low it can play.
Woofer
A large driver, which plays the lowest to midrange frequencies. Its
physical size limits how quickly it can move and therefore how high and
low a frequency it can reproduce.
Amplifier
An electronic device which amplifies a signal that is sent to it, providing the power to make a speaker operate.
Power Handling
A measurement of how much power a speaker can accept. Since much of the
signal sent to a speaker is converted into heat, this also relates to
how much heat the speaker can dissipate. The Maximum Power rating is a
measurement of how much clean power a speaker can accept, over a long
period of time, without sustaining damage.
Frequency Response
The measurement oh how well a speaker reproduces every frequency in a
human's audible spectrum. Since most humans can hear from approximately
20Hz to 20kHz (20 cycles per second which is deep bass, to 20,000
cycles per second which is very high frequencies), this measurement
depicts how wide of a spectrum the speaker can reproduce. It is
important to note that although some speakers can play a wide range of
frequencies, the most important fact is ensuring it plays all
frequencies at the same level. A speaker that, for example, reproduces
more high frequencies than low frequencies will sound "bright" in
comparison to speakers with a smooth response.
Okay, that's all the info that I could capture this month!
(Coffee break over)
Til next time,
Roger Fortner
