A speaker unit does not exist without its cover. The cover can be a dedicated wood or plastic box at stand-alone speakers or the cavity created between a plaster and a concrete wall with built-in speakers.
The size of a speaker cover should be related to the size of the room. A loudspeaker designed for a much larger room will not sound good in a smaller room. The size of the speaker cover determines the volume of the air movement and thus the sound energy that such a speaker system can create in a room.
Speaker covers are available in different shapes like bass reflexes or ported enclosures that have a hole in front or back to leak more bass into the room. Well-designed sealed inclusions tend to produce more accurate sound.
Well-made speaker covers use a reinforced structure called a stapled casing to ensure that the casing vibrates as little as possible. Enclosure vibration adds unwanted colors to allow especially at the enclosure resonance frequency; This tends to be closer to the upper bass frequencies.
The braking membrane is attached to the metal basket via a flexible environment at one end and one spindle on the other. The entire membrane / voice coil is free to move in accordance with the motion created by the voice coil in response to the electrical signal.
Faster high-quality driver membranes use either aluminum or titanium; These are mainly used in advanced tweeter speakers. But cheaper materials like reformed silk, paper and some plastics also provide excellent sound.
This is often defined in nominal power (Watts RMS).
Impedance represents the resistance a speaker offers to the electrical signal; The lower the impedance, the more power (power) comes a speaker to pull from the amplifier for a given output voltage.
This means that a 4-ohm speaker will charge more an amplifier for the same output level than an 8-ohm one. So do not just buy speakers without taking into account your AV receiver or amplifier specifications.
One of the most critical speaker specifications is speaker sensitivity. This is stated in dB (decibel), with a test tone of a watt measured one meter from the speaker.
This means that sensitivity affects how much power your system needs to work well in your configuration. The average speaker sensitivity is at about 87 to 88 dB. Note that this action is logarithmic, which means that a 3DB decrease in speaker sensitivity requires doubling of the amplifier effect to produce the same volume in the room.
Speaker Frequency Response
Given that speaker frequency response is not constant throughout the range, answers are often specified within a variance limit - usually ± 3dB. This ± 3dB represents reasonable consistency; Some manufacturers also indicate an increased frequency response at ± 6dB, but it is self-evident since it would require up to four times the loudspeaker amplifier speakers as loud as the speakers in the range.
A loudspeaker with a specified frequency response ranging from, for example, 40Hz to 22kHz ± 3dB can be considered to have quite a good coverage ranging from good bass to high frequency just above the average upper limit of human hearing.
Speaker dispersion (H x V) specifies speaker sound radiation pattern along different angles. It tells how the noise varies when moving from the speakers main axis. If you look at the specifications for speaker cassettes, you should see the nominal angle of high-frequency dispersion in horizontal and vertical planes.
Magnetic shielded speaker
The permanent magnets used in the speakers are extremely strong magnets that can interfere with the electromagnetic TV field used to divert the electron beam. The result is a distorted TV or home theater system image or when the speakers are placed close to the screen. Speakers intended for this purpose should use magnetic shielding.