altoparlanti altoparlante loudspeakers loudspeaker
Altoparlanti
Loudspeakers are avery important part of audio system. The loudspeakers are almost always the limiting element on the fidelity of a reproduced sound in either home or theater. The other stages in sound reproduction are mostly electronic, and the electronic components are highly developed. The loudspeaker involves electromechanical processes where the amplified audio signal must move a cone or other mechanical device to produce sound like the original sound wave. This process involves many difficulties, and usually is the most imperfect of the steps in sound reproduction.
The ugly truth: Any length of speaker cable degrades performance and efficiency. A simple fact to remember on speaker cables: Current needs copper, voltage needs insulation.
Copper is a very good conductor of electricity, but it isn't perfect. It has a certain amount of resistance, determined primarily on its cross-sectional area (but also by its purity and temperature). This wiring resistance is "seen" by the amplifier output as part of the load in sreias of the actual load. Since increasing the load impedance decreases current flow, decreasing power delivery, we have lost some of the amplifier's power capability merely by adding the series resistance of the cable to the load. There is a definite impact on the amplifier damping factor caused by cabling resistance/impedance. Damping, the ability of the amplifier to control the movement of the speaker, is especially noticeable in percussive low-frequency program material like kick drum, bass guitar and tympani. Boomy, mushy bass is the result of poor damping and clean "tight" bass is a sign of good damping at work. In short, you need thick enough wires and you are happy with the losses caused by resitance and on the damping factor. Aonither rule of thumb is that 4-ohm load should require conductors with twice the copper of an 8-ohm load, assuming the length of the run to the speaker is the same and you want same performance.
The extremely low impedance nature of speaker circuits makes cable capacitance a very minor factor in overall performance and the dielectric properties of the insulation used are nowhere critical on speaker cables compared to the effect of speaker wire resistance. If the spaker cable is going to be soldered to the connector the most important consideration for insulation for speaker cables is then probably heat resistance (so that the cable insulation van take the soldering temperature nicely).
Banana plugs(4mm diameter) are very traditional speaker connectors. Banana plug is good connector for speaker signals, both mechanically and electrically. You can see those connectors on many audio amplifiers and speakers. Banana plugs make reliable connection and those connectors are available in hifi industry for even very thic cables. In Europe the audio industry is moving away from banana connectors. European safety standard EN 60065 for consumer electronics effectively bans the use of the 4mm 'banana' type plug commonly used for connecting loudspeakers to amplifiers. The reasoning behind the prohibition of cable-mounted 4mm (and smaller-sized) plugs is that they can be inserted into a European mains socket with possibly fatal consequences.
Audio industry seems to be moving away from banana connectors and replace them with other alternative. There has been many ideas what this connector coul be. Professional audio industry seems to prefer Speakon connector. For home HiFy systems there is no uniform wiring standard (other than insulated screws which take bare wire).
You should always use the recommended load for your amplifier. This means selecting suitable speaker type or wiring multimpe speakers in the right way. Most solid-state amplifiers would rather look at an open circuit (no speaker at all) than a load. Therefore, you can usually use a load that is higher than the recommended load without any problems or damage. Most powerful tube amplifiers need a load to avoid transformer or tube socket damage. If a mismatch can not be avoided on a tube amp, it is usually better to go towards a lower impedance rather than too high of a speaker impedance (this may stress the tubes more than normal operation).
Typical specifications on speakers you can see is impedance, power rating, recommended amplifier power, frequency response, distortion and effiency. You can often see also other specifications.
Impedance is the AC equivalent of resistance in a DC circuit. Speaker impedance is usually largely dependent on frequency. The impedance rating told on speaker specifications is the "average impedance" (the impedance stays in the operation usually at higher or lower than this, but generally stays above 75% of nominal impedance). Generally when you are buying or connecting a speaker to an amplifier, check that the speaker impedance is equal or higher than that is the lowest allowed impedance on your amplifier intended to drive those spakers (some aplifiers are limited to 8 ohms, some other can go to 4 ohms or even lower).
Often used speaker power handling capacity test standard is IEC 268-5, which specify filtered pink noise test signal. The nominal power (RMS power) for speakers is defined by supplying continous power is measured by pink noise rather than a sinousoidal signal and it is applied for 24 hours. Maximum power rating is a value which means almost nothing, but is used nonetheless by manufacturers to entice the unsuspecting into purchasing their product based solely on the big number. Technically, it is the maximum wattage that an audio component can deliver/handle as a brief burst during a musical peak. Most reputable manufacturers will provide both an RMS and Max power rating. Typically, the given value for the maximum power rating is twice to three times that of RMS.
Frequency Response is the frequency range to which the speaker can respond. Full-range speaker is a speaker designed to reproduce all or most of the sound spectrum within human hearing (20Hz - 20KHz). Typical speakers are not able to play back this whole frequency range.
Harmonic Distortion means that harmonics are artificially added by the non-linearities of thespeaker, and are generally undesirable (but can not be completetely avoided). It is expressed as a percentage of the original signal.
The loudspeaker element involves electromechanical processes where the amplified audio signal must move a cone or other mechanical device to produce sound like the original sound wave. This process involves many difficulties, and usually is the most imperfect of the steps in sound reproduction. An enormous amount of engineering work has gone into the design of today's dynamic loudspeaker.
Dust cup in spaker element is sometime talked about. The function of the dust cup is dust and other foreign matter out of the voice coil gap. Any small grit that gets in there could easily lodge in the gap and cause distortion and possible failure. Additionally, depending upon the design, it could seal the enclosure and it could be used to radiate higher frequencies on some speaker elements.
Once you have chosen a good loudspeaker element from a reputable manufacturer and paid a good price for it, you might presume that you would get good sound reproduction from it. But you won't without a right enclosure. Right type of enclosure is an essential part of sound production.
Marche di Altoparlanti
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
|