Komplett passivt PA set hitta...
  • Visa endast omgående tillgängliga varor
  • Jämför produkter
Aktuell Kategori
Sagt om oss

Tack för er service ! Jag är enormt imponerad över Thomann avseende pris, sortiment och service !

Petter den 27.09.2013

Online Guide PA Speakers
Technical Data

 


Power

Generally, when comparing the load capacities of loudspeakers, only one measurement counts - Root Mean Square, or ‘RMS’. It is the measure of the speaker’s capacity to handle sound across the entire frequency range over a long period of time. Beware of figures expressed as maximums - they may be higher than the
RMSRoot Mean Square: a way of calculating the average power over time to give a meaningful value representing the power of an audio signal. Generally thought to be the most meaningful way of measuring amplifier power output.
RMS
figure, but operating at maximum capacity is not sustainable and will quickly destroy your speaker.

Speaker

The higher the
RMSRoot Mean Square: a way of calculating the average power over time to give a meaningful value representing the power of an audio signal. Generally thought to be the most meaningful way of measuring amplifier power output.
RMS
value, the greater the load capacity of the speaker. It is usually expressed in Watts (W) - 100W
RMSRoot Mean Square: a way of calculating the average power over time to give a meaningful value representing the power of an audio signal. Generally thought to be the most meaningful way of measuring amplifier power output.
RMS
, 500W
RMSRoot Mean Square: a way of calculating the average power over time to give a meaningful value representing the power of an audio signal. Generally thought to be the most meaningful way of measuring amplifier power output.
RMS
and so on. Note that the power output of your
AmplifierA device for increasing the power of a signal by taking power from a supply and shaping the output to match the input signal.
amplifier
in
RMSRoot Mean Square: a way of calculating the average power over time to give a meaningful value representing the power of an audio signal. Generally thought to be the most meaningful way of measuring amplifier power output.
RMS
terms should generally be greater than the speaker’s, taking into account to the
ImpedanceThe term for electrical resistance when applied to AC current.
impedance
of each device. See our PA
AmplifierA device for increasing the power of a signal by taking power from a supply and shaping the output to match the input signal.
Amplifier
Online Advisor for more information on this.


Transmission range

This is an important measure for musicians in particular, because it indicates the most suitable use for a speaker. Is it good for high, mid, or low-frequency sound? Is it suitable for
BassThe lowest part of the audio frequency range; in popular music, a (generally) rhythmic, low frequency melodic line emphasising the root notes of the chord progression.
bass
(35 - 3,000Hz), guitar (75 - 7,000Hz) or vocals (80 - 16,000Hz)?

Most people can hear sound in the range between 20Hz and 20,000Hz (Hz = cycles per second). The ideal loudspeaker would be able to transmit effectively across the entire frequency range, although in practice this is virtually impossible.

So the
KeyAn additional input on a dynamics processor such as a compressor or noise gate, enabling the dynamics of one signal to control the level of another. This can be used for many functions, including ducking (compressing a music signal when a DJ or announcer speaks), synchronised gating, and (in conjunction with an equaliser) de-essing.
key
question is whether or not the loudspeaker can transmit consistently and with good quality within its ideal frequency range. This is known as linear transmission.

Linear transmission is measured as the difference between the input frequency levels and the output frequency levels. It is usually shown as a curve, giving a good indication of the range of frequencies for which the speaker performs best.

The industry uses frequencies separated by a musical third, and the levels are expressed in decibels (dB). Frequency response diagrams are pretty easy to read, in that a positive or negative curve shows which frequencies are transmitted or absorbed by the speaker being measured. A measure of zero indicates a perfect frequency response – but don’t expect to find it anywhere soon!

A loudspeaker’s frequency response is strongly affected by the physical construction of the whole device. By contrast, a mixing desk should be able to produce a zero curve because it is simply transmitting electronic signals, whereas
MicrophoneA device which converts airborne sound into an electrical signal.
microphones
will often have the lower ranges raised artificially to produce more power.

Typically, if a frequency response is shown as 40 - 20,000Hz, +/-3dB, you can assume that the
BassThe lowest part of the audio frequency range; in popular music, a (generally) rhythmic, low frequency melodic line emphasising the root notes of the chord progression.
bass
frequencies were raised at around the +3dB level, and that the higher frequencies were dampened at around -3dB. The usual warning about manufacturer data always applies - they will tend to use the figures that flatter their equipment, though most reputable companies will show fairly accurate frequency response data and
RMSRoot Mean Square: a way of calculating the average power over time to give a meaningful value representing the power of an audio signal. Generally thought to be the most meaningful way of measuring amplifier power output.
RMS
values.


Sound pressure

Sound pressure means
Volume1) In audio and music, the loudness or amplitude of a signal. 2) In computing, a fixed amount of storage space, addressed as a single entity ('C:', 'D:' etc). A physical drive may contain more than one volume, but a single volume may also span more than one drive!
volume
- the higher the pressure of the sound wave striking your ears, the louder it sounds. It’s measured, perhaps appropriately, in Pa (short for Pascals in this case - strength per unit area).

In fact, humans have a fairly limited audible range, from around 100Pa (the pain
ThresholdThe parameter in dynamics processing defining the level which an input signal must rise above (or fall below) to activate the circuit. A compressor is activated above the threshold, whereas an expander or gate is activated below the threshold.
threshold
for most of us) to about 20uPa. The ear detects these as logarithmic values, measured in deciBels. Zero dB roughly equates to 20uPa, and it usually starts to hurt for us at around 130dB. We
FilterA circuit used to remove or accentuate frequencies in a sound source. Common types are found on mixing consoles equalisation, synthesizers and dedicated processors such as graphic equalisers.
filter
out most high and low frequencies, though there are those who believe we respond to them at a subconscious level. When considering speakers, the sound pressure level (SPL) is usually shown in decibels. For example a speaker may be shown as 400W
RMSRoot Mean Square: a way of calculating the average power over time to give a meaningful value representing the power of an audio signal. Generally thought to be the most meaningful way of measuring amplifier power output.
RMS
, 118dB
SPLSound Pressure Level: acoustic sound volume, measured in decibels (dB).
SPL
.

As with other data, manufacturer information about the sound pressure capabilities of their speakers cannot always be compared reliably. It’s not that the manufacturers are dishonest - simply that there are many different ways of measuring sound pressure. What you are looking for is an indication of how much of the signal received is converted faithfully to moving
AIRSome artists and producers believe that AIR - Always In Record - is a valuable technique, because it can capture moments of musical magic that may otherwise go unrecorded. It simply means that the tape or hard drive never stops running during a session.
air
. The higher the number, the greater the
EfficiencyA specification, expressed as a percentage, measuring how efficiently a speaker converts an audio signal (watts) into sound waves (dB). As in any conversion process there is usually some kind of loss, which in this case is turned into heat.
efficiency
and/or sound pressure produced by the speaker.

If, for example, you compare two speakers that have a difference of 3dB in their sound pressure ratings, then you can assume that you will need roughly twice the power to achieve the same
Volume1) In audio and music, the loudness or amplitude of a signal. 2) In computing, a fixed amount of storage space, addressed as a single entity ('C:', 'D:' etc). A physical drive may contain more than one volume, but a single volume may also span more than one drive!
volume
from the lower rated, and therefore less efficient.


ImpulseA signal or sound with a very short (in theory infinitely short) duration.
Impulse
response

This is another indication of the speaker’s ability to transmit a true sound in real time. You need an oscilloscope to measure it, so in truth your best measurement system is your ears. Just how good does it sound at the kind of volumes you will need?

 

[<< tidigare Sida] [nästa sida >>]

 

Innehållsförteckning:

[Innehåll] [Overview] [Types of Speaker] [Technical Data] [Making Connections] [Cabinets] [Decibels] [Choosing your Speakers] [Hotdeals] [Conclusion and Feedback]