Search results
Results from the WOW.Com Content Network
All multi-driver speakers (unless they are coaxial) are difficult to measure correctly if the measuring microphone is placed close to the loudspeaker and slightly above or below the optimum axis because the different path length from two drivers producing the same frequency leads to phase cancellation. It is useful to remember that, as a rule ...
The measure of the low frequency (many tens of Hz) noise contributed by the turntable of an analogue playback system. It is caused by imperfect bearings, uneven motor windings, vibrations in driving bands in some turntables, room vibrations (e.g., from traffic) that is transmitted by the turntable mounting and so to the phono cartridge.
Mercury-in-glass thermometer measuring an ambient temperature of 23 °C (73 °F) a little above the normal "room temperature" range. Room temperature, colloquially, denotes the range of air temperatures most people find comfortable indoors while dressed in typical clothing. Comfortable temperatures can be extended beyond this range depending on ...
Dynamic range is a measure of how small you can measure a signal relative to the maximum input signal the device can measure. Expressed in decibels, the dynamic range is 20 log (Vmax/Vmin). For example, a device with an input range of ±10 V and a dynamic range of 110 dB will be able to measure a signal as small as 10 μV.
In the simplest form, subtract the height of the voice-coil winding from the height of the magnetic gap, take the absolute value and divide by 2. This technique was suggested by JBL 's Mark Gander in a 1981 AES paper, [ 23 ] as an indicator of a loudspeaker motor's linear range.
One must be careful when measuring temperature to ensure that the measuring instrument (thermometer, thermocouple, etc.) is really the same temperature as the material that is being measured. Under some conditions heat from the measuring instrument can cause a temperature gradient, so the measured temperature is different from the actual ...
Required for measuring the acoustics in buildings is a signal generator that provides pink or white noise through an amplifier and omnidirectional speakers. In fact, the omnidirectional speaker, or sound source, should provide an equal dispersion of sound throughout the room. To achieve accurate measurements, sound should radiate evenly.
When measuring the sound pressure created by a sound source, it is important to measure the distance from the object as well, since the sound pressure of a spherical sound wave decreases as 1/r from the centre of the sphere (and not as 1/r 2, like the sound intensity): [3] ().