Operating instructions

5-1a) DEFINITION
This test defines the product’s bandwidth and measures any variations in the product’s
output level as a function of frequency. In consumer audio the test is performed from
20Hz to 20,000Hz. In broadcast, this test is typically performed from 50 Hzto 15,000Hz.
Generally, the frequency response specification is referenced to an arbitrary 0dB. Any
deviation from this 0dB reference is specified as plus and/or minus dB over the stated
bandwidth. The frequency response specification varies greatly between manufacturers.
A typical frequency response spec is “+/- .5dB 20Hz-20kHz.” It is generally accepted that
a person with good hearing can hear a level change as small as .2dB.
5-1b) TEST
The test is performed with an audio signal generator and a voltmeter* (or oscilloscope).
The signal generator is connected either balanced or unbalanced to a console input.
The voltmeter is connected either balanced or unbalanced to a console output (such
as Program Left Output). The frequency of the signal generator is varie over the audio
band of interest (20Hz-20kHz or 50Hz to 50kHz) while recording the Program output
level on the voltmeter. nay variatin in the output level is noted over the entire frequency
range. many newer model digital voltmeters measure in absolute and relative dB which
makes the test very simple. if you do not have this type of voltmeter, then you must
calculate dB using the following formula (see next page).
SPECIFICATIONS & TESTING
5-0)
Arrakis Systems, inc. --- 6604 Powell st., Loveland, CO 80538 --- 970-461-0730 --- www.arrakis-systems.com
5.0
INTRODUCTION
The performance test listed this section are:
1) Frequency Response
2) Signal to Noise Ratio
3) Total Harmonic Distortion
4) Crosstalk
The purpose of this section of the manual is to provide a general description of the mea-
surement techniques used by Arrakis Systems. Information is also provided regarding vari-
ations in test data due to differences in equipment and procedure.
IMPORTANT - many types of test equipment, test setups, test conditions and test methods
are used in our industry. It is impossible to provide information for all the various combina-
tions used in the real world. For this reason all specifications listed in this manual, or in
any other published literature on these products, are general. Specifications amy change
without notice and may differ between the manual and other literature.
*WARNING: some voltmeters are optimized for AC line measurements (50/60Hz) and are not accurate over the entire
audio frequency range (20Hz-20kHz).
5-1) FREQUENCY RESPONSE