Track 32. The signal switches back to the stereo, and the sound stage should recover without changes in the level and spectral balance. This is a very difficult test for all systems. In addition to be an ideal acoustical environment. However, when asked to build a good stereo-picture in a specific room, the track will be very useful.
Track 33. The track contains 45-sekundny music piece on a normal level. It will be used as a reference for the following tracks : from 34 to 40. At each of these tracks keyboard reduced by the amount of 10 dB. This test will show the ability of your system accurately reproduce signals low, which is often a difficult task for many TsAP-ov and filtering circuits. The longer your system will be able to work without noise or distortion, the better. On a good track system to the level of 40 -70 dB must be clearly heard.
Track 34. Recorded with the level of -10 dB.
Track 35. Recorded with the level of -20 dB.
Track 36. Recorded with the level of -30 dB.
Track 37. Recorded with the level of -40 dB.
Track 38. Recorded with the level of -50 dB.
Track 39. Recorded with the level of -60 dB.
Track 40. Recorded with the level of -70 dB.
Track 41. This track is a digital signal zero. Ideally, the track should play as a complete silence and is used to measure the background noise components or systems.
Track 42. This track contains the high-frequency signal of low level with alternating values of 0000 and 1111. On this path nothing must be audible. This signal is useful for evaluating the converter Cd of record player and its interaction with the analog circuits.
Attention!
Lower level of volume before play the following tracks!
Track 43. Korrelirovany pink noise at a frequency of 20 Hz to 20 kHz.
Track 44. Nekorrelirovany pink noise at a frequency of 20 Hz to 20 kHz. When setting up a multi-system always useful to compare the results with korrelirovanym (mono) and nekorrelirovanym (stereo) noise. The trek useful if the place to listen is not the same distance from the loudspeakers.
Track 45. This track demonstrates changes in the level with a step of 1 decibel. The level of pink noise rises on 1 dB every three seconds. You will focus attention, that increase in noise for one step is very small, and nevertheless it is possible easily to hear that the overall level increases.
Track 46. Like track 45, except that in this track are four steps in increments of 3 dB. Remember that each step requires twice as much energy than before - despite the fact that changes at the hearing are still low.
Tracks 47-56. These paths contain pink noise, which is filtered into sequential thirds of octaves, beginning with 25 Hz. each track it contains three thirds, which constitute one octave. Paths are the following:
Track № Frequencies, Hz
47 25 31,5 40
48 50 63 80
49 100 125 160
50 200 250 315
51 400 500 630
52 800 1000 1200
53 1600 2000 2500
54 3150 4000 5000
55 6300 8000 10000
56 12500 16000 20000
These filtered strips should be used to measure the tonal balance system, if you do not have a spectral analyzer. To assess the sensitivity of each frequency band can be measured with a simple audio signal decibel meter. These bands are useful for the final evaluations listening. When reproducing data frequencies, especially the highest, the system must play each of the strips in the center of the sound stage.
Track 57. The track provides a smooth change in the frequency of 20 Hz to 20 kHz for subjective assessment fluidity acoustic sensitivity in the listening. This procedure applies to exclude the effects of standing waves. The device will indicate the peaks and failures encountered in the reproduction of the track.
Track 58. This track is a signal from 100 Hz to 20 Hz for subjective assessment sabvuferov. The good part of the sound should be heard clearly up to the lowest frequency (20 Hz), which sounded at the end of the track.
Track 59. The track contains divided on the frequencies of 10 Hz to 99 Hz. Each of the frequency lasted 5 seconds. If your CD player displays indexes, each index will be in line with its ten kilohertz.
Index Frequencies
1 10-19
2 20-29
3 30-39
4 40-49
5 50-59
6 60-69
7 70-79
8 80-89
9 90-99
The sinusoidal waves with low distortion required for the detection of low-frequency resonant frequency speakers in the room in the calculation of standing waves, etc.
Tracks 60-62. These tracks contain sweep-signal 20-20 kHz with a very smooth and the characteristic low-distortion test the frequency response of electronic components. It is not intended for acoustic assessments, reflection or standing waves can cause interference. The acoustic measurements are better suited noisy tracks. Трек 60 gave sweep-signal from 20 to 200 Hz, трек 61 - from 200 to 200 to 2 kHz and трек 62 - 2 to 20 kHz.
Track 63. The trek includes music from A (440 Hz). It can be used as a reference to customize tools to verify the accuracy or speed of your player. If you are confident in your player, you can use it to your musical instruments or check your tuning fork. You can also compare two players.
Track 64. This track contains 100- Hertz tone impact with operating cycle 25 %. the power, consumed between the impacts, composes 1% of the power of tone message. This trot adapts for checking the dynamic characteristics of amplifiers, loudspeakers, and especially, for the sources of power of amplifiers. It will also measure a voltage drop in the 12- voltage automobile systems with the testing on the high power by unsuperfluous.
Track 65. This track accurately the same as track 64, with exception of frequency, which now is 1 kHz.
Track 66. This track exactly the same as track 64, but the frequency is 10 kHz. Be careful, because in testing can be damaged high dynamics.
Track 67. This track is square wave with a frequency of 100 Hz for evaluating the electrical circuits of components with the aid of the testing facilities. In order to qualitatively reproduce the undistorted waveform, is required frequency band from 1/10 to the tenfold fundamental frequency. Signal also can be used for evaluating the quality of the working background of equipment up to the frequencies on the threshold of audibility, i.e., below 20 Hz. square waves are also useful for checking the evaluation of the dynamic characteristics of filters and loudspeakers, where the distortions will appear in the form of flicks and fragment.
Track 68. Same as track 67, with the exception of the frequency of 1 kHz.
Track 69. This track record includes the original full momentum and is intended to be a reference for the next track. In addition to comparing the records to the following accomplished with dynamic compression, this track can be used to verify the accuracy of instrument testing peaks. Check the highest testimony to reproduce this track. Then, without changing the volume, and compare it with the testimony measured at the next track. The difference between them is the value of that equipment is not able to respond quickly to the musical passages short duration.
Track 70. The track recorded with exactly the same peak levels as the previous track, but you were wearing dynamically. The dynamic compression is quite common in modern records and started to make record singing loudest at the expense of dynamic range. If it sounds better than the previous track, meaning your system lacks the power and momentum to adequately reproduce audiofilskie record.
Track 71. This track tests your system for radiated distortion. Sinusoidal wave of the so-called Pretsizionnoy Audiosistemy One (Audio Precision System One), and processed a special device which enables to regulate the required amount of distortion. The start signal was distortion 0.0004%. He has been processed and recorded on a track 71, as a score for the subsequent tracks. The track has the tone distortion 0,03%. In each subsequent track distortion is increased by about 10 dB. If you have a distortion analyzer, you can test the calibration, since the value of distortions in the following tracks very accurately. Naturally, if you have a "noisey" CD player or bad CD, the coefficient of nonlinear distortion THD + N and influence, reducing the testimony of dough. If you do not have the distortion analyzer, you can use these tracks, as a test of "masking". The principle of "obscuring" the next. Beginning with low levels of distortion and increasing until it becomes audible, you get testimony threshold distorting your system or your ability to feel it. Start with a track 71. If you are unsure of what seems a distortion, immediately go to the track 76, because it has 10% nd distortion to be clearly heard any audience, even on a bad audio. The distortion is a weak sales, podmeshannoe to clean tone. If you can not notice a difference between any of these tracks, then your distortion of a very high (> 10%) or just poorly hear. Most people can easily hear the distortion of 1% to a good system to run in waves.
Track 72. Same as track 71, only with the distortion of 1%.
Track 73. Same as track 71, only with the distortion of 3%.
Track 74. Same as track 71, only with the distortion of 1%.
Track 75. Same as track 71, only with the distortion of 3%.
Track 76. Same as track 71, only with the distortion of 10%.
Track 77. This test, like the previous test, except that the signal is used as a piece of music. Source distortions affecting all frequencies equally and does not affect the standard. Therefore, the test is more informative than the tests distortions which depend on the frequency or level. We believe that the musical material with a distortion of 3%, some listeners will be able to hear the sound system, but hardly anyone will be able to detect a distortion of 1%. Of course, a distortion of 10% should be obvious to all systems.
Track 78. Same as track 77, only with the distortion of 1%.
Track 79. Same as track 77, only with the distortion of 3%.
Track 80. Same as track 77, only with the distortion of 1%.
Track 81. Same as track 77, only with the distortion of 3%.
Track 82. Same as track 77, only with the distortion of 10%.
Track 83. The musical piece written without the added time delay and is intended as a reference for the next track. Much has been said and written about the different perceptions of frequencies human ear and the impact of this particular quality music reproduction. Often, the error was evaluated along with the rest, making its determination.
Track 84. The musical piece-demonstration group delay. The signal passed through the phase filter with a total delay at low frequencies around 7 milliseconds. This is tantamount to shifting the loudspeaker at a frequency below 100 Hz by nearly 7 feet (2.1 m) in relation to the rest of acoustic bands. The chain is able to demonstrate a reasonable delay in the absence of actual changes in the frequency domain. After you proslushaete both these two paths, ask somebody to switch, so you do not know what track is playing. Decide for yourself whether heard lag distorts sound at the hearing.
NOTICE : Effects on the following tracks to listen to on headphones or special loudspeakers. (See note)
The following tracks were included in disk in order to demonstrate several principles, which give to us the possibility to localize sounds. Extensive work by construction of lateral sonic scene was accomplished since the beginning of the appearance of stereo-system, while the ability audiosistem to completely surround us, was not central objective until recently.
These paths demonstrate the interesting procedure of record, using a process known as record "in the ear" (ITE). This procedure uses a pair of small laboratory sensors, it is less than 1/16 inches (1,6 mm) in the diameter, the established at a distance approximately 0,05 inches (1,27 mm) from each eardrum of human ear. With the use of this procedure, the transfer function of heads, channel of ear and pinna they are coded into the record. If we listen to this on the system with greater than 20 dB by separation into right and left channels (both acoustically and electrically), feeling of space, direction and environment it is fixed with the stunning realism. Even sounds, which occur behind you, they are determined very accurately. Take into consideration, that the requirements for the acoustic separation actually determine almost all diagrams of the arrangement of stereo-dynamics loudspeaker. Traditional audisistemy can reproduce lateral sonic component, but as a rule they not very well transfer its depth and height because of to the so-called auditory cross-correlation. This when left ear hears right loudspeaker just as leftist, and right ear in exactly the same manner hears left loudspeaker as right.
Records were made on Pit Row in 1994 during the races on Indianapolis Motor Speedway (that you will say about the large sonic scene?)
Track 85. You stand between Roger Penski team pit and the straight on the main track. Emerson Fittipaldi team behind and left of you and Jacques Villeneuve crew regulates pressure in the rear tyres and the right. Directly in front of you on the main road sweeping vehicles at a speed exceeding 220 miles per hour, Emerson starts in his car and left.
Track 86. You are walking along the pit lane. They are located from you from the left side, and racing track - from the right. Racing automobiles drive up they from behind and pass to the right. The position of announcer changes, since you go between the loudspeakers, divided by distance into 50 feet (15 m). We attempted to find one of the new engines of Mercedes in order to write down his sound, and you hear, as the Don to the left of you he speaks, "here that that we want". We attempt to rise more highly, since automobiles everywhere. You can hear, as drove up the automobile Of vil'neva, and it stopped less than in 6 feet (1,8 m) behind you, after which the pneumatic jacks raised it from the earth.
