| Русская версия | Max/MSP DJ Stuff |
| Last update: 2008-05-28 | the program allowing to replace the traditional DJ-equipment by a computer and MIDI-controllers |
| 1. | During mix do not use the keyboard - sometimes pressing of keys leads to short-term sound distortion. When program work in mixing mode the keyboard is not required. Removal of the won tracks from Foobar playlist can make without the keyboard, from the contextual menu (item Remove), though it undoubtedly is less convenient. |
| 2. | If you want to minimize Max/MSP DJ Stuff window,
then press button "minimize all windows". Do not minimize it
separately from other windows - it can cause short-term distortions of a sound.
 |
| 3. | Sometimes switching-off the program Max/MSP DJ Stuff
leads to its crash. After restart program the sound may not work.
The problem is solved by restart a computer, may be also required to
specify again the driver in DSP Status window. |
| 4a. | A 3-band equalizer for mixing.
The principle of work of an equalizer is shown in figure.
Whole sound range is divided by crossovers to 3 independent bands. The level of each band is adjusted by handles of an equalizer. After regulators all 3 band are summarized. Thus, the given device allows independent adjustment of a level in each of 3 bands. In traditional DJ equipment Linkwitz-Riley crossover are used. Lack of such equalizers is what he turns a phase on 360 degrees on cut frequency of each crossover, and because we have two crossovers, then total turn of a phase is equal 720 degrees. Therefore, various frequency components have a different time delay, that leads to distortions of the form of an initial sound signal. For example, sawtooth signal frequency of 400 Hz will looks like this (before and after EQ): 
Therefore the task has been put to get rid of phase distortions. Result of this work became an equalizer offered in the given program. Except rid of phase distortions the given equalizer differs a smaller steepness of frequency response of crossovers (about 7 dB per octave, Linkwitz-Riley crossovers have 24 dB per octave). It allows to influence more softly to a sound, for the account of smoother line of frequency response. Very much frequently, a DJ enters a track in a mix, having adjusted an equalizer so what strongly to muffle low frequencies, little bit middle frequencies and slightly high frequencies (approximately as shown in figure). 
At such position of handles of an equalizer, his frequency response will look like this: 
The top screenshot corresponds to an equalizer on the basis on Linkwitz-Riley crossovers, bottom - to an equalizer applied in the program. On screenshots it is visible, that line of an equalizer on the basis of Linkwitz-Riley crossovers less smooth. The cut frequency of crossovers of the equalizer applied in the program is equal 301 Hz and 2107 Hz. |
| 4b. | Equalizer of correction block. This equalizer in fact a graphic equalizer. Traditional graphical equalizer based on resonant filters. Defect of a traditional equalizer is that at significant displacement of handles of an equalizer from average position, it frequency response become wavy (look at the picture).
This phenomenon can be reduced by reduction of slope of filters, but then mutual influence of bands will increase, i.e. adjustment of the chosen band wiil affect to neighbour bands. The given program has a graphic equalizer, which free from such defects. He allows to create very smooth frequency response, which inaccessible at use of traditional equalizers. 9-band stereophonic equalizer applied in the correction block contains 32 2-nd order filters. This cause high requirements to the processor. Besides, for achievement of symmetry frequency response of the low and high bands of an equalizer, it was necessary rise up sampling rate up to 88200 Hz, that also toughens system requirements. Central frequency of an equalizer: 37, 80, 173, 374, 811, 1757, 3807, 8249, 17872 (Hz) - in 9-band mode; 37, 173, 811, 3807, 17872 (Hz) - in 5-band mode. |
| 5. | Program EQ9 is 9-band graphic equalizer. It can be used with player Foobar. Inputs of the program are 1 and 2 ASIO-inputs, outputs are 1, 2, 3, 4 ASIO-outputs. Adjustment is completely similarly to Max/MSP DJ Stuff.
Download: EQ9.zip (2.1 MB) MIDI setup: low - 20 mid - 21 hi - 22 volume - 23 |
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