Wednesday, December 29, 2010
【 Weak current College 】 how to buy a digital recording device 】
In recent years, radio, television and audio-visual company, and even some personal MIDI Studio, etc. are faced with the problem of digital devices, and market a wide variety of digital devices, model updates fast, complex functions, in order to be able to care for a little bit of digital devices, here only to reference several digital audio device a brief comparison. In accordance with the record carrier, digital audio equipment probably can be divided into: tape, magnetic discs and hard drives. Tape recording devices tape in a cassette class-DCC, fixed head opening machine-DASH format recorder, rotating head of ADAT, etc. 1. ordinary cassette digital recorder DCCDCC is an ordinary cassette developed, compatible analog cassette digital recording format. From specification, DCC has reached the CD audio quality, but also to record some relevant text information. 2. fixed head digital recorder digital recorder DASH format is a fixed digital tape recorder, tape width and belt speed, of which there are several format, its appearance and operation methods are opening machine almost, have gained some used a simulated opening machine people of all ages, but because the tape exposed at work, on tape, unloading zone is very easy to make tape with dust, with fingerprint or being scratched, increased error rate. 3. rotating head digital recorders rotating head of digital recorders, known as ADAT, is by far the more commonly-used types, two-rail track DAT DAT and more. ADAT in 1970, adopted on the basis of the video recorder PCM coding development. In recent years there have 8-track digital recorder of rotating head, FOSTEX, ALISES, TESCAM, companies have different models of the 8-track DAT, some are small 1/2 video, while others are used in the Po recorder Hi-8 videos. Radio out records live, TV out party, audio-visual sector programs strip, as well as radio communication between the program, now most of the ADAT recorders. 4. problems with tape-based digital recorder, sound quality, do not have too many problems, but after all, is not divorced from the tape, the head of these wear media, tape damaged after losing code noise, often unbearable noise; 8-track DAT tape used to be before 1 hour format; plus, high-speed rotating drum is also very easy to wear, causing an error such as timecode, cannot synchronize, or even impossible to recording and playing sounds. As the broadcast production departments, often to do some tedious, complex clip work, such as cut a word before and after the transfer order, and so on, that this tape of digital audio recording device can do about it. Magnetic disc types of recording equipment 1. magnetic disc MOMO (MagneticOpticalDisk, magneto-optical disk) has been developed into a digital audio recording medium. At home and abroad have come out with MO sound recorder. From a performance point of view, MO is not using data compression techniques, but you can make some nonlinear editing, playback, you can use a CD, is more suitable for radio and TV stations in their daily work. However, MO just appear, because the magnetic disc price has not been reduced to a universal level, thus affecting this type of product promotion. 2. MD of small magnetic discs and MO's is very similar to MD (MiniDisk), just MD uses data compression technology. Data compression theory is built on the sound amplitude masking and time masking, masking effect removal because without actually listen and sense of redundant and irrelevant information, you can save a considerable portion of storage space. A subjective quality evaluation, 6: 1 data compression, the human ear is essentially did not recognize changes in sound quality. Playback, MD using polarized light in a magnetic polarization direction of twist, read the magnetic signal of the disc; recording, first to laser heating, magnetic material on the disc, and then through demagnetizing tape heads from new magnetized. Furthermore, MD uses the data buffer technology, earthquake performance good, the service is also very convenient. The MD is cheaper, for example, MD interview machine also updates quickly, its price has started to seven thousand down to two thousand or so. Therefore, the current radio station, TV station MD usage is very high. Many new MD machine program editing and production on the more powerful, MD of increasingly widespread. 3. other disks, CD recorder in addition to the magnetic disc types of digital recorders, and some use computer 3 inch disk recorder, record time before dozens seconds, most used to play the radio station's Edition head and advertising, with the radio digital, networked processes continued to deepen, this disk recorder will soon have to be eliminated. CD class and CDR (writable CD), also there are many models available, while there may be repeated erased by CDR, used for programs such as Exchange, information is saved, but the producers over and not much in use. Hard drive type of recording device 1, hard disk recorders (HardDiskRecorder) hard disk recorder, despite relatively late, but has evolved so rapidly. General use more is 8, 16 track hard drive machine. Hard disk read time machine, in addition to possess and MO, MD similar shear (CUT or DEVIDE), move (MOVE), merge (COMBINE or PASTE), delete (DELETE) and elimination (ERASE) and other editing functions, copy (COPY), undo (UNDO) and other features that use will be more flexible. For example, some hard disk machine with eight real-world tracks, each track, you can have lots of virtual track. If the original program was off, and the possible effect of reinforcing sing even worse than the original, so the hard machine provides false tracks, as long as the hard disk space allows, you can at the same real track record several hypocrisy in orbit, and then you can compare it again the best choice. Hard drive for another advantage is that accurate, easy synchronization feature. DAT will with time synchronization is poor out few frames or even more, especially on television ads, synchronization requirements are very strict. Alternatively use the tape recorder and MIDI sequencer, the first to record a track synchronization code, consumingAlso covers track. General hard disk recorders have been more perfect synchronization feature, you can synchronize with the video device can also be synchronized with the MIDI device, and the other hard drive machine synchronization, synchronization codes have SMPTE codes, MTC code MIDI and other types. Do national musical instrument recording, MIDI sampling often out smells, so that you always want to MIDI devices and can be registered in the real musical instruments sound recorder synchronization, then hard drive machine large useful field. As long as the MIDI sequencer not speed, pitch shifting, sync up hard drive machine is equivalent to a recordable MIDI device for real musical instruments, and some hard disk machine also offers a variety of time display, for example, sometimes, minutes, seconds, frames, forms, or a section, movement, in the form of a time value. Hard disk recorders generally 16bit quantization, sampling frequency is 48kHz, 44.1kHz, 44.05kHz etc, linear no compression, the amount of storage on the hard disk requires a larger hard drive, 8 rail 540MB may be taken 2 minutes; if you get 2 GB of hard drive, 8-track recording to 50 minutes or so. Hard disk machines are generally provides simple mixer, jumper disk functions, you can also display card, equipped with the track signal waveform and the appropriate action on the computer monitor display, much like a digital audio workstation. 2, digital audio workstations digital audio workstation DAW (DigitalAudioWorkstation), is by far the most State-of-the-art digital recording devices, not only for stand-alone editing functionality has been improved, audio workstation is moving in the direction of the network, especially suitable for radio and television stations, the use of the radio unit. Digital audio workstation for editing features stronger than hard drive machines and many, in addition to the cut, paste, copy, delete, etc, also increased in the past by peripheral equipment to complete audio signal processing functions, such as delay, reverb, chrome, compression, limiting, expansion, noise gate, balanced, and provides the number of time pressure spread function, that is, you can do the diminutive of variable speed is not changed, not speed, this is past all the audio device does not function on. This function is particularly suitable for advertising such as advertising, 32 seconds without getting high tone, you can compress to 30 seconds. The latest digital audio workstation also offers special audio processing functions, such as noise, in the past, people have been using dbx or DolbyA these complementary principle of Denoiser, but for some audio history information, old records, old tapes, Denoiser, you can do about it. At the workstation, you can first be old recordings of the sound, fried beans and old tape Shua Shua, sampling, then press the sample extraction of these noise, after this a few times after treatment, the effect will increase a lot. 3. digital audio network each audio workstation as a network user, and then accompanied by the required management station, broadcasting stations, can establish digital audio network. For radio and television broadcasting institutions in the past to do a show, editors are looking much better sound, music data with, and then recording, synthesis, and then copy to play with the broadcasting sector. In digital audio network, audio, music, information from the network server or database, call for resource sharing; program in finished recording workstation, or sent to the server, such as edit, broadcast editing workstation. Network in addition to handling sound signal, you can also send text messages. Online information management, recording, editing, broadcasting management, broadcast, and many other features, is the future trend of development of radio and television. Any digital audio recording device that has its own range of use, for example, in the staging of multitrack production, into singing, inevitably often a connector changing, although powerful workstation to the editing functions, but are not comfortable with this same point near the place over and over again, so digital multitrack DAT also has considerable market; whereas in some family music workshop, use multitrack hard disk might be more convenient; radio, television, advertising, production, audio workstation will show, the press, an audio recording, MD may also be used; the Exchange program, you can use DAT, CDR, and so on.