552 or 7-Series Recorder?
The introduction of the 552 mixer brings a powerful new feature to field mixers, a high-quality integrated audio recorder. It is unquestionably convenient to have a built-in recorder with a field mixer. With the addition of its recorder, one question that comes up is whether the 552 can be substituted in place of a 7-Series recorder. The short answer is...yes...and no.
This article will point out key differences between the recorder in the 552 mixer and Sound Devices 7-Series recorders. Depending on your application, one of these may be more suitable than the other.
While both the 552 and 7-Series recorders have excellent audio performance, when the lowest noise recording is required, the 7-Series recorders are the choice. The combination of the 7-Series' extended bandwidth microphone preamplifiers and their high-dynamic range analog-to-digital converters provides increased dynamic range and sensitivity. This translates to lower noise recordings, especially when distant micing low level sound sources. If your microphones can take advantage of the low noise, the 7-Series will outperform them. The 702, 702T, 722, and 744T mic inputs have 114 dB of dynamic range, and the 788T microphone inputs have 123 dB of dynamic range. The figures on the 788T approach the theoretical limit of A-to-D performance.
The 552 is a capable performer, as well. It has 103 dB of dynamic range and is suitable for most applications. Its A-to-D performance is the biggest difference, with the 552 having a bias toward increased power efficiency and the 788T having a bias towards increased performance, especially noise performance. When the widest bandwidth and lowest noise recording is required, choose the 7-Series.
Input Routing Options
The 552 provides fixed routing options for selecting outputs and input signals for recording. From the factory the left/right outputs are sent to the recorder, perfect for a recording of a dual-mono or stereo mix. Other options are available, including input pairs 1/2 and 3/4, plus combinations of inputs and outputs. The same source selected for recording are available for digital output using the AES A output pair. 552 sound files are always two-track polyphonic WAV files.
7-Series recorders, whether two, four, or eight input, allow any input to be routed to any recording track. This allows any possible routing combination and offers a great deal of flexibility. Additionally, 7-Series recorders can record either monophonic WAV files or poly WAV files.
Operational run time from batteries is an important measure for many applications. The 552 mixer and the 7-Series recorders operate off their own internal, or attached power sources. Because of their higher power consumption, the 7-Series recorders operate from larger capacity rechargeable Lithium Ion batteries with 7.4 V nominal voltages. The all-digital topology of 7-Series recorders means that signals are digitized right at the input and are routed through the system digitally. Analog outputs such as line level outputs and headphone outputs are fed from digital-to-analog converters. Often, 7-Series recorders are powered from external DC power sources to extend their runtime.
The efficient 552 operates from four AA-type batteries, consuming similar power as its all analog predecessor, the 442 mixer. Since the 552 is an analog mixer first and a digital recorder second, its power consumption benefits from the reduced burden of this mixed analog and digital topology.
User Interface / Ease of Use
The UI of the 552's recorder control and that of the 7-Series is very different. Because recording on the 552 is a secondary function, its recording control is smaller and less prominent on the control surface. Because 7-Series recorders are designed as full featured recorders, their record control is more comprehensive. Both design directions are valid, depending on the application.
Advantage - Tie, since it is product specific
The 552 has a time code input connection which is used to stamp sound files with received time code. Time code sent from a camera or a sync box can be connected to the unit as its source. The time code signal is auto-sensed for its time code rate and that time code value and rate is added to the recorded file metadata. There is no time code generator on the mixer.
The 702T, 744T, and 788T are full-features time code devices with high-precision time code generators. They can read external code as well as generate their own code. Their record control can be activated from cameras using the auto-record feature. 7-Series recorders are often used as the master time code source on set and implement Ambient-compatible tuning circuitry to allow multiple units to be tuned for spot-on accuracy.
Advantage - 7-Series Recorders with Time Code
The 552 has a fixed syntax for file naming and folder generation. A new daily folder is generated each day a recording is made and recordings are saved into the daily folder. Files follow a syntax using date and file number for its file name. For example, a file recorded on August 20, 2009 will have a file name of
09Y08M20-001.WAV. Playback of any recorded file can be done by moving from folder to folder by listening to SVEN say folder names and listening to SVEN state the file number.
7-Series recorders allow for multiple folder options, including project, daily, and scene folders. File names can have any file naming syntax and scene names can be pre-loaded for quick change during recording. Playback of any take is selected from the file view list.
Advantage - 7-Series
Time code and user bit data are text metadata added to the headers of sound files. As the number of tracks and files increases, this text data becomes important and more complete metadata support and management becomes important. The 7-Series recorders support comprehensive BEXT (Broadcast Extension) and iXML metadata. For instance, files from the 788T include track names, notes, and other data which enhances the post production workflow. Metadata values can be changed directly on the recorders using either the units controls or an attached keyboard.
The 552 records Broadcast WAV metadata in every file every time the unit records. If a time code source is connected to the recorder, that time code value is written to metadata. If not, the time-of-day is recorded in the time code value and a note is place in the note field mentioning that time code equals time of day. The 552 has no provision for post-record metadata viewing or editing.
Sound Devices' own Wave Agent File Utility Software is a helpful tool for viewing and editing metadata from files recorded by both the 7-Series recorders and 552 mixer.
Advantage - 7-Series
Flexibility is essential for sound mixers. One day may require a single boom with audio sent to camera. The next day may require isos on everything that makes a sound. No matter the application, there is now a way to make high quality recordings. Having a recorder built in to a field mixer has its obvious advantages. For applications requiring more power and flexibility, stand alone recorders are an important tool in the sound mixer's kit. Let your application be your guide.