White Instruments 4000
31 band EQ w/x-over
Model DetailsThe Series 4000 Active Equalizer incorporates RLC elements for response control in an
audio system. It contains 1/3 octave filter sections, continuously adjustable from +10 dB
of emphasis to -10 dB of cut, in each 1/3 octave band.
Integrated circuit operational amplifiers are used in a NEGATIVE feedback circuit with
very low distortion.
The low distortion and low noise of the Series 4000 equalizers make them well-suited for
recording and broadcast program equalization. Shelving, peaking, and band-limiting
functions all can be performed simultaneously. Also, the relatively narrow bandwidth of
individual filter sections makes it possible to "scrub" unwanted hum and noise from tape
Series 4000 equalizers can be used in conjunction with established 1/3 octave acoustic
measuring techniques and instrumentation, such as the White Instruments Model 140
Sound Analyzer, to improve the performance of almost any program reproducing chain.
An explanation of detailed equalization procedures is beyond the scope of this manual;
however, the following brief hints may be helpful:
1. Know the characteristics of your measuring microphone. A laboratory-quality, nondirectional
unit such as the Bruel & Kjaer 4134 is recommended. But all microphones
become somewhat directional at high frequencies and it is important to avoid
erroneous measurements resulting from microphone characteristics.
2. Average two or three sets of readings for each listening location. Using a single fixed
microphone location can introduce errors of several decibels in comparison with the
average response in an imaginary two-foot diameter sphere occupying the same
position as a listener's head.
3. Don't equalize for flat high frequency response. Depending on listener preference and
the particular loudspeaker system used, acoustic response of recording studio
monitors is usually rolled off above 5 kHz or so. Home high fidelity systems usually
require greater rolloff, typically starting around 2.5 kHz.
- Standard automatic interface switching allows all active ports to transmit their data to the printer
- Prints high-resolution (600 x 600 dpi) text and graphics at a fast 32 pages per minute
- Paper capacity of up to 3,100 sheets allows for longer print runs
- The upper and lower cassettes and the multi-purpose tray offer you a wide variety of paper sizes for added flexibility
- Optional network modules facilitate easy connectivity in both Ethernet and Token Ring environments