User manual NADY SPM-4250

[. . . ] POWERED MIXER OWNER'S MANUAL SPM-4250 4-Channel Stereo Powered Mixer SPM-4250 4 Channel Stereo Powered Mixer Congratulations on your choice of the NADY AUDIO SPM-4250 Stereo Powered Mixer -- you have purchased one of the finest stereo powered mixing units on the market today. This unit was developed using the expertise of professional sound engineers and working musicians. You will find that your new SPM-4250 has superior performance and greater flexibility than any other stereo powered mixer in its price range. Please read this manual carefully to get the most out of your new unit. [. . . ] You do not want the Peak LED to light except very intermittently. If it lights persistently, reduce the GAIN CONTROL (4). (4) GAIN CONTROL The GAIN control adjusts the input sensitivity of the mic and line inputs on each channel. This control can be adjusted to accommodate input signals from a wide variety of sources, from the high outputs of keyboards or drum machines to the small signal outputs of microphones. The best balance of S/N and dynamic range will be achieved if you adjust the GAIN control on each channel separately so that the maximum signal level can be input without distortion. While speaking, singing, or playing an instrument at maximum performance level, increase the GAIN control until the PEAK LED (3) flashes, then turn down the GAIN control until the flashing stops. (5) EQUALIZER CONTROLS All input channels are fitted with a three-band EQ - HIGH, MID, and LOW. All three bands have up to 15 dB of cut and boost, with a center detent for OFF. The frequency response is flat when all three EQ knobs are in the center detent position. The HIGH and LOW shelving controls have their frequencies fixed at 12 KHz and 90Hz respectively. The MID control has a peaking response at 2KHz. The channel EQ is a valuable feature of the mixer as it allows the user to control the tonal characteristics of each channel separately. For example, boosting the LOW can fatten the 5 (7) (4) (5) (6) (8) (9) (3) (2) (1) FRONT CONTROLS AND CONNECTIONS sound, add warmth to vocals, or extra punch to bass, drums and synths; the MID control can be used to define the midrange or bring out the vocals; and adjusting the HIGH control can provide a crisp sounding high end. Another very important, yet often overlooked technique is to use the EQ to subtract from the mix. Cutting the HIGH control can reduce unwanted sibilance, hiss, cymbals, or high frequency feedback, while attenuating the MID or LOW can also eliminate feedback or clear up a muddy sounding mix. Cutting the HIGH and LOW, then pushing up the VOLUME CONTROL (9) is equivalent to mid range boost![Note: Always reset a channel's input GAIN CONTROL (4) (or external device's output level) after altering the amount of equalization. ] The key to successful equalization is to avoid excess. Too much equalization on the input channels will result in a mix that is smeared together with nothing specifically defined. During rehearsals, experiment with the equalizer controls on various instruments, vocals and combinations of these mixed together to become familiar with various equalizer settings. (6) PFL CONTROL The PFL (pre-fader listen) control adjusts the volume of the mono signal sent to the HEADPHONES (22) provided the master section PFL SWITCH(23) is enabled. The signal is post EQ (5) and independent of the channel VOLUME (9) or EFFECTS (7). Adjusting the PFL never affects the AUX SEND (18), RECORD OUT (20), or SPEAKER OUTPUTS (26). [. . . ] Stereo headphone connection with 1/4" TRS plug 3. 1/4" mono (TRS) plug used as unbalanced input/output 4. 1/4" stereo (TRS) plug used as balanced input/output 5. RCA pin plug for unbalanced input/output 9 SPECIFICATIONS 1. [. . . ]