To supplement and perhaps clarify some comments by others in this thread:
The SLM jack on the ADC SoundShaper Three IC is not for a “sound level microphone”. Rather this jack is for a “Sound Level Meter”, which is essentially a meter with a built in microphone. This is typically used to help the user to adjust the sliders and turnover switches to compensate for the frequency deficiencies of your listening room. ADC used to make a sound level meter that would work, I believe the model name was SLM-300. My guess is that you can get any basic sound level meter to work if it can be physically plugged into the jack. You were supposed to play a pink noise record or tape through your speakers and use the meter to adjust the sliders on the equalizer until you had balanced frequency response in your room. These days you can use a PC to generate pink noise, there are free programs that you can download that will do this, such as the Marchand Audio generator.
The ADC SA-1 frequency spectrum analyzer also has a front jack. This jack actually is for a microphone. ADC included a nice looking, slim silver microphone with the SA-1, although if you buy a used SA-1, the mic is often missing. The SA-1 can do what a sound level meter can do, but the SA-1 has the pink noise generator built in. A sound level meter is usually used for adjustments, and then stored away somewhere. Whereas the SA-1 is a gorgeous piece of audio hardware designed to sit on the shelf with your other audio equipment. It is a stunning companion to any of the ADC blackface equalizers. It is not as wide or tall as the ADC Soundshaper Three IC (which is, I think the biggest of the ADC equalizers).
The set of sliders at the bottom of the Soundshaper Three IC are not sliders at all, but three position switches. Each switch adjusts the corresponding upper frequency slider control. Think of each upper slider as controlling a band of frequencies. The corresponding lower switch allows you to slightly increase or decrease the band of frequencies controlled by the slider. For a hypothetical example, assume there is a slider that would normally control the band of 5,000-7000 hertz, then the switch underneath that slider would let you select the effective center of that slider as 5,500 hertz, 6,000 hertz, or 6,500 hertz. The entire frequency band would move, for instance, on the first 5,500 hertz position, your new band controlled by the corresponding upper slider would be 4,500 hertz to 6,500 hertz. Essentially, these bottom switches allow you to fine tune the sound adjustments possible from this equalizer. This is also why this equalizer can be called a ‘paragraphic’ equalizer. The “graphic” term means it has sliders, and is not therefore a ‘parametric’ equalizer. But since you can adjust the center frequency of each slider, it has some of the characteristics of a parametric equalizer, hence the hybrid term, “paragraphic” is sometimes used to describe it.
The SLM jack on the ADC SoundShaper Three IC is not for a “sound level microphone”. Rather this jack is for a “Sound Level Meter”, which is essentially a meter with a built in microphone. This is typically used to help the user to adjust the sliders and turnover switches to compensate for the frequency deficiencies of your listening room. ADC used to make a sound level meter that would work, I believe the model name was SLM-300. My guess is that you can get any basic sound level meter to work if it can be physically plugged into the jack. You were supposed to play a pink noise record or tape through your speakers and use the meter to adjust the sliders on the equalizer until you had balanced frequency response in your room. These days you can use a PC to generate pink noise, there are free programs that you can download that will do this, such as the Marchand Audio generator.
The ADC SA-1 frequency spectrum analyzer also has a front jack. This jack actually is for a microphone. ADC included a nice looking, slim silver microphone with the SA-1, although if you buy a used SA-1, the mic is often missing. The SA-1 can do what a sound level meter can do, but the SA-1 has the pink noise generator built in. A sound level meter is usually used for adjustments, and then stored away somewhere. Whereas the SA-1 is a gorgeous piece of audio hardware designed to sit on the shelf with your other audio equipment. It is a stunning companion to any of the ADC blackface equalizers. It is not as wide or tall as the ADC Soundshaper Three IC (which is, I think the biggest of the ADC equalizers).
The set of sliders at the bottom of the Soundshaper Three IC are not sliders at all, but three position switches. Each switch adjusts the corresponding upper frequency slider control. Think of each upper slider as controlling a band of frequencies. The corresponding lower switch allows you to slightly increase or decrease the band of frequencies controlled by the slider. For a hypothetical example, assume there is a slider that would normally control the band of 5,000-7000 hertz, then the switch underneath that slider would let you select the effective center of that slider as 5,500 hertz, 6,000 hertz, or 6,500 hertz. The entire frequency band would move, for instance, on the first 5,500 hertz position, your new band controlled by the corresponding upper slider would be 4,500 hertz to 6,500 hertz. Essentially, these bottom switches allow you to fine tune the sound adjustments possible from this equalizer. This is also why this equalizer can be called a ‘paragraphic’ equalizer. The “graphic” term means it has sliders, and is not therefore a ‘parametric’ equalizer. But since you can adjust the center frequency of each slider, it has some of the characteristics of a parametric equalizer, hence the hybrid term, “paragraphic” is sometimes used to describe it.
Parted with it a few years back just because it was taking up rack room that I needed, and I realized that I hadn't actually used it in a long time. If you are going to have an EQ, these are great ones to have.
Any help on SM would be great, thanks all.
