Pad: Difference between revisions - Bose Portable PA Knowledge

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We use them with our Bose Systems when running a pro level +4 dBu signal (e.g. output from a mixer) to the XLR inputs on Channels 1 or 2 on the PS1 Powerstand. We want to do this because the input sensitivity for these inputs is set for microphones. To get a better match for levels between the source and our inputs, we can use a pad.

Values of attenuation are expressed in decibels, dB. dBu/dBV/dBm are ratios/references. (dBm is a ratio of power, relative to 1mW. dBu and dBV are ratios of voltage, relative to 0.775V and 1V, respectively.) When determining how much of a pad is needed, we want to compare apples-to-apples by converting specs (e.g. http://www.sengpielaudio.com/calculator-db-volt.htm) to a common reference. For the 'mixer line-output to PS1 mic-input' scenario, -20 dB is a good choice because it brings the hot, line-level signal down to a lower voltage range that a mic pre can easily handle.

Values of attenuation are expressed in decibels, dB. dBu/dBV/dBm are ratios/references. dBm is a ratio of power, relative to 1mW. dBu and dBV are ratios of voltage, relative to 0.775V and 1V, respectively. When determining how much of a pad is needed, we want to compare apples-to-apples by converting specs (e.g. http://www.sengpielaudio.com/calculator-db-volt.htm) to a common reference. For the 'mixer line-output to PS1 mic-input' scenario, -20 dB is a good choice because it brings the hot, line-level signal down to a lower voltage range that a mic pre can easily handle.

Pads can also help when connecting the PS1 Line Outs to ''semi-pro'' or ''consumer'' recording devices. If the PS1 Line Outs are too ''hot'' for the recorder's inputs, a pad can be used to prevent overdriving those inputs into (clipping) distortion.

A -20dB pad is also a good choice when connecting the PS1 Line Outs to a house PA, or other off-stage system. This would ensure that the house mixing console's inputs can handle the signal level without being overdriven into distortion, especially if the house console has insufficient built-in pads, or none at all. (beware of the potential for Ground Loops here.)

Another application (although relatively rare) is if you want to daisy-chain the Line-Out of one PS1 Powerstand to Channel 1 or 2 of another. In that case you probably want to have a -20 dB pad inline, between the Line-Out of the first System and the Channel 1 or 2 XLR input of the second.

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 We use them with our Bose Systems when running a pro level +4 dBu signal (e.g. output from a mixer) to the XLR inputs on Channels 1 or 2 on the PS1 Powerstand. We want to do this because the input sensitivity for these inputs is set for microphones. To get a better match for levels between the source and our inputs, we can use a pad.
-Values of attenuation are expressed in decibels, dB. dBu/dBV/dBm are ratios/references. (dBm is a ratio of power, relative to 1mW. dBu and dBV are ratios of voltage, relative to 0.775V and 1V, respectively.) When determining how much of a pad is needed, we want to compare apples-to-apples by converting specs (e.g. http://www.sengpielaudio.com/calculator-db-volt.htm) to a common reference. For the 'mixer line-output to PS1 mic-input' scenario, -20 dB is a good choice because it brings the hot, line-level signal down to a lower voltage range that a mic pre can easily handle.
+Values of attenuation are expressed in decibels, dB. dBu/dBV/dBm are ratios/references. dBm is a ratio of power, relative to 1mW. dBu and dBV are ratios of voltage, relative to 0.775V and 1V, respectively. When determining how much of a pad is needed, we want to compare apples-to-apples by converting specs (e.g. http://www.sengpielaudio.com/calculator-db-volt.htm) to a common reference. For the 'mixer line-output to PS1 mic-input' scenario, -20 dB is a good choice because it brings the hot, line-level signal down to a lower voltage range that a mic pre can easily handle.
 Pads can also help when connecting the PS1 Line Outs to ''semi-pro'' or ''consumer'' recording devices. If the PS1 Line Outs are too ''hot'' for the recorder's inputs, a pad can be used to prevent overdriving those inputs into (clipping) distortion.
+A -20dB pad is also a good choice when connecting the PS1 Line Outs to a house PA, or other off-stage system. This would ensure that the house mixing console's inputs can handle the signal level without being overdriven into distortion, especially if the house console has insufficient built-in pads, or none at all. (beware of the potential for Ground Loops here.)
 Another application (although relatively rare) is if you want to daisy-chain the Line-Out of one PS1 Powerstand to Channel 1 or 2 of another. In that case you probably want to have a -20 dB pad inline, between the Line-Out of the first System and the Channel 1 or 2 XLR input of the second.