I find the specs of many preamplifiers indicating level of loudness usually uses reference point at -30dB. Unfortunately, my amp’s faceplate doesn’t have a dB scale on volume. Thus, how can I find the point where -30dB is located on the scale of volume knob? It would be helpful if one could describe it in “o’clock” scale. Thanks in advance
They are all different. If you want to calibrate it, electrically set the output of the line stage
for unity gain with the volume control. Mark this setting as 0dB. Say this level is 1Vrms at 1kHz.
Then reduce the output level with the volume control from 1Vrms down to 0.0315Vrms.
This setting is -30dB.
for unity gain with the volume control. Mark this setting as 0dB. Say this level is 1Vrms at 1kHz.
Then reduce the output level with the volume control from 1Vrms down to 0.0315Vrms.
This setting is -30dB.
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The amount of gain in a line stage in a home preamp could be anything from 0dB to perhaps 35dB.
The front panel marking of 0dB at the full volume control setting just means that the preamp
is operating at its maximum gain, whatever that is.
Home audio equipment has no standards for output level. Even different CD players
will vary somewhat in their maximum output levels. Professional practice is different,
and 0dB actually means something on an absolute basis. For more info, read this:
VU meter - Wikipedia
The front panel marking of 0dB at the full volume control setting just means that the preamp
is operating at its maximum gain, whatever that is.
Home audio equipment has no standards for output level. Even different CD players
will vary somewhat in their maximum output levels. Professional practice is different,
and 0dB actually means something on an absolute basis. For more info, read this:
VU meter - Wikipedia
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No ! Volume pot position depends on the input signal level.
dB is a comparative scale. You compare an input signal with an output signal.
0dB is the point at which the amplifier nor amplifies, nor attenuates.
Say 1V in, 1V out. Unity gain as Rayma pointed out.
You can only make a scale if You apply always the same signal level.
... But as amplifiers usually have gain ...input signal is multiplied by this "gain"
The 0dB Power led on the amp or the 0dB Power mark on the VU is where the amplifier clips.
The 0 dB here compares the input signal *gain with the rated power output signal.
dB is a comparative scale. You compare an input signal with an output signal.
0dB is the point at which the amplifier nor amplifies, nor attenuates.
Say 1V in, 1V out. Unity gain as Rayma pointed out.
You can only make a scale if You apply always the same signal level.
... But as amplifiers usually have gain ...input signal is multiplied by this "gain"
The 0dB Power led on the amp or the 0dB Power mark on the VU is where the amplifier clips.
The 0 dB here compares the input signal *gain with the rated power output signal.
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Usually loudness have effect when volume knob is at position lower than 12h.
Because loudness tap is at that position of volume potentiometers.
The lower you go, example 9h = more bass and treble boost.
At 8h even more boost than at 9h.
That is for most common type of loudness, with loudness button.
Yamaha loudness works different, Grundig amps with double loudness taps are flat at 2h (second loudness tap)...
Because loudness tap is at that position of volume potentiometers.
The lower you go, example 9h = more bass and treble boost.
At 8h even more boost than at 9h.
That is for most common type of loudness, with loudness button.
Yamaha loudness works different, Grundig amps with double loudness taps are flat at 2h (second loudness tap)...
This is both right and wrong. Yes, dB is a ratio expressed as a logarithm, but "loudness" as referred to here is "loudness compensation", the application of a special form of equalization meant to spectrally compensate for the playing of material at a level lower level that that at which it was mixed, and necessitated by human hearing's lessening sensitivity to low frequencies as overall level drops. The levels being discussed relate to the point at which a certain amount of loudness compensation should be applied. The problem is that the correct compensation is not related to knob position at all, but rather is related to the differential SPL between the original mix level and your own play level. Most people give up and just adjust it by ear until it sounds right, but having the right curve matters too, and Fletcher-Munson, the most common, is wrong.
As to "reference", the film industry has a reference level that refers both to a specific SPL (and means of measuring it), and a level in therms of dBFS. AV receivers with proper calibration can scale their volume controls such that when it says "0dB", the acoustic level of calibration noise will be identical to the same signal reproduced on a film dubbing stage, and in a calibrated theater or screening room. The reference level is 85dB and the digital reference level is -20dBFS.
You can do that with a stereo system too, but it may be wrong if used for attempting to apply loudness compensation because the music industry is not bound to an industry-wide reference level for anything, mixing or release. Thus, the loudness comp curve could be off by as much as 15dB. And, such calibration only works if the source device is included, as there are no firm standards there either.
The basic procedure is to play band-limited noise recorded at -20dBFS and adjust your volume knob so you can measure 85dB SPL at the listening position. That position becomes "reference level" or "0dB". Then make sure all sources have their levels identical, or are compensated for elsewhere. But it's sort of big guess because you don't know anything about production mix levels outside of the film industry.
Have fun.
I don't think this is correct. Reading the first post it seems clear that the OP meant loudness in the sense of how loud the sound is.
Jan
It is probably Pioneer amplifier, loudness control is specified at -30dB position of the volume knob.
All Pioneer amps from series A have even tone controls connected to loudness tap on volume potentiometer, and tone control specs are too defined at -30dB position of volume knob.
All Pioneer amps from series A have even tone controls connected to loudness tap on volume potentiometer, and tone control specs are too defined at -30dB position of volume knob.
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