My question was “any way to tell how much current my amp/s are putting out at X dBs”?
Your original question was difficult to answer, but now you have just made it a little easier by substituting power with current.
As you know, it is dependent on the sensitivity, distance, and the impedance characteristics of the speaker under test. You still need to specify the distance at which the "X" dB is measured. For demonstration, let's just assume the dut is a KEF R500.
sensitivity: 88 dB/2.83V/1m (That's nominal, so let's measure it in your own room)
Impedance: 5 ohms at 500 Hz
https://www.soundstage.com/index.php?option=com_content&view=article&id=793:nrc-measurements-kef-r500&catid=77:loudspeaker-measurements&Itemid=153
There are different ways, below are just two I can think of right now:
Option A
1. Play a 500 Hz sine wave test tone, turn the volume up until you get 2.83 V at the amplifier output terminal, or speaker terminals.
2. Measure the spl at 1 meter distance, using C weighting slow.
3. Measure the current with a clamp on meter that is specified for true rms up to 1000 Hz.
4. Repeat 1 but increase distance to 1.5 meter and turn the volume higher until you get the same "X" dB at the new distance of 1.5 meter.
5. Measure the amp output voltage when you reach "X" dB again at the increased distance.
6. Repeat 3. to get the new current reading at the increased distance and increased voltage.
You can keep going, and in the end you will have your chart of current in amperes versus distance, at "X" dB, assuming that's what you are asking for.
That's only good for a 500 Hz sine wave signal, and the readings will be change as you change the frequency of the signal because the impedance of the speaker varies with frequency.
Using a low cost so called true rms clamp on ammeter will not be very accurate as their accuracy are typically best at 50 to 60 Hz and deteriorate rapidly with frequency even for low crest factor signal such as the sine wave.
Option B
Same as above, except ignore step 3, that is, no need to use an ammeter, but simply calculate the current using the formula Current = Voltage/Impedance.
For the 500 Hz sine wave signal, look up the impedance value from the impedance vs frequency graph attached (thanks to Soundstage.com). In this case, it is about 5 ohms at 500 Hz, so the current should be equal to:
Current = 2.83/5 = 0.566 A
Note: If you increase the distance to 1.5 meter again, the spl will drop, so you have to increase the preamp/avr volume until you reach "X" dB again. Then measure the voltage, depending on your room gain, it should be around 4-4.25 V, say 4 V, then
current = 4/5 = 0.8 A
So with option B, you can still obtain a chart/graph of Current versus distance, at "X" dB, without a clamp on ammeter, but you still need a reasonably good true rms multimeter that offers reasonable accuracy for say up to 1000 Hz.
You also need either a signal generator (preferred) or various sine wave test tone generator from software such as REW, or down load a bunch of sine wave tones at different frequencies.
It is not difficult to measure current at X dB, you just have to realize that realistically your chart will likely be limited to somewhere around 20-1000 Hz by using a low cost multimeter only, and you also need a good impedance vs frequency graph in order to calculate the current, unless you also have a suitable ammeter.
Back to your original question:
Amplifier power output at a dB level? RX A3080 150W AMP max. Any chart ?
That's a tough one because in any case you will then also need a good phase angle vs frequency chart as well because due to the reactive nature of the moving coil loudspeakers, power cannot be calculated from voltage, current and/or the magnitude of the impedance alone, you need the phase angle as well.
