I use Aiyima A07 amplifier with black brick adapter 32v 5A.
Then I bought a multimeter and kwh meter because I am curious how much power does it need from the wall, and how much power does it output to the speaker.
My default listening volume is at 9-10 o'clock, mostly 9.
KWH meter shows Aiyima A07 + 32v 5A adapter is only using 4 watt of power from the wall.
Checking AC Voltage going thru the speaker reveals only 0.6V (playing 50hz sound wave), and only 0.2-0.4v playing music.
We can calculate watt to speaker from the voltage acquired from multimeter, right ? Using P=V^2/R ? if it's 0.2-0.4v playing music, then average is 0.3v * 0.3v / 6ohm (wharfedale spkr) = 0.09/6 =0.015 watt.
Why is it so low ? Is there something I'm missing ?
Then I bought a multimeter and kwh meter because I am curious how much power does it need from the wall, and how much power does it output to the speaker.
My default listening volume is at 9-10 o'clock, mostly 9.
KWH meter shows Aiyima A07 + 32v 5A adapter is only using 4 watt of power from the wall.
Checking AC Voltage going thru the speaker reveals only 0.6V (playing 50hz sound wave), and only 0.2-0.4v playing music.
We can calculate watt to speaker from the voltage acquired from multimeter, right ? Using P=V^2/R ? if it's 0.2-0.4v playing music, then average is 0.3v * 0.3v / 6ohm (wharfedale spkr) = 0.09/6 =0.015 watt.
Why is it so low ? Is there something I'm missing ?
Quick thoughts...
kWh meters may not be very accurate at low current draws.
Power factor might come into this with an SMPS. In other words the kWh meter might not show true power.
Music is to transient and spiky for a DVM to get anything like an accurate voltage reading across a speaker.
Try a 400Hz test tone and an 8 ohm dummy load and see how that compares. 400Hz should be in the range of most DVM's and a voltage of 2.8 volts across the load would be equivalent to 1 watt rms.
kWh meters may not be very accurate at low current draws.
Power factor might come into this with an SMPS. In other words the kWh meter might not show true power.
Music is to transient and spiky for a DVM to get anything like an accurate voltage reading across a speaker.
Try a 400Hz test tone and an 8 ohm dummy load and see how that compares. 400Hz should be in the range of most DVM's and a voltage of 2.8 volts across the load would be equivalent to 1 watt rms.
If you play at levels of ordinary speaking conversation - yes it will be low. It also depends on speaker efficiency which can vary quite a lot upto 10, 15 dB.
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I see, but even if it has margin of error, looking at the low voltage thru the speaker and the low watt from kwh meter, then they're quite comparably low.
For comparison, my Cambridge Azur 640a.v2 consumes 26-30 watt, but when I test it, it's 1v iirc.
Is it common for amplifiers to output low voltage/watt to speaker at normal level ? because I check ppl on youtube and their amp output quite high voltage, but they do it up to a point the speaker vibrates like crazy. While I just use normal listening volume.
@TNT : I use wharfedale 9.2 87db spkrs, and another local brand with 90db sensitivity, and yea it's louder on the 90db at the same volume. But I am still wondering about the low voltage to speaker, is that normal to output only low watt ? Less than 1 watt in this case.
I thought since spec is Output power: 300W+300W (on Aiyima page) but recommended psu 48v,7.5A, then if I use 32v5A even though it will output less, it won't be this low. Or that's just how it is ? I read speaker spec that says x db means it will produce x db with 1 watt power at 1m distance, and my listening distance is more or less 1m.
Have a read at this. Most listening takes place at surprisingly low levels.
A Test. How much Voltage (power) do your speakers need?
A Test. How much Voltage (power) do your speakers need?
Speaker driver impedance will vary with frequency, so normally load use are pure resistor.
Normally a good brick adapter will have less than 0.5W when not connect to amp, check that out first.
Normally a good brick adapter will have less than 0.5W when not connect to amp, check that out first.
I have two brick adapters.
32v 5A , this one draws 0.4w after I pull the dc jack from Aiyima A07
48v 5A, this one draws 1.7-1.8w.
So the 32v is the better one ?
Wow 40% less than 2v lol. So that's quite normal. All my life, my perception of WATT from speakers/amp is so wrong.
People with higher than 2v probably have big room or big speakers or both, over 20v probably use stage sound system.
look for some music that has a wide dynamic range, look at the dynamic music and compare it to some modern music with a program like Audacity.
Also your ears are mostly logarithmic, to sound 2x as loud you need 10x the power. 4x as loud 100x the power.
go to a concert that is 100% acoustic. No PA system at all. You will be surprised how loud a Jazz quartet or an opera singer can be. To recreate that volume level in your home you need power.
Also your ears are mostly logarithmic, to sound 2x as loud you need 10x the power. 4x as loud 100x the power.
go to a concert that is 100% acoustic. No PA system at all. You will be surprised how loud a Jazz quartet or an opera singer can be. To recreate that volume level in your home you need power.
Things can get big very quickly though with music as multisync is saying.
'Loud-ish' might only see a couple of volts, 'Loud' could see 6 or 7 volts and 'Very Loud' could see peaks of 30 or 40 volts across the speaker.
I should have included the SPL calculator to illustrate why speakers typically draw less than 1w:
SPL calculator
SPL calculator