Hi everyone, there are some threads about this but not with the answer I looking for. How much watt does a amplifier use with different frequencies. I know a 100 watt amp will give 100 watt at every frequency, so a flat sounding speaker with 90db sensivity will give you 110db at every frequency( 100hz, 500hz, 10000hz), but how much power( watt) will it use. Is there some theoretical information about that...
An example - - > if I play a 100hz sinewave for 1 hour and a 200hz sinewave for 1 hour, what will the difference be.
I want to know because I have 4 drivers wich can take 6 watt RMS each so total of 24 watt RMS... I want to give it 50 watt RMS but highpass at 50hz, hope this will cut off some power...
An example - - > if I play a 100hz sinewave for 1 hour and a 200hz sinewave for 1 hour, what will the difference be.
I want to know because I have 4 drivers wich can take 6 watt RMS each so total of 24 watt RMS... I want to give it 50 watt RMS but highpass at 50hz, hope this will cut off some power...
The output power (with the same voltage amplitudes) will be the same regardless of frequency,
because power is defined as rms, which is averaged over an entire cycle of the sine wave.
A lossless high pass crossover will reduce the amplifier's output power (less current output
for the same voltage), and the power into the speaker (less voltage at its terminals),
if the input signal contains frequencies below the high pass filter's corner frequency.
because power is defined as rms, which is averaged over an entire cycle of the sine wave.
A lossless high pass crossover will reduce the amplifier's output power (less current output
for the same voltage), and the power into the speaker (less voltage at its terminals),
if the input signal contains frequencies below the high pass filter's corner frequency.
Last edited:
I would say most speakers burn because the VC cant dissipate the heat generated by application of power. Doesnt matter what frequency or combination of frequencies. Other failure mechanisms such as mechanical disintegration are frequency dependent - and your high pass filter could keep these speakers from being destroyed by low frequency content.
Also, consider that pretty much no music plays continuous tones for an hour, so besides torture testing, such power dissipation requirements are unrealistic. Most music is transient in nature; it can have moments of pushing lots of power, followed by other moments of a lot less. The average over minutes of time is what cooks the voice coil.
They say you can plug a Bose 901 into the 120V AC line and it'll take it - but they dont say for how long. That's a key. One time I was programming an AC source for imparting transients and one thing it could do was a single cycle of 120VAC. I went looking for a speaker and found one, connected it up and imparted it with a single cycle of 120VAC.
No issue - it took it. I tried 2 cycles - took it. I didnt take it to the point of blowing the speaker, as I didnt want to stink up the lab (and bring attention to what I was doing...)
I wouldnt worry about your 50W playing real music - versus a continuous tone at that power.
Also, consider that pretty much no music plays continuous tones for an hour, so besides torture testing, such power dissipation requirements are unrealistic. Most music is transient in nature; it can have moments of pushing lots of power, followed by other moments of a lot less. The average over minutes of time is what cooks the voice coil.
They say you can plug a Bose 901 into the 120V AC line and it'll take it - but they dont say for how long. That's a key. One time I was programming an AC source for imparting transients and one thing it could do was a single cycle of 120VAC. I went looking for a speaker and found one, connected it up and imparted it with a single cycle of 120VAC.
No issue - it took it. I tried 2 cycles - took it. I didnt take it to the point of blowing the speaker, as I didnt want to stink up the lab (and bring attention to what I was doing...)
I wouldnt worry about your 50W playing real music - versus a continuous tone at that power.
Thanks( all of you ) that was the answer I was looking for.. Kind off..
Some detail about my project I have in mind...
I want to use 4 tangband w1-2121s in a 850ml cabinet tuned with some passive radiators and highpass them at 50hz( steep roll of below 50hz)...i want to use a
Dayton dspb 250 amp with dsp so I can equalize it and add highpass to it. The amp have 50 + 50 watt at 4 ohm so I guess 25 + 25 watt at 8ohm ( 2 speakers in series)
W1-2121S - 1" Alum. Full Range - TB SPEAKER CO., LTD.
A little bit over excursion, but with dsp I can flatten that out I hope ( around 80 - 120 hz)
Attachments
Thanks, there is not a definite answer but they say music is less dense as given amplifier power( almost 10 times?) so I must be good with a 25 rms speaker and 50 watt amp power( like someone said before)... I wondering how bass heavy songs will affect this because there is some strong sinewave like parts in them sometimes.
Seems that below 350hz there is not much difference in power consumption but if I play bass heavy songs on a bleutooth speaker it will faster discharge then when I play relaxed music...
You're right bass heavy will push an amp hard, classical music doesn't stress an amp unless its Tocata and Fugue in D minor on a decent organ with 32' pipes 🙂
You play dub reggae you need real watts, not marketing watts.
You play dub reggae you need real watts, not marketing watts.
Pink noise has an interesting property that it has equal power in bands like those used in a graphic EQ. So you could think of a 10 band EQ, with each band contributing 5W of power out of your 50W amp - given each is set at the same level. Your speaker voice coil(s) will still have to burn 50W.
Music of course isnt pink noise and some loud pure tone can be rendered at any time, in which case most of the amplifier power will be used providing that tone.
The battery drain you observed in a BT speaker could be from the necessary EQ in that speaker for it to make any bass at all! For all we know, the bass frequencies could be 4 or 8X the power of all the rest, to get that little speaker in a little enclosure to make bass perceptibly at the same level as the rest of the audio frequencies. In this case, the amplifier definitely uses more power at different frequencies - the bass frequencies.
Back to the graphic EQ with pink noise; turn up the 50Hz control 3db and that doubles the power the amplifier is providing in that band to 10W. Turn it up 6 db (another +3) and now the amp is providing 20W in that band. You'd have 30W to split among the other 9 bands, so they'd have to be turned down to compensate.
I'm sure others will let me know if my thinking is right.
Music of course isnt pink noise and some loud pure tone can be rendered at any time, in which case most of the amplifier power will be used providing that tone.
The battery drain you observed in a BT speaker could be from the necessary EQ in that speaker for it to make any bass at all! For all we know, the bass frequencies could be 4 or 8X the power of all the rest, to get that little speaker in a little enclosure to make bass perceptibly at the same level as the rest of the audio frequencies. In this case, the amplifier definitely uses more power at different frequencies - the bass frequencies.
Back to the graphic EQ with pink noise; turn up the 50Hz control 3db and that doubles the power the amplifier is providing in that band to 10W. Turn it up 6 db (another +3) and now the amp is providing 20W in that band. You'd have 30W to split among the other 9 bands, so they'd have to be turned down to compensate.
I'm sure others will let me know if my thinking is right.
Last edited: