That's the right spirit. If you have different values of rail capactance at hand, you can experiment with that as well. The amp should struggle with bass if there's too little.This difference in peak vs. average output power seems really big, I'm tempted to try and make an amplifier with a tiny transformer, but that has a rather high secondary voltage to see what an 5W average, but 80W peak amplifier sounds like
Hi Guys
I think a poll would be good BUT it should be to see how many people have actually measured the SPL in their listening room at their usual listening position.
I have.
If you make measurements, set the meter to 'C' to have the full import of the sonic energy in the room. 'A' reads 5-6dB lower and ignores 3/4 of the sound energy and thus most of the physical impact.
90dB SPL is NOT what I can listen to. I have to leave the room.
Average levels are in the 60dBs with "loud" going to mid 70s.
Listening to 75dB continuously for an hour takes a day to recover from.
I find that it is much easier to hear the detail of the music at lower SPLs as the protective aural compression we have is not kicking in so much. This means that what I think I hear and what I actually hear are more nearly coincident than at high SPLs, where aural compression kicks in hard and my impression of the sound is completely inaccurate.
I have measured how much power is being used along with the resulting SPLs, with all kinds of music and signal sources. My speakers are 90dB/1W/1m and are quite unforgiving to bad mixes, bad recordings, bad sound quality in general. So, I have PAs that have THD I cannot measure in the normal listening range - which is milliwatts - all the way up to skull crushing 4W+.
Someone asked about a listening position 15m from the speakers. Wow! That is a cathedral. Could be serious problems with reflections. But your chances of hearing God could be pretty high, too.
Have fun
I think a poll would be good BUT it should be to see how many people have actually measured the SPL in their listening room at their usual listening position.
I have.
If you make measurements, set the meter to 'C' to have the full import of the sonic energy in the room. 'A' reads 5-6dB lower and ignores 3/4 of the sound energy and thus most of the physical impact.
90dB SPL is NOT what I can listen to. I have to leave the room.
Average levels are in the 60dBs with "loud" going to mid 70s.
Listening to 75dB continuously for an hour takes a day to recover from.
I find that it is much easier to hear the detail of the music at lower SPLs as the protective aural compression we have is not kicking in so much. This means that what I think I hear and what I actually hear are more nearly coincident than at high SPLs, where aural compression kicks in hard and my impression of the sound is completely inaccurate.
I have measured how much power is being used along with the resulting SPLs, with all kinds of music and signal sources. My speakers are 90dB/1W/1m and are quite unforgiving to bad mixes, bad recordings, bad sound quality in general. So, I have PAs that have THD I cannot measure in the normal listening range - which is milliwatts - all the way up to skull crushing 4W+.
Someone asked about a listening position 15m from the speakers. Wow! That is a cathedral. Could be serious problems with reflections. But your chances of hearing God could be pretty high, too.
Have fun
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I routinely push 110dB on my guitar amp to get acoustic feedback. Thanks to a few dB boost from room reflections that requires about 500mW. The musician's earplugs I use are pretty good but it's still disturbingly easy to overdo the SPL and have my ears bother me a bit after practice. At this point I know how far I can go with the volume knobs in the rig and if I need to push it I watch the output level from the amp's LM3886 with an oscilloscope.
At the other extreme, in normal listening around 55 or 60dB RMS levels on my speaker's tweeter channels are about 11uW with peaks around 11mW. That's a 60dB crest factor as it's an LR6 crossed three way; most all spectral content which converges RMS and peak values is assigned to the mids and woofers. Currently using an LME49600 as the power device on the tweeter channels. It's overkill, really, but the headroom's nice when working with uncompressed material straight off the amp or mics.
At the other extreme, in normal listening around 55 or 60dB RMS levels on my speaker's tweeter channels are about 11uW with peaks around 11mW. That's a 60dB crest factor as it's an LR6 crossed three way; most all spectral content which converges RMS and peak values is assigned to the mids and woofers. Currently using an LME49600 as the power device on the tweeter channels. It's overkill, really, but the headroom's nice when working with uncompressed material straight off the amp or mics.
Hi Guys
When I measured my system at its loudest setting (where I can't stay in the room with it), the scope showed no clipping ever. The highest peak recorded was 4Vpk, which is a 4W peak into the 4R sub and 2W peak into the 8R main.
twest80 - you can get note feedback at 60-70dB easily with the right amp voicing and/or gain and/or compression. A discussion for email rather than here. Glad you are using ear plugs!
djk - Modern sound systems for concerts use heavy compression to keep amplifiers from clipping, so speakers won't be damaged. The last concert I went to, the idiot sound man was distorting the PA running CDs prior to the opening act coming out. Surprisingly it was even louder after and we left.
Have fun
When I measured my system at its loudest setting (where I can't stay in the room with it), the scope showed no clipping ever. The highest peak recorded was 4Vpk, which is a 4W peak into the 4R sub and 2W peak into the 8R main.
twest80 - you can get note feedback at 60-70dB easily with the right amp voicing and/or gain and/or compression. A discussion for email rather than here. Glad you are using ear plugs!
djk - Modern sound systems for concerts use heavy compression to keep amplifiers from clipping, so speakers won't be damaged. The last concert I went to, the idiot sound man was distorting the PA running CDs prior to the opening act coming out. Surprisingly it was even louder after and we left.
Have fun
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Hi Guys
OSHA's recommendations are outright wrong. They pander to big business in not requiring much of any action to be taken to reduce or eliminate physiologically disruptive noise. Workers are provided with earplugs and earmuffs but if they complain about noise levels they end up unemployed.
The problem is 'A' weighting.
'A' weighting IGNORES 75% of the sound energy.
'A' weighting IGNORES the most annoying part of the sound spectrum.
The bass that 'A' weighting ignores is the most difficult to filter and the most difficult to eliminate. By ignoring this frequency range, the din of the industrialised nations grows ever higher and broader. All those silly V-twin motorcycles have no purpose other than to tell you someone with low self-esteem is approaching. Nicely quieted motorcycles have better performance all the way around, better reliability, go faster, and do not upset the whole county. So it can be done and therefore the noisier examples should be outlawed - my opinion.
Things like motorcycle noise CAN be regulated. So can those idiotic bass boomers for cars. These are useless from an engineering view as the passenger cabin of a car is too small for the listener to hear the bass fully. Rather, the vehicles around all act as resonant chambers and those drivers have their ears throbbing and are now impaired for proper attention to road hazards.
The tests that show hearing loss in a 65yr old man in the Western world having a 40dB loss of sensitivity to treble does NOT show hearing loss due to aging. Rather, it shows TYPICAL LOSS for someone exposed to industrial noise - including the roar of modern highways, subways, machinery, gas-powered toys, etc. Tests of aboriginal peoples around the world show no difference in treble sensitivity between a 20yr old and a 90yr old man because they live in a quiet environment.
OSHA's guide is therefore not worth much except for raising some awareness of sound issues.
Each of us has to protect our own hearing.
As far as subwoofers go, most are truly woofers in a separate box. The bulk of audio power is needed in this range if bass is to balance mids and highs. However, one should do a proper installation and use two subs as bass is directional. Each sub should be placed near its related satellite for a cohesive soundscape. It is good to have some power for the subs, but it does not have to be as low-THD as for the satellites since it will only cover a range up to 80Hz typical, 160Hz max. Almost any amp circuit you throw together that functions will suffice hear.
The whole theatre sound at home thing is economically driven. Tiny satellites and a tiny single woofer are a lot cheaper to build and ship than are two proper speaker cabinets. Power is inexpensive, so the availability of many 100s of watts is used as a bandaid to try to overcome the deficiencies of the devised speaker arrangement. A home sound system optimised for music will be much better for movies at home than the nominal "home theatre" system.
My system is a "2.2", with two true subs and two satellites that go to 70Hz. My subs are efficient and need no more than 4W peak (2Wrms) at the loudest possible SPL I've tested. For normal listening it is much lower, like milliwatts.
Have fun
OSHA's recommendations are outright wrong. They pander to big business in not requiring much of any action to be taken to reduce or eliminate physiologically disruptive noise. Workers are provided with earplugs and earmuffs but if they complain about noise levels they end up unemployed.
The problem is 'A' weighting.
'A' weighting IGNORES 75% of the sound energy.
'A' weighting IGNORES the most annoying part of the sound spectrum.
The bass that 'A' weighting ignores is the most difficult to filter and the most difficult to eliminate. By ignoring this frequency range, the din of the industrialised nations grows ever higher and broader. All those silly V-twin motorcycles have no purpose other than to tell you someone with low self-esteem is approaching. Nicely quieted motorcycles have better performance all the way around, better reliability, go faster, and do not upset the whole county. So it can be done and therefore the noisier examples should be outlawed - my opinion.
Things like motorcycle noise CAN be regulated. So can those idiotic bass boomers for cars. These are useless from an engineering view as the passenger cabin of a car is too small for the listener to hear the bass fully. Rather, the vehicles around all act as resonant chambers and those drivers have their ears throbbing and are now impaired for proper attention to road hazards.
The tests that show hearing loss in a 65yr old man in the Western world having a 40dB loss of sensitivity to treble does NOT show hearing loss due to aging. Rather, it shows TYPICAL LOSS for someone exposed to industrial noise - including the roar of modern highways, subways, machinery, gas-powered toys, etc. Tests of aboriginal peoples around the world show no difference in treble sensitivity between a 20yr old and a 90yr old man because they live in a quiet environment.
OSHA's guide is therefore not worth much except for raising some awareness of sound issues.
Each of us has to protect our own hearing.
As far as subwoofers go, most are truly woofers in a separate box. The bulk of audio power is needed in this range if bass is to balance mids and highs. However, one should do a proper installation and use two subs as bass is directional. Each sub should be placed near its related satellite for a cohesive soundscape. It is good to have some power for the subs, but it does not have to be as low-THD as for the satellites since it will only cover a range up to 80Hz typical, 160Hz max. Almost any amp circuit you throw together that functions will suffice hear.
The whole theatre sound at home thing is economically driven. Tiny satellites and a tiny single woofer are a lot cheaper to build and ship than are two proper speaker cabinets. Power is inexpensive, so the availability of many 100s of watts is used as a bandaid to try to overcome the deficiencies of the devised speaker arrangement. A home sound system optimised for music will be much better for movies at home than the nominal "home theatre" system.
My system is a "2.2", with two true subs and two satellites that go to 70Hz. My subs are efficient and need no more than 4W peak (2Wrms) at the loudest possible SPL I've tested. For normal listening it is much lower, like milliwatts.
Have fun
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He was probably trying to heat everything up and drive it into power compression. Then it actually sounds louder and more dynamic when he backs off later. That and ring out any problems that may exist before the headline band takes the stage. I've heard my share of "oh, s***!" moments that they've had to quickly find solutions for on the fly - ten minutes or even an hour into a show ... when it sounded pretty nice with the pre-show music at low levels.
Ah, the ones who didn't lose their hearing due to otitis media at an early age, or through diabetes at a later stage.
Add to that the average life expectancy of <70 years for males, plus hearing loss as a result of shooting rifles by e.g. indigenous folks in Alaska/Greenland.
Which leaves one heck of a statistical population for a proper scientific study.
Those laws are needed to protect the morons......
Going to a loud rock concert? take ear protection.
Working with heavy machinery? where ear protection.
Going out for some fun at a shooting range? where ear protection.
Want to sit in a car with sub's cranking out 1000 Watts? Can't help you there, expect to need a hearing aid a age 38.......
A persistent lack of common sense in the world is why the population requires such nanny-ing.
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