This isn't related to solid state amps directly, I'm speaking of amplifiers in general so perhaps this is not the right place for this thread?
Assuming the amplifier is for a pair of speakers in an average living room and not at some concert, how powerful should an amplifier be? I'm thinking of an amplifier that would be able to drive any pair of speakers to the threshold of hearing pain, I'm not talking about subwoofers as I see that it would probably be possible to produce 20hz waves with 1 billion watts without hitting any pain threshold. So, assuming a rather large living room, the least sensitive full-spectrum speakers there are and no equalizing, how many watts do I need to feel the need to hold my hands over my ears?
Assuming the amplifier is for a pair of speakers in an average living room and not at some concert, how powerful should an amplifier be? I'm thinking of an amplifier that would be able to drive any pair of speakers to the threshold of hearing pain, I'm not talking about subwoofers as I see that it would probably be possible to produce 20hz waves with 1 billion watts without hitting any pain threshold. So, assuming a rather large living room, the least sensitive full-spectrum speakers there are and no equalizing, how many watts do I need to feel the need to hold my hands over my ears?
Hi,
Most domestic speakers quite rightly cannot do 120dB,
especially the insensitive one, so your asking a very
loaded question that has no simple answer.
Any number you come up with will be way too high.
If you want to explore the maximum loudness of
domestic speakers sympathetic matching is required.
If you like it loud, high power handling, max SPL
and efficiency is required.
Large rooms need bigger speakers with higher max SPL,
to get the same SPL as smaller speakers in smaller rooms.
rgds, sreten.
Most domestic speakers quite rightly cannot do 120dB,
especially the insensitive one, so your asking a very
loaded question that has no simple answer.
Any number you come up with will be way too high.
If you want to explore the maximum loudness of
domestic speakers sympathetic matching is required.
If you like it loud, high power handling, max SPL
and efficiency is required.
Large rooms need bigger speakers with higher max SPL,
to get the same SPL as smaller speakers in smaller rooms.
rgds, sreten.
All speakers introduce dynamic compression. Some speakers introduce a whole lot of dynamic compression. Smaller speakers, and less efficient speakers, are the worst offenders. A really good speaker will introduce 4-6 dB of compression @ 110 dB. Most speakers are worse in this regard. Think about that; that represents huge power.
You can calculate that your speakers can achieve 120 dB spl with your amplifier, and when you measure the spl you'll find that you're not even close.
I am using a large old Fisher amplifier right now, rated 130 watts /channel, and it allows me to listen without clipping (most of the time). The hot tip is to have enough power so you virtually never clip. A good rule of thumb for reasonably efficient (90 dB), reasonably dynamic speakers is 100 W/ channel. But I built some speakers back in the day (way back in the day) out of old Electro Voice PA drivers; 15" "woofers" and big horn midranges and tweeters. They were huge and around 100 dB/ watt efficient, and with 20 watts RMS/ channel they could play as loud as you could bear (around 110 dB). Now try that trick with living room (wife) friendly speakers, and be sure to post the plans. You can achieve 110 dB, but probably not with 20 watts.
You can calculate that your speakers can achieve 120 dB spl with your amplifier, and when you measure the spl you'll find that you're not even close.
I am using a large old Fisher amplifier right now, rated 130 watts /channel, and it allows me to listen without clipping (most of the time). The hot tip is to have enough power so you virtually never clip. A good rule of thumb for reasonably efficient (90 dB), reasonably dynamic speakers is 100 W/ channel. But I built some speakers back in the day (way back in the day) out of old Electro Voice PA drivers; 15" "woofers" and big horn midranges and tweeters. They were huge and around 100 dB/ watt efficient, and with 20 watts RMS/ channel they could play as loud as you could bear (around 110 dB). Now try that trick with living room (wife) friendly speakers, and be sure to post the plans. You can achieve 110 dB, but probably not with 20 watts.
The advice so far is good.
Basically though, if you distill it all down, "100 watts per channel" is a pretty solid answer. Most of the time you'll never get close to using the wattage on average. However, the peaks in the music source may well come close to the dynamic range limit of the amplifier. Whenever it happens, unfortunately, there is a loud crackling sound from clipping.
At our parish church, I was in charge of outfitting a set of speakers for the whole gospel setup. Out of dire economy (there are few churches that have much in the way of spare funds!) I got the idea of using a bunch of Craigslist amplifiers from Alesis. The Alesis RA–100 in particular, since they could and can be had for less than $75 each.
These proved to be a spectacularly good investment. Tough as nails, clean and transparent. By buying 5 of them, we had 10 channels to individually control the different speakers that got 'found' or 'donated'. This was key since they each had quite good power handling, but also vexingly different watt→dB sensitivity. The 10 knobs allowed individual balancing and tailoring, easily.
The point that still stands out to me though was, "100 watts per channel" is quite, quite adequate in general.
By comparison, I have had a fair amount of experience using Crown (and other) "old school" amplifiers in the 1000 W/channel power level and higher. Not digital, but big ol' hunks of immobile iron. At low volume (around what the much less powerful RA–100s were running), the output of the 1000 W/channel Crowns was just as clean. But, as the PA speakers (hooked in series-parallel of identical types to divide up the power) were driven much harder the output seemed to become substantially less musical. Perhaps because with all that more power, the amplifier was having to overcome a whole lot more reverse EMF. Dunno.
Lastly, again in my experience from working with a number of audiophiles having almost wickedly different tastes in music, amplification and the amount of money that they ploughed into their systems, again I was struck by the “sweet spot” in quality vs. cost that about 100 W to 200 W per channel delivers. The 5× to 7× cost to get to 500 W/channel on the few systems I've heard … clearly wasn't doing anything more than giving a higher ceiling for clipping. For that, I think it is almost worth it. But really … for 5× to 7× the cost, really ought to just get better speakers. They're the Achilles Heel of any system, in almost every case.
GoatGuy
Basically though, if you distill it all down, "100 watts per channel" is a pretty solid answer. Most of the time you'll never get close to using the wattage on average. However, the peaks in the music source may well come close to the dynamic range limit of the amplifier. Whenever it happens, unfortunately, there is a loud crackling sound from clipping.
At our parish church, I was in charge of outfitting a set of speakers for the whole gospel setup. Out of dire economy (there are few churches that have much in the way of spare funds!) I got the idea of using a bunch of Craigslist amplifiers from Alesis. The Alesis RA–100 in particular, since they could and can be had for less than $75 each.
These proved to be a spectacularly good investment. Tough as nails, clean and transparent. By buying 5 of them, we had 10 channels to individually control the different speakers that got 'found' or 'donated'. This was key since they each had quite good power handling, but also vexingly different watt→dB sensitivity. The 10 knobs allowed individual balancing and tailoring, easily.
The point that still stands out to me though was, "100 watts per channel" is quite, quite adequate in general.
By comparison, I have had a fair amount of experience using Crown (and other) "old school" amplifiers in the 1000 W/channel power level and higher. Not digital, but big ol' hunks of immobile iron. At low volume (around what the much less powerful RA–100s were running), the output of the 1000 W/channel Crowns was just as clean. But, as the PA speakers (hooked in series-parallel of identical types to divide up the power) were driven much harder the output seemed to become substantially less musical. Perhaps because with all that more power, the amplifier was having to overcome a whole lot more reverse EMF. Dunno.
Lastly, again in my experience from working with a number of audiophiles having almost wickedly different tastes in music, amplification and the amount of money that they ploughed into their systems, again I was struck by the “sweet spot” in quality vs. cost that about 100 W to 200 W per channel delivers. The 5× to 7× cost to get to 500 W/channel on the few systems I've heard … clearly wasn't doing anything more than giving a higher ceiling for clipping. For that, I think it is almost worth it. But really … for 5× to 7× the cost, really ought to just get better speakers. They're the Achilles Heel of any system, in almost every case.
GoatGuy
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I also see a comment about "3.5 watts" per channel. This is good advice if taken in the contest of 3.5 watts of average music power. So long as the amplifier has a really tolerant range for clipping (and soft clipping at that), then it is also a good number.
The guy having 0.35 W/channel (350 mW) also very likely has an amplifier that can reproduce peaks in excess of 5× the average voltage at 350 mW. (8 W peaks)
The guy having 0.35 W/channel (350 mW) also very likely has an amplifier that can reproduce peaks in excess of 5× the average voltage at 350 mW. (8 W peaks)
that depends on speaker efficiency and spl required
Loudspeaker Sensitivity and Amplifier Power Requirement
Loudspeaker Sensitivity and Amplifier Power Requirement
Let's have a poll !
I had 35w , not enough. 95w hk680 , thought it was enough.
200+ w , I'm still exploring.
The speakers are 150w , you must be careful. The SQ and how
"interesting" the music is .... is what is different at the greater power.
Not louder from 95 to 200w+ , but you want to hear what your best (recording)
will sound like loud , how "interesting" it is. Detail is better since
the amp does not strain with anything at any level.
PS- from a amp standpoint, a pair MT-200 large BJT's with 50Kuf will do 100W
with 200W peaks (HK 680 power level w/ a better PS). Sufficiently "interesting". With 90db/w/m speakers .....
OS
I had 35w , not enough. 95w hk680 , thought it was enough.
200+ w , I'm still exploring.
The speakers are 150w , you must be careful. The SQ and how
"interesting" the music is .... is what is different at the greater power.
Not louder from 95 to 200w+ , but you want to hear what your best (recording)
will sound like loud , how "interesting" it is. Detail is better since
the amp does not strain with anything at any level.
PS- from a amp standpoint, a pair MT-200 large BJT's with 50Kuf will do 100W
with 200W peaks (HK 680 power level w/ a better PS). Sufficiently "interesting". With 90db/w/m speakers .....
OS
I do not listen to the threshold of pain, at normal listening levels, when I measure signal on the speaker terminal, its about 250 to 500 milliwatts, yes, milliwatts, rarely reaching one watt of power, so 2 watt Magnavox is enough...but that is at moderate listening with quite efficient speakers. If you want loud, you need both, power and highly efficient speakers. If one is already fixed (speakers sitting at home), then amp power required can be calculated easily.
You need enough power to play whatever music style(s) you enjoy loud enough to enjoy and properly appreciate the music on what ever speakers you have and in the environment you are listening in without any appreciable clipping or added distortion. Too many variables to give a specific answer. That said, for a domestic space with reasonably efficient speakers (read as not grossly inefficient) and a source capable of decent dynamic range, an amplifier of about 100w per channel of average output should suffice under most circumstances. The practical range would be anywhere from 50wpc to 250wpc, IMHO.
If your ears are bleeding it is loud enough.
Went to a Status Quo rock concert in 1977.
Couldn't hear for 3 days afterwards.
There are laws now that cover sound levels at concerts.
Went to a Status Quo rock concert in 1977.
Couldn't hear for 3 days afterwards.
There are laws now that cover sound levels at concerts.
Thanks for some great answers, I understand that this was not easy to get a specific answer to.
So by having an amplifier that can output 2x100W average and perhaps 2x300-400W peaks it should be able to drive just about anything? What would the worst case scenario look like? Let's say I'm sitting 15m from my speakers and they are the least sensitive speakers commercially available (what type of speakers would that be by the way?)?
So by having an amplifier that can output 2x100W average and perhaps 2x300-400W peaks it should be able to drive just about anything? What would the worst case scenario look like? Let's say I'm sitting 15m from my speakers and they are the least sensitive speakers commercially available (what type of speakers would that be by the way?)?
available now, or available ever? The original Apogee full range and scintilla were pigs to drive and inefficient. 79dB efficiency (at 3m, panels are odd) and 1 ohm nominal impedance, but dropping much lower in places. They ate anything short of a krell or similar. You could rewire some models for 4 Ohms but that was not considered manly!
How nicely an amplifier clips is very important. As is the match between the amplifier & its load. If you have an ugly load you will need a more robust amplifier (not more power). Amplifier shouldnever really beconsidered independent of the speakers it will be used with.
My regular amp is 20w and satisfies most of my needs. It has developed a buzz and i am currently using 5w ACA amps which do very well (they clip very benignly)
dave
My regular amp is 20w and satisfies most of my needs. It has developed a buzz and i am currently using 5w ACA amps which do very well (they clip very benignly)
dave
"...what this country needs is a good 2 watt amplifier." Paul Klypsch
It depnds on the efficiency level of your loudspeaker/s
Loudspeakers SHOULD be rated for efficiency: spl level in db with 1watt input measured 1 meter from the front on axis, so most good efficiency rations would be listed as 98db/1watt/1meter. Speakers below 90db/1w/1m is approaching FAIR and below 85db.1w.1meter is IMHO POOR. The whole point in this is have an efficient load on the amp where it will never be forced into clipping. Clipping causes the amp to internally hemorage distortion from every pore.
Also you should be aware that exposure to over 90db of continuous sound for an extended period of time is hazardous to your hearing.
It depnds on the efficiency level of your loudspeaker/s
Loudspeakers SHOULD be rated for efficiency: spl level in db with 1watt input measured 1 meter from the front on axis, so most good efficiency rations would be listed as 98db/1watt/1meter. Speakers below 90db/1w/1m is approaching FAIR and below 85db.1w.1meter is IMHO POOR. The whole point in this is have an efficient load on the amp where it will never be forced into clipping. Clipping causes the amp to internally hemorage distortion from every pore.
Also you should be aware that exposure to over 90db of continuous sound for an extended period of time is hazardous to your hearing.
As important as the above number is the loudspeakers impedance curve... this cannot be understated.
if it is ugly & 98 it might not play as loud as 90 and nice...
dave
decibels are weird units, in a way. They're basically empirical, remembering Mr. Bell, who found that loudness to humans covers a huge range of sound pressure, but where oddly, also logarithmic in perception.
“planet₁₀” above recommends (paraphrased) 'pick the speaker, match an amplifier to it'. Seems like good advice, but the theory always (and I mean always) degenerates into recommending “more” in a variety of departments. More watts. Higher damping coefficients. Larger, or smaller impedance output. Servos, no servos. Feedback, no feedback; pushy-pulley, or single ended, or more tubes in parallel, or higher tube driver voltage. Or NOS from Western Electric. Or Shugungs. But basically "more".
I've never yet heard an argument that cites having too much in the amplifier department as being "the reason" why a particular speaker doesn't sound all that good. Oh, there are many arguments and discussions about what happens when there is "too little" (of all the abstract parameters). And recommendations for more. Yes there are raised eyebrows when I tell people, that I hooked a nice pair of German dormatory-shelf speakers to a 4,000 watt all-analog Crown. Clearly that is "too much". But only if you turn the knob to 10!
I think the original advice I gave "100 watts" per channel, is still nearly perfect for all domestic listening situations where one is not trying to show off, but rather listen critically to some good recording material. If your speakers aren't particularly efficient, 100 watts still will have enough oomph to deliver some darn loud music. If your speakers are wonderfully efficient, same deal, but you'll just drive the amp less.
If you choose an amplifier that has active output feedback in the "servo" sense, then its excellent low-impedance output and high damping-factor will be able to drive a really broad range of speakers ranging from finicky to rock-solid. If you really want to listen 15 meters away, then get larger speakers. By one of the odd quirks of sound-pressure-level, larger speakers will have a lower 'dB/watt' rating, but will also project further at higher sound-pressure levels.
That's not something you hear from people who pout about some brand's 79 dB/watt rating … at 3 meters. At 10 meters the sound pressure has only dropped by 6 dB, in an open space. Since most domestic listening areas are not very open spaces, the losses will be different, but could be either less or more depending on what-all is in the way.
Shag carpets are terrible. Sound-suckers.
Low pile carpets aren't any better for higher-timbre sound.
Prickly-wall interior stucco (popular in the 1960s, 1970s and early 80s) also is poor.
But hardwood floors? (or concrete) Bonus!
And wood-panel walls and/or ceilings? Bonus!
And relatively low ceilings? Bonus!
Those surfaces will reflect the speaker output multiple times before it hits your ears. If volume is all you're after, then volume you most certainly will achieve - at distance. But if quality is what you're aspiring to, then these surfaces are the Antichrist.
As would be a tall ceiling that is efficiently reflective.
This is why in concert halls, you may see plentiful folds of fabric hanging in waves up at the ceiling. To suck up the sound and not reflect it back down, if possible.
GoatGuy
“planet₁₀” above recommends (paraphrased) 'pick the speaker, match an amplifier to it'. Seems like good advice, but the theory always (and I mean always) degenerates into recommending “more” in a variety of departments. More watts. Higher damping coefficients. Larger, or smaller impedance output. Servos, no servos. Feedback, no feedback; pushy-pulley, or single ended, or more tubes in parallel, or higher tube driver voltage. Or NOS from Western Electric. Or Shugungs. But basically "more".
I've never yet heard an argument that cites having too much in the amplifier department as being "the reason" why a particular speaker doesn't sound all that good. Oh, there are many arguments and discussions about what happens when there is "too little" (of all the abstract parameters). And recommendations for more. Yes there are raised eyebrows when I tell people, that I hooked a nice pair of German dormatory-shelf speakers to a 4,000 watt all-analog Crown. Clearly that is "too much". But only if you turn the knob to 10!
I think the original advice I gave "100 watts" per channel, is still nearly perfect for all domestic listening situations where one is not trying to show off, but rather listen critically to some good recording material. If your speakers aren't particularly efficient, 100 watts still will have enough oomph to deliver some darn loud music. If your speakers are wonderfully efficient, same deal, but you'll just drive the amp less.
If you choose an amplifier that has active output feedback in the "servo" sense, then its excellent low-impedance output and high damping-factor will be able to drive a really broad range of speakers ranging from finicky to rock-solid. If you really want to listen 15 meters away, then get larger speakers. By one of the odd quirks of sound-pressure-level, larger speakers will have a lower 'dB/watt' rating, but will also project further at higher sound-pressure levels.
That's not something you hear from people who pout about some brand's 79 dB/watt rating … at 3 meters. At 10 meters the sound pressure has only dropped by 6 dB, in an open space. Since most domestic listening areas are not very open spaces, the losses will be different, but could be either less or more depending on what-all is in the way.
Shag carpets are terrible. Sound-suckers.
Low pile carpets aren't any better for higher-timbre sound.
Prickly-wall interior stucco (popular in the 1960s, 1970s and early 80s) also is poor.
But hardwood floors? (or concrete) Bonus!
And wood-panel walls and/or ceilings? Bonus!
And relatively low ceilings? Bonus!
Those surfaces will reflect the speaker output multiple times before it hits your ears. If volume is all you're after, then volume you most certainly will achieve - at distance. But if quality is what you're aspiring to, then these surfaces are the Antichrist.
As would be a tall ceiling that is efficiently reflective.
This is why in concert halls, you may see plentiful folds of fabric hanging in waves up at the ceiling. To suck up the sound and not reflect it back down, if possible.
GoatGuy
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