13-Jul-2019, 22:07
@Confused
Interesting comments.
You said: "Although one thing I would say is that the thread has drifted a little onto how much power does a Devialet produce and how does it do it, and a little away from the "How much power do you really need" question". Yes, it has in some ways but it's hard to separate the question of how much power you need from the questions of how much power a Devialet produces and how it does it. We usually ask how much power we need in the context of deciding whether we have enough power for our needs and answering that often involves issues of how much power our amp actually produces in real life situations and how it does that.
You commented on the levels the music played at in the video and the fact that people could be heard speaking during the music. My background isn't in electronics or audio or recording. I worked in health and safety before I retired and things like hearing protection were part of what I studied to get my professional qualification though I never worked in that area. At one stage, however, I was involved in some issues around the design of a telephone call centre and was asked for an assessment/explanation of the acoustic design of the sound absorption characteristics of the dividers between the workstations. That was something that hadn't been covered in anything I'd been taught, we're speaking here of sound pressure levels well below the kind of levels which trigger hearing protection issues, but I found the bit of research I did interesting because at that time I was starting to get interested in acoustic treatment for home listening rooms since I was starting to read reviews in magazines of some early room treatment products and I was wondering whether or not I would get any benefit from them in my room.
To cut to the chase, normal speech levels tend to run in the mid-60s dB range and it is basically accepted that background noise levels of around 65 dB interfere with speech comprehension. That doesn't mean that a background level of 65 dB means you won't be able to hear someone speaking to you at a normal level, it means that you will probably be having difficulty understanding what they're saying at least part of the time. As you know, the louder the background noise becomes, the more you raise your voice so that the person you're speaking to can understand you rather than so that they can hear you. There's a difference between being able to hear that someone is speaking to you and being able to understand what they're saying.
Things are a bit messier than that, however, because frequency plays a part. Music contains sounds at different frequencies and we can hear what a violin is doing in a string quartet and appreciate it's contribution to the music even if the violin is playing softly and the 'cello, which is playing a couple of octaves lower, is playing much louder and carrying the main musical message. There's a thing called "masking" also involved and louder sounds will mask other sounds in the same frequency range more than they mask other sounds in a different frequency range. That means that a background noise level of 65-70 dB will mask speech at a normal volume level and make it harder to understand if the background noise is in the same frequency range as the speech than if it is in a different frequency range and has little content in the speech range.
I didn't watch much of the video so I didn't see the section you mentioned but another factor is likely to the proximity of the people speaking to the camera and mic. They were probably a lot closer than the speakers were and that means that the level of the sound produced by the speakers is going to have dropped a lot more by the time it reached the mic than the level of the voices had. For the people actually speaking to each other, they would have been very close to each other, probably only 30-40 cm separating their heads if they were sitting next to each other in the demo room because they were probably leaning a bit towards each other given that there was music playing, and the speakers were probably 2-3 metres away. That means that there would have been a lot less difference in the levels of the speech they were hearing and the music from the speakers than you would think so they were probably having little difficulty understanding each other. At the greater distance from the people that the mic was placed at, the sound of the music would have been louder relative to that of the voices and the impact on speech intelligibility greater.
The take away from all of that is that when it comes to listening to music it's not only level that is important to how we hear what's going on and our assessment of how loud is loud enough (the main factor in deciding how much power you need) but also the frequency of the various elements of the music and room acoustics plays a big part there.
My room is acoustically treated and I've experimented with acoustic treatment of my room for around 25 years now in 2 different rooms (I don't move house often) starting with DIY treatments and ending up with commercial products. It's been a fascinating experience in many ways and it's taught me a few interesting things. One is that acoustic treatment only affects reflected sound, not the direct sound reaching your ears in a straight line from the speakers. That makes sense because acoustic treatment only affects the sound striking the treatments and you don't put acoustic treatment products in the path of the direct sound. The reflected sound arrives later and is lower in level than the direct sound (greater travel distance, absorption at the surfaces it reflects off along the way, scattering due to diffusion etc) and higher frequencies decay faster than lower frequencies (they're absorbed more easily and even increasingly absorbed by air at frequencies above 7-8 kHz or so). Acoustic treatment results in a greater difference in level between the direct sound and the reflected sound reaching your ears and music becomes clearer and more "understandable", just as speech is more understandable when background noise is lower. I listened, and still listen, at a higher level in a room without acoustic treatment than I do in a room which is well treated, simply because the music is clearer and it's easier to hear everything in the music. One of the reasons we turn the level up is because we can't hear something in the music as clearly as we want to hear it and turning the volume up tends to make it easier for us to hear elements we want to hear and usually the things we want to hear more clearly, the things we lump under the label of "detail", are at higher frequencies. Even with bass, the details of the sound of an acoustic or electric bass, tend to come with the tonal characteristics and those characteristics are linked to the overtone structure of the sound so they start an octave above the fundamental note. Detail holds up better than fundamentals because it occurs at higher frequencies and cleaning up lower frequencies which is one of the main purposes of treating a room makes detail easier to hear. There's less need to turn the volume up to enhance the "intelligibility" of the music in a well treated room and you end up listening at lower levels which need less amplifier power.
And finally there's your choice of music. If your main listening choices are, say, solo clavichord music and a clavichord probably struggles to produce a level of 65 dB on peaks (it's a very soft instrument) then you don't need much power at all to produce realistic levels. A string quartet takes a bit more power but doesn't dig into the bass range where power demands start increasing drastically but solo piano can go a good half octave lower than an acoustic or electric bass and requires more power for realistic reproduction. An acoustic jazz trio doesn't produce the levels of a chamber orchestra which doesn't produce the level of a symphony orchestra and that doesn't approach the levels that some rock bands routinely produce in live performance. If your musical preference is stadium level rock performances then you're going to need a fair bit of power to get satisfying sound, even though you're not going to produce the same kind of level in your living room as you hear at a live performance and you also don't need enough amplifier power to put a strain on the electricity grid supplying your home.
"How much power do you need?" is a complicated question and I think there's a tendency to think that there's a simple answer based on speaker choice/sensitivity and the peak volume your speakers are capable of but it isn't as simple as that and in reality you can find 2 people with the same speakers, one of whom might be really happy and perfectly satisfied with a 140 Pro and another who needs a 1000 Pro and who can't wait for Devialet to produce a 2000 Pro.
As for Art Dudley, and I enjoy Art's reviews and share a few of his musical tastes, he likes a lot of small group acoustic music with the deepest bass content supplied by an acoustic bass or a piano which doesn't dig into its bottom octave all that often in the music. In his room he's getting good results with Harbeth's and modest amps because they deliver enough power for good reproduction of those instruments at listening levels he's happy with, and those are probably similar levels to what I like. He's also happy to accept symphony orchestra reproduction that doesn't deliver as well in the low bass as it does in the upper bass and mids, and that doesn't impact on the emotional impact of the music for him. He's willing to compromise with some music provided he doesn't have to compromise on getting what he wants from a lot of other music. That's a big factor also. His needs would be a hell of a lot greater if he "wanted it all" with all of the music he listens to, and he might not be able to satisfy his needs if that were the case. He's a happy man because he's willing to settle for a lot rather than demanding everything, he's willing to compromise. A lot of this discussion often gets conducted on the basis of compromise being unacceptable. Compromise is unavoidable, we can't have it all, and the only question is how much we're personally prepared to compromise. The decision we make on that determines whether we can be as happy as Art Dudley is or whether we're always going to be chasing more of something and being a lot less happy than Art. I like being as happy as Art is.
Interesting comments.
You said: "Although one thing I would say is that the thread has drifted a little onto how much power does a Devialet produce and how does it do it, and a little away from the "How much power do you really need" question". Yes, it has in some ways but it's hard to separate the question of how much power you need from the questions of how much power a Devialet produces and how it does it. We usually ask how much power we need in the context of deciding whether we have enough power for our needs and answering that often involves issues of how much power our amp actually produces in real life situations and how it does that.
You commented on the levels the music played at in the video and the fact that people could be heard speaking during the music. My background isn't in electronics or audio or recording. I worked in health and safety before I retired and things like hearing protection were part of what I studied to get my professional qualification though I never worked in that area. At one stage, however, I was involved in some issues around the design of a telephone call centre and was asked for an assessment/explanation of the acoustic design of the sound absorption characteristics of the dividers between the workstations. That was something that hadn't been covered in anything I'd been taught, we're speaking here of sound pressure levels well below the kind of levels which trigger hearing protection issues, but I found the bit of research I did interesting because at that time I was starting to get interested in acoustic treatment for home listening rooms since I was starting to read reviews in magazines of some early room treatment products and I was wondering whether or not I would get any benefit from them in my room.
To cut to the chase, normal speech levels tend to run in the mid-60s dB range and it is basically accepted that background noise levels of around 65 dB interfere with speech comprehension. That doesn't mean that a background level of 65 dB means you won't be able to hear someone speaking to you at a normal level, it means that you will probably be having difficulty understanding what they're saying at least part of the time. As you know, the louder the background noise becomes, the more you raise your voice so that the person you're speaking to can understand you rather than so that they can hear you. There's a difference between being able to hear that someone is speaking to you and being able to understand what they're saying.
Things are a bit messier than that, however, because frequency plays a part. Music contains sounds at different frequencies and we can hear what a violin is doing in a string quartet and appreciate it's contribution to the music even if the violin is playing softly and the 'cello, which is playing a couple of octaves lower, is playing much louder and carrying the main musical message. There's a thing called "masking" also involved and louder sounds will mask other sounds in the same frequency range more than they mask other sounds in a different frequency range. That means that a background noise level of 65-70 dB will mask speech at a normal volume level and make it harder to understand if the background noise is in the same frequency range as the speech than if it is in a different frequency range and has little content in the speech range.
I didn't watch much of the video so I didn't see the section you mentioned but another factor is likely to the proximity of the people speaking to the camera and mic. They were probably a lot closer than the speakers were and that means that the level of the sound produced by the speakers is going to have dropped a lot more by the time it reached the mic than the level of the voices had. For the people actually speaking to each other, they would have been very close to each other, probably only 30-40 cm separating their heads if they were sitting next to each other in the demo room because they were probably leaning a bit towards each other given that there was music playing, and the speakers were probably 2-3 metres away. That means that there would have been a lot less difference in the levels of the speech they were hearing and the music from the speakers than you would think so they were probably having little difficulty understanding each other. At the greater distance from the people that the mic was placed at, the sound of the music would have been louder relative to that of the voices and the impact on speech intelligibility greater.
The take away from all of that is that when it comes to listening to music it's not only level that is important to how we hear what's going on and our assessment of how loud is loud enough (the main factor in deciding how much power you need) but also the frequency of the various elements of the music and room acoustics plays a big part there.
My room is acoustically treated and I've experimented with acoustic treatment of my room for around 25 years now in 2 different rooms (I don't move house often) starting with DIY treatments and ending up with commercial products. It's been a fascinating experience in many ways and it's taught me a few interesting things. One is that acoustic treatment only affects reflected sound, not the direct sound reaching your ears in a straight line from the speakers. That makes sense because acoustic treatment only affects the sound striking the treatments and you don't put acoustic treatment products in the path of the direct sound. The reflected sound arrives later and is lower in level than the direct sound (greater travel distance, absorption at the surfaces it reflects off along the way, scattering due to diffusion etc) and higher frequencies decay faster than lower frequencies (they're absorbed more easily and even increasingly absorbed by air at frequencies above 7-8 kHz or so). Acoustic treatment results in a greater difference in level between the direct sound and the reflected sound reaching your ears and music becomes clearer and more "understandable", just as speech is more understandable when background noise is lower. I listened, and still listen, at a higher level in a room without acoustic treatment than I do in a room which is well treated, simply because the music is clearer and it's easier to hear everything in the music. One of the reasons we turn the level up is because we can't hear something in the music as clearly as we want to hear it and turning the volume up tends to make it easier for us to hear elements we want to hear and usually the things we want to hear more clearly, the things we lump under the label of "detail", are at higher frequencies. Even with bass, the details of the sound of an acoustic or electric bass, tend to come with the tonal characteristics and those characteristics are linked to the overtone structure of the sound so they start an octave above the fundamental note. Detail holds up better than fundamentals because it occurs at higher frequencies and cleaning up lower frequencies which is one of the main purposes of treating a room makes detail easier to hear. There's less need to turn the volume up to enhance the "intelligibility" of the music in a well treated room and you end up listening at lower levels which need less amplifier power.
And finally there's your choice of music. If your main listening choices are, say, solo clavichord music and a clavichord probably struggles to produce a level of 65 dB on peaks (it's a very soft instrument) then you don't need much power at all to produce realistic levels. A string quartet takes a bit more power but doesn't dig into the bass range where power demands start increasing drastically but solo piano can go a good half octave lower than an acoustic or electric bass and requires more power for realistic reproduction. An acoustic jazz trio doesn't produce the levels of a chamber orchestra which doesn't produce the level of a symphony orchestra and that doesn't approach the levels that some rock bands routinely produce in live performance. If your musical preference is stadium level rock performances then you're going to need a fair bit of power to get satisfying sound, even though you're not going to produce the same kind of level in your living room as you hear at a live performance and you also don't need enough amplifier power to put a strain on the electricity grid supplying your home.
"How much power do you need?" is a complicated question and I think there's a tendency to think that there's a simple answer based on speaker choice/sensitivity and the peak volume your speakers are capable of but it isn't as simple as that and in reality you can find 2 people with the same speakers, one of whom might be really happy and perfectly satisfied with a 140 Pro and another who needs a 1000 Pro and who can't wait for Devialet to produce a 2000 Pro.
As for Art Dudley, and I enjoy Art's reviews and share a few of his musical tastes, he likes a lot of small group acoustic music with the deepest bass content supplied by an acoustic bass or a piano which doesn't dig into its bottom octave all that often in the music. In his room he's getting good results with Harbeth's and modest amps because they deliver enough power for good reproduction of those instruments at listening levels he's happy with, and those are probably similar levels to what I like. He's also happy to accept symphony orchestra reproduction that doesn't deliver as well in the low bass as it does in the upper bass and mids, and that doesn't impact on the emotional impact of the music for him. He's willing to compromise with some music provided he doesn't have to compromise on getting what he wants from a lot of other music. That's a big factor also. His needs would be a hell of a lot greater if he "wanted it all" with all of the music he listens to, and he might not be able to satisfy his needs if that were the case. He's a happy man because he's willing to settle for a lot rather than demanding everything, he's willing to compromise. A lot of this discussion often gets conducted on the basis of compromise being unacceptable. Compromise is unavoidable, we can't have it all, and the only question is how much we're personally prepared to compromise. The decision we make on that determines whether we can be as happy as Art Dudley is or whether we're always going to be chasing more of something and being a lot less happy than Art. I like being as happy as Art is.
Roon Nucleus+, Devilalet Expert 140 Pro CI, Focal Sopra 2, PS Audio P12, Keces P8 LPS, Uptone Audio EtherREGEN with optical fibre link to my router, Shunyata Alpha NR and Sigma NR power cables, Shunyata Sigma ethernet cables, Shunyata Alpha V2 speaker cables, Grand Prix Audio Monaco rack, RealTRAPS acoustic treatment.
Brisbane, Qld, Australia
