08-Jul-2019, 04:49
I've got a different take on peak levels and how much power you need.
Back in 2001 I bought a pair of Dynaudio Contour 1.3 Sys with a rated sensitivity of around 85 dB and I seem to remember seeing a test report that put their sensitivity lower, around 83 dB. One thing I noticed about Dynaudio speakers in general is that it didn't seem to matter how big an amp you had, they always seemed to sound better with a bigger amp. I listen at what I think most people would regard as low levels. When I measured volume levels at my listening position around 2 metres from the speakers most of the time they were running below 80 dB, often close to 70 dB but using the hold function on the meter I was seeing peaks around the 85 dBC mark. The meter could also display instantaneous peak levels and they tended to run in the mid 90's so an amp capable of delivering 100 W into 4 Ohms was certainly capable of delivering the instantaneous peaks I was getting at my listening levels and I never noticed distortion or clipping on peaks. My amp could deliver 170 W into 4 Ohms but despite that I noticed an improvement if I used a more powerful amp. In the end I came to believe that the difference had little or nothing to do with output capability and everything to do with the amp's power supply and it's capability to deliver high power quickly when transients occurred and also it's ability to quickly recover from those high output demands and be ready to keep delivering on demand. Smaller amps tend to have less capable power supplies than larger amps and I ended up deciding that what the bigger amps bought to the table in terms of delivering better sound quality wasn't more output power but rather a power supply that was capable of delivering peak output more capably at your chosen listening level.
When I replaced that 170 W amp in 2016, I replaced it with a Devialet 130 Pro which had less rated output than my previous amp. Despite that, it actually delivered better sound quality and better peaks and transient response than the previous amp. Since sound quality improved with lower peak output capability it was obvious that I wasn't getting clipping with the previous amp, if I had been running into clipping with it then I should have been running into clipping more often with the Devialet but just as I hadn't noticed clipping with the previous amp I wasn't noticing it with the 130. I used SAM with the Dynaudio and didn't notice any issues from a lack of power when using SAM.
Subsequently I replaced the Dynaudio with my current Focal Sopra 2s which have a 91 dB sensitivity rating. Still no noticeable problems. My listening levels haven't changed and I usually set my volume setting at around -20 dB for most of the music I play though with some softer recordings I do increase the volume setting a bit, rarely to more than -10 dB. At those volume levels I could raise the volume setting by over 20 dB, even by close to 30 dB, before I hit maximum volume. My feeling is that for my listening levels the 140 has more than sufficient power and a power supply more than capable of keeping up with the transient demands of the music I listen to which is mostly small group acoustic jazz. Things might well be different if I were playing rock at high levels but that isn't my scene. When I held a meeting of my local audio club here a bit under 2 years ago there were a number of members who do like rock at high levels and they proceeded to "kick the tyres" on my system by listening to the kind of music they like at the kind of levels they like (I left the room and left them to it) and they all seemed to like the result so I don't think the 140 failed to deliver at higher levels with the Sopras.
I do think bigger amps can deliver benefits with many speakers and those benefits may sometimes be related to avoiding clipping at peak levels but I do think more often the benefits of a larger amp are simply related to a bigger and better power supply rather than the ability to deliver more watts without clipping. If I were still listening to the kind of music I listened to in the '70s and 80's at the level I listened at then and were still using lower sensitivity speakers like Dynaudio and/or I had a bigger room then I would definitely be running a bigger amp than the 140 but I'm not and so far the 140 is meeting all of my needs and delivering the best sound quality I've ever had. YMMV.
Back in 2001 I bought a pair of Dynaudio Contour 1.3 Sys with a rated sensitivity of around 85 dB and I seem to remember seeing a test report that put their sensitivity lower, around 83 dB. One thing I noticed about Dynaudio speakers in general is that it didn't seem to matter how big an amp you had, they always seemed to sound better with a bigger amp. I listen at what I think most people would regard as low levels. When I measured volume levels at my listening position around 2 metres from the speakers most of the time they were running below 80 dB, often close to 70 dB but using the hold function on the meter I was seeing peaks around the 85 dBC mark. The meter could also display instantaneous peak levels and they tended to run in the mid 90's so an amp capable of delivering 100 W into 4 Ohms was certainly capable of delivering the instantaneous peaks I was getting at my listening levels and I never noticed distortion or clipping on peaks. My amp could deliver 170 W into 4 Ohms but despite that I noticed an improvement if I used a more powerful amp. In the end I came to believe that the difference had little or nothing to do with output capability and everything to do with the amp's power supply and it's capability to deliver high power quickly when transients occurred and also it's ability to quickly recover from those high output demands and be ready to keep delivering on demand. Smaller amps tend to have less capable power supplies than larger amps and I ended up deciding that what the bigger amps bought to the table in terms of delivering better sound quality wasn't more output power but rather a power supply that was capable of delivering peak output more capably at your chosen listening level.
When I replaced that 170 W amp in 2016, I replaced it with a Devialet 130 Pro which had less rated output than my previous amp. Despite that, it actually delivered better sound quality and better peaks and transient response than the previous amp. Since sound quality improved with lower peak output capability it was obvious that I wasn't getting clipping with the previous amp, if I had been running into clipping with it then I should have been running into clipping more often with the Devialet but just as I hadn't noticed clipping with the previous amp I wasn't noticing it with the 130. I used SAM with the Dynaudio and didn't notice any issues from a lack of power when using SAM.
Subsequently I replaced the Dynaudio with my current Focal Sopra 2s which have a 91 dB sensitivity rating. Still no noticeable problems. My listening levels haven't changed and I usually set my volume setting at around -20 dB for most of the music I play though with some softer recordings I do increase the volume setting a bit, rarely to more than -10 dB. At those volume levels I could raise the volume setting by over 20 dB, even by close to 30 dB, before I hit maximum volume. My feeling is that for my listening levels the 140 has more than sufficient power and a power supply more than capable of keeping up with the transient demands of the music I listen to which is mostly small group acoustic jazz. Things might well be different if I were playing rock at high levels but that isn't my scene. When I held a meeting of my local audio club here a bit under 2 years ago there were a number of members who do like rock at high levels and they proceeded to "kick the tyres" on my system by listening to the kind of music they like at the kind of levels they like (I left the room and left them to it) and they all seemed to like the result so I don't think the 140 failed to deliver at higher levels with the Sopras.
I do think bigger amps can deliver benefits with many speakers and those benefits may sometimes be related to avoiding clipping at peak levels but I do think more often the benefits of a larger amp are simply related to a bigger and better power supply rather than the ability to deliver more watts without clipping. If I were still listening to the kind of music I listened to in the '70s and 80's at the level I listened at then and were still using lower sensitivity speakers like Dynaudio and/or I had a bigger room then I would definitely be running a bigger amp than the 140 but I'm not and so far the 140 is meeting all of my needs and delivering the best sound quality I've ever had. YMMV.
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
