26-07-2016, 08:42 AM
Hi Mark
The problem is that extreme music compression is sadly becoming the norm, very well summed up here https://www.youtube.com/watch?v=u9Fb3rWNWDA , the generic term for which is the "Loudness war". The exceptionally small dynamic range, with pegged VU meters and "managed distortion" means that the peak to average power is now very small indeed.
Loudspeaker power handling is another "interesting" topic. Particularly since good driver manufacturers (such as SEAS) publish rather comprehensive power handling data. That seems to go out the window once a manufacturer puts these drivers in a box. I suspect that is to prevent users blowing up an expensive speaker, and then arguing that they used an amplifier that met the quoted power handing.
The most representative signal to use for power handling, and a mimic of "real" music is a pink noise signal in which one can adjust the crest factor. What seems an eternity ago now I was CTO of Wharfedale, during which time we acquired FANE. The survival test for a FANE driver was to mount it in a concrete bunker and feed it with pink noise at the rated power level (which could be 1kW peak and 500W average) for 24 hours, after which it not only had to survive, but also have unchanged acoustic response. These were used at rock concerts and had to survive all kinds of abuse.
I'm currently listening to these http://www.linkwitzlab.com/LX521/Description.htm actively crossed over and EQ'd dipoles. I'm using Douglas Self Blameless power amps, 2x100W and 2x50W per channel. My build is the ninth one down here http://www.linkwitzlab.com/LX521/PhotoGallery.htm.
Thinking of Self, at the end of his book on Power Amplifiers he considers power transistor dissipation for real world loudspeaker loads, which makes for interesting reading. It needs a serious rethink about what an amp actually needs regarding thermal management when driving a loudspeaker.
Craig
The problem is that extreme music compression is sadly becoming the norm, very well summed up here https://www.youtube.com/watch?v=u9Fb3rWNWDA , the generic term for which is the "Loudness war". The exceptionally small dynamic range, with pegged VU meters and "managed distortion" means that the peak to average power is now very small indeed.
Loudspeaker power handling is another "interesting" topic. Particularly since good driver manufacturers (such as SEAS) publish rather comprehensive power handling data. That seems to go out the window once a manufacturer puts these drivers in a box. I suspect that is to prevent users blowing up an expensive speaker, and then arguing that they used an amplifier that met the quoted power handing.
The most representative signal to use for power handling, and a mimic of "real" music is a pink noise signal in which one can adjust the crest factor. What seems an eternity ago now I was CTO of Wharfedale, during which time we acquired FANE. The survival test for a FANE driver was to mount it in a concrete bunker and feed it with pink noise at the rated power level (which could be 1kW peak and 500W average) for 24 hours, after which it not only had to survive, but also have unchanged acoustic response. These were used at rock concerts and had to survive all kinds of abuse.
I'm currently listening to these http://www.linkwitzlab.com/LX521/Description.htm actively crossed over and EQ'd dipoles. I'm using Douglas Self Blameless power amps, 2x100W and 2x50W per channel. My build is the ninth one down here http://www.linkwitzlab.com/LX521/PhotoGallery.htm.
Thinking of Self, at the end of his book on Power Amplifiers he considers power transistor dissipation for real world loudspeaker loads, which makes for interesting reading. It needs a serious rethink about what an amp actually needs regarding thermal management when driving a loudspeaker.
Craig
