For those that don’t have professional requirements, I often wonder why some ASR posters have such high SPL requirements. Why would a system need to be run at levels that cause heating damage? For this reviewer it seems clear he would have been satisfied by KH 310
Some posters aren't using monitors as monitors. If you are using them in a theater room, it is useful to have the SPL to be able to sit 15 ft. from the speakers instead of 3 ft. in a monitoring situation. With 6 dB lost per each doubling in distance, the quoted SPL at 1 meter is 12 dB lower at 4 meters. That is still over 100 dB for the KH 420. But the charts above are at 1% or 3% THD. I could see some preferring to have more headroom because you aren't paying Neumann money to have > 1% THD, so knock off another 10 dB to ensure that the speakers aren't running near clipping and are operating at the high linearity you expect. Then you may want 10 dB more of headroom between the average passage and peaks to account for dynamic music. With this kind of logic, it is possible to see why someone would get a speaker which is capable of 120 dB at 1 meter @ 3% THD and listen to it at 4 meters and 85 dB.
