My JBL Control 1 Plus speakers are about 30 years old and have an intermittent fault. In the process of fixing them, though, I found incandescent light bulbs attached to their crossovers...and the reason why is very clever. Jan Beta's Control 1 foam surround replacement video: https://www.youtube.com/watch?v=SqkOdF3LTuU Sources: Yamaha NS-10 photo: http://forum.cakewalk.com/FindPost/3387511 Yamaha NS-10s in studio photo: https://commons.wikimedia.org/wiki/File:REC_STUDIO_GC.jpg JBL Pro III photo: https://en.audiofanzine.com/active-monitor/jbl/Pro-III JBL L150 photo: https://i.pinimg.com/originals/fe/42/86/fe4286c540ddf179d06b6c9879e45bf2.jpg Voice coil photo: https://en.wikipedia.org/wiki/Voice_coil#/media/File:Loudspeaker_voice_coil,_three_inch_diameter.jpg Magnepan input terminal fuse photo: http://hifiup.com/shops/6058 JBL Control 5 photo: https://en.audiofanzine.com/passive-monitor/jbl/Control-5/medias/pictures/#id:2345881 ---------------------------------------­------------------------------------ Please consider supporting my work on Patreon: https://www.patreon.com/thisdoesnotcompute Follow me on Twitter and Instagram! @thisdoesnotcomp ---------------------------------------­------------------------------------ Music by Epidemic Sound (https://www.epidemicsound.com/). Intro music by BoxCat Games (https://freemusicarchive.org/music/BoxCat_Games).