Loudspeakers for home use generally have efficiencies of no more than 91 dB SPL per Watt of input power at 1 meter. That means you are looking at 1 kW to get to 120 dB SPL, which I believe is considered a damage threshold for human ears for extended periods of time. I don't keep up on the audiophile market that much, but I don't think there are that many kW amplifiers or speakers. Of course specs on SPL rely on an anechoic chamber or free field measurement. If you put the speaker in a small reflective room you will get higher results. But I think you have to apply some common sense here.
Dynamic speakers use permanent magnets. I am unaware of safety limits for dc magnetic fields. Any high intensity ac fields would be of short duration, low duty cycle, and likely contained in a very small volume. I am totally ignorant of any standards involved, but this doesn't seem to me to be an area in need of standardization - on the other hand I think that is true of many technical disciplines that are already standardized. > From: "Sosnoski, Michael" <[email protected]> > Reply-To: "Sosnoski, Michael" <[email protected]> > Date: Fri, 5 Mar 2004 08:41:51 -0600 > To: [email protected] > Subject: Pace makers, speakers, magnetic fields > > > All, > I know speakers are part of the audio/video world, but IEC 60065 does not go > much into safe limits of sound pressure, and magnetic fields. > Can anyone point me into some standards, text, or general safety > considerations with respect to loudspeakers? > Mike > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ieee-pses.org/ > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc > This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ieee-pses.org/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
