On Mar 26, 2004, at 3:33 PM, Scott Mueller wrote: > How does a Floating ground adaptor work? I'm only guessing, but very likely it is simply a pair of isolation transformers that permit the use of a common return on the speaker side while maintaining DC isolation on the amp side. Part of the confusion here is that there are really two separate issues; (1) sound quality, and (2) electrical "correctness": 1. Sound Quality - - As David T. correctly points out, speakers are AC devices -- it is the change of relative voltage between the two wires that makes the speaker cones move; "ground" is a red herring (which why "return" is a more correct term). Speakers don't really have + and - terminals--they are only marked that way so that they get connected consistently so they stay "in phase" (i.e., you don't want one "pushing" while the other is "pulling", else they tend to cancel each other out). In theory, it doesn't matter whether or not two speakers share a common return, as long as that return has sufficient capacity to carry all the current spikes that are produced by both of the speakers. In a high-power audio setup, these spikes can be very significant, and with a common return, one wire has to support both speakers. If it can't, the speakers won't be independent from each other, and you will get various kinds of distortion. Rather than using a single huge return wire, it makes more sense to just use separate returns and be done with it, which is what most high-end amps are designed to do. 2. Electrical "Correctness" -- Given the above, designers of said high-end amps feel free to design their circuitry under the assumption that there will be D.C. isolation among all the speaker "return" connections. If you connect them together, you create D.C. 'leakage' paths that may or may not seriously degrade the performance of the amp, or even possibly damage it. Depends on your amp. A "floating ground adpator" can easily address the second issue, only rewiring can address the first. When I did the "Invisible Audio Upgrade" ( http://www.dmcnews.com/Techsection/invisibleaudio.htm ), I first tried it without the adaptor. It mostly worked, but there was significant distortion at high volumes. The adaptor cleared it up completely to my ear. But, as Dave says, "purists" will insist that separate returns are essential to that je ne c'est qua of the listening experience. [Of course, they will also insist that Monster Cable would sound better than an electrically-equivalent piece of Romex (oops, just started a flame-war :-) ] --Pete Lucas VIN #06703 To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/