2x amp, 2 inverted electro-coil magnets = speaker

[petemoore]

  The title is phrased as a statement but it is just a thought experiment at this point, I tried out a couple of coils, and coil 1 laying on coil 2...when they recieve opposite polarity voltage...they wiggle or jump...so basic concept played with in DC works, proof made barely audible noise ! !
  Main problem I see is two amps would be 'fighting' through say 8 ohms, and they'd float around or something.
 Concept being that like an electromagnetic field sorta like a field coil speaker, but instead of a fixed mag-field as referenece for the fluctuating mag-field [as with fixed magnet or field coil speakers] both mag-fields push < away  or > toward push/pulling the cone-suspesion-coil as it is counterforced magnetically.
 1 fixed coil where fixed magnet would be has amplifier swinging +/-, the voice coil [typical voice coil] would also have an amplifier swinging -/+ [inverted amps or inverted coil windings].
 I know it'd 'work' but suspect it is a complete ball of string wax that would require...
 Anyway seems like 2 coils, <> one inside the other, connected to 2 cones [also connected by flex around, could make a speakerball which would radiate near equal in all directions thus eliminating by a first order Bs any cancellation/peak problems of room/cabinet], the cones-make-sealed,-size changing ball, the cone-cab perhaps offering preferrable characteristics to a cabinet.
 Perhaps some swing or bias feedback between the two amps to keep the idle cone centered etc. ?
 Thinking...back in the day field coil wasn't any harder to do and required 1 output amplifier...preferrable to needing 2. These days it's different though, no output transformers or 2 output amplifiers isn't that big a deal.

[ashcat_lt]

Omindirectional radiation will not reduce acoustic phenomena like standing waves and null points.  Most speakers are omni in the lowest freqs and we still have the problem. 

Also, it seems like the two cones moving in opposite direction would be working against each other and tend to acoustically cancel one another if they are physically very close together.  So maybe a whole lot of work to achieve (near) silence.

Then I'm thinking the two coils will try to act like a transformer, inducing current in one another which could damage the amps, or something.

[petemoore]

  Thanks for thinking it over Ashcat !
 The omni part is something I read and seemed to be an interesting approach, whether it negates standing waves in reality is another matter untested anyway...all kinda acedemic at this point, I'm not attemting an omnidirectional speaker right now...would be kinda neat to have 1 big speaker-ball though..
 Also, it seems like the two cones moving in opposite direction would be working against each other and tend to acoustically cancel one another if they are physically very close together.  So maybe a whole lot of work to achieve (near) silence.
 It'd compress/decompress the internal air cavity like a regular sealed enclosure as I see it, this would allow waves to transmit outside the cabinet.
 Then I'm thinking the two coils will try to act like a transformer, inducing current in one another which could damage the amps, or something.
 These are thoughts I too had and was kind of hoping for a viable shoot down or some obvious reasons why this type of speaker wasn't considered into prototype or production.
 Seems like if a field coil can do it a field coil swinging +/- could do it.
 I think the real problem lies in having an 8ohm wire [speaker coil] connecting two amps working, one pushing, one pulling, across an 8 ohm load.
  The ideas roamed around a conventional speaker re-do or a homebrew DIY type of driver construction. I'm just voicing curiosity now, but was about to wind a couple coils [one voice, on fixed] and see what happens a few days ago.