JBL K140

[Ruediger]

K. E. Stahl, “Synthesis of Loudspeaker Mechanical Parameters by Electrical Means: A New Method for Controlling Low-Frequency Loudspeaker Behavior,” Journal of The Audio Engineering Society, vol. 29, no. 9, pp. 587-596, (1981 Sept.).

[Tiger]

http://reconingspeakers.com/2010/06/...erse-polarity/

Thats very informative. Now the next thing would be, should I continue to plug them in reverse (original), or should I go with the modern (push) method? Would there be any sound quality difference, and could it damage the speaker? Inside the cone on one of them theres a date of May 1982. I, assume they're both original, I'd hate to damage them after having them for so long.

[paragon]

A method for extending bass response and lowering distortion in loudspeaker systems, which differs from both equalized and servo or feedback systems, is described. It can be seen as an extension of the technique to increase loudspeaker damping by giving the driving amplifier a negative output resistance. However, this method also controls the moving mass and compliance. Very good results, such as flat frequency response down to 20 Hz and excellent distortion data, have been achieved with moderately sized bass-reflex enclosures.

[Eaulive]

Thats very informative. Now the next thing would be, should I continue to plug them in reverse (original), or should I go with the modern (push) method? Would there be any sound quality difference, and could it damage the speaker? Inside the cone on one of them theres a date of May 1982. I, assume they're both original, I'd hate to damage them after having them for so long.

Sound is AC so the speaker will be pushing and puliing alternately anyways. It changes nothing on the sound and it won't damage it if you connect it one way or the other, the thing is you have to get the proper polarity if you want to match this speaker in a multiple driver setup.

If you use only one driver, no difference, if you have two or more, then you want them to be "pushing and pulling" together, not one against the other. (it's really more complicated than that but you get the idea ;-)