No LFM on RTA12's

Michael8it
Michael8it Posts: 192
edited August 2011 in Vintage Speakers
I picked these up from the original owner, and based on the dates on the drivers these were made in late 1980.

Based on the schematic (found on this forum):

The LF Module consists of two ??? - I dont know what they are. Diodes? The value shows 6.5, but I dont recognize the symbol.

In any case, my 12's have NO LFM - they are wired directly to both of the drivers from the posts on the back. This does not seem right.... Anyone have any idea as to why it would be this way? And should I install the components shown on this schematic?

I am working on an overhaul of the crossovers, and the bass on these seems a bit muddy, so I am hoping this will tighten things up. I am concerned though about these drivers and no LFM.

thanks,
Mike
Carver C-1, M-500 MKII, Yamaha HTR-5835, Polk RTA 12BM's (M-for mod'd).
Post edited by Michael8it on
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Comments

  • drumminman
    drumminman Posts: 3,396
    edited August 2011
    That symbol is for for the mid range drivers. The 6.5 refers to their diameter: 6.5 inches.

    Polk uses the same one on the schematics for the other versions of the RTA 12's
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • Michael8it
    Michael8it Posts: 192
    edited August 2011
    Ah...... I get it. Thank you!
    Carver C-1, M-500 MKII, Yamaha HTR-5835, Polk RTA 12BM's (M-for mod'd).
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