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View Full Version : 250ti Crossover Capacitor Replacement, dull upper midrange performance



MattBishop
04-13-2018, 06:01 PM
Would it be advisable to replace the capacitors in the crossover networks in my roughly 30 year old 250tis? Do they deteriorate and change electrical characteristics over 30 years? I have had all of the LE14Hs and 108Hs professionally reconed and installed brand new 104Hs. I also have a brand new pair of 104H2 that I have temporarily installed with no perceivable difference in sound. The original tweeters seem to work perfectly and appear to be untouched since the speakers left the factory. I took a test listen to a new pair of PARADIGM Persona towers recently and realized my JBLs do not have nearly as good of clarity and transparency in the mids and highs. Could the old capacitors be negatively affecting the sound? I remember when these were, by far, the best sounding speakers made and I would like to restore them to their original glory. I'm driving them with an ADCOM GFA555-MKII amplifier. Something is still just not quite right about the clarity of tenor voices and the higher notes from, say a plucked guitar or banjo. I would greatly appreciate the advice/ opinions from you wise fellow JBL enthusiasts. Thanks.

My grilles are completely gone, I suppose the good lord called em home or termites ate em up, who knows? Any ideas where to get a pair of new or reproduction grilles?

DavidF
04-13-2018, 07:07 PM
Would it be advisable to replace the capacitors in the crossover networks in my roughly 30 year old 250tis? Do they deteriorate and change electrical characteristics over 30 years? I have had all of the LE14Hs and 108Hs professionally reconed and installed brand new 104Hs. I also have a brand new pair of 104H2 that I have temporarily installed with no perceivable difference in sound. The original tweeters seem to work perfectly and appear to be untouched since the speakers left the factory. I took a test listen to a new pair of PARADIGM Persona towers recently and realized my JBLs do not have nearly as good of clarity and transparency in the mids and highs. Could the old capacitors be negatively affecting the sound? I remember when these were, by far, the best sounding speakers made and I would like to restore them to their original glory. I'm driving them with an ADCOM GFA555-MKII amplifier. Something is still just not quite right about the clarity of tenor voices and the higher notes from, say a plucked guitar or banjo. I would greatly appreciate the advice/ opinions from you wise fellow JBL enthusiasts. Thanks.

My grilles are completely gone, I suppose the good lord called em home or termites ate em up, who knows? Any ideas where to get a pair of new or reproduction grilles?

Matt, assuming the xover has not been altered and the connections to the drivers are correct as to polarity, I would suspect the tweeter before the xover components. There is/was some foam placed under the dome that is subject to rot and getting down into the coil gap. To check on this in not for the casual tweaker. Suggest some research on the site under "044ti".