Carlspeak Posted June 21, 2010 Report Share Posted June 21, 2010 It's become apparent to me recently the tweeter in the subject model speaker was plagued with a common malady caused by corrosion of the tinsel wires. The attached document shows a step-by-step method to make the repair. A jumper wire is fabricated that bypasses the corroded area and is afixed at each end with solder to make a positive connection between the voice coil leads and the connectors where the tweeter wires attach at the back side.Allison_AL_120_tweeter_repair_doc.pdf Link to comment Share on other sites More sharing options...
Zilch Posted June 22, 2010 Report Share Posted June 22, 2010 I'm currently repairing a tweeter out of an AL-120 speaker. If that's the one of interest, I'll try and get some polars when it's fixed and re-installed in the cabinet. Let me know.Yes, please.... Link to comment Share on other sites More sharing options...
Carlspeak Posted June 22, 2010 Author Report Share Posted June 22, 2010 Yes, please.... Polars taken at 1 meter with ECM 6000 test mic. My angles are approximate as I don't have a calibrated rotating table.The speaker was elevated off the floor. The test software does not use a gated signal. Plot resolution is 1/3 octave smoothed. Test was done with the Al-120 grille on. Link to comment Share on other sites More sharing options...
Zilch Posted June 23, 2010 Report Share Posted June 23, 2010 Here for comparison are my results on two samples of 110 at the same resolution and smoothing with the intermediate 15°, Yellow/Brown.I have set the cursors at -6 dB: Link to comment Share on other sites More sharing options...
Zilch Posted June 23, 2010 Report Share Posted June 23, 2010 This time with the correct title: Link to comment Share on other sites More sharing options...
Carlspeak Posted June 23, 2010 Author Report Share Posted June 23, 2010 This time with the correct title:Were your polars taken with a grille on? The grille on the 120 is made up of a curved perferated plate covered with a black fabric. Resp tests done with the grille on and off show up to 5 db drop and it could have an influence on polars as well. Again we need to compare apples to apples for a valid test. I also suspect test set ups could affect the outcome. Link to comment Share on other sites More sharing options...
Zilch Posted June 23, 2010 Report Share Posted June 23, 2010 Were your polars taken with a grille on? The grille on the 120 is made up of a curved perferated plate covered with a black fabric. Resp tests done with the grille on and off show up to 5 db drop and it could have an influence on polars as well. Again we need to compare apples to apples for a valid test. I also suspect test set ups could affect the outcome.Grille construction is similar, and I ran Unit #2 both with the grill in place and without. See the legends:With: http://www.classicspeakerpages.net/IP.Boar...ost&id=5688Without: http://www.classicspeakerpages.net/IP.Boar...ost&id=5699Click between them to view the difference.I presented the original data with 1/6 octave smoothing, and the post-processing at 1/2 octave. The full sets are here:With: http://www.classicspeakerpages.net/IP.Boar...amp;#entry84951Without: http://www.classicspeakerpages.net/IP.Boar...amp;#entry84960 (to +/- 45° only.)Here are the waterfalls:With: http://www.classicspeakerpages.net/IP.Boar...ost&id=5686Without: http://www.classicspeakerpages.net/IP.Boar...ost&id=5700 (again, to +/- 45° only.)As you suggest, the difference is substantial.... Edit:Here are the waterfalls for both at 45°With: http://www.classicspeakerpages.net/IP.Boar...ost&id=5749Without: http://www.classicspeakerpages.net/IP.Boar...ost&id=5700 Link to comment Share on other sites More sharing options...
dynaco_dan Posted February 4, 2012 Report Share Posted February 4, 2012 It's become apparent to me recently the tweeter in the subject model speaker was plagued with a common malady caused by corrosion of the tinsel wires.Hi CarlI read your tweeter repair article recently and saw your photos.Very well done. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.