karlson3 Posted June 11, 2018 Share Posted June 11, 2018 seems like it was 1uF ? - might have been a bit less - think it went as follows (?) Quote Link to comment Share on other sites More sharing options...
Deang Posted June 11, 2018 Share Posted June 11, 2018 No 1uF in that network unless they were paralleling it with another 1uF to make a 2uF. There are three 2uF capacitors in the tweeter section of that network. Quote Link to comment Share on other sites More sharing options...
karlson3 Posted June 11, 2018 Author Share Posted June 11, 2018 DJK mentioned that a long time ago - tried it once but did not take measurements I added the 1uF to that drawing - should have titled this - - "AB Style Tweeter Section Mod" - can't remember if the value recommended was 1uF - or perhaps ~0.68uF ? Quote Link to comment Share on other sites More sharing options...
JohnA Posted June 11, 2018 Share Posted June 11, 2018 A 1uF was not used in the original Type AA or AB networks. Quote Link to comment Share on other sites More sharing options...
karlson3 Posted June 11, 2018 Author Share Posted June 11, 2018 thanks - its was DJK's acoustic Butterworth mod for the AA network tweeter section (with stock 2uF cap values) - I think the bridge cap was 1uf but not sure Quote Link to comment Share on other sites More sharing options...
karlson3 Posted June 12, 2018 Author Share Posted June 12, 2018 I think "this" is the general effect of using the bridging 1uF cap - possibly flatten the passband and to create a notch around 3K5 . A good measurement could be put into Xsim to get more of the story. In a Diyaudio thread, there's a comment saying the aB type behaves more like a 1st order highpass with a notch than 3rd order. With an AA, it would be easy to try and switch be wired to jumper the cap when desired for comparison. Apparently, KEF used theirs tuned to the resonance frequency of the tweeter. Quote Link to comment Share on other sites More sharing options...
JohnA Posted June 12, 2018 Share Posted June 12, 2018 Two things: the K-77-M has a response hump in the 6 to 9k range and runs about 105 dB there. The Type AA eq's the hump out and drops the output to match the rest of the speaker. That hump is the ONLY thing I didn't like about Al K's Universal xovers. The tweeter was just too hot. Mr. Paul was right. Quote Link to comment Share on other sites More sharing options...
karlson3 Posted June 12, 2018 Author Share Posted June 12, 2018 Thanks for the perspective ( - can't remember why DJK suggested the aB mod -?) otherwise, did you like ALK's Universal better than an AA? Where there two schemes? (I bought parts for one but might misplaced them ) I think my graph below is with Type A and mic height at K400's center less smoothing Quote Link to comment Share on other sites More sharing options...
Deang Posted June 13, 2018 Share Posted June 13, 2018 5 hours ago, JohnA said: Two things: the K-77-M has a response hump in the 6 to 9k range and runs about 105 dB there. The Type AA eq's the hump out and drops the output to match the rest of the speaker. That hump is the ONLY thing I didn't like about Al K's Universal xovers. The tweeter was just too hot. Mr. Paul was right. All of the replacement tweeters that people are using also run on the high side through that area - so the AA works well for those too. Quote Link to comment Share on other sites More sharing options...
JohnA Posted June 13, 2018 Share Posted June 13, 2018 6 hours ago, karlson3 said: Thanks for the perspective ( - can't remember why DJK suggested the aB mod -?) otherwise, did you like ALK's Universal better than an AA? Where there two schemes? (I bought parts for one but might misplaced them ) I think my graph below is with Type A and mic height at K400's center I liked the ALKs a little better, but the tweeter was too much, plus Type AA Klipschorns were the ones I first heard and it is the sound I expect from Klipsch. BTW, that's a fine looking in room response curve! Quote Link to comment Share on other sites More sharing options...
karlson3 Posted June 13, 2018 Author Share Posted June 13, 2018 I wish my Khorns sounded as good as the graph - the walls are flexy and "boooommmm" - just when tapped with one's hand. Maybe false corners are the only salvation for that room. Quote Link to comment Share on other sites More sharing options...
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