enigmasse Posted June 5, 2011 Share Posted June 5, 2011 I have a pair of stock '86 industrial La Scalas, having the K-77_, K-55M, K-43 and AK (possibly a AK-3?) crossover. I recently purchased a stock '79 LSBR La Scala for a center channel, having the k-77_, k-55V(push terminals), K-33 and AA crossover. The sound difference is much more than I anticipated. The '79 sounds hot, squawky (like a megaphone), not dynamic and just unnatural sounding like the '86 industrials. Even pink noise sounds lifeless! I am having a hard time meshing the sound with the '86 La Scalas. - I know the idustrial has the newer plastic/resin horn while the LSBR has the metal horn. From what I read, this shouldn't make a difference and dynamating the outside won't help. - Could it be the different cross-over? I know the AA is hotter, however does it make it sound squawky and not as dynamic? I also read that if I replace it with a new crossover from someone on the forum, it would probably sound even hotter with new caps. - Could it be the difference between the K-55V and the K-55M driver? - Could it be a K-55V diaphragm issue? How about the alinco magnet? Can I tell this by measuring the ohms between the two terminals? I am hoping to get ideas on how to match the sound to the industrial La Scalas (prefered) with minimal cost. I didn't expect this much difference, there must be something wrong! Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 5, 2011 Share Posted June 5, 2011 AK series crossovers where designed for the khorn. double check your 86 lascala's, and see if they have AL, AL-2, AL-3 crossovers. Quote Link to comment Share on other sites More sharing options...
enigmasse Posted June 5, 2011 Author Share Posted June 5, 2011 You're right, I got the back panel off and it has the "AL" crossover. I went ahead and posted a picture. They look clean! Quote Link to comment Share on other sites More sharing options...
enigmasse Posted June 5, 2011 Author Share Posted June 5, 2011 Here is the AA crossover on the LSBR. I also noticed the LSBR has a K-77-M tweeter while the industrials have the K-77. Is the K-77-M the original driver type for a '79 LSBR? Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 5, 2011 Share Posted June 5, 2011 I see a lot of corrosion in the picture of the AA xover. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 5, 2011 Share Posted June 5, 2011 Is the K-77-M the original driver type for a '79 LSBR? nope....and check the wiring to it....it looks like the wire with the black stripe is connected to the screw with the red dot. go out and get you a pack of #6 star lock washers and remove all the screws on the AA crossover connection strip one t a time, clean off the corrosion, and re-assemble using a star lock washer. those inductors look like the windings may have issues. And of course, it's highly unlikely those caps are still in spec. Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 5, 2011 Share Posted June 5, 2011 those inductors look like the windings may have issues Ya think? They look very suspicious to me, too. For sure the caps... Quote Link to comment Share on other sites More sharing options...
enigmasse Posted June 5, 2011 Author Share Posted June 5, 2011 I double checked the wiring and it is correct as far as I can tell; picture angle is deceiving. I'll have to research how to rebuild the crossover. I can easily find sites for replacing the caps, but haven't found anything on the inductors yet; still searching. I am sure there are tutorials somewhere. Assuming I get the crossover refreshed, ultimately, how will it compare to the AL network? The industrial La Scalas have a square magnet and say K-77. The LSBR are square too and say K-77M. In this post, http://forums.klipsch.com/forums/p/48970/464148.aspx#464148, Tom states: "AFAIK if it has the square magnet and is a K-77 it is a K-77-M". Can someone confirm this? I checked the K-55v and it has a resistance of 10.7 Ohms... Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 5, 2011 Share Posted June 5, 2011 I replaced the AL crossovers in my '86 LS, with one designed by a forum member. Some like them and some don't. If you give Bob Crites a call: http://www.critesspeakers.com/ he could give you some honest advice (not that the others who sell on here don't..., I've only dealt with Bob). You will find him extremely nice and full of great info. In any case, the AA needs work. Bruce Quote Link to comment Share on other sites More sharing options...
djk Posted June 6, 2011 Share Posted June 6, 2011 "Is the K-77-M the original driver type for a '79 LSBR?" Yes, that is the part they came with. Replace the caps and see how it sounds before doing anything else. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted June 6, 2011 Share Posted June 6, 2011 Everyone used to blow tweeters back in the late 70s with the stock setup (crossover/tweeters) and powerful s/s amps of that time. Not surprised to see M tweeters in there. They were probably replaced a few times. The crossovers look shot. I would replace the caps at the very least. Then test them to ensure they actually crossover where they are supposed to. I have a '77 lascala and a pair of '90 lascalas. I restored the '77 to the V tweeter (alnico), and replaced the crossover and it sounds excellent compared to the '90s. 1 Quote Link to comment Share on other sites More sharing options...
djk Posted June 6, 2011 Share Posted June 6, 2011 "Everyone used to blow tweeters back in the late 70s with the stock setup (crossover/tweeters) and powerful s/s amps of that time." Not hardly. The K77M version showed up in 78 and in AA (zener) networks was quite reliable. I had customers using amps as big as the Phase Linear 700 on Klipsch speakers. Of course if they had type B or E networks they got zeners added the first time they blew a tweeter, or at time of sale if it was deemed a hard use application. Quote Link to comment Share on other sites More sharing options...
enigmasse Posted June 7, 2011 Author Share Posted June 7, 2011 I called Bob and after talking to him, I'll have him test the crossover out and give me a synopsis on what it needs. When I pulled the crossover out of the speaker, one of the leads that connected to the 2uF capacitor was disconnected from the plastic spindle (with the brass screw). Not sure how that would affect the sound! Looks like someone at one point tried to solder it poorly. Depending on how the AA sounds, he may just convince me to replace the AL in the industrials to AA too. [^o)] This is getting more expensive than I originally anticipated. [:'(] Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted June 7, 2011 Share Posted June 7, 2011 I would keep two things in mind. Stay with a network designed for your mid drivers (K55M or K55V) they are differences that's why the AL2 and AL3 came about. Stay with later designs for driver protection through steeper slopes (less lows going into mid and high drivers), as networks evolved more components were used and steeper slopes offered better driver protection. Quote Link to comment Share on other sites More sharing options...
enigmasse Posted June 8, 2011 Author Share Posted June 8, 2011 This is going to be a subjective question though I still want to get feedback: How will this center channel LSBR sound in relation to the industrials in a home movie setup (industrial - LSBR - industrial)? Will it sound close enough that the sound would meld together or will I always be able to distinguish the sound from the LSBR as being different? I hope with an AA rebuild, the difference will be tolerable. Quote Link to comment Share on other sites More sharing options...
enigmasse Posted June 8, 2011 Author Share Posted June 8, 2011 I replaced the AL crossovers in my '86 LS, with one designed by a forum member. Some like them and some don't. Marvel: Did you replace them with AA crossovers? How do you compare the sound differences? Quote Link to comment Share on other sites More sharing options...
djk Posted June 8, 2011 Share Posted June 8, 2011 There is room for improvement in the AL network, I would suggest upgrading to a later AL version. The AA will sound a lot like the later AL3 it you bridge a 1µF cap across the two 2µF caps. Alternately you could remove the elliptical filter on the AL networks (which would be my choice). That just requires lifting the lead from the 500µH inductor to the 2µF cap. Quote Link to comment Share on other sites More sharing options...
enigmasse Posted June 20, 2011 Author Share Posted June 20, 2011 I received the AA crossover back from Bob Crites last week. He replaced the capacitors and checked everything else. I am pleasantly surprised by his quality workmanship and by the sound difference! It still clearly has a different tone than the Industrials but so far, it isn't too distracting that I am going to do anything about it. Thanks for the crossover advice, well worth the expense. I am glad I didn't go down the diaphragm path or anything else more drastic... I wonder how the AL with new caps would sound! Or moving to a AA altogether. Maybe another day... Quote Link to comment Share on other sites More sharing options...
MelissaDaisy99 Posted June 23, 2011 Share Posted June 23, 2011 Well, great work! You have helped me to improve my knowledge about this field. Thank you so much for sharing. __________________watch movies online free Quote Link to comment Share on other sites More sharing options...
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