chops Posted March 9, 2006 Share Posted March 9, 2006 I'm just curious... Has anyone ever tried the "open baffle" approach with the CW II's? Or even tried reversing the polarity of the midrange? I wonder if this would help any with the slight heaviness in the lower to midrange area. Don't get me wrong, the CW's sound darn fine as is, but they do tend to have just a hint of congestion in the midrange. I suspect it's probably centered around the x-over point. Since I have my CW's crossed over to my sub at 80Hz, there's no real need for them to dig deep into the bass. I'm guessing that the enclosure is probably large enough that they would still reach down to about a strong 50-60Hz with the rear panel removed (a.k.a. - open baffle) and the port covered up from the rear, which BTW would be fully reversable. And since they are crossed over at 80Hz, I wouldn't have to worry about the bass driver getting out of control with no resistance in the rear. Do any of you think good results could be found by doing any of this? Any thoughts would be greatly appreciated. [] Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted March 9, 2006 Share Posted March 9, 2006 Open baffles have their place, but running the woofer as an open baffle speaker will not likely help the sound. Open baffle set ups can be sweet in the midrange (thus their allure), but the bass is problematic. Also, an open baffle woofer needs a fairly high Qts (like and infinite baffle woofer). The K33 has a pretty low Qts more suitable to horn loaded and ported applications. Specs wise, the K33 is very happy in that ported Cornwall cabinet. Andy Quote Link to comment Share on other sites More sharing options...
chops Posted March 9, 2006 Author Share Posted March 9, 2006 Open baffles have their place, but running the woofer as an open baffle speaker will not likely help the sound. Open baffle set ups can be sweet in the midrange (thus their allure), but the bass is problematic. Also, an open baffle woofer needs a fairly high Qts (like and infinite baffle woofer). The K33 has a pretty low Qts more suitable to horn loaded and ported applications. Specs wise, the K33 is very happy in that ported Cornwall cabinet. Andy Like I said, they are crossed over at 80Hz, so the loading on the driver shouldn't matter, as the lack of bass output does not matter either. Same thing goes for the Qts of the K33 driver. IIRC, the crossover point is at 600Hz, which is well into the meat of the midrange where the OB effects would probably help, which is also probably where that little bit of midrange congestion is at. Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted March 9, 2006 Share Posted March 9, 2006 Well your still getting significant energy below the 80Hz, unless the crossover slope is real steep. The best thing to do is just try it. At first you may like it, but I'll venture to say that you'll get tired of it in a couple of weeks. Let us know. I have a nice pair of Bozak 209 midranges I have thought about using in an open baffle design for the nice mids. The bass section would be in a box though. Hybrid. Quote Link to comment Share on other sites More sharing options...
BiggerIsBetter Posted March 9, 2006 Share Posted March 9, 2006 You can swap the polarity on hte mids, but don't expect a huge difference (a few dB in the xover region). Your results may vary as I tried it with a B-2 xover and corn 1 drivers. Quote Link to comment Share on other sites More sharing options...
chops Posted March 9, 2006 Author Share Posted March 9, 2006 Well the open baffle idea is out, due to the fact that I have 5 very nosey kitties that like crawling into my Cornwalls and sniffing around. I never even tried giving them a listen with the backs off. However, reversing the polarity of the mids did help... A LOT! Not only did it resolve the congested midrange issue, but for the very first time ever in the life of these CW's, they actually pulled off the "disappearing act" with flying colors! I couldn't believe it. After buttoning up the back of the CW's, I popped in Coldplay's "A rush of blood to the head" CD, sat down and turned up the volume to a reasonable listeining level. I immediately noticed the more lively, effortlessly open and deep soundstage. After playing a couple of tracks, I sat back and closed my eyes. That's when the magic happened! The last time I heard music so three dimentional and "alive" from my system was when I was running a pair of Magnepan MGLR-1's in my bedroom system and I was sitting 5' in front of them. I never thought it was possible for a loudspeaker this old with a front baffle so large to be able to disappear like this. Screw watching a movie tonight. I'm listening to music all night until I hit the sack! BTW, these are in fact CW I's built in '79, not CW II's like I thought. They have the K77 tweeter, K-55V mid, K33B woofer and Type "B" network. Not like it matters either way because the babies are here to stay![] Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted March 9, 2006 Share Posted March 9, 2006 I recently replaced the original caps in my 1977 Cornwalls with some GE oil cans from Bob Crites. The old caps were really hurting the high end and overall tonal balance of my speakers. The old caps were bad and they have been a controlled ac environment and never abused. With the new caps my Cornwalls literally sprang to life and have never sounded better. Very nice detail in the K77. If the original caps are in your Cornwalls, I recommend replacement very, very highly (and I am a non-audiophile (I do not claim to hear the inaudible), keep it orignal kind of guy). I was so reluctant to change my old caps, I even soldered the old ones back in after initial removal then took them back out just to give the new ones a listen. I am glad I did. I posted a couple of pictures in the odds and mods section under "Upgraded B balancing network." Andy 1 Quote Link to comment Share on other sites More sharing options...
chops Posted March 9, 2006 Author Share Posted March 9, 2006 Yeah, my CW's are virgins, except for the reversed polarity if you really want to call that a "mod". Everything is original on these speakers. I have noticed since I have been using them again that one of the tweeters sounds a little quieter than the other but never used to be that way. To solve that problem, I just put the left speaker on the right and the right speaker on the left since the left side of my room tends to be a tad bit hotter than the right in the treble. Needless to say, I am a little concerned. I was kind of thinking that one of those K77's might be on their way out for whatever reason. Now you are mentioning the caps and I'm wondering if that could be the problem instead. So now I either have to replace or rebuild the K77 or replace the caps in the network. Should I first measure the resistance of the K77 with an ohm meter to see if that is actually the problem? How can I pin-point the culptrut? Also, if you don't mind, how much do those replacement caps go for, or should I just contact BEC directly about that? Thanks! Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted March 9, 2006 Share Posted March 9, 2006 Here's the deal in my experience: As the Cornwall caps wear out the tweeters get overly mellow and lose their "sparkle" and detail. The mids mellow and lose some big Klipsch "zing." The decreased mids and highs upset the overall tonal balance towards a bass heavy speaker that sounds a little tubby. Some new oil cans can be bought directly from the gentleman Bob Crites. They are good caps. You will be amazed at the difference. I'll bet your tweeters are fine. You'll probably want to put that mid back in phase. Right now you are likely using an induced frequency peak to compensate for the bad caps. I am thrilled to say the least - and I gave it a week of listening before saying anything here, just to make sure I wasn't giving bad advice. Andy 1 Quote Link to comment Share on other sites More sharing options...
chops Posted March 9, 2006 Author Share Posted March 9, 2006 Hey, thanks again Andy. I just PM'ed Mr Crites about my situation. So I guess I'll just have to wait and see what he has to say. Just as a side note, I am listening to Diana Krall's "All for You" CD and can not believe how excellent it sounds. Quote Link to comment Share on other sites More sharing options...
3dzapper Posted March 9, 2006 Share Posted March 9, 2006 Chops, You might try loosening and retightening the screws on the xovers to the tweeters. That may also explain some of the improvement in the mids. Rick Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted March 10, 2006 Share Posted March 10, 2006 Yeah, my CW's are virgins, except for the reversed polarity if you really want to call that a "mod". Everything is original on these speakers. I have noticed since I have been using them again that one of the tweeters sounds a little quieter than the other but never used to be that way. To solve that problem, I just put the left speaker on the right and the right speaker on the left since the left side of my room tends to be a tad bit hotter than the right in the treble. Needless to say, I am a little concerned. I was kind of thinking that one of those K77's might be on their way out for whatever reason. Now you are mentioning the caps and I'm wondering if that could be the problem instead. So now I either have to replace or rebuild the K77 or replace the caps in the network. Should I first measure the resistance of the K77 with an ohm meter to see if that is actually the problem? How can I pin-point the culptrut? Also, if you don't mind, how much do those replacement caps go for, or should I just contact BEC directly about that? Thanks! chops talk about timing. I had posted about this in another thread and of course like others have said check your crossover connections first but if it looks like the K-77 then read the following which might help you. One thing that I have seen alot with the K-77 tweeters is a variation in the SPL by just touching the Wire terminals on the K-77s. This is due to the fact that on alot of the K-77s the Wire Terminal is riveted to the diaphram houseing and in alot of cases the Voice Coil is soldered to the inside of the rivet with only the pressure of the rivet making contact with the Wire Terminal and so over many years that mechanical connection can become corroded and cause a drop in SPL. If you measure the K-77 with an OHM Meter you should read Approximately 6.2 ohms if the connection is good. I have actually had them read as high as 200 ohm with very low SPL Output. Anyway if you have a K-77 acting up with varying output levels you can possibly repair if you can solder by taking a very fine piece of copper wire (I often use an old AC Cord which has many small gauge wires) and being carefull solder one end of the wire to the center of the rivet and wrapping the wire around the Wire Terminal and soldering it. mike[] Quote Link to comment Share on other sites More sharing options...
chops Posted March 10, 2006 Author Share Posted March 10, 2006 Chops, You might try loosening and retightening the screws on the xovers to the tweeters. That may also explain some of the improvement in the mids. Rick Funny you say that. That is exactly what Bob Crites suggested that I do too. Like I told Bob, when I was inside the CW's last night, I made sure all the connections were tight, but I didn't loosen them and retighten them. I'll be doing that tonight when I get home from work. [] Quote Link to comment Share on other sites More sharing options...
chops Posted March 10, 2006 Author Share Posted March 10, 2006 chops talk about timing. I had posted about this in another thread and of course like others have said check your crossover connections first but if it looks like the K-77 then read the following which might help you. One thing that I have seen alot with the K-77 tweeters is a variation in the SPL by just touching the Wire terminals on the K-77s. This is due to the fact that on alot of the K-77s the Wire Terminal is riveted to the diaphram houseing and in alot of cases the Voice Coil is soldered to the inside of the rivet with only the pressure of the rivet making contact with the Wire Terminal and so over many years that mechanical connection can become corroded and cause a drop in SPL. If you measure the K-77 with an OHM Meter you should read Approximately 6.2 ohms if the connection is good. I have actually had them read as high as 200 ohm with very low SPL Output. Anyway if you have a K-77 acting up with varying output levels you can possibly repair if you can solder by taking a very fine piece of copper wire (I often use an old AC Cord which has many small gauge wires) and being carefull solder one end of the wire to the center of the rivet and wrapping the wire around the Wire Terminal and soldering it. mike[] Yeah I saw that thread of yours. That sounds like a good idea as well. We'll see what happens after I try the "loosening and retightening" tip above. BTW, I love that avatar or yours! Quote Link to comment Share on other sites More sharing options...
chops Posted March 11, 2006 Author Share Posted March 11, 2006 Well I did the whole "loosen and retighten" bit last night which was recommended by Bob Crites and others here. I am pleased to say that that did the trick! However, I do plan on updating the original caps in the networks and upgrading the K77's with Bob's CT125's. At that time, I'll also have the K77's diaphrams replaced just for good measure. I just need to get all of my ducks in a row first before I can do anything else to my CW's. I do want to thank everyone for the quick "fix" tip to get the tweeters back to sounding equal again. I really do appreciate it![] Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted March 11, 2006 Share Posted March 11, 2006 I wouldn't recommend changing diaphragms unless they're bad. I may be mistaken, but I think that Alnico magnets change spec as soon as they are disassembled. Of course, if you have to, you have to. Also, you may want listen to your K77's with the new caps before making an upgrade. Mine lit up like fireflys. Andy Quote Link to comment Share on other sites More sharing options...
chops Posted March 11, 2006 Author Share Posted March 11, 2006 I plan on doing the caps first, since they are the least expensive upgrade that can be done and has proven positive results. However, I can honestly say that I am quite happy with the clean and smooth sound of the treble that the K77's are putting out already. We'll see what happens in the future of these CW's. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted March 12, 2006 Share Posted March 12, 2006 chops said: BTW, I love that avatar or yours! -------------------------------------------- Thanks chops thats my little buddy Poncho who is one year old now. Here is another picture of him when he was young. Glad the connections fixed your problem! mike[] Quote Link to comment Share on other sites More sharing options...
chops Posted March 12, 2006 Author Share Posted March 12, 2006 You're welcome Mike. I'm an animal lover so I just had to say something. [] And I too am glad that the connects tip fixed my problem! [] Although, in doing so, it has also shown me that I really do have to replace those caps in the networks. Over that last couple of days of watching movies and mostly listening to a wide range of music, both regular CDs and SACDs, I can definately tell that the K77's are really rolling off sooner than they used to. Also, I could have sworn I read in one of these other threads that someone mentioned something replacing the stock oil type cap for the tweeter over to some kind of audiophile grade cap, but was a little pricey. Maybe it was DeanG that mentioned it. Does anyone know what I'm talking about? Quote Link to comment Share on other sites More sharing options...
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