Daddy Dee Posted January 29, 2015 Share Posted January 29, 2015 (edited) I prefer the CT-125 over K-77 and Beyma. To my ears, the CT-125 sounds more like the actual sound of instruments like cymbals. I use this tweeter with the K-55 driver crossed at 4500hz and Type A crossover. Edited January 29, 2015 by Daddy Dee Quote Link to comment Share on other sites More sharing options...
OO1 Posted January 29, 2015 Share Posted January 29, 2015 I prefer the CT-125 over K-77 and Beyma. To my ears, the CT-125 sounds more like the actual sound of instruments like cymbals. I use this tweeter with the K-55 driver crossed at 4500hz and Type A crossover. amazing for such an inexpensive apt 50 motor - versus Beyma cp21 - yoiu can buy 4 apt 80 tweeters for 115$ - 1 Quote Link to comment Share on other sites More sharing options...
kodomo Posted January 29, 2015 Share Posted January 29, 2015 Well, I have gone through 3 tweeters and ended up with Fostex t500amkII's. They are so much better than anything I have tried before! However, keep in mind, my midranges are also Greg's V-Tracs with BMS 4592nd-mid compression drivers. I tried the stock tweeters, the beyma tweeters, the volti t-1 (these were very good as well) but these Fostex are in another league. Sound is so much less fatiguing. It is smooth yet you can hear all the high frequency information. It feels like I can hear the whole room the recordings were made in. The soundstage also has somehow widened and the localisations of the sounds are better perceived. The only downside is they are very very expensive. Quote Link to comment Share on other sites More sharing options...
moray james Posted January 29, 2015 Share Posted January 29, 2015 I prefer the CT-125 over K-77 and Beyma. To my ears, the CT-125 sounds more like the actual sound of instruments like cymbals. I use this tweeter with the K-55 driver crossed at 4500hz and Type A crossover.amazing for such an inexpensive apt 50 motor - versus Beyma cp21 - yoiu can buy 4 apt 80 tweeters for 115$ - The CT125 is NOT an Eminence driver. The original APT tweeter was not an Eminence drive but Polish made and sold by Eminence then Eminence figured they could make their own and increase their profit and the popularity dropped. Bob has the original Polish company build his CT125. Clearly you get what you pay for. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
OO1 Posted January 29, 2015 Share Posted January 29, 2015 I prefer the CT-125 over K-77 and Beyma. To my ears, the CT-125 sounds more like the actual sound of instruments like cymbals. I use this tweeter with the K-55 driver crossed at 4500hz and Type A crossover.amazing for such an inexpensive apt 50 motor - versus Beyma cp21 - yoiu can buy 4 apt 80 tweeters for 115$ - The CT125 is NOT an Eminence driver. The original APT tweeter was not an Eminence drive but Polish made and sold by Eminence then Eminence figured they could make their own and increase their profit and the popularity dropped. Bob has the original Polish company build his CT125. Clearly you get what you pay for. Best regards Moray James. the new apt 50 is not bad at all - as a matter of tact the graphs are pretty good and very comparable to the old driver -there was a batch that was not good but the later productions were just as good -- Quote Link to comment Share on other sites More sharing options...
Marvel Posted January 29, 2015 Share Posted January 29, 2015 I prefer the CT-125 over K-77 and Beyma. To my ears, the CT-125 sounds more like the actual sound of instruments like cymbals. I use this tweeter with the K-55 driver crossed at 4500hz and Type A crossover.amazing for such an inexpensive apt 50 motor - versus Beyma cp21 - yoiu can buy 4 apt 80 tweeters for 115$ - The CT125 is NOT an Eminence driver. The original APT tweeter was not an Eminence drive but Polish made and sold by Eminence then Eminence figured they could make their own and increase their profit and the popularity dropped. Bob has the original Polish company build his CT125. Clearly you get what you pay for. Best regards Moray James. You are making an assumption on the popularity dropping for the APT50, since Bob found the Polish ones to be better so he switched to the original vendor. We have no idea whether or not Eminence sales of the APT-50 driver dropped or not. I purchased the APT150 (100x50 horn flare on APT-50 driver), and they sounded excellent. Mine may still have been the original driver, though, as my horn flares still use the older threading and not the more standard 1 3/8. Bruce Quote Link to comment Share on other sites More sharing options...
Max2 Posted January 29, 2015 Share Posted January 29, 2015 Well, I have gone through 3 tweeters and ended up with Fostex t500amkII's. They are so much better than anything I have tried before! However, keep in mind, my midranges are also Greg's V-Tracs with BMS 4592nd-mid compression drivers. I tried the stock tweeters, the beyma tweeters, the volti t-1 (these were very good as well) but these Fostex are in another league. Sound is so much less fatiguing. It is smooth yet you can hear all the high frequency information. It feels like I can hear the whole room the recordings were made in. The soundstage also has somehow widened and the localisations of the sounds are better perceived. The only downside is they are very very expensive. Are the Fostex a $1000 a piece or $1000 a pair? Quote Link to comment Share on other sites More sharing options...
Axz Hout Posted January 29, 2015 Share Posted January 29, 2015 d Quote Link to comment Share on other sites More sharing options...
kodomo Posted January 31, 2015 Share Posted January 31, 2015 it is 1000 each! Quote Link to comment Share on other sites More sharing options...
jcmusic Posted February 1, 2015 Share Posted February 1, 2015 Well, I have gone through 3 tweeters and ended up with Fostex t500amkII's. They are so much better than anything I have tried before! However, keep in mind, my midranges are also Greg's V-Tracs with BMS 4592nd-mid compression drivers. I tried the stock tweeters, the beyma tweeters, the volti t-1 (these were very good as well) but these Fostex are in another league. Sound is so much less fatiguing. It is smooth yet you can hear all the high frequency information. It feels like I can hear the whole room the recordings were made in. The soundstage also has somehow widened and the localisations of the sounds are better perceived. The only downside is they are very very expensive. Did you try the 90A's before these? Quote Link to comment Share on other sites More sharing options...
kodomo Posted February 1, 2015 Share Posted February 1, 2015 I have heard 900a's in shop and 500amkII's were better than those so I did not try the 90A's. Quote Link to comment Share on other sites More sharing options...
delta88343 Posted March 20, 2015 Share Posted March 20, 2015 (edited) It is important to remember that the stock K77 tweeter has a response peak right at 5k. If you move up the cross over frequency to flatten out that 5k peak (using a first order network), the K77's sound much more sweeter and balanced. Also, those that prefer a speaker that has a flat frequency response to 20k or higher, I'll bet if you have your hearing tested, you're not hearing anything above 15k Hz. Even if you are, the content at those frequencies is extremely minimal. Yes, I agree a speaker should be flat out to 20k. I'm simply stating there's not much there and what is there cannot be heard by the vast, vast majority of people. And regarding the Fostex "super" tweeter, look at its frequency response. It's flat from 3.5k to 10k which is great, but then there is a 10db shelf peak between 10k & 30k. hardly flat. You certainly dont have to worry about bats or mice infestations. Edited March 20, 2015 by delta88343 Quote Link to comment Share on other sites More sharing options...
kodomo Posted March 20, 2015 Share Posted March 20, 2015 The fostex is generally crossed over 10khz so people do not care about that bump. However, I did cross mine around 6.5khz and still it works very well. The results on axis are quite flat too. Actually more flat than their chart? I do not know if it sounds good because it extends to high frequency extreme, but it does sound very relaxed and accurate. Its quite interesting for me to hear that much high frequency information with a relaxed presentation. I guess it is as important to have minimal distortion as being flat. Also some people consider +/-3db flat and some consider +/-1db flat. My system with the exception of a small low midbass bump and the tweeter crossover point is quite flat from 20hz to 20khz. It deviates less than 3db's and the bump I have is around 5db's at 160hz-180hz. The dip I have around 6.5khz is also around 4db's. My plan to get over that dip was to add another horn and a compression driver between 2khz and 10khz. It would also widen the sweet spot but putting a horn like that in between mids and tweeter, the tweeters and the new horn move physically so high that it starts presenting another challenge. To overcome that challenge I need to change the corner midbass with something shorter... The neverending story Quote Link to comment Share on other sites More sharing options...
John Warren Posted March 20, 2015 Share Posted March 20, 2015 (edited) IMO, if there's an advantage to changing the tweeter it's really in putting the K401 mid on narrower range of use. There are a few compression horn tweeters made by Faital that use polymeric diaphragms that sound quite good. I was sent a pair of Faital HF108s with the STH102 horns for measurement. It goes a lot lower than the K77. So by lowering the crossover between the mid and the HF unit, the harshness, spit, shout (or whatever you call it) from the mid, at high output levels, seems to go way I'd say that much of dismay leveled at the stock mid can be traced back to the output above about 4kHz. I settled on a crossover of 2.8kHz, with grill on. Narrowing the expected bandwidth of the mid improves the distortion numbers. In this case the bandwidth is less than less than 3 octaves which goes along way to improve things. First plot shows the K401 with an AA net (purple) and a modified AA (blue) that was used to crossover to the Faital. The tweeter section of the AA is out. Second plot is the Faital HF108 with the K401. The mod takes a new baffle board to be installed in the top section, not a difficult task. Also you can just put the tweeter on top and not mess with the baffle. I'll post the network mods on a page on my site and link it here. Edited March 22, 2015 by John Warren Quote Link to comment Share on other sites More sharing options...
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