PM15 Posted February 28, 2022 Share Posted February 28, 2022 Like many others I am down the rabbit-hole of panning to build a pair of Cornscala "D Style". I chose the 2 way design to simplify the construction, design and availability of parts. Being based in Italy my main problem is finding crossovers for a reasonable price; with ALK and Crites both based in the US I would spend more in shipment + taxes than the actual product. Are there available (for sell too) some schematics/details shots of a crossover for a 2-way Cornscala (single crossover at 500Hz)? I am willing to DIY it. My components are: - Faital HF140 Driver - Faital LTH142 Horn - Eminence Kappa-15C Woofer (is there something from Faital or B&C that can compare?) Any help is much appreciated! Thank you 1 Quote Link to comment Share on other sites More sharing options...
Deang Posted February 28, 2022 Share Posted February 28, 2022 How are you buying the autotransformers? Quote Link to comment Share on other sites More sharing options...
parlophone1 Posted March 7, 2022 Share Posted March 7, 2022 Why not going active? Quote Link to comment Share on other sites More sharing options...
henry4841 Posted March 7, 2022 Share Posted March 7, 2022 Why use an autotransformer on a speaker that is not an old Klipsch speaker? Just added expense with no significant advantage. Klipsch has not used them in decades themselves. I can understand trying to keep an older Klipsch original sounding and stock as PWK designed it but not something I would use on a diy speaker. Not something that I know of anyone doing on a crossover they design for a diy speaker. At least not something I would do. Having designed many crossovers for different speakers I still use AA's with autotransformers on my old LaScala's but not for any other speaker. Quote Link to comment Share on other sites More sharing options...
uteman1011 Posted March 11, 2022 Share Posted March 11, 2022 On 2/27/2022 at 6:15 PM, PM15 said: Like many others I am down the rabbit-hole of panning to build a pair of Cornscala "D Style". I chose the 2 way design to simplify the construction, design and availability of parts. Being based in Italy my main problem is finding crossovers for a reasonable price; with ALK and Crites both based in the US I would spend more in shipment + taxes than the actual product. Are there available (for sell too) some schematics/details shots of a crossover for a 2-way Cornscala (single crossover at 500Hz)? I am willing to DIY it. My components are: - Faital HF140 Driver - Faital LTH142 Horn - Eminence Kappa-15C Woofer (is there something from Faital or B&C that can compare?) Any help is much appreciated! Thank you Please post pics of the process! I'm going to be doing the same project. I'll be curious to see how you choose to do the cabinets. Good luck! Quote Link to comment Share on other sites More sharing options...
Deang Posted March 11, 2022 Share Posted March 11, 2022 On 3/7/2022 at 7:07 AM, henry4841 said: Why use an autotransformer on a speaker that is not an old Klipsch speaker? Just added expense with no significant advantage. So why did PK use them? He value engineered practically everything, but chose the most expensive solution available for attenuation. Sometimes you use what you understand over something you don't. I'm not a network design engineer, but I know how to scale the parts. It's an elegant, simple solution, and sounds great. Quote Link to comment Share on other sites More sharing options...
captainbeefheart Posted March 11, 2022 Share Posted March 11, 2022 Why are we discussing the autoformer which attenuates the mid-horn for the 3-way network where the OP is building a 2-way speaker? I could be missing information or not understand the situation. 1 Quote Link to comment Share on other sites More sharing options...
Deang Posted March 11, 2022 Share Posted March 11, 2022 You can still use an autoformer to attenuate the HF driver. Quote Link to comment Share on other sites More sharing options...
geoff. Posted March 12, 2022 Share Posted March 12, 2022 Yes, the Crites CS500 2-way crossover uses an autoformer. But the more complex Crites 2-way pictured below does not. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted March 12, 2022 Share Posted March 12, 2022 How long has it been since Klipsch used autotransformers, 30 years? If they are so much better why are they not using them now? Do they not want their speakers to sound the best they can? Dean profits from building crossovers using autotransformers so naturally he would prefer them. My understanding is PWK used them to get every bit of power he could out of the amplifiers of the 50's he could. I can see no reason whatsoever for anyone to design a new crossover network for a diy project using an autotransformer that even Klipsch does not use anymore. No offense meant to Dean, he serves a purpose for those wanting to keep their old speakers original and from all accounts does a good job building them. Quote Link to comment Share on other sites More sharing options...
Curious_George Posted March 12, 2022 Share Posted March 12, 2022 17 hours ago, Crankysoldermeister said: You can still use an autoformer to attenuate the HF driver. Of the three ways to attenuate (standard rotary l-pad, l-pad made from 2 discrete resistors or autoformer), I prefer the autoformer or discrete solution, until the design is finalized or it is a loudspeaker I am going to constantly tinker with. Why? The autoformer allows you precise steps and you can easily set the two channels at the same level. Same with a 2 resistor l-pad. The rotary l-pad has no detents or references and it is difficult to set each channel to the same level unless you take a lot of time and make measurements and reference marks on a faceplate or such. Those marks may not be too precise either. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 12, 2022 Share Posted March 12, 2022 "If they are so much better why are they not using them now?" Resistors don't cause phase issues like inductors do. Also, one costs fifty times more than a resistor. "My understanding is PWK used them to get every bit of power he could out of the amplifiers of the 50's he could." I don't think that was the reason. Below is from my notes: ”A pad will divorce damping between the amplifier and the driver, resulting in a higher peak-to-trough ratio in amplitude (resulting in rougher response).” Obviously not a hill to die on, since there is no shortage of great sounding loudspeakers that don't use autotransformers. Network design has come a long way in 50 years. 1 Quote Link to comment Share on other sites More sharing options...
consistent Posted March 13, 2022 Share Posted March 13, 2022 I agree with Curious George...I have designed L-Pads and used autoformers and compared...the resistors in an L-pad destroy the 'cleanliness' that the autoformer provides! If you wish to change the values to even out various speaker resistances (more precise matching of drivers) just use a good resistor to 'swamp' the autoformer. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted March 13, 2022 Share Posted March 13, 2022 8 hours ago, consistent said: I agree with Curious George...I have designed L-Pads and used autoformers and compared...the resistors in an L-pad destroy the 'cleanliness' that the autoformer provides! If you wish to change the values to even out various speaker resistances (more precise matching of drivers) just use a good resistor to 'swamp' the autoformer. I disagree. Having tried many different crossovers, over 30, with my LaScala's years ago the best sound IMHO was without an autotransformer. Probably because of the more phase shift an autotransformer has and me being sensitive to phase shift. That being said the difference between the two is subtle and not earth shaking. After trying many different combinations I have AA crossovers in my LaScala's now. As the country boy says, "there are many different roads to town." I still see no need for someone building a crossover network for a diy project to use an autotransformer. Let see, $120 plus shipping for a pair of autotransformers or $4 for 4 resistors. Not a hard decision for me if I ever design and build another crossover network. The only manufacturer I know of still using autotransformers for audio is McIntosh but not in a crossover network but rather in their SS amplifiers. Different story if someone is restoring an old pair of speakers wanting to preserve the sound of that era. Mentioning a swamping resistor is going to open another can of worms. There has been a lot of discussions on that subject in the past. Personally when using an autotransformer I like using ALK's swamping resistor networks with the ability to change attenuation on the fly. Easier to adjust the sound to ones room. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted March 13, 2022 Share Posted March 13, 2022 From discussion on another thread it seems the engineers at Klipsch at some point in time took a different direction for attenuation using just one resistor designing the network with the value of the resistor plus the speaker impedance. I can see how it can be done but do not understand the advantage of doing it that way but I am sure the engineers at Klipsch had their reasons. As said above many different roads to town. Designed properly all should sound just fine. In electronics I put more emphasis on design then component choices. 1 Quote Link to comment Share on other sites More sharing options...
mboxler Posted March 13, 2022 Share Posted March 13, 2022 30 minutes ago, henry4841 said: From discussion on another thread it seems the engineers at Klipsch at some point in time took a different direction for attenuation using just one resistor designing the network with the value of the resistor plus the speaker impedance. I can see how it can be done but do not understand the advantage of doing it that way but I am sure the engineers at Klipsch had their reasons. Wouldn't the main advantage of a single resistor be the ability to use smaller value capacitors? A single series resistor equal to the impedance of the driver (-6db) would require a capacitor half the value vs a -6db lpad. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted March 13, 2022 Share Posted March 13, 2022 Possible explanation. The speaker industry standard is using a discrete L-pad or an adjustable one, at least that is my knowledge of all the crossovers for speakers I have seen. I am almost positive if 6 engineers from 6 different companies were put together in a room there would be a lively discussion on the best way for attenuation. PWK carried his button when in the presence of other engineers who he disagreed with. Quote Link to comment Share on other sites More sharing options...
consistent Posted March 14, 2022 Share Posted March 14, 2022 ...I do agree with the cost aspect, to me that is the driver in using simple and cheap resistors instead of autoformers! Quote Link to comment Share on other sites More sharing options...
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