chops Posted June 22, 2006 Author Share Posted June 22, 2006 My hearing is in question but I love stuff that sounds like crap. Infact, I am partial to the smell of it. Chops, I am no expert. I have piddled a bit with this CW K33 bass bins. The 511/902 combo is very good. I would stay the course of what was mentioned above. The one strong point I will add is to consider getting away from crossing the tweeter at 4500Hz. The 902 does great out there and there is no good reason I can think of to cut the 902 off at 4500Hz. The second strong point is to not rush into a new change quickly. Dean is right on this one (he has said it to me before too). I used to get too excited about a particular mod or change and then make a decision. It is quick and easy to mod/upgrade but its evaluation takes awhile. You are on the right track. The 902/511 combo is a winner in my book. jc Hi jc, Boy, and people think I'm weird for liking the smell of gas... gasoline that is. LOL Anyway, like I just mentioned above, I am staying on the current course of action as Dean suggested. About the tweeter at 4500, I may end up not using it at all depending on how I like the 902 flat out on the 511B horn. If it gives me enough extension, or at least more extension that my old alnico K77s, then I might be happy without a tweeter altogether. Only time will tell. However, if I am not totally satisfied with the extension of the 902, I will want to pass the CT125 as high as possible just so I can get the most out of the 902. Maybe 8 or 10kHz? Charels Quote Link to comment Share on other sites More sharing options...
Deang Posted June 22, 2006 Share Posted June 22, 2006 "Am I right in assuming that adding a Mills 10 ohm / 12 watt resister across taps #0 & 5 will pretty much make the network a constant impedence design like you and Al keep mentioning about?" Not quite. When you do that, you're stepping down the impedance of your midrange from 60 ohms down to about 8, and this changes the parts values. Reading through the following thread will answer a lot of your questions about this, but will raise some new ones as well. http://forums.klipsch.com/forums/thread/606374.aspx Like me, JC has tried just about everything, so definitely get his input. I'm pretty sure we've reached similar conclusions on some things. I will say that with a room the size of yours, and if you're into live listening levels -- this pretty much mandates higher order filters (unless you move your couch up:) to keep distortion levels down. This subject taken as a whole is extremely complex, and it doesn't help matters that people who do a lot of this kind of thing invariably come to different conclusions on some things. However, the advantage of learning and doing it on your own means you will eventually draw your own conclusions -- and find the way that works best for you personally (your room, gear, music, and listening habits). In another thread, 'speakerfritz' mentioned the necessity of a matrix of sorts for all of these different networks. He also liked the 'good, better, best' approach that Al uses on his website. I actually had this need mentioned to me by Mark Deneen in a telephone conversation last year -- my response was that it was impossible to do. There are simply too many variables to juggle. Not only do you have the various acoustic and weaknesses associated with design -- but you have the fact that people just plain hear differently. Some are just used to a certain sound, and have trouble if the signature strays too far off from the thing they are used too. I'm one of those people, and since getting into this 30 years ago -- I have always gravitated towards loudspeakers using low order filters. The truly funny thing is that I didn't realize this until I became interested in crossovers and started learning about the designs used in the speakers I grew up with: they all used first order designs -- with the exception of the Old Advent, which was second order. I'm still there -- I love the sound of a first order filter section on a horn midrange. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 22, 2006 Share Posted June 22, 2006 Stretch as many octaves through the middle as possible -- it sounds freaking glorious! Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted June 22, 2006 Share Posted June 22, 2006 Dean, In late March, Dr. Readall B. Davis, M.D. evaluated my hearing. His findings contradict yours. I have a bit of HF loss that is typical for a man my age, according to the doctor. Hell, if I had been aware of your expertise in internet hearing tests.......and on-line evaluations......I could have saved 50 bucks! But...... I guess if what you listen to is Robert Plant screeching his guts out.....a loss might be a good thing. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 22, 2006 Share Posted June 22, 2006 Terry -- I was kidding! BEC says you take your listening pretty seriously, and I know JC is relentless with this stuff. It wasn't meant as a cheap shot -- I was just ribbing you guys. I used that recording of Plant because it excites the resonances and exasperates the problem with the RF-7 top end. If I had used a good recording for the demonstration, you guys would have heard a difference, but it wouldn't have been near as dramatic. Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 "Am I right in assuming that adding a Mills 10 ohm / 12 watt resister across taps #0 & 5 will pretty much make the network a constant impedence design like you and Al keep mentioning about?" Not quite. When you do that, you're stepping down the impedance of your midrange from 60 ohms down to about 8, and this changes the parts values. Reading through the following thread will answer a lot of your questions about this, but will raise some new ones as well. http://forums.klipsch.com/forums/thread/606374.aspx Like me, JC has tried just about everything, so definitely get his input. I'm pretty sure we've reached similar conclusions on some things. I will say that with a room the size of yours, and if you're into live listening levels -- this pretty much mandates higher order filters (unless you move your couch up:) to keep distortion levels down. This subject taken as a whole is extremely complex, and it doesn't help matters that people who do a lot of this kind of thing invariably come to different conclusions on some things. However, the advantage of learning and doing it on your own means you will eventually draw your own conclusions -- and find the way that works best for you personally (your room, gear, music, and listening habits). In another thread, 'speakerfritz' mentioned the necessity of a matrix of sorts for all of these different networks. He also liked the 'good, better, best' approach that Al uses on his website. I actually had this need mentioned to me by Mark Deneen in a telephone conversation last year -- my response was that it was impossible to do. There are simply too many variables to juggle. Not only do you have the various acoustic and weaknesses associated with design -- but you have the fact that people just plain hear differently. Some are just used to a certain sound, and have trouble if the signature strays too far off from the thing they are used too. I'm one of those people, and since getting into this 30 years ago -- I have always gravitated towards loudspeakers using low order filters. The truly funny thing is that I didn't realize this until I became interested in crossovers and started learning about the designs used in the speakers I grew up with: they all used first order designs -- with the exception of the Old Advent, which was second order. I'm still there -- I love the sound of a first order filter section on a horn midrange. Man, I just got done reading this thread from beginning to end. http://forums.klipsch.com/forums/1/514028/ShowThread.aspx Now you want me to read another one?! LOL Nah, seriously, I enjoy reading this stuff. Unfortunately though, you guys start getting a little too technical and I get a little lost in all of it. But still, it's all helpful and I pick up a little bit here and there. And just to clear up a little bit about my listening habbits. On a realistic level, I would say 90% of the time, I listen to my stereo at "normal" levels, probably somewhere between 70-85dB. Only when I'm listening to a particular CD or song that I really like, or if I'm watching a really good, action packed movie, do I have the system playing near or slightly above 100dB. I'm not as crazy as some. [] If I can get away with a lower slope rate and still be safe on the 902, then that's fine. I just don't want to blow the darn things. I was thinking also, if I was to bump the crossover freq back up a little on the 902, and since if I will have the entire tweeter section disconnected, AND if I do use the tweeter again but at a higher crossover freq as well, that means I would have at least one spare 2uF cap from the tweeter section. So with that in mind, and the fact that the current 7uF cap bank for the midrange gives me 375Hz, and the stock 4uF gives me 600Hz, then what would 5uF and 6uF give me? I feel the same away about what you said in your next post about letting the 902 play as wide a range as possible. That's what I'm trying to get to, but without running the risk of damage to the driver. Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 Say if I get the 902 down to 500Hz, and the K33 up to 500Hz, what cap values would I need? I have that 68uF cap on the K33 right now which gets me 437Hz, so would say a 50uF get me closer to 500Hz? Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted June 22, 2006 Share Posted June 22, 2006 I, and as Terry will tell you ... don't belive you will blow that Altec driver......... the most important limit will be reached in Excursion, and the power the driver recieves <600 Hz... what's the \' Half Power " point ..??? 350 Hz ....????? where both drivers in a system recieve the same wattage don't forget the Fc of the 511............. ain't what it's rated at .... DJK explained this a while ago.... I was Wrong ...!!.........[:$] well, it was the literature, that was misleading .....[] Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 I, and as Terry will tell you ... don't belive you will blow that Altec driver......... the most important limit will be reached in Excursion, and the power the driver recieves <600 Hz... what's the \' Half Power " point ..??? 350 Hz ....????? where both drivers in a system recieve the same wattage don't forget the Fc of the 511............. ain't what it's rated at .... DJK explained this a while ago.... I was Wrong ...!!.........[:$] well, it was the literature, that was misleading .....[] Duke, the most important limit will be reached in Excursion, and the power the driver recieves <600 Hz... what's the \' Half Power " point ..??? 350 Hz ....????? where both drivers in a system recieve the same wattage If possible, do you think you could elaborate on your post a little? I kind of at a loss here on what you are saying. don't forget the Fc of the 511............. ain't what it's rated at .... DJK explained this a while ago.... I was Wrong ...!!.........[:$] well, it was the literature, that was misleading ..... Are you referring to the 511B horn being able to properly load a driver well below 500Hz? If I remember correctly, I was reading something on the Altec User Board a while back where someone stated that they successfully had their 511B and driver (can't remember if it was a 902 or not) playing down to 265Hz or 365Hz without distorsion. It was something like that. Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted June 22, 2006 Share Posted June 22, 2006 Terry -- I was kidding! BEC says you take your listening pretty seriously, and I know JC is relentless with this stuff. It wasn't meant as a cheap shot -- I was just ribbing you guys. I used that recording of Plant because it excites the resonances and exasperates the problem with the RF-7 top end. If I had used a good recording for the demonstration, you guys would have heard a difference, but it wouldn't have been near as dramatic. I saw the at the end. We have been trading shots back and forth about the SPL's at Hope. All in good fun. I knew exactly what you were doing with the Plant stuff. The crossover mod made a believer out of me. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 22, 2006 Share Posted June 22, 2006 Say if I get the 902 down to 500Hz, and the K33 up to 500Hz, what cap values would I need? I have that 68uF cap on the K33 right now which gets me 437Hz, so would say a 50uF get me closer to 500Hz? Are we talking about a b series network or AA network. I can post a pic to help clarify. I think you will find that the 68uf cap is not an in-line cap, but rather a shunt one. Meaning it does not establish the cutoff of the k-33, just the roll off. The roll of is the level reduction of adjacent higher octaves in the case of a woofer. The crossover point for the k-33 is established by an interaction of the in line inductor of the k-33 and the in-line cap for the horn. if you want to change the crossover point for your woofer and horn, both the in-line woofer inductor and in-line horn capacitor would have to change. the rolloff for each is effected by the shunt devices across the driver terminals....rolloff for woofer is controlled by a capacitor across the woofer terminals...rolloff for the horn is controlled by an inductor across the horn driver terminals. The shunt componets are located on the xover board. you should use a crossover calculator to establish the values needed for your in-line componets of your xover. Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted June 22, 2006 Share Posted June 22, 2006 . "I, and as Terry will tell you ...don't belive you will blow that Altec driver......... the most important limit will be reached in Excursion, and the power the driver recieves <600 Hz...".... The alleged []126db at Hope was through 511/902's crossed at 400. I have thought for sometime that Altec rated them conservatively due to their "pro" use. With the phase plug in, I think that they could take anything that I could throw at them (at 400hz) amd still stay in the room. tc Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 Say if I get the 902 down to 500Hz, and the K33 up to 500Hz, what cap values would I need? I have that 68uF cap on the K33 right now which gets me 437Hz, so would say a 50uF get me closer to 500Hz? Are we talking about a b series network or AA network. I can post a pic to help clarify. I think you will find that the 68uf cap is not an in-line cap, but rather a shunt one. Meaning it does not establish the cutoff of the k-33, just the roll off. The roll of is the level reduction of adjacent higher octaves in the case of a woofer. The crossover point for the k-33 is established by an interaction of the in line inductor of the k-33 and the in-line cap for the horn. if you want to change the crossover point for your woofer and horn, both the in-line woofer inductor and in-line horn capacitor would have to change. the rolloff for each is effected by the shunt devices across the driver terminals....rolloff for woofer is controlled by a capacitor across the woofer terminals...rolloff for the horn is controlled by an inductor across the horn driver terminals. The shunt componets are located on the xover board. you should use a crossover calculator to establish the values needed for your in-line componets of your xover. I'm working off of a modified Type B network. As for the 68uF cap being a "shunt" or whatever, all I know is that when Bob was doing some testing on different value caps for the K33 for his Cornscala IIs, he first tried a 100uF cap and he said that the K33 started rolling off in the 300ish Hz range, which was obvioulsy too low. When he tried the 68uF cap, the K33 rolled off around 437Hz. Since the 2.5mH inductor never changed, then I automatically assumed the cap was making the final decision on the crossover point. Or maybe because the K33's 1mH VC and the 2.5mH inductor makes it a -12dB slope, then adding the 100uF or 68uF cap makes it a -18dB slope. Now please keep in mind, I am in the early stages of learning all of this crossover stuff, so most of what I know is only from what others tell me or from what I have read in other threads. I still don't know how what does that to who, and where it is when it does it, and why. I have tried the different crossover calculators before, but they are no good. As Al K has pointed out to me, those calculators ONLY assume a static driver impedance. They do not consider the VC inductance nor do they consider the impedance swings throughout the frequency range, so the component values are not correct. This has been proven the case several times while I have tried to model the simple Cornwall driver/Type B network combo (4 ohm woofer, 16 ohm midrange, 8 ohm tweeter / XO points of 600Hz and 6000Hz). If those calculators worked properly, I would at least get something close to the 2.5mH inductor on the woofer, 2uF and 4uF caps on the squawker and tweeter. But these calculators never come close to those values. Unfortunately, I don't have the luxury of spending $50-100 on crossover parts every couple of weeks to do experimental work on crossovers and end up with a bunch of wrong parts because those calculators told me the wrong values. That's why I am asking so many questions and wanting to do proven mods so I can get where I need to be. That way, I can be up and running ASAP and get all the bugs worked out before taking the plunge of building a pair for myself with all new and better parts. As much as I'd love to do all of this on my own, I can't. I'd much rather leave all the guess work up to the ones who know what they're doing. And trust me guys, all of your input is greatly, greatly appreciated! [] Quote Link to comment Share on other sites More sharing options...
jwc Posted June 22, 2006 Share Posted June 22, 2006 Chops. It is embarrasing how many damn Solen caps I have laying around from testing/trying stuff. jc Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 Chops. It is embarrasing how many damn Solen caps I have laying around from testing/trying stuff. jc LOL... I can imagine. Just think what Bob's, Dean's and Al's collection must look like. [] At one point when I was younger, I probably had somewhere around 20-30 raw drivers just laying all over the place; in the corners of my bedroom, in the closet, under my bed, on shelves out in the garage (which there are still three 15" Pyle Pro drivers out there), some in the hallway closet, and I think I still might have a few hiding in one of my brothers closets! LOL Quote Link to comment Share on other sites More sharing options...
Deang Posted June 22, 2006 Share Posted June 22, 2006 "I have tried the different crossover calculators before, but they are no good. As Al K has pointed out to me, those calculators ONLY assume a static driver impedance. They do not consider the VC inductance nor do they consider the impedance swings throughout the frequency range..." They also don't factor in the reactive component. At any rate, now you know why we step down impedance, and lock it in using the swamping resistor. The other advantage is that you can now use the autoformer as a pure attenuator for the midrange -- and adjust attenuation on the fly by using different tap combinations without shifting the crossover points. You can also build using two autoformers, and use the second as a pure attenuator for the tweeter if you are using one that's more sensitive than a K-77 or CTS-125 (but with a 20 ohm resistor). The constant impedance types definitely sound better to me with the stock drivers and horns, but the Klipsch types quickly pull even when you change to better horns and drivers. Don't ask me why this is -- I simply don't know. If you build the way you are building (no swamping resistor), and stay first order all the way -- the shifting of the crossover points with the impedance swings aren't as dramatic as you might think, that is -- there is so much overlap between the drivers, that the shifting back and forth from an acoustical perspective amounts to exactly nothing. Something else to consider is that the inductive and resistive parameters of a VC change as it heats up. When prototyping -- buy inexpensive caps. I like the Dayton Audio's from partsexpress, they sound very good for the money. You could fill a shoebox with them and barely put a dent in your beer money. When you get what you want nailed down -- buy some Kimbers, Auricaps, or mortgage your house and get some V-caps. "...This has been proven the case several times while I have tried to model the simple Cornwall driver/Type B network combo (4 ohm woofer, 16 ohm midrange, 8 ohm tweeter / XO points of 600Hz and 6000Hz)." O.K., there is only one three-way calculator on the net that's worth a crap: http://www.kbapps.com/audio/speakerdesign/calculators/Default.htm The reason your values aren't coming up right is because you aren't accounting for what the autoformer is doing to the impedance your amplifier sees. The first cap coming off of your input is called the primary cap, or highpass cap, and it goes to tap 5. The value of the cap is determined by a combination of the high pass crossover point you want along with the impedance that the autoformer is reflecting back to the cap from the output side. That is -- whatever tap the midrange is hooked to. It works like this: Tap 4, the impedance of the squawker x 2Tap 3, the impedance of the squawker x 4Tap 2, the impedance of the squawker x 8Tap 1, the impedance of the squawker x16 If you are off of tap 3 with a 16 ohm driver, the reflected impedance back to the primary cap position is 64 ohms. So, if you need to calculate for something on the input side of the autoformer, you need to make sure you have the correct impedance. Now we do the output side: Taps 1-4 are output taps. These taps sit between the driver and autoformer directly. Anything you calculate here is based on the raw impedance of the driver/horn -- and you do not have to scale. When you use the calculator, you will have to do calculations twice. The first time will be to get the highpass value at the higher, reflected impedance -- the second time will be to get your low pass inductor value for the squawker bandpass -- which resides on the output side of the autoformer (16 ohms). Notice that the calculator factors in the reactive component, and also will not let you create any filters that are less than three octaves apart. A couple of things you will eventually figure out by playing with it is that 1) the Klipsch networks are based on 15 ohms and multiples thereof, and 2) there has never been a 6000Hz "crossover point." http://www.trueaudio.com/st_xov_1.htm http://www.xtant.com/html/techSupport/crossoversFilters.cfm Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 Edit... Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 22, 2006 Share Posted June 22, 2006 Say if I get the 902 down to 500Hz, and the K33 up to 500Hz, what cap values would I need? I have that 68uF cap on the K33 right now which gets me 437Hz, so would say a 50uF get me closer to 500Hz? Are we talking about a b series network or AA network. I can post a pic to help clarify. I think you will find that the 68uf cap is not an in-line cap, but rather a shunt one. Meaning it does not establish the cutoff of the k-33, just the roll off. The roll of is the level reduction of adjacent higher octaves in the case of a woofer. The crossover point for the k-33 is established by an interaction of the in line inductor of the k-33 and the in-line cap for the horn. if you want to change the crossover point for your woofer and horn, both the in-line woofer inductor and in-line horn capacitor would have to change. the rolloff for each is effected by the shunt devices across the driver terminals....rolloff for woofer is controlled by a capacitor across the woofer terminals...rolloff for the horn is controlled by an inductor across the horn driver terminals. The shunt componets are located on the xover board. you should use a crossover calculator to establish the values needed for your in-line componets of your xover. I'm working off of a modified Type B network. As for the 68uF cap being a "shunt" or whatever, all I know is that when Bob was doing some testing on different value caps for the K33 for his Cornscala IIs, he first tried a 100uF cap and he said that the K33 started rolling off in the 300ish Hz range, which was obvioulsy too low. When he tried the 68uF cap, the K33 rolled off around 437Hz. Since the 2.5mH inductor never changed, then I automatically assumed the cap was making the final decision on the crossover point. Or maybe because the K33's 1mH VC and the 2.5mH inductor makes it a -12dB slope, then adding the 100uF or 68uF cap makes it a -18dB slope. Now please keep in mind, I am in the early stages of learning all of this crossover stuff, so most of what I know is only from what others tell me or from what I have read in other threads. I still don't know how what does that to who, and where it is when it does it, and why. I have tried the different crossover calculators before, but they are no good. As Al K has pointed out to me, those calculators ONLY assume a static driver impedance. They do not consider the VC inductance nor do they consider the impedance swings throughout the frequency range, so the component values are not correct. This has been proven the case several times while I have tried to model the simple Cornwall driver/Type B network combo (4 ohm woofer, 16 ohm midrange, 8 ohm tweeter / XO points of 600Hz and 6000Hz). If those calculators worked properly, I would at least get something close to the 2.5mH inductor on the woofer, 2uF and 4uF caps on the squawker and tweeter. But these calculators never come close to those values. Unfortunately, I don't have the luxury of spending $50-100 on crossover parts every couple of weeks to do experimental work on crossovers and end up with a bunch of wrong parts because those calculators told me the wrong values. That's why I am asking so many questions and wanting to do proven mods so I can get where I need to be. That way, I can be up and running ASAP and get all the bugs worked out before taking the plunge of building a pair for myself with all new and better parts. As much as I'd love to do all of this on my own, I can't. I'd much rather leave all the guess work up to the ones who know what they're doing. And trust me guys, all of your input is greatly, greatly appreciated! [] sounds you like you have a b-3 network. schematic attached. the capacitor across the woofer termials does not establish the cutoff frequency....it establishes the rolloff. B3.pdf Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 22, 2006 Share Posted June 22, 2006 "I have tried the different crossover calculators before, but they are no good. As Al K has pointed out to me, those calculators ONLY assume a static driver impedance. They do not consider the VC inductance nor do they consider the impedance swings throughout the frequency range..." They also don't factor in the reactive component. At any rate, now you know why we step down impedance, and lock it in using the swamping resistor. The other advantage is that you can now use the autoformer as a pure attenuator for the midrange -- and adjust attenuation on the fly by using different tap combinations without shifting the crossover points. You can also build using two autoformers, and use the second as a pure attenuator for the tweeter if you are using one that's more sensitive than a K-77 or CTS-125 (but with a 20 ohm resistor). The constant impedance types definitely sound better to me with the stock drivers and horns, but the Klipsch types quickly pull even when you change to better horns and drivers. Don't ask me why this is -- I simply don't know. If you build the way you are building (no swamping resistor), and stay first order all the way -- the shifting of the crossover points with the impedance swings aren't as dramatic as you might think, that is -- there is so much overlap between the drivers, that the shifting back and forth from an acoustical perspective amounts to exactly nothing. Something else to consider is that the inductive and resistive parameters of a VC change as it heats up. When prototyping -- buy inexpensive caps. I like the Dayton Audio's from partsexpress, they sound very good for the money. You could fill a shoebox with them and barely put a dent in your beer money. When you get what you want nailed down -- buy some Kimbers, Auricaps, or mortgage your house and get some V-caps. "...This has been proven the case several times while I have tried to model the simple Cornwall driver/Type B network combo (4 ohm woofer, 16 ohm midrange, 8 ohm tweeter / XO points of 600Hz and 6000Hz)." O.K., there is only one three-way calculator on the net that's worth a crap: http://www.kbapps.com/audio/speakerdesign/calculators/Default.htm The reason your values aren't coming up right is because you aren't accounting for what the autoformer is doing to the impedance your amplifier sees. The first cap coming off of your input is called the primary cap, or highpass cap, and it goes to tap 5. The value of the cap is determined by a combination of the high pass crossover point you want along with the impedance that the autoformer is reflecting back to the cap from the output side. That is -- whatever tap the midrange is hooked to. It works like this: Tap 4, the impedance of the squawker x 2 Tap 3, the impedance of the squawker x 4 Tap 2, the impedance of the squawker x 8 Tap 1, the impedance of the squawker x16 If you are off of tap 3 with a 16 ohm driver, the reflected impedance back to the primary cap position is 64 ohms. So, if you need to calculate for something on the input side of the autoformer, you need to make sure you have the correct impedance. Now we do the output side: Taps 1-4 are output taps. These taps sit between the driver and autoformer directly. Anything you calculate here is based on the raw impedance of the driver/horn -- and you do not have to scale. When you use the calculator, you will have to do calculations twice. The first time will be to get the highpass value at the higher, reflected impedance -- the second time will be to get your low pass inductor value for the squawker bandpass -- which resides on the output side of the autoformer (16 ohms). Notice that the calculator factors in the reactive component, and also will not let you create any filters that are less than three octaves apart. A couple of things you will eventually figure out by playing with it is that 1) the Klipsch networks are based on 15 ohms and multiples thereof, and 2) there has never been a 6000Hz "crossover point." http://www.trueaudio.com/st_xov_1.htm http://www.xtant.com/html/techSupport/crossoversFilters.cfm can we at least agree on the parts on his network and what their purposes are. he wants to change values to existing componets to change his cutoff. I attached a schematic of the b-3 network, based on his report of having a 68uf capacitor. B-2 only has a 20, b-1 has not capacitor in woofer circut. to change the xover point, the 4mh inductor and the 5uf (looks like a 5 anyway) going to the autoformer would have to both be changed. I don't think changing the 68uf capcitor will change his crossover point at all, only his rolloff, and even that won't change much till he gets down to 20uf. he won't blow anything by tinkering with the 68uf cap, but very little change will be occuring on the horn. B3.pdf Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 The reason your values aren't coming up right is because you aren't accounting for what the autoformer is doing to the impedance your amplifier sees. The first cap coming off of your input is called the primary cap, or highpass cap, and it goes to tap 5. The value of the cap is determined by a combination of the high pass crossover point you want along with the impedance that the autoformer is reflecting back to the cap from the output side. That is -- whatever tap the midrange is hooked to. It works like this: Tap 4, the impedance of the squawker x 2 Tap 3, the impedance of the squawker x 4 Tap 2, the impedance of the squawker x 8 Tap 1, the impedance of the squawker x16 If you are off of tap 3 with a 16 ohm driver, the reflected impedance back to the primary cap position is 64 ohms. So, if you need to calculate for something on the input side of the autoformer, you need to make sure you have the correct impedance. Now we do the output side: Taps 1-4 are output taps. These taps sit between the driver and autoformer directly. Anything you calculate here is based on the raw impedance of the driver/horn -- and you do not have to scale. When you use the calculator, you will have to do calculations twice. The first time will be to get the highpass value at the higher, reflected impedance -- the second time will be to get your low pass inductor value for the squawker bandpass -- which resides on the output side of the autoformer (16 ohms). Notice that the calculator factors in the reactive component, and also will not let you create any filters that are less than three octaves apart. A couple of things you will eventually figure out by playing with it is that 1) the Klipsch networks are based on 15 ohms and multiples thereof, and 2) there has never been a 6000Hz "crossover point." http://www.trueaudio.com/st_xov_1.htm http://www.xtant.com/html/techSupport/crossoversFilters.cfm Since the K55 was connected to tap #3 and gave me a 64 ohm load, that's why I am now using tap #2 with the 902, it still gives me 64 ohms. Still, most of this stuff is greek to me when only reading it. I usually need "hands-on" to really take hold of the whole concept. Once I get a hang of it though, watch out, cause I'll be going like crazy trying to learn new ways and get more involved in the whole deal. Once I find a genuine interest in something, I learn all I can about it and go full steam into it. Hence the reason for asking all of these dang questions. Thanks Dean! [] Charles Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.