BEC Posted June 14, 2007 Author Share Posted June 14, 2007 Getting closer. Bob Quote Link to comment Share on other sites More sharing options...
BEC Posted June 14, 2007 Author Share Posted June 14, 2007 Done. Bob Quote Link to comment Share on other sites More sharing options...
soundbound Posted June 15, 2007 Share Posted June 15, 2007 New crossovers completely built in less than one hour. Way nice... You the Man! Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted June 15, 2007 Share Posted June 15, 2007 Michael has two hands, so he does two crossovers at once. Bob spoken like a proud poppa! LOL you definitely have the work flow down to a science. I would imagine the Crites clan sitting around the kitchen table, making up baskets of those little jumper wires of an evening... lets see we need 50 ea at 3.5", 100 at 4.25".....do you buy those crimp spade lugs by the bushel? btw, can you give a part number are those little guys? nice work Bob, I'm getting your 400/4500's fropm Bhendrix, and putting those and the CT125's in my home Scalas, and trading your A/AA's into my Khorns. The LS are HT mains and get hard use and my Khorns are for more subdued listening. Do you agree with the swap? Is your phone ringing a lot these days? Michael Quote Link to comment Share on other sites More sharing options...
BEC Posted June 15, 2007 Author Share Posted June 15, 2007 Michael, We buy those in bulk bags of a thousand from a local place called Shamrock Bolt and Screw company. I don't know a brand name for them. Bob Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted June 15, 2007 Share Posted June 15, 2007 Bob, Thanks for posting this "documentary". I noticed that you left the diodes in nor did you snip their leads. I went through a similar process and concluded that the diode protection was probably not necessary since :1) the high pass to the tweeter is 3rd order and not the older 1st order filter, 2) the diodes "may" have an impact on the sound at less than protection-levels (I m not sure if this is a myth or not) and 3) one should know better than cranking the volume up so loud that you would need such tweeter protection. What are your thoughts on this or is the goal to preserve the factory design? Good Luck, -Tom Quote Link to comment Share on other sites More sharing options...
BEC Posted June 15, 2007 Author Share Posted June 15, 2007 Tom, I like the diodes. Still the very best tweeter protection available and the only method that it really fast enough to protect a tweeter from transients. The diodes do absolutely nothing to the signal until you get a 10.2 volts peak to peak to the tweeter. Then, the diodes will start to conduct and limit the voltage to that value. They do not "short the amp" or do anything else bad. They only effect the signal when that signal is higher than it should ever get to the tweeter. I expect the reason that Klipsch went away from the zener diodes was cost. Those 10 watt zeners are over $10.00 each. That is over $40.00 per pair of crossovers compared to about 2 bucks for the later polyswitch in the crossovers. Those things DO effect the signal at all levels by adding almost 1 ohm of resistance in the tweeter circuit. Bob Crites Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 23, 2007 Share Posted June 23, 2007 Great work. It's refreshing to see how, with a little practice, it's just not that difficult to refresh or completely rebuild a pair of crossovers. The template Michael used would lend itself toward a 'full' or complete crossover kit (not just replacement caps), including boards, coils, caps, autoformers, and simple instructions. If all connections were made by way of crimping rather than soldering (I prefer both), someone wouldn't have to be familiar with or own soldering equipment. A new DIY pair of crossovers would still be within the realm of possibility. Thanks for posting. Erik Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted June 23, 2007 Share Posted June 23, 2007 I'm getting your 400/4500's fropm Bhendrix, and putting those and the CT125's in my home Scalas, and trading your A/AA's into my Khorns. Yessiree!!! The 4500 crossover (and if you want to get ambitious...) swap out the K-55's with Selenium DX-250's (with a Mills 8ohm/12 watt attenuator in line) will put you right in row 1, center stage with the LS's..... Make you wanna cry, sell them Cornwalls (to me... real cheap...), and otherwise make your beer taste better!![H] Quote Link to comment Share on other sites More sharing options...
Ki Choi Posted July 5, 2007 Share Posted July 5, 2007 Hi Bob: I have a set of your early rebuild factory AA with new GE oil caps that are in my Khorns, and a set of your new AAs with modern caps. I have not tried the new modern capped AAs yet (too lazy...). You said both Oil Cap AA and modern cap AA do sound the same. Have you heard from other customers if they hear the same? Ki Quote Link to comment Share on other sites More sharing options...
BEC Posted July 5, 2007 Author Share Posted July 5, 2007 Ki, Not very many have tried both types of caps. I don't think anyone would hear a difference, but give it a try and let us know. Bob Quote Link to comment Share on other sites More sharing options...
Ki Choi Posted July 6, 2007 Share Posted July 6, 2007 Bob: I am trying to build a new set of Tractrix 300Hz mid horn and CP25 set up that I can place them away from the bass bins and away from the front wall. The new AA with new caps will be used and will give me a good idea how different they are if any. Thanks, Ki PS. If anyone could point me to a use wood 300Hz Tractrix horns or equivalent commecial horns I can buy, I would appreciate it. Quote Link to comment Share on other sites More sharing options...
BEC Posted July 17, 2007 Author Share Posted July 17, 2007 Trey, You are wrong, but are in a unique position to prove this one way or the other. Take a type AA crossover and use a meter on the input terminal of the AA crossover measuring impedance. Terminate all the outputs with resistors. Now while measuring the impedance, short the zener diodes. You will see the impedance go UP. So, really it unloads the amps if the zeners short. ALso check up on how zener diodes work. They do not short. They conduct to maintain 10.2 volts across them. By logic, a device with 10.2 volts across it is not shorted. So, to summarize, they don't short, but if they did they still would not hurt the amp. Bob Crites Quote Link to comment Share on other sites More sharing options...
Guest " " Posted July 18, 2007 Share Posted July 18, 2007 "Now while measuring the impedance, short the zener diodes. You will see the impedance go UP. So, really it unloads the amps if the zeners short." When DC is applied under this senerio, the capacitors are charging, resulting in the percieved impedance rise......if AC is applied....there will be both a charge and a discharge....the percieved impedance rise would not exits, but rather would be a constant. Zener diodes and normal diodes are funny devices. But the reason why there really is no short is due to the way they are connected, their gates are tied together. SInce thse diodes have a forward voltage drop, there is some insertion loss in both directions, a resulting bit of impedance in both directions of the zener diodes that are tied together. Quote Link to comment Share on other sites More sharing options...
Klipsch Employees Trey Cannon Posted July 19, 2007 Klipsch Employees Share Posted July 19, 2007 I was just trying to help, I wont do that anymore. Quote Link to comment Share on other sites More sharing options...
BEC Posted July 19, 2007 Author Share Posted July 19, 2007 Trey, Please try what I asked you to try. Measure the impedance at the input of the Type AA crossover then short the tweeter output simulating what would happen if the zener diodes were to short. I was surprised when I did that and ALK was surprised when he verified it. The impedance goes up, unloading the amp. I think you are considering the zeners to be directly across the output of the amp. They are instead at the end of an LC network. People using the polyswitch arrangement with very high power are blowing tweeters pretty frequently. The problem goes away when the zeners are used. I guess the polyswitch is good to protect against high power, but not fast enough to handle a fast transient. Bob Quote Link to comment Share on other sites More sharing options...
Klipsch Employees Trey Cannon Posted July 19, 2007 Klipsch Employees Share Posted July 19, 2007 As we no longer use zenors in any passive product we build now, I can not preform your test. Nor do I have time to waste on 40 year old network design. You boys have fun now, ya hear. Quote Link to comment Share on other sites More sharing options...
Blvdre Posted July 19, 2007 Share Posted July 19, 2007 As we no longer use zenors in any passive product we build now, I can not preform your test. Nor do I have time to waste on 40 year old network design. You boys have fun now, ya hear. ...and he stormed off in a puff of talc. Quote Link to comment Share on other sites More sharing options...
Marvel Posted July 19, 2007 Share Posted July 19, 2007 As we no longer use zenors in any passive product we build now, I can not preform your test. Nor do I have time to waste on 40 year old network design. You boys have fun now, ya hear. Trey may be correct, but there are still plenty of those networks in service in Klipsch products throughout the U.S. Bruce Quote Link to comment Share on other sites More sharing options...
Deang Posted July 20, 2007 Share Posted July 20, 2007 As we no longer use zenors in any passive product we build now, I can not preform your test. Nor do I have time to waste on 40 year old network design. You boys have fun now, ya hear. Man Trey, that was harsh. The Old Man would have put you over his knee for that one! Quote Link to comment Share on other sites More sharing options...
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