babadono Posted February 9 Share Posted February 9 An Ak3 in a LaScala? Does it sound OK? Looks like the Fc of the lowpass filter is about 251 Hz. Is this ok @Deang? Quote Link to comment Share on other sites More sharing options...
babadono Posted February 9 Share Posted February 9 4 minutes ago, Deang said: If I build something and it stops working, I expect the end user to send it back to me. I will stand behind my work, and there will be no charge, regardless of what I find. However, If they start poking around, etc. - all bets are off and they are going to get billed for the work. I can’t really figure out this insistence on digging into this network when I’m pretty sure Michael would take care of it at no charge. fair enough, sorry. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 9 Share Posted February 9 I get it, everyone wants to be helpful. It’s admirable. I hadn’t noticed the value on the electrolytic. Yeah, it look like he’s running AK-3’s in his AL-3 La Scalas. Very little difference of course - just that low pass shunt cap. Now, if you want details - You will have to check with my technical lead (who actually understands math). @mboxler 2 Quote Link to comment Share on other sites More sharing options...
Gregavi Posted February 9 Author Share Posted February 9 2 hours ago, babadono said: This AK3? Yes Quote Link to comment Share on other sites More sharing options...
Gregavi Posted February 9 Author Share Posted February 9 1 hour ago, babadono said: An Ak3 in a LaScala? Does it sound OK? Looks like the Fc of the lowpass filter is about 251 Hz. Is this ok @Deang? Sounds great, when the tweeter was working. Quote Link to comment Share on other sites More sharing options...
Gregavi Posted February 9 Author Share Posted February 9 3 hours ago, Deang said: It’s an AL-3. Using your fully functioning La Scala, loosen the two screws for the tweeter and remove the tweeter connections. Now connect your non working tweeter to those connection points on the barrier strip. Play some music. If you hear the tweeter the other network has an issue. I did this. Tweeter is working. Quote Link to comment Share on other sites More sharing options...
mboxler Posted February 9 Share Posted February 9 12 hours ago, babadono said: Looks like the Fc of the lowpass filter is about 251 Hz. If you are referring to the electrical cutoff, it's closer to 350hz on an AK3 Klipschorn. I imagine it's still close to that on a La Scala, but I'll measure the impedance of a K33 mounted in a La Scala later today to be sure. Mike Quote Link to comment Share on other sites More sharing options...
babadono Posted February 9 Share Posted February 9 Mike, how is that figured? I just plugged in the 4mH and 100 uF into the basic equation. Do you have to take voicecoil L into equation as well? Quote Link to comment Share on other sites More sharing options...
mboxler Posted February 9 Share Posted February 9 45 minutes ago, babadono said: Mike, how is that figured? I just plugged in the 4mH and 100 uF into the basic equation. Do you have to take voicecoil L into equation as well? Yes you do. One of the few things ALK stated that I agree with is that the K33 looks like a 1mh inductor with a DCR of 6 ohms @400hz. What equation are you using? Here's an LTSpice simulation of an AK-3 woofer low pass as well as a REW voltage plot. Mike Quote Link to comment Share on other sites More sharing options...
babadono Posted February 9 Share Posted February 9 just the BASIC cutoff freq of an LC lowpass filter..I think the keyboard here will make it not exactly how I would write it on a piece of paper Fc = 1/2 x Pi x SqRt of L x C. Quote Link to comment Share on other sites More sharing options...
Gregavi Posted February 10 Author Share Posted February 10 On 2/8/2024 at 5:35 PM, Deang said: I get it, everyone wants to be helpful. It’s admirable. I hadn’t noticed the value on the electrolytic. Yeah, it look like he’s running AK-3’s in his AL-3 La Scalas. Very little difference of course - just that low pass shunt cap. Now, if you want details - You will have to check with my technical lead (who actually understands math). @mboxler I chatted with Michael Crites last night and he wants me to send it to him for repair. I am doing a full swap tonight as a last test before I ship it to him. I'm still not totally convinced that it is the x over that's the problem. He said, concerning the difference between the AK 3 vs the AL 3 "the AL-3 has a different tweeter circuit and slightly different woofer circuit. its not earth shattering changes, but likely does sound slightly different" Quote Link to comment Share on other sites More sharing options...
Gregavi Posted February 10 Author Share Posted February 10 I swapped x overs & the speaker with the tweeter problem didn't swap with it. Looks like a tweeter issue. Was thinking it wasn't the tweeter bc I got results consistent with a good tweeter when I connected a battery to it got popping sound and it measured at 6 ohms. In your opinion, can the tweeter be blown even if it passed those 2 tests? I'm assuming yes. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 10 Share Posted February 10 AL-3 has a polyswitch for tweeter protection. Other than that, the midrange and tweeter filter sections of the AL-3 and AK-3 are identical. You might consider sending the tweeter too. 1 Quote Link to comment Share on other sites More sharing options...
OO1 Posted February 10 Share Posted February 10 17 hours ago, Gregavi said: I swapped x overs & the speaker with the tweeter problem didn't swap with it. Looks like a tweeter issue. grab the good tweeter and test it on 2 crossovers with music playing at low level , does it work ? yes both networks are A1 - if the good tweeter does not work on 1 of the 2 networks , you have a bad network you can do the same test with the 2nd tweeter to confirm. - However....... if 1 tweeter fails on both networks , you got a bad tweeter diaphragm https://reconingspeakers.com/products-page/klipsch-k77f-127126-diaphragm/ Quote Link to comment Share on other sites More sharing options...
billybob Posted February 10 Share Posted February 10 13 hours ago, Deang said: AL-3 has a polyswitch for tweeter protection. Other than that, the midrange and tweeter filter sections of the AL-3 and AK-3 are identical. You might consider sending the tweeter too. Yes Quote Link to comment Share on other sites More sharing options...
Skichuck77 Posted February 10 Share Posted February 10 I had a K-77 tweeter that I could test the resistance on and sometimes it would test fine and other times it would test open. You may have a similar problem since the “bad” tweeter worked ok when you hooked it up to the other crossover. Intermittent issues can be a real pain in the butt. 35 years as a maintenance technician taught me to just keep testing the suspect component until I was certain it was the culprit. I replaced the diaphragm and that took care of the problem. 1 Quote Link to comment Share on other sites More sharing options...
avguytx Posted February 10 Share Posted February 10 Is this the same thread that's going on at multiple places with mainly the same people? 2 3 Quote Link to comment Share on other sites More sharing options...
OO1 Posted February 10 Share Posted February 10 ...... 1 Quote Link to comment Share on other sites More sharing options...
avguytx Posted February 11 Share Posted February 11 Another redacted statement. Go figure. 2 1 Quote Link to comment Share on other sites More sharing options...
Gregavi Posted February 13 Author Share Posted February 13 On 2/10/2024 at 8:50 AM, OO1 said: grab the good tweeter and test it on 2 crossovers with music playing at low level , does it work ? yes both networks are A1 - if the good tweeter does not work on 1 of the 2 networks , you have a bad network you can do the same test with the 2nd tweeter to confirm. - However....... if 1 tweeter fails on both networks , you got a bad tweeter diaphragm https://reconingspeakers.com/products-page/klipsch-k77f-127126-diaphragm/ I swapped x overs and the problem tweeter stayed with the same speaker which indicates a bad tweeter. The reason why I was assuming it was a bad x over is because the non working tweeter passed the Ohm and battery tests. 1 Quote Link to comment Share on other sites More sharing options...
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