Infinity crossover coil value
in [Repair]
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From: BOB Urz "sound" on 19 Jan 2007 19:36 I had a customer bring in an Infinity KPX00 crossover for a 6.5" car unit. Coil L2 has burnt marks on it, Its a 24db linkquitz riley filter (or so the spec sheet says). Customer claims low tweeter output http://manuals.harman.com/INF/CAR/Owner's%20Manual/KAPPA%20PERFECT%206-1%20om.pdf in: (+) -------| | == C=15.7ufd | C=14ufd R=(1,2,4) OUTPUT |------------][------------/\/\/\/\/\------| > | >L2 (burnt) | > * (tweeter) | * | | ------------------------------------------------ (-) (-) So, the input is a series cap inductor combination with a 15.7 MFD and unknown coil in series with the amp. The center tap of the two feeds a 14MFD cap and then goes through a series resistor adjustable pad to the tweeter. I tried to read the coil on my sencore, and it measures about .3 MH. It won't pass any ring test (air core) so i know turns are shorted and this value is suspect. Any clue on the value of this coil? Strange, this seems to be a 3rd order filter rather than what the tear sheets says. Only one coil on the high pass with two caps. Minus the pad, it looks like the 3rd order 18 DB filter here: http://www.apicsllc.com/apics/Misc/filter2.html and these calculated 3500hz values are (4 ohm nominal) C=7.5 ufd L=0.1364 mh C2=22.7 standard replacement coil values are .1,.13,.15,.20,.27,.33 and etc. Thoughts? Bob ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =----
From: Richard Crowley on 19 Jan 2007 20:40 "BOB Urz" < wrote ... >I had a customer bring in an Infinity KPX00 crossover for a 6.5" car > unit. Coil L2 has burnt marks on it, You can't measure (or observe) the one on the other side?
From: BOB Urz "sound" on 19 Jan 2007 21:05 Richard Crowley wrote: > "BOB Urz" < wrote ... > >I had a customer bring in an Infinity KPX00 crossover for a 6.5" car > > unit. Coil L2 has burnt marks on it, > > You can't measure (or observe) the one on the other side? While not quite symmetric, the other channels crossovers coil is burnt worse than the one i am looking at now. So, no chance for a good part measurement. Bob ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =----
From: Arny Krueger on 19 Jan 2007 21:29 "BOB Urz" <"sound"@(remove) inetnebr.com> wrote in message news:1169258413_9495(a)sp6iad.superfeed.net > Richard Crowley wrote: > >> "BOB Urz" < wrote ... >>> I had a customer bring in an Infinity KPX00 crossover >>> for a 6.5" car unit. Coil L2 has burnt marks on it, >> >> You can't measure (or observe) the one on the other side? > > While not quite symmetric, the other channels crossovers > coil is burnt worse than the one i am looking at now. So, no > chance for a good part measurement. How badly burnt? I've seen some pretty ugly messes based on an heavy-gauge wire choke that was still OK. For openers, unless they were burnt open or fused, I'd measure both coils and see if they still measure the same. On a really bad day, wind up a coil of the same gauge wire and same number of turns in the same form factor and measure it.
From: Ross Herbert on 19 Jan 2007 23:13
On Fri, 19 Jan 2007 18:36:48 -0600, BOB Urz <"sound"@(remove) inetnebr.com> wrote: >I had a customer bring in an Infinity KPX00 crossover for a 6.5" car >unit. Coil L2 has burnt marks on it, Its a 24db linkquitz riley filter >(or so the spec sheet says). >Customer claims low tweeter output > >http://manuals.harman.com/INF/CAR/Owner's%20Manual/KAPPA%20PERFECT%206-1%20om.pdf > >in: >(+) >-------| > | > == C=15.7ufd > | C=14ufd R=(1,2,4) OUTPUT > |------------][------------/\/\/\/\/\------| > > | > >L2 (burnt) | > > * >(tweeter) > | * > | | >------------------------------------------------ >(-) (-) > >So, the input is a series cap inductor combination with a 15.7 MFD and >unknown coil in series with the amp. The center tap of the two feeds a >14MFD cap and then goes through a series resistor adjustable pad >to the tweeter. I tried to read the coil on my sencore, and it measures >about .3 MH. It won't pass any ring test (air core) so i know turns are >shorted and this value is suspect. Any clue on the value of this coil? > >Strange, this seems to be a 3rd order filter rather than what the tear >sheets says. >Only one coil on the high pass with two caps. >Minus the pad, it looks like the 3rd order 18 DB filter here: > >http://www.apicsllc.com/apics/Misc/filter2.html > >and these calculated 3500hz values are (4 ohm nominal) >C=7.5 ufd >L=0.1364 mh >C2=22.7 > >standard replacement coil values are .1,.13,.15,.20,.27,.33 and etc. > >Thoughts? > >Bob > > >----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- >http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups >----= East and West-Coast Server Farms - Total Privacy via Encryption =---- I would be rather concerned about what actually caused the inductor/s to be cooked so badly. Assuming you managed to replace them and get it going again, what's to say that the owner is not going to repeat the exercise? He would have to be driving these things extremely hard to cause the burnouts so perhaps they are not matched to his amps power output and speakers correctly or he is running both amp and speakers into severe overload. In this case I would suspect that the speakers aren't in too good a shape either. |