danowood 2,167 Posted July 10, 2014 Posted July 10, 2014 I'm going to be doing a rebuild of a pair of JBL 200t3 speakers in the near future. I'm purchasing some drivers, and crossovers from Snow. I will be making new cabinets, refoaming the woofers, and rebuilding the crossovers. I have contacted a supplier for parts for the crossovers, the same company I used when I rebuilt the ones for my daughters Jensen L-6s. He has posed a question to me and am not sure so thought I would throw the question to the members and get their input. First here is the schmatics for the speaker. http://www.jbl.com/resou...alsheet//L200t3%20ts.pdf the crossover is the section i'm refering to. Here's the question: " I'm not sure about the 1mH coil that indicates "with 7.5 Ohm". I do not know if that means the coil measures 7.5 Ohms, or has a 7.5 Ohm resistor in parallel or series... I'd suspect that we would just add a resistor in series to the new coil for a 7.5 Ohm result."Any ideas?
dennismiller55 4,823 Posted July 10, 2014 Posted July 10, 2014 Can you check the link. I get an error on opening it.
danowood 2,167 Posted July 10, 2014 Author Posted July 10, 2014 It's the link Snow gave me and it opened for me. The link works but after it's posted to this site it doesn't work of f of the site. I don't know why. Maybe try tuping it in or copy and paste in the browser and see if it works.
B-Man 4,783 Posted July 10, 2014 Posted July 10, 2014 Neither one works for me ?? If you can get to the page, copy the entire URL from the address bar in your browser and then paste it as plain text here.
compwaco 1,129 Posted July 10, 2014 Posted July 10, 2014 Try this: http://www.jbl.com/resources/Brands/jbl/Products/ProductRelatedDocuments/en-US/technicalsheet//L200t3%20ts.pdf 1
fill35U 1,847 Posted July 10, 2014 Posted July 10, 2014 Is this the correct schematic for those JBL L200t3 speakers? 1
fill35U 1,847 Posted July 10, 2014 Posted July 10, 2014 It would appear to actually be a 1mH inductor in series with a 7.5 ohm resistor. See the bottom post here: L200t projects at audioheritage.org Hope that helps- good luck! 1
dennismiller55 4,823 Posted July 10, 2014 Posted July 10, 2014 The inductors in your crossover should not need replacement unless you are changing the crossover. It would be a good idea to replace the capacitors. 2
loner_t 2,571 Posted July 10, 2014 Posted July 10, 2014 My 2c. It looks like a L+R circuit (the symbols on the 3mH and the 1mH + 7.5ohm are different) which will induce a phase shift in the current across the Inductor as compared to the Resistor, typically in a series connection.
fill35U 1,847 Posted July 10, 2014 Posted July 10, 2014 And, from the same site, here's another thread showing a DIY crossover: DIY JBL crossover project 1
fill35U 1,847 Posted July 10, 2014 Posted July 10, 2014 My 2c. It looks like a L+R circuit (the symbols on the 3mH and the 1mH + 7.5ohm are different) The 3mH has an "iron" core, denoted by the parallel lines over it. The 1mH is an air core (no lines). The iron core one will have more nonlinearities and could saturate, giving distinct sound qualities. Resistance or power handling obviously isn't much of an issue for the 1mH, so it doesn't need a core.
danowood 2,167 Posted July 10, 2014 Author Posted July 10, 2014 My 2c. It looks like a L+R circuit (the symbols on the 3mH and the 1mH + 7.5ohm are different) which will induce a phase shift in the current across the Inductor as compared to the Resistor, typically in a series connection. Shouldn't they be different? L is low frequency and the other is not R but Hi frequency...?
fill35U 1,847 Posted July 10, 2014 Posted July 10, 2014 My 2c. It looks like a L+R circuit (the symbols on the 3mH and the 1mH + 7.5ohm are different) which will induce a phase shift in the current across the Inductor as compared to the Resistor, typically in a series connection. Shouldn't they be different? L is low frequency and the other is not R but Hi frequency...? "L" is the symbol for inductance, "R" is the symbol for resistance. Nothing inherently to do with high or low frequencies, depends how they are used. Please forgive me if I'm misreading your question! 2
loner_t 2,571 Posted July 10, 2014 Posted July 10, 2014 @Dano... Fill35 is correct. I had forgotten about iron cores. 2
danowood 2,167 Posted July 11, 2014 Author Posted July 11, 2014 LOL that shows what a DA I am. I though you were referring to left and right channels LOL The schematic shows a L frequency and Hi frequency. I'm following you guys now, same page and book LOL
danowood 2,167 Posted July 11, 2014 Author Posted July 11, 2014 does anyone know a supplier that have Jupiter Vintage Flat Stacked 2.2uF 100VDC capacitors reasonably priced? 75.00 a pop seems very high, I've only found 2 suppliers and both are wanting blood from my first born for them.....
fill35U 1,847 Posted July 11, 2014 Posted July 11, 2014 I don't know about those Jupiter caps. But if you want very tough, flat, and affordable caps that should sound pretty good, check these out: WIMA 2.2uF 180VAC PP cap at Mouser.com Kemet 2.2uF 220VAC PP cap at Mouser.com 1
danowood 2,167 Posted July 11, 2014 Author Posted July 11, 2014 thanks Fill for the info however, I'm going to be using these in a high end jbl speaker rebuild. This is why I was leaning towards the Jupiter caps. They came highly recomended by a crossover designer engineer, and they have very good reviews.. "Jupiter HT BeesWax Paper 600VDC - 5% toleranceTechnical specifications (according to manufacturer): "Old Concept New Technology - A unique blend of the old sound with refinements of the new. New high temp series replaces the original beeswax/paper design. Jupiter Condenser HT line of capacitors features a reinforced beeswax paper dielectric and (with further improved impregnation techinques) is now cased in a non drip/melt casing and can withstand higher operating temperatures. Perfect for DIY and OEM use where natural sound is demanded. Operating Temperature: 70°C; Voltage: 600VDC - Tested at 1200VDC at two stages of production; Aluminum Foil; Silver Lead wire 20awg; Cryogenic Treatment; Made in USA of US materials."Sound: I found the Jupiter HT BeesWax Paper to be very spatious and rich in harmonic texture. They are clear and open but there is never and over-emphasis on any area. Compared to AmpOhm aluminium foil types the Jupiter has more air and they produce a wider image where as the AmpOhm project more front to back. Still not quite as neutral and coherent sounding as the Duelund VSF but at the same high quality level as the top of the range Mundorf's. They have a nice fleshy treble with a rich midrange to match. They act well under all conditions and don't seem to have any preferences. I find them very pleasing to listen to. (When I tested the Jupiter HT BeesWax Paper they were still available in larger values. These have now been replaced by the Flat-Stacked type which I have not tested)." The flat stacked types are suppose to be even a greater improvement...\
fill35U 1,847 Posted July 11, 2014 Posted July 11, 2014 Youre welcome, Dan! Thanks for the info! I meant, "I don't know about {where to find for cheap} those Jupiter caps". Beeswax is much more expensive than paraffins or vegetable waxes. The cap packaging is an unusual shape. They require vacuum impregnation to survive long. Even then, they are only rated to 70°C, so other concessions must be made to help keep losses and operatibg temperature down. The leads are solid silver? Then they are "cryo treated", although I can't imagine why. They have no commercial application outside of a tiny, tiny niche market. And they are priced by prestige, not actual specifications. Why *wouldn't* you pay a fortune for them? Since it's for a restoration, using high-end caps should add extra to the price/value of the speakers. And knowing that you put the very best into a project is priceless! Where does your crossover designer friend get his from? He must buy in bulk, maybe he can get you a couple at a discount?
danowood 2,167 Posted July 11, 2014 Author Posted July 11, 2014 he works for sonicap and is located in Texas, although the company hq is in Ar. He gave me a 20% discount but are still 60.00 a pop. The rest of the caps are reasonable enough. here's a quote invoice. QTY. DESCRIPTION PRICE AMOUNT 2 Jupiter Vintage Flat Stacked 2.2uF 100VDC 75.00 150.00 2 Mills MRA-12 20 Ohm 4.95 9.90 2 Sonicap 20uF 200VDC 31.46 62.92 Sales discount -44.56 -44.56 Freight 15.95 15.95 1
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