ButchH Posted February 19, 2017 Share Posted February 19, 2017 (edited) I bought my Mark IV Fraziers in 1973. In 2001 I gave them to my son-in-law. Last fall I decided I would build a set of my own and I'm at a point of needing some tech assistance on the cross over. There are two foiled caps along with what appears to be some sort of coil inside. Only markings on it is 2.25. Question is what is it and is there a work around. Is it some sort of an inductor? I have pictures of it if needed but I would need to reformat them as they're too big. Edited February 21, 2017 by ButchH Quote Link to comment Share on other sites More sharing options...
DizRotus Posted February 19, 2017 Share Posted February 19, 2017 Pictures would help. That sounds like an inductor crossover coil used to filter out high frequencies from the signal sent to the woofer. Does it look anything like the iron core inductor in the attached photo? An air core inductor would be a coil of wire in a larger diameter circle without the iron bar to arrive at the same value. Perhaps you can source one from: http://www.parts-express.com/erse-super-q-20mh-16-awg-500w-inductor-crossover-coil--266-904 You could also wind your own. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted February 21, 2017 Share Posted February 21, 2017 Frazier would typically do a series crossover. Cap(s) and inductor, caps in parallel to woofer, inductor in parallel to L-PAD / tweeter with caps and inductor in series. Considering the crossover frequency of those, I would think it was a cap values were what you stated. The inductor would likely be smaller that 2.25 MH. Could be wrong though 1 Quote Link to comment Share on other sites More sharing options...
ButchH Posted February 24, 2017 Author Share Posted February 24, 2017 (edited) The caps are 3mfd x 50VDC and if you look close on the coil you can see 2.25 hand written. Edited February 24, 2017 by ButchH Quote Link to comment Share on other sites More sharing options...
pzannucci Posted February 24, 2017 Share Posted February 24, 2017 Likely a 2.25 MH choke. The inductor DizRotus suggested above would likely be good. The bad part is if you don't have matching components to the originals (unlikely), you may have to voice your new speaker drivers. This means you may be better off starting from scratch as the crossover points and impedance may not correlate to your new drivers. 2 Quote Link to comment Share on other sites More sharing options...
DizRotus Posted February 24, 2017 Share Posted February 24, 2017 To be clear, I wasn't suggesting that specific choke (although it would probably be adequate), I was suggesting PE as a possible source of chokes in general. What drivers are you using? I suspect not original Frazier offerings. As Peter Z. says, you might need, or want, to start from scratch, depending upon the drivers. Good luck and please post your progress and results. 1 Quote Link to comment Share on other sites More sharing options...
ButchH Posted March 14, 2017 Author Share Posted March 14, 2017 I'm going to use Parts Express' tech help but I'm a little bit on the blind side of understanding what I need to either ask or even know before I ask for help. I would assume I need to know the frequencies of the speakers but I can't seem to find this info. I do know the 10" number but there is no number on the tweeter. Also, I'm not sure what you mean by drivers. I do know the model number, p1028-270-8446 for the 10" and n4850f for the 3x7 tweeter. Any feedback will be greatly appreciated. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 15, 2017 Share Posted March 15, 2017 So you are talking about a http://www.ebay.com/itm/like/162148341117?lpid=82&chn=ps&ul_noapp=true 10 inch woofer = Frazier F1028 270-8446. http://www.ebay.com/itm/FRAZIER-3X7-HORN-TWEETER-N4850-F-FOSTER-FOSTEX-2X6-/162371386380?hash=item25ce16bc0c:g:awsAAOSw9GhYiOw1 Fostex tweeter? PE is not likely not going to be able to help unless lucky. The only way to be accurate is to test the speaker components (drivers equal woofer and tweeter). If these are original type parts, you should be able to go stock crossover components. If you go here http://www.ebay.com/itm/NICE-PAIR-Walnut-Frazier-Mark-IV-039-s-With-3x7-Horns-Rare-Set-of-Speakers-100-Ready-/160713671030 The original caps (which should be replaced) were 2 x 3 ohm (same as concerto and others). Since they were parallel, you will need 6 uf , get a good 2.25 (approx 2 mh air core inductor - coil) and an 8ohm lpad. Now if you can get the right drivers. Again Fraizier's crossovers in these speakers were likely series type. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 15, 2017 Share Posted March 15, 2017 ButchH, You did not say where you are located. There are some good used Concertos around which may be a better option than trying to build. Quote Link to comment Share on other sites More sharing options...
ButchH Posted March 15, 2017 Author Share Posted March 15, 2017 pzannuci, I'm located in a suburb south of Dayton, OH called Kettering. I did find the inductor and caps at Parts Express. I guess the only reason I'm trying to go new or as close as I can with the speakers is the fear of paying for bad/damaged speakers. My cabinets are built, short of veneering. I have $75 in the project so far. Caps and inductors are cheap enough so the next big expense will be the speakers themselves. I'm estimating a total of no more than $250 for both speakers. I've even found a Dual 1214 turntable which is what was matched to the system when new. With any luck down the road I'll find the Sony amp...I know where one is but I won't take it back from my son-in-law;-). At 70yrs old it has become my "project". I do do know that on the back of the original cabinets is a sticker saying 25watts. See attached photo. My other reason for trying for new speakers is that I realized the cones and magnets change with time, however, staying as close as I can to original frequencies will help with output for the size of the cabinet. I'm open to all suggestions and inputs. You can even call me stupid or weird as I transgress back to my days of sitting in front of my system and playing my drums with the Rascles, Who, Three Dog Night, Chicago etc. Thanks for the feedback. PS 2 weeks ago tomorrow I was Coded on an operating table. I want my legacy to be this project. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 16, 2017 Share Posted March 16, 2017 ButchH, The problem you will have is finding the speaker components. The L-PAD https://www.parts-express.com/parts-express-speaker-l-pad-attenuator-50w-mono-1-shaft-8-ohm--260-255 , caps https://www.parts-express.com/dayton-audio-dmpc-62-62uf-250v-polypropylene-capacitor--027-427 and inductor https://www.parts-express.com/erse-22mh-14-awg-perfect-layer-inductor-crossover-coil--266-375 or https://www.parts-express.com/erse-20mh-14-awg-perfect-layer-inductor-crossover-coil--266-370 are close enough (ones from P-E) to use for this project. The links on E-Bay I sent are likely the closest you will get. You can always do some mods to make it not quite what the Frazier was, but better if you can't find all the relevant components. Then it will be your legacy, not Jack Frazier's. Quote Link to comment Share on other sites More sharing options...
minermark Posted March 16, 2017 Share Posted March 16, 2017 Give bob a call, refer him to this thread, he could just help you out http://www.critesspeakers.com/ Quote Link to comment Share on other sites More sharing options...
ButchH Posted March 17, 2017 Author Share Posted March 17, 2017 Okay, thanks. I'll post my outcome as I progress. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 17, 2017 Share Posted March 17, 2017 22 hours ago, minermark said: Give bob a call, refer him to this thread, he could just help you out http://www.critesspeakers.com/ Bob has some old Frazier parts? Quote Link to comment Share on other sites More sharing options...
minermark Posted March 17, 2017 Share Posted March 17, 2017 20 minutes ago, pzannucci said: Bob has some old Frazier parts? I did not say that. Mr Crites knows xovers, he may be able to help. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 17, 2017 Share Posted March 17, 2017 2 minutes ago, minermark said: I did not say that. Mr Crites knows xovers, he may be able to help. O, I wish Bob did have a line on some old 12" woofers. Slot loaded they actually went quite deep. Yes, ButchH can bounce some stuff off him. The links I posted do apparently have some original Frazier parts, inexpensive. The hardest time here will be finding the horn and woofer. The other parts are simple off the shelf and a look at a few pictures on the internet show pretty much what is needed to put this together. Frazier crossovers were very simplistic. I believe that is one of the reasons for their high efficiency. Not a lot of drag by the crossover. A very easy project to build PROVIDED you can get the woofer and horn. The cap, l-pad, and coil are the easy parts. as I pointed out above. Cap being 6uf and the coil being 2-2.2mh. Likely a series crossover, woofer in parallel with cap, tweeter parallel with coil. I rebuilt my Frazier Mark Va pair into a Sevens. Wonderful speaker and used it from 1976-1990. Did miss the beautiful Frazier black walnut. ButchH got me thinking, I myself would have done the Concerto with the added piezo (but the cabinets are already done) if parts were readily available. 4" fullranges used for midrange are pretty scarce for something like a Seven again. 1 Quote Link to comment Share on other sites More sharing options...
ButchH Posted March 17, 2017 Author Share Posted March 17, 2017 My luck is that my original speakers are still available and in great shape. My son-in-law has them. At Thanhsgiving I removed the backs and took measurements and pictures. Only change I'm making is the front trim and the way the speakers can be removed. I'm using blind nuts on the woofers. The tweeters were front mounted and recessed so you had to pull the material back to hold/remove the mounting screws and nuts. I'm trimming the fronts out in mahogany to match the mahogany veneer. I haven't totally worked the out yet. Because of the tweeter shapes but once I'm allowed to start using my left arm again I'll get to it. My caps are 3uF 50vdc as seen in this pic. I did find the P-E links very helpful. second image is the best I've done in finding info on the IV's. In mentions some of the inner workings. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 18, 2017 Share Posted March 18, 2017 Good Luck and best to you on your recovery. Fairly easy build on the crossovers so you shouldn't sweat it, once you've found the woofer and tweeter. Quote Link to comment Share on other sites More sharing options...
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