Clipped and Shorn Posted February 11, 2002 Share Posted February 11, 2002 Rescued from the trash: one old mono tube receiver, and two homemade speaker cabinets. Finally got inspired to plug the receiver in and to open the backs of the speaker cabinets to see what was in there. One cabinet contains an enormous 15" University model 315 Triaxial speaker, 50 watt, 8 ohm. I can only see the back, does the term "triaxial" mean that there are horns in the center of that woofer? There is a crossover box mounted on the side of the speaker and wires to an exposed control. Could not find much web info on the "University" brand, but I do remember it was widely sold in the 50s in the Allied Radio catalog and was economical for DIYers. By todays standards are these things any good? Was University somehow associated with the Altec company? The second cabinet contains another DIYer's efforts: one University 12" adjustable response woofer, model C12W, 30 watt, 8 ohm, a Mid.T Driver and cast iron horn (9" long opening to a rectangle about 5+"x7+", plus a 15watt Tweeter (Calrad), there are two other units (University brand boxes-like some kind of transformer) in there which I assume are crossover related, one has 6 numbered terminals and the other has 8, everthing is wired up and there is an exposed control on the front of the cabinet. I am assuming that the number "1" is the common terminal judging by how many wires are connected to it. This assumption will allow me to determine which side is the + since nothing is notated. All these speakers look very well built, but I have not heard any raves about University speakers, is that because they are so obscure today or because they were nothing special? The receiver on closer examination turns out to be a Pilot HF-56 High Fidelity and is strictly mono with only one phono plug and only one speaker connection. It uses 2 -KT66, 2 -6sn7 and a mess of miniature tubes most of which are shielded. I put a plug on this thing and it lit up, so I attached a speaker and it seems to work on a locally strong FM station. After a while there was some intermittent cutting out of the signal, don't know at what stage this problem comes from. Although it is only mono, it might be fun to hook up one of those old University speakers to it. Another question: is there an "approved" way for hooking up two speakers to a mono output. There is an 8ohm and a 16 ohm option on the receiver. The speakers are 8ohm. If I hook two 8ohm speakers in parallel, which terminal do I choose, the 8 or the 16? How does that theory work anyway? I wish there were two of everything here instead of just one set of things, but, hey, many of my old records are mono, maybe I will take them up the hill to the studio where I have all this old junk. It did cross my mind to design a cabinet to house all of this stuff, but unfortunately there is only one of everything and thus not enough for two channel. It seems unlikely that I would find more of these same old speakers. The triaxial definitely looks impressive, I would be curious to know more about this concept in speakers. When I did an internet search I didn't find much on University but I did stumble onto a bunch of reference articles about speaker designs, with many regarding Klipsch. http://invalid.ed.ntnu.no/~dunker/refs02.html http://melhuish.org/audio/horninfo.htm - recycled and horded This message has been edited by Clipped and Shorn on 02-11-2002 at 10:58 PM Quote Link to comment Share on other sites More sharing options...
mike stehr Posted February 11, 2002 Share Posted February 11, 2002 Damn! Where is that Trash Bin?! Those University's are probably Vintage, I have no idea of Value. You could series wire the speaker's from the old reciever,(it's mono). Out hot to the first hot terminal on the speaker, ground terminal from that speaker to the next hot terminal on the next speaker, and then the ground terminal from that speaker to the reciever. One wire connection through the speakers. Two 8ohm speakers in parallel will make 4ohms. Series wiring 8ohm speakers will make it either 8 or 16. Old School Mono. Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted February 12, 2002 Author Share Posted February 12, 2002 Cool, so your suggestion is a series wiring (I didn't know you could do that, interesting) and the two 8 ohms in series will make it 16ohm? I will dig out my old electronics book. Actually a neighbor hired me and my truck to clean up an old storage shed and take a bunch of stuff to the dump, these goodies were in there, so I held them back) and one of the other speaker cabinets was a thrift store discard from their "as is dept." think it was $3 at the most. I am anxious to hook the speakers up to something so I can report on how they sound. I think I heard somewhere that a triaxial speaker is a woofer with a mid and tweeter horn built in the middle. I cannot see the front because it is covered with grill cloth which has no apparent way of removal. The cabinet is decent so I will temporarily leave this thing intact. {fini, you should come over and look at this good junk} maybe tomorrow I will hook it up. -diced and spliced Quote Link to comment Share on other sites More sharing options...
Stig Posted February 12, 2002 Share Posted February 12, 2002 Clipped, My 1960 Lafayette Electronics catalog lists the University 15" 315 Triax as their top of the line. It cost $152.88 in 1960. An Altec Lansing 605A Duplex went for $189.00 in the same catalog. Mint condition Altecs go for pretty good money on E-bay. Don't think the collector demand is as high for the University but you might check it out. If it is the same unit it has a horn tweeter crossing over at 5K and Diffusicone mid, both with volume pots. Stig Quote Link to comment Share on other sites More sharing options...
John Warren Posted February 12, 2002 Share Posted February 12, 2002 If it is the driver I am thinking of it has a gold screen covering the concentrically mounted tweeter horn. It is not a triaxial driver, but a coaxial with a diffuser ring attached to the near apex of the woofer cone. They have limited value, replacement cones are not available. University Loudspeakers was originally located in White Plains, NY later being purchased (along with Altec) by the parent of EV. The production equipment was then moved to Oklahoma. Quote Link to comment Share on other sites More sharing options...
Stig Posted February 12, 2002 Share Posted February 12, 2002 John, On second look in the catalog you are right ...they don't call it a tri-ax but do call it a 3-way with mid Diffusicone crossing at 1000cps with volume pot. The tweeter horn used is H-600 with T-50 driver also with volume pot. 61/2 lb. Alnico 5 magnet. 50 watt rating with (quote from catalog)"response from below 25 cps to inaudibility" ...wow, which I guess means when the horn cuts off... the party's over Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted February 12, 2002 Author Share Posted February 12, 2002 If I am not mistaken the term "triaxial system" was on the back of this unit Model 315. I wasn't really thinking of of ebaying it out right away. It might be fun to see what it sounds like first and if it is good I could use it in a two channel with the other cabinet that has the 12" and horn that I described. This brings up another question. What is the "balance" control on a receiver really for. I never really need it so I just keep it in the middle, but if I had slightly different speakers on either side maybe it would be necessary to tweak the balance between them? - equipped and hornswoggled Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted February 12, 2002 Author Share Posted February 12, 2002 I only see one control pot on the cabinet housing the 15" triax, so maybe there are some other terminals on that crossover unit attached to the side of the speaker for hooking up a second control. Maybe I will take a closer look at the unit and get back here. -clpd &shrn Quote Link to comment Share on other sites More sharing options...
John Warren Posted February 12, 2002 Share Posted February 12, 2002 C&S- "Triax" and "Triaxial" are a copyrighted trademarks of Jensen as was the "Duax. University and EV could not use the term to describe their 3-element systems. EV resorted to the term "TRX", University used "3-way Diffaxial". The 315-C, introduced in 1963 is the best version of this type of driver, few were made. Regardless of the dash number, the sound wasn't anything worth writing home to grandma about. IMO, the best full range speaker system made by University was the Model 312 Series 200 12" driver, cast basket, co-axially mounted Sphericon tweeter and a "whizzer" diffusicone. Spooky realism. You cannot get a better loudspeaker for low level, critical listening. I have a pair of these the bedroom, mounted in Onken style enclosures. The wife loves them. This message has been edited by John Warren on 02-12-2002 at 08:33 PM Quote Link to comment Share on other sites More sharing options...
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