Members Mr. Spoon Posted April 16, 2012 Members Share Posted April 16, 2012 Hey guys. This is probably a stupid question with a very simple answer, but I'm going to ask anyway. I bought an older Ampeg 4x12 (V412TC with 16? Celestion speakers) to complement my current 2x12 (Bugera 212VBK with 8? Bugera speakers). My amp (Bugera 333XL) has two outputs with a 16/8/4? toggle switch for impedance. The 212VBK has two jacks with the left jack being 16? mono and the right jack being 4? mono and a toggle switch for stereo/mono. The V412TC has a toggle switch for 16/4? and three jacks: in mono, left/middle are out/in (respectively), and in stereo, middle/right are left/right (respectively). I am also assuming notching the impedance toggle to the middle will do 8? for stereo. I tried 16/16? for the cabinets and 8? for the amp, and got signal out of only the 212VBK. At least I think it was 16? for the V412TC. I'm assuming left=16? and right=4? with this cabinet. I know it's old, but I just got it, so I'm not really familiar with it. I flipped the switch to the other side (which I would assume is the 4? side and received signal from the lower left speaker of the V412TC and both from the 212 VBK. I can provide pictures of the jack panels and the V412TC's wiring too, if it'll help. I can't recall each of the variations I tried, but I can't seem to get the V412TC to output signal from all four speakers while the 212VBK is plugged in also - I'll only get sound out of one side. Playing through just the V412TC DOES seem to give signal through all four speakers, though. Is there something I'm missing about wiring the two cabinets together? I've also considered the possibility that the jack panel may be messed up - the previous owner did have the rightmost jack mess up on him, but a little temporary soldering fixed that until I can find a replacement jack panel PCB (which is pretty damn hard for this cabinet) Link to comment Share on other sites More sharing options...
Members guitarbilly74 Posted April 16, 2012 Members Share Posted April 16, 2012 I would just remove the PCB and switch on your 4x12 and wire the speakers in series parallel to a single jack for 16ohms. Then use the 16ohms input on your 2x12 and set the amp to 8. Sounds like the jack assemble on the 4x12 is {censored}ed up. Link to comment Share on other sites More sharing options...
Members Mr. Spoon Posted April 16, 2012 Author Members Share Posted April 16, 2012 Thanks for the idea! It might take a while to find the same panel for a cabinet this old, and your idea would definitely work in the interim. I have two questions, though. I though parallel was positive to positive all the way through, same for negative, and you would divide impedance making it 4 ohms. Should it be in series, or am I mixing this up? Also, tip + and sleeve - right? Link to comment Share on other sites More sharing options...
Members guitarbilly74 Posted April 16, 2012 Members Share Posted April 16, 2012 Thanks for the idea! It might take a while to find the same panel for a cabinet this old, and your idea would definitely work in the interim. I have two questions, though. I though parallel was positive to positive all the way through, same for negative, and you would divide impedance making it 4 ohms. Should it be in series, or am I mixing this up? Also, tip + and sleeve - right? This is how you should wire it (disregard the output jack): As far as the jack, it really doesn't matter whether you wire the positive to tip or ring, it won't make a difference but the convention is tip + / ring -. No sleeve, do not use a TRS (stereo) jack. Link to comment Share on other sites More sharing options...
Members Mr. Spoon Posted April 16, 2012 Author Members Share Posted April 16, 2012 Thanks, man. Hopefully this works! Link to comment Share on other sites More sharing options...
Members sleewell Posted April 17, 2012 Members Share Posted April 17, 2012 6 12s is sweet Link to comment Share on other sites More sharing options...
Members Dolf Posted April 17, 2012 Members Share Posted April 17, 2012 6 12s is sweet What do you mean? Link to comment Share on other sites More sharing options...
Members GRIMESPACE Posted April 17, 2012 Members Share Posted April 17, 2012 I would suggest checking the 16 ohm jack on your 4x12 cab using a multimeter - you should be seeing around 12-13 ohms. I'm running 2 cabs same as you - 4x12 w/ 16 ohm speakers, 2x12 w/ 8 ohm speakers. My 4x12 jacks were wired to a PCB that gave me options to split into 8 ohm pairs (speakers wired parallel), or 4 ohms in mono (all speakers in parallel). I removed the PCB and rewired everything with a 3rd jack to do 16 ohms mono (all speakers series-parallel) or 8 ohm pairs. I did similar with my 2x12, except I added a switch (same as Marshall 1960 wiring) so that I can do 8 ohm split, 4 ohm parallel, or 16 ohm series. I use the 16 ohm jacks on both cabs to my 8 ohm outputs on my JCA50H, which are wired in parallel. I'm not sure about other amps, but you may want to confirm that your output jacks are set up same. I don't have access to my diagrams right now, but if you're interested, I can post them. Good luck PS: Dolf - that 6x12 is total badass - I just wouldn't want to have to lug it around Link to comment Share on other sites More sharing options...
Members Mr. Spoon Posted April 17, 2012 Author Members Share Posted April 17, 2012 I wired up the speakers according to the picture guitarbilly74 provided, and I am getting the bottom two speakers regardless of if my amp has ONLY this plugged in @ 16? or both the 412 and 212 plugged in with the amp at 8? and the 212 also at 16?. I am not going to rule out this jack, so I ordered a few from Parts Express and I'll probably be testing the two top speakers by themselves just to rule out the possibility of there just being something wrong with them. GRIMESPACE, I'll definitely take a look at the diagrams if you post them. The plate for the jacks is just fine , it's the PCB and/or the jacks that are jacked up. Being able to get it back to 16/4? mono and 8? stereo without needing to find the PCB would be great. Link to comment Share on other sites More sharing options...
Members sleewell Posted April 17, 2012 Members Share Posted April 17, 2012 Dolf, that made me mess in my pants. Link to comment Share on other sites More sharing options...
Members GRIMESPACE Posted April 17, 2012 Members Share Posted April 17, 2012 I wired up the speakers according to the picture guitarbilly74 provided, and I am getting the bottom two speakers regardless of if my amp has ONLY this plugged in @ 16? or both the 412 and 212 plugged in with the amp at 8? and the 212 also at 16?. I am not going to rule out this jack, so I ordered a few from Parts Express and I'll probably be testing the two top speakers by themselves just to rule out the possibility of there just being something wrong with them. GRIMESPACE, I'll definitely take a look at the diagrams if you post them. The plate for the jacks is just fine , it's the PCB and/or the jacks that are jacked up. Being able to get it back to 16/4? mono and 8? stereo without needing to find the PCB would be great. Obviously, something isn't right - do you have a multimeter? If so, I'd suggest testing each speaker independent of the others - you'll need to pull one or both of the wires before testing, otherwise, you're picking up the group. You should be getting around 6.2 ohms per 8 ohm speaker and 12 ohms per 16 ohm speaker. If this sounds confusing, just know that what the meter is looking for is resistance - speakers aren't resistors, they're inductors (or simply, wired as a coil), and the ohm's stated is a measure of impedance. Here's the wiring I used on my 4x12 running 16 ohm speakers. This gives me the two options I was looking for - either 16 ohms total (all 4 in series / parallel) or 8 ohm pairs. Note: I would have wired it using the standard Marshall series/mono switch (see last diagram), but I found this one first. This is the modified Marshall-type wiring I did on my 2x12 running 8 ohm speakers, which gives me ultimate flexibility. With the switch set to Mono, I get 4 ohms (parallel) or 16 ohms (series) depending on which jack I plug in. When the switch is set to Stereo, the speakers are split so that I can use either (or both) jack independently. And the standard Marshall 4x12 wiring, which I will probably rewire to at some point. Link to comment Share on other sites More sharing options...
Members guitarbilly74 Posted April 17, 2012 Members Share Posted April 17, 2012 I wired up the speakers according to the picture guitarbilly74 provided, and I am getting the bottom two speakers regardless of if my amp has ONLY this plugged in @ 16? or both the 412 and 212 plugged in with the amp at 8? and the 212 also at 16?. I am not going to rule out this jack, so I ordered a few from Parts Express and I'll probably be testing the two top speakers by themselves just to rule out the possibility of there just being something wrong with them. GRIMESPACE, I'll definitely take a look at the diagrams if you post them. The plate for the jacks is just fine , it's the PCB and/or the jacks that are jacked up. Being able to get it back to 16/4? mono and 8? stereo without needing to find the PCB would be great. your jack is fine or you wouldn't get signal to anything, I suspect you have either bad speakers or internal wires. Did you wire it straight to the jack and bypassed the PCB altogether? Link to comment Share on other sites More sharing options...
Members Stonedtone Posted April 17, 2012 Members Share Posted April 17, 2012 I always run my Univalve w/Weber 2X10 and Celset 2X12 together. Huge sound Link to comment Share on other sites More sharing options...
Members Lucius Posted April 17, 2012 Members Share Posted April 17, 2012 I always run my Univalve w/Weber 2X10 and Celset 2X12 together. Huge sound lol, and I have a rabbit that eats those rocket candies. Cheers, Lucius Link to comment Share on other sites More sharing options...
Members Reauchambeau Posted April 17, 2012 Members Share Posted April 17, 2012 I wouldn't bother running a 2x12 with as 4x12 off the same head, you'll get some comb filtering because of the mismatched cabs and the 4x12 will probably/should bury the 2x12. you'll end up with a tighter more focused sound by just running the 4x12 by itself. a 6x12 with matched speakers makes sense but in reality a 4x12 should be more than enough. Link to comment Share on other sites More sharing options...
Members Mr. Spoon Posted April 20, 2012 Author Members Share Posted April 20, 2012 Well, I found the problem. I ran each speaker individually through the jack and found that one g12t-75 was bad. Luckily I had 2 v30's around here so I was able to get the cabinet going again with four speakers. Thanks for the help guys, some times I need another set of eyes to attack a problem. Link to comment Share on other sites More sharing options...
Members scotttroyer Posted May 16, 2013 Members Share Posted May 16, 2013 I think sleeve, not ring, is the right term. 1/4" jacks and plugs are either TRS or TS (not TR). In the case of using a TRS jack, wiring to either the ring or sleeve will do the same thing when a TS plug is inserted. Link to comment Share on other sites More sharing options...
Members Nagol5178 Posted May 17, 2013 Members Share Posted May 17, 2013 There is a way to do this safely. I have done it before. Now I mostly just use my 2x12 but at one time I was using a 2x12 and a 4x12 at band practice. I had 160hms and 4ohms. I cannot remember but I believe I set the amp to 8 ohms. Before I did it I checked with a professional and he explained to me how to do it. Call your music store and they will know. If not, just go with one cab. I prefer 2x12's myself. I'm now running two 2x12's instead of a 4x12 and 2x12. Link to comment Share on other sites More sharing options...
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