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Speaker Cabinet Wiring

Discussion in 'Recording' started by JesterMasque, Jul 9, 2007.

  1. JesterMasque

    JesterMasque Active Member

    I have a Madison 4x12 cabinet. It has Eminence Symphony drivers and on the plate in back it has MONO, STEREO, and OUTPUT. The problem is that only the MONO side of the cabinet works. It is not the speakers, because when I plug into the STEREO side instead the other half of the cabinet works. Therefore, this must be a wiring issues. This goes out to all you wiring experts out there!!!

    Could someone please post a diagram for the proper wiring of a 4x12 cabinet with a mono and stereo input PLUS a single output? Thank you very much! I will rewire this entire cabinet if I must, but I paid for stereo amping.

    Any questions? Please ask me! Your better understanding means my better ending!
     
  2. Davedog

    Davedog Distinguished Member

    The stereo input jack is a STEREO input jack.....most likely... tip/ring/sleeve....The mono jack probably has a switch on it so when the stereo jack is used the mono jack CANNOT be used and cause a problem with the speaker impedances.
     
  3. JesterMasque

    JesterMasque Active Member

    No, it's meant for two inputs from an amp for stereo usage. My old drummers dad was the guy whom I bought it from and that's how he uses it. He was the dealer for the company at the time. Plus I used it like this for a long time.
    FYI: There is no switch.
     
  4. Boswell

    Boswell Moderator Distinguished Member

    What you describe is exactly what one would expect when using a mono jack (TS) in the stereo input. The two normalling connections in the stereo jack socket will be both wired to the mono jack. My guess is that one of these normalling connections is dirty or has become bent and is not making contact.

    What happens if you use a stereo jack (TRS) in the stereo input? For mono, you could try a TRS jack in the stereo input but with the T and R wired together. Care with speaker impedances, though.
     
  5. JesterMasque

    JesterMasque Active Member

    Last night, just to make sure, I tried a TRS source in the stereo input and got the same result: it just comes out of the other half (right side) of the cabinet. The inputs are set up to have one source drive the left side and another drive the right. This is how I used it since I bought it until half of my tubes blew out a few months ago (more like 15). Now I get a fresh set of tubes and it does not work the same way...
     
  6. Davedog

    Davedog Distinguished Member

    The 'switch' I was referring to cannot be seen...it is simply a contact point on the jack itself that moves part of the connection out of the way should it be needed for the stereo connection.

    I agree with Bos....something is bent.
     
  7. JesterMasque

    JesterMasque Active Member

    Oh... ok. Because I have seen cabinets that actually have flippable switches for impedence/mono/stereo/etc.

    I will check it something is bent... but in all honesty both of the jacks work independently for their own side of the cab respectively. It is only when I plug both in at the same time that I only get sound coming from the mono side only.

    I guess that clarifies my problem a bit more, in more simple terms. Anyone else with ideas please feel free to post.

    Thanks Davedog and Boswell for your help thus far!
     
  8. RemyRAD

    RemyRAD Well-Known Member

    It's not unusual that one must occasionally trace wires. From your descriptions, I get the impression that this particular cabinet is not necessarily miswired? When you say that only the mono side of the cabinet works, do you mean that sound only comes from 2 of the 4 speakers in the cabinet? Or do all of the speakers function when you plug into the mono input? I believe you'll find that all 4 work when plugged into the mono input. I believe your "stereo" input (?) is actually just a TS 1/4" mono connector and not an actual TRS stereo connector. If you plug into the stereo input as you plug into the Mono input, I think you'll find that perhaps it interrupts the wiring to 2 of the speakers or, produces no output at all as I suspect? If it does work, you might find that sound only comes out of 2 of the 4? You of course would need 2 amplifiers with a stereo output stomp box. Of course, you wouldn't really perceive much stereo that way but I'm not the person who designed that. The "output" is most likely a loop through of the Mono input, to feed another cabinet directly.

    Conversely, the stereo jack may in fact be an additional output with some sort of resistive pad network that knocks the power of the amplifier down so that the amplified speaker's output could be plugged into a second amplifier input, without fear of destruction. And it may in fact be a Mono 1/4" TS jack? Time to pull a speaker out and trace the wires.

    Tracing my past experiences
    Ms. Remy Ann David
     
  9. Cucco

    Cucco Distinguished Member

    Dumb question...

    Do you mean it has a stereo input as in:
    It has a solitary input which is labelled stereo and is designed for a TRS plug?

    Or...

    Does it have a stereo input labelled suchly and it has two inputs labelled "left" and "right"?

    I've seen a cabinet made in the latter category. It's purpose was so that you could drive it with two different sounds from the same cabinet. So you could have a crazy distortion pedal going into left and a flanger going into right (works MUCH differently than using them in serial!)

    I don't recall the make of the cab (hell, I'm not much of a guitar guy. If a cabinet comes in and I like the sound, I mic it. That's about it.)

    This might help clear up the topic. Or, I might just be a dumbass and have missed all of this.

    J.
     
  10. JesterMasque

    JesterMasque Active Member

    Ok...
    To clarify, rather then addressing individual questions about the same thing, I will explain normal operation and how I used to run it:

    I run the Left/Mono and the Right output from my POD Pro into channels A and B respectively on my Mesa. It is a dual channel power amp so it is if each input has it's own amp. I then ran from the A side out to the input labeled MONO on the cab and did the same with channel B to STEREO.

    Together, both inputs power all four speakers. Individually, they only run two each: MONO gives me the right side, STEREO gives me the left (I just double checked it again tonight and realized I had my L/R mixed up when I went to mic it up). Would this be called paralell wiring by the way?
    Each jack on the cab is only TS/mono input.

    To go along with your second theory Cucco, that is correct, except it is labled MONO and STEREO (capitalization for bolding only); however, they may as well be labled LEFT and RIGHT.

    Also, I checked the jacks on the panel, and nothing is bent. This cab was left at somebody's house for quite a while (about 4 1/2 months and I just got it back a few days ago) so I'm wondering if some jack ass tried to run his setup like mine and screwed it up or something. But just to be sure, I want a wiring diagram to just double check all of the connections and make sure that it is all hooked up properly.

    Many, many thanks to all of you who are helping me. The local music store guy said he wanted $25 up front just to look at it. I know how to solder and hook up wires, all I need to know is WHERE to hook them up to, haha.
     
  11. SonOfSmawg

    SonOfSmawg Well-Known Member

    Take the back off of the cabinet and physically inspect all of the wiring and jacks. Make sure that all of the soldering connections are still connected. If everything appears to be connected and you don't see anything that looks suspect, then you'll need to go through all of the wiring with a VOM, checking for an open circuit, dead short, bad plug, or bad switch. Fix or replace as needed.

    If you should happen to put your VOM across a drivers' tabs and it measures a couple of ohms less than the stated impedence, don't freak out. The stated impedence of a driver is nominal, but it's voice coil's resistance is lower.
     
  12. JesterMasque

    JesterMasque Active Member

    Ok, thanks a lot SOS. I just realized that someone else posted in here this morning. I will run through the whole deal this weekend probably. I will post my results.
     
  13. Kent L T

    Kent L T Active Member

    I have a dumb question as well you have been focusing on your cabinet but do both channels of your amp work? Have you tried switching the outputs from the amp to the opposite speaker jacks to see if the outage follows the switch? If so it could be the amp(since you mentioned you blew half the tubes in it, it was the first thing that came to my mind)
     
  14. JesterMasque

    JesterMasque Active Member

    The amp works fine. It is most definitely a wiring or speaker issue. My dad and I will be testing all of the connections with a multimeter. As soon as he gets time, I will post my results if we can not fix the problem. Thanks for your query Kent!
     

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