Please help w/my Tempest sonosub problem

Discussion in 'Archived Threads 2001-2004' started by Aaron D, Aug 4, 2001.

  1. Aaron D

    Aaron D Stunt Coordinator

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    Well, I have spent all summer building my sonosub (you'll understand why it took so long when you see the pics) and I am almost done, save for the final finish.
    Being the impatient person I am, I decided to hook everything up and see how it sounds. When I did- I heard much buzzing and very little bass. Disappointment abounds!!
    Anyway, I thought maybe my homemade interconnect was at fault, so out came a store-bought cheapy. No change.
    I thought maybe it was my sub out on my receiver, so I hauled the whole thing to my neighbor's house. No change.
    I thought maybe it was my amp (Audiosource Amp 5.3), but when I hooked it to my front speaker (even using the homemade interconnect), it was fine.
    So, as a last resort, I scrapped my homemade speaker cable for some Monster Cable I had laying around and did the whole thing over again. Again, no change.
    I put an ohm meter to the cables, wire, and speaker. Everything looked OK to me. One question, though. When testing the speaker, I expected to see the 8 ohm resistance on each voice coil, but the needle barely crept off of the zero mark. I have the VC's wired in parallel, but, again, the test showed barely any resisance through them.
    As you can see, I am completely stumped, so any suggestions would be helpful.
    Thanks,
    Aaron
     
  2. Julian Data

    Julian Data Second Unit

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    Check your VC connections.. You should have 4 Ohms total.
    Connect the VC positive to positive, negative to negative.
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  3. Aaron D

    Aaron D Stunt Coordinator

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    Julian, I went back and rechecked everything (+ to + and - to -), but still only got buzzing from the speaker. When I checked resistance, I checked each VC separately and also when wired in parallel with the results listed above.
    Could I have a problem with the Tempest itself?
    Aaron
    [Edited last by Aaron D on August 04, 2001 at 01:49 PM]
     
  4. Julian Data

    Julian Data Second Unit

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    Aaron:
    What were the Ohms of each VC? I am trying to validate the continuity of the VCs.
    It should be 7 or so Ohms per VC.
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  5. Dan_D

    Dan_D Stunt Coordinator

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    when i ohmed my Tempest out in | | i got 3.5ohms
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  6. Patrick Sun

    Patrick Sun Moderator
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    You've got a short circuit somewhere.
    Take off all the wires connected to the Tempest voice coil leads. Simply measure the resistance of one voice coil. It should read nearly 7 ohms (this is DC resistance - near the value of Re). Measure the other voice coil. If you still have little or no resistance being measured, then your Tempest has a problem.
     
  7. Brian Fellmeth

    Brian Fellmeth Supporting Actor

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    Try hooking just one VC up and leaving the other open. If it still sounds bad, switch to the other VC.
     
  8. Aaron D

    Aaron D Stunt Coordinator

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    Well, I went back to check myself AGAIN, so I stripped off the wires and began testing. I couldn't believe that BOTH VC's were "bad," so I decided to test my front speakers to see if the meter was working.
    Behold, it registered the same thing I was getting with the Tempest (nothing, no resistance metered).
    It looks like I'm stuck until I can get a new meter tomorrow at the shack.
    I'll update as soon as I can test it again.
    Thanks so far, but stay tuned till the next episode!!
    Aaron
    BTW, if the Tempest IS messed up, I think I'm screwed, I read somewhere that they're backordered!!
     
  9. Julian Data

    Julian Data Second Unit

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    Wow Aaron! [​IMG]
    So you measured each coil and they were open. Hmm.. Take a look at the pic, I need to make sure you are not measuring two different connections thus giving you an open circuit
    [​IMG]
    You see how the VCs are presented?
    Each + and - connection for ONE VC are opposing each other.
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  10. Aaron D

    Aaron D Stunt Coordinator

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    Julian, I bought a new multimeter today and checked the Tempest and speaker cables. Everything was as it should be- i.e. 7 ohms per VC and 3.5 in parallel.
    I hooked up the Amp 5.3 to the sub out of my receiver to see if it was receiving a signal- which it was (indicated by a red "Signal" LED flashing in time with the bass). I will test the Tempest free-air style to see what happens later.
    Yesterday I found that I had inadvertantly broken the RCA connector on my interconnect running the sub out while testing everything.
    Question: Could shorting this connector at the receiver affect the output temporairly?
    It seems to be working now, but yesterday it wasn't outputting at all (even with new interconnects).
    If this isn't the problem, I have no idea what else to do. (Maybe buy a new receiver? [​IMG] )
    Thanks Again,
    Aaron
    PS- Happy Bday (belated)!!
    [Edited last by Aaron D on August 05, 2001 at 03:15 PM]
     
  11. Julian Data

    Julian Data Second Unit

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    Aaron,
    Shorting could affect performance "momentarily".
    If the resistance were read by the new meter, then the driver is fine.
    Thanks for the "props". [​IMG]
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  12. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    FYI
    no resistance = infinite conductance = short circuit
    infinite resistance = no conductance = open circuit
     
  13. Julian Data

    Julian Data Second Unit

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    Ryan,
    That doesn't make sense it should be switch around.
    Open circuit.. on meter when reading continuity.. no reading
    Short circuit.. infinite resistance. As one of the connections is touching something conductive.
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  14. Aaron D

    Aaron D Stunt Coordinator

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    Well, after all this head-scratching testing and frustration, I have come to the conclusion that my amp has to be bad. It is the only common denominator to every test. The wire, cables, and receiver was changed to no avail in addition to testing EVERYTHING with a multi-tester (a new one at that).
    So, my solution is to try a new amp or borrow someone's receiver to see if this is, indeed, the case.
    Of course, I will update as I can.
    Aaron
     
  15. Kevin Kloet

    Kevin Kloet Agent

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    Julian, Ryan is right....
    As for the original poster.... why don't you just run the sub off of one of the channels in the reciever?
    If your sub is ported, just run the left and right off one of the reciver's channels and plug straight in... that would tell you straight off whether there's a problem with the sub or the amp.
     
  16. Julian Data

    Julian Data Second Unit

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    Ryan,
    I am still confused.. I know this is "OT" but I still don't comprehend.
    Short circuit..yes still can complete a circuit but via another path, thus showing an infinite resistance. Whereas, an open circuit, can't complete the circuit, thus no reading on the meter when checking continuity.
    [​IMG]
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  17. Brian Bunge

    Brian Bunge Producer

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    Julian,
    An open circuit is infinite resistance. Think about it, what has a higher resistance? A wire between two contacts or air between two contacts (or an open circuit)? The air of course. What type of reading would you expect to see for infinite resistance? Maybe the symbol for infinity, but that's hard to do with a 7-segment LED.
    Even if you measure across a short circuit there will be a minimal amount of resistance across that short. Any piece of wire will have some amount of resistance. Now the scale of your meter may not be low enough to properly measure it, but it's still there. That's why it's a short. It has a lower resistance than the speaker's voice coil. And since current flows through the path of least resistance it will flow through the short and not the voice coil.
    Does this help?
    Brian
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  18. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    (Please don't be offended if I go into stuff you already know)
    Think of "resistance" as "the ability to resist or prevent the flow of current". So a material with a high resistance won't allow much current to flow. Plastic, for instance, has an extremely high resistance and allows so little current through it that its often used as an insulator.
    Think of "conductance" as "the ability to conduct current". That's the inverse of resistance. So a material with a high conductance, like metal, will allow lots of current to flow. And hence it has very low resistance.
    If you've got an open-circuit then there's some gap or opening in the circuit that's preventing current from flowing. The gap is resisting the flow of current. So its very high resistance.
    Now think about powering a speaker with an amplifier. If you're not careful connecting the wires to the speaker, some of the strands may touch from the negative terminal to the positive. That's a short circuit. The conductive metal strands have created a shorter path back to the amplifier than the intended path through the speaker coil.
    So short circuits are due to high conductance/low resistance. And open circuits are due to low conductance/high resistance.
    [Edited last by Ryan Schnacke on August 07, 2001 at 09:43 AM]
     
  19. Brian Bunge

    Brian Bunge Producer

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    OK, so Ryan explained it better than I did! [​IMG]
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  20. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    Forgot this:
    When using a multimeter for continuity test, the meter will display resistance. And it will beep if the resistance = 0. That indicates that theres a conductive path between the 2 probes with virtually no resistance. If you switch from continuity to resistance measurement then you'll see the same reading, but it will no longer beep.
     

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