Tempest wiring question

Discussion in 'Archived Threads 2001-2004' started by Rudy D, May 30, 2002.

  1. Rudy D

    Rudy D Extra

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    I have a Crest Audio 2 channel amp. 225 watts per side. Should I bridge the amp and run 1 speaker line, or keep the amp in stereo and run 2 lines since the Tempest has a dual voice coil. What are the advantages to each way. I currently have 1 high grade speaker wire that is only long enough for 1 line. If it is better to run it in stereo I will go buy another one. I just dont know if it makes a difference. Thanks.
     
  2. Michael R Price

    Michael R Price Screenwriter

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    Well, you'll get more power if you bridge the amp and run it 4 ohms mono. However, be sure to check your amp's literature to make sure it can handle a 4 ohm load in bridged mode. Most amps can't.
     
  3. Rudy D

    Rudy D Extra

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    Yes, I can bridge and 8 ohm speaker, dropping it to 4 ohms. Thanks
     
  4. Michael R Price

    Michael R Price Screenwriter

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    Rudy, you may have misunderstood that. When you wire the voice coils in parallel to get the Tempest to be 1 load, it is 4 ohms not 8. Check your amp's literature again. You could just run in stereo to be on the safe side.
     
  5. Rudy D

    Rudy D Extra

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    Here is exactly what it says "The recommended minimum nominal load impedance in the bridged mode is 8 ohms, which is equivalent to driving both channels at 4 ohms. Driving bridged loads of less that 8 ohms will result in a loss of power and possible thermal overload". I bridged the amp with my previous sub, which was also 8 ohms. and everything was fine.
     
  6. Brian Fellmeth

    Brian Fellmeth Supporting Actor

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    Rudy,

    The Crest amp manual is specifically advising you NOT to bridge the amp and drive the tempest coils parallel. They say bridged is ok into an 8 ohm load in which case the amp would deliver power similar to a hypothetical single channel driving a 4 ohm load.
     
  7. Brian Bunge

    Brian Bunge Producer

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    Rudy,

    Since the Tempest has dual 8 ohm voice coils then you should run your amp in stereo mode and run one voice coil on each channel. If you parallel the voice coils (creating a 4 ohm load) and then bridge the amp, it will effectively "see" a 2 ohm load.

    In other words, don't bridge the amp.

    Brian
     
  8. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    This just got me confused...

    What if he bridged the amp so it's 4 ohms and wired it in series to the dual voice coils which would be 16 ohms.

    Or if he bridged the amp to 4 ohms and wired it to just one voice coil on the tempest which is 8 ohms and he shorted the other.

    What you're saying is that bridging the amp is not an option?
     
  9. Michael R Price

    Michael R Price Screenwriter

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    OK... When you wire the Tempest in series, it's 16 ohms and bridging your amp there would make it see an 8 ohm load. If you wire it in parallel, it's 4 ohms and your amp sees a 2 ohm load if bridged. Just run one VC off each channel to be safe.

    Chris, shorting one coil would lower the efficiency and power handling of the Tempest. I think it's better off running both coils, even if you get less power from the amp.

    The reason bridging halves the effective load is that the two channels of the amplifier are effectively paralleled - the signal is split, and the inverted signal goes to the other channel of the amp. This is like a differential amplifier in that each channel 'sees' half the load. It's also why you gain 3-4x the power by bridging. In your case, it's not a safe idea with the Tempest.
     
  10. Rudy D

    Rudy D Extra

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    Ok, I will run it in stereo. I did mis-understand it. To me it sounded like it is ok to bridge and 8 ohm speaker. I did have this amp bridged before with my last sub. What could I have damaged by doing this. Everything sounded ok though. Boy, I hope I didnt hurt anything. Thank you all very much.
     
  11. Chris Carswell

    Chris Carswell Supporting Actor

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    I think you got is squares away but this diagram might help some other people as well. It only goes to 6 ohms but you shpuld be able to do the math for 8 ohms.
    SUB WIRING
     
  12. Brian Fellmeth

    Brian Fellmeth Supporting Actor

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