Is this amp good enough for a shiva

Discussion in 'Home Theater Projects' started by Anthony*gw, Nov 15, 2003.

  1. Anthony*gw

    Anthony*gw Stunt Coordinator

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    Greetings, I am just about finished building my 140L sub,with it i will be using a Dynaco 400 stereo amp,it was my uncle's,i guess he doesn't want it anymore so he handed it down to me (lucky me),and i will be using the shiva driver that i ordered already but unfortunately it is not available right now,but i am willing to wait because Bob Reimer from creativesound said that they expect to have more by end of month.Since it's a stereo amp how should i wire shiva to get 4ohm load?


    here are some specs for my amp:Specifications:

    Power Output:

    20 Hz to 20 KHz, both channels driven:

    200 watts continuous average per channel @ 8 ohms;
    300 watts continuous average per channel @ 4 ohms;
    100 watts continuous average per channel @ 16 ohms.
    Monophonically:
    600 watts rms @ 8 ohms.

    Intermodulation Distortion: Less than 0.1% at any power level up to 200 watts rms per channel into 8 ohms with any combination of test frequencies. Distortion reduces at lower power levels. Typically less than 0.03%.

    Harmonic Distortion: Less than 0.25% at any power level up to 200 watts rms per channel into 8 ohms at any frequency between 20 Hz and 20 KHz with both channels driven. Distortion reduces at lower power levels. Typically less than 0.05%.

    Power at Clipping, single channel, 2500 Hz, less than 1% distortion:

    235 watts @ 8 ohms;
    350 watts @ 4 ohms;
    135 watts @ 16 ohms.
    Ppower bandwidth: 5 Hz to 35 KHz at less than 0.25% total harmonic distortion - half power output, 8 ohm load.

    Frequency Response: +0, -1 dB, 8 Hz - 50 KHz @ 1 watt into 8 ohms; ±0.5 dB, 20 Hz - 20 KHz @ 200 watts.

    Hum and Noise: Better than 100 dB below rated output, full spectrum.

    Input: 50,000 ohm load; 1.6 volts for 200 watts @ 8 ohms.

    Slewing Rate: 8 volts per microsecond.

    Damping Factor:

    Greater than 80 to 1 KHz into 8 ohms;
    Greater than 30 to 10 KHz into 8 ohms.
    Channel Separation: Greater than 60 dB by IHF standards. sorry for the long post.
     
  2. Anthony*gw

    Anthony*gw Stunt Coordinator

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  3. GrahamT

    GrahamT Supporting Actor

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    I suggest you use the left channel for one coil and the Right for the other. THis way the amp is seeing an 8 ohm load. I am not sure what the specs mean either. This will be plenty of power for the shiva. BTW I bought my amp and Tempest from Bob.
     
  4. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    Clipping is when you ask for more signal amplitude than the power supply can support. Music is made up of sinusoidal signals. Think about what a sine wave looks like. Now imagine if your power supply gave up before the signal reached the peak of the sine wave. The signal would go flat once the supply reached its limit. Then as the input signal curves back down again the output will start to follow it again. This waveform would be a sinusoid with the peaks "clipped" off.

    This is tough on the amp because you're asking it to perform beyond its abilities. Its tough on the driver because during the flattened peaks you're putting a DC voltage on the coils. Its especially tough on tweeters because the transition from the normal sine wave to the flat signal is abrupt. Abrupt transitions like this are really composed of many high frequency signals, in this case at very high power levels. Clipping is probably the most common cause of blown tweeters.
     
  5. Anthony*gw

    Anthony*gw Stunt Coordinator

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    Hey thanks for the input guys.so is there no way i can get 4ohms from the stereo amp and still use both channels,or will the 8ohm load to both coils be enough power?
     
  6. GrahamT

    GrahamT Supporting Actor

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    I think that 400 watts into 8 ohms will be more than enough fo the shiva. If you really want more maybe that amp can be bridged but I am not sure.
     
  7. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    You've got two voice coils at 8 ohms each. If you hook one coil to each amp channel then you'll have up to 400 watts available - more than enough to bottom that woofer out in most of the recommended alignments.

    You could wire the the to coils in parallel and connect to one amp channel. You'd have 300 watts which is just about right. But I'd probably just run one coil to each channel since the 8 ohm load is easier on the amp.
     
  8. DanWiggins

    DanWiggins Second Unit

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    In that box, 200W is plenty. I'd just wire the two voice coils in parallel and hang them off of one channel - 300W is more than enough for that large box.

    Dan Wiggins
    Adire Audio
     
  9. Anthony*gw

    Anthony*gw Stunt Coordinator

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  10. Anthony*gw

    Anthony*gw Stunt Coordinator

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