Ohm questions

Discussion in 'Speakers' started by Allen Marshall, Dec 9, 2003.

  1. Allen Marshall

    Allen Marshall Supporting Actor

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    If an amp only tells you the wattage at 8 and 4 ohms would it be bad to use a 6 ohm speaker? Also if you have 2 or more kinds of speakers in one setup with different ohms then the others like, fronts 6 ohms and rears 8 ohms would there be any kind of a problem there?
     
  2. David Judah

    David Judah Screenwriter

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    If an amp can handle 4 ohm loads nominal then it can handle 6 ohm as well because it gets easier as the impedance rises.

    There's little problem mixing impedance as long as the amp can handle them(the lower loads)and the speakers are level matched.

    DJ
     
  3. Allen Marshall

    Allen Marshall Supporting Actor

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    if it tells you the watts for 8 ohms and 4 ohms how do you figure out how many watts it would be for 6?

    can you rewire a speaker to get less ohms?
     
  4. RobertWe

    RobertWe Auditioning

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    My Sony 5ES manual says, if any speaker in set-up (5.1/6.1) is below 8-ohms set amp at 4-ohm setting. I have Energy Audisey 3+2-1's that are 6-ohm speakers and the rest of speakers in system are 8-ohm and amp is set for 4-ohm for best power output. Oh yea, the reason for this is because a lower ohm speaker will require a higher amp load and setting amp to 4-ohm insures amps are there when needed.
     
  5. Allen Marshall

    Allen Marshall Supporting Actor

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    i think i may be confused, if a speaker is 8 ohms nominal can or cant it do 6 ohms?
     
  6. GrahamT

    GrahamT Supporting Actor

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    Ohm's law: one volt of electrical pressure will push one amp of current through one ohm of resistance.

    The danger of running a receiver with speakers with nominal impedences below the recommendation is that they will draw to much current creating too much heat in the transistors, transformers, integrated circuits etc. Usually (hopefully) the receiver will go into a safe mode before anything melts.
    If the receiver is rated for 4 ohms then it will do anything above, ie 5 ohms.

    As for the wattage rating, look at ohms law. If the amp is rated for 100W into 8 ohms and 200W into 4 ohms then it will do around 150W into 6ohms.
     

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