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Z9 What Ohm ?

Discussion in 'AV Receivers & Amplifiers' started by docsmith2k1, Dec 31, 2003.

  1. docsmith2k1

    docsmith2k1
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    I have been setting this up for the last few days - The Z9 defaults to an 8ohm setting for speaker impedence but can be switched to 6ohms on start-up. I have M+K's rated at 4ohms. What should I do - leave the amp set for 8ohms or switch to 6ohms?
    Thanks in advance for any help - I have never really understood the problems or damage that can be caused by speaker impedence.:confused:
     
  2. buns

    buns
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    Hopefully Yamaha are being conservative, with a big thing like the Z9 i would HOPE it should manage 4 ohm speakers. I would switch to the 6 ohm setting (assuming there isnt one for 4 ohms).

    The only worry you have is that the difficult load the speakers present will cause the amp to trip protection circuitry which would prevent damage. So you SHOULDNT be able to cause it particular damage. If you notice the amp trips itself off at high volumes, i suggest not worrying but trying to listen at slightly lower volumes

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  3. docsmith2k1

    docsmith2k1
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    Cheers Buns - there is no 4 ohm setting, and I have had no problems yet, but I will reset to 6ohms. Documentation does quote the wattage into a 4ohm load but the amp only has 8 and 6 ohm settings.
     
  4. docsmith2k1

    docsmith2k1
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    Interestingly when I went into the setup options to change the setting to 6 ohms it had done so automatically. Don't know if this is part of the auto configuration that the amp does when you use the microphone.
     
  5. buns

    buns
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    it is more likely just that it defaults to this..... it would make sense to default to the setting which is going to do least damage should you not know what you are doing and attach a tough load

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  6. docsmith2k1

    docsmith2k1
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    I thought so too - but the manual does state that the default setting is 8ohms, and advises you to change to 6 if your speakers have this rating. It does also seem strange that 4ohms is not an available setting?
     
  7. mr_blah

    mr_blah
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    I just checked my KEF TDM's Impedance are 4ohms, so i will check to see what setting it has changed too and if it is at 6ohms, then i'll give the 6ohms setting a try.
     
  8. buns

    buns
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    it is interesting..... maybe there is some way it calibrates itself..... sounds like something unusual to include but i guess possible!

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  9. General Skanky

    General Skanky
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    Hmmm.................

    Well, the Yamaha did an auto set up calibration.

    It did a frequency sweep of the audio spectrum with white noise to set levels etc on each speaker.

    Therefore it must have detected the load presented by each speaker as it panned round.

    As part of the auto set up, it determines the 'type' of speaker you have, to set things like load, graphic equalization, distance etc.

    As a speaker is never exactly as stated load wise, but fluctuates anywhere from 1 ohm through to 16 ohms, the Yamaha detected this and calculated an average.

    Therefore set your amp at 8 ohm speaker loads.

    Good eh?;)

    Been playing Balderdash.:laugh:
     
  10. rags

    rags
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    Isnt the Z9 THX Ultra certified - if so I am surprised the option doesnt allow lower than 6 ohms. Either way though I would imagine it's amplification to be pretty tough so probably will be able to handle it without problems.
     
  11. docsmith2k1

    docsmith2k1
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    It is indeed THX Ultra 2 certified. Don't get me wrong - is sounds ballistic when it needs to and controlled and rich when it needs too. (just been listening to a live recording of Fleetwood Mac - and the level of control and clarity is spine tingling) I just wanted to make sure that I wasn't going to damage anything by an incorrect setting. Thanks to the responses here I feel reassured.:)
     
  12. jhjerpe

    jhjerpe
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    When I went for a Demo at Yamaha UK they stated it would support 4ohm speakers without any problems.

    I just got my Z9 up and running and it's fantastic!
     
  13. buns

    buns
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    it probably says 6 ohm simply as a safety...... it likely handle 4 without issue..... but from a manufacturers perspective, underspeccing something like this is a good idea

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  14. rags

    rags
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    Andrew - what MK's have you got by the way ?
     
  15. docsmith2k1

    docsmith2k1
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    I have the S150s across the front, and 4 SW-95s at the back - and a 350 sub.:)
     
  16. mr_blah

    mr_blah
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    So doc did you leave it at 6ohms or put it back to 8ohms?

    When i checked mine i think it was on 8ohms but flicked quickley on to 6ohms it is silly holding down A button then power on the Amp for i didn't know how long to press the A button for and i just look away for a spilt second and now i don't know if it was 8 or 6ohms, i must get the mic out again, now that i know how the switching of the ohms is handled, i have to be quick & looking straight at it.

    But is there a great difference, i noticed it to be a bit louder, more treble, and the amp gets a lot hotter(i think), also doc have you had the Z9 on long enough to notice that it gets warm to the touch? it must be hitting 80+ on tmp with me, the built in fan has also been on more than once, i may have to look in to getting a new stand, or something sorted. :/
     
  17. mr_blah

    mr_blah
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    Are you sure it didnt change quickley, cause i did a wee test, i left it on 8ohms and when ever i went back in to it again it was at 6ohms it changes fast from 8ohms, and if you leave it on 6ohms whilst holding down the A button it would seem that i left it on 8ohms, basicly if you blink you might have missed it change, but i guess the idea is to get the match for Amp to Speaker as close as possible?
     
  18. docsmith2k1

    docsmith2k1
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    I have left the setting to 6Ohms as this was mor eappropriate for my 4Ohm speakers. I agree the amp does get warm but it has never been more than warm. Not as hot as my apple powerbook gets!!!. As I have used the amp - extensively - over the last few weeks it has got better and better. There is beautiful detail, and bucket loads of power, but also a warmth and richness which I think most people wold agree, has often been lacking from Yamaha amps - and audio products in general - I think they are on to a winner with this one. When you start to see the reviews in the mags over the next few months, I think it will depose the Pioneer and Denon as the top high end combined amp.
     
  19. mr_blah

    mr_blah
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    Yeah i agree with what your saying, it has got lots of power in the sound and the quality doesn't twitch at any level, each DSP setting i have tryed has a distinguished characteristic and works very well, the Z9 is going to last me a very long time, best Yamaha Amp todate & in the past have had a DSP-3090 & a DSP-A1.

    Do you think it is necessary to optimize the sound settings again after switching from 8ohms to 6ohms, maybe that makes no difference to the settings?
     
  20. rags

    rags
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    It's also the most expensive Yamaha to date.
     
  21. Reiner

    Reiner
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    The Ohm setting should not effect the power output, volume or sound quality at normal volumes as all it does is to limit the current to the power amplification stage, protecting it from damage (due to overloading/-heating).
    And that you should/would only notice when you require high dynamics or extreme volume levels.
     

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