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    hooking up 6ohm speakers into an m-125

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    Skyfrog

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    Join date : 2013-03-03
    Location : Raleigh, NC

    hooking up 6ohm speakers into an m-125

    Post by Skyfrog on Tue Aug 25, 2015 10:11 pm

    hi guys (or Bob)
    i have built my m-125s for 8 ohms speakers option. Can I hook up 6 ohm speakers to them?
    thanks everybody

    GP49

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    Re: hooking up 6ohm speakers into an m-125

    Post by GP49 on Tue Aug 25, 2015 10:37 pm

    No problem, in all likelihood. Most of the time, over most of the audio range, a loudspeaker's impedance will be higher than its rating, which is generally the minimum.

    Skyfrog

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    Location : Raleigh, NC

    Re: hooking up 6ohm speakers into an m-125

    Post by Skyfrog on Tue Aug 25, 2015 10:57 pm

    the resistance measured across the speakers is 4.6 ohms on some Polk Monitor 7Cs

    skriefal

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    Re: hooking up 6ohm speakers into an m-125

    Post by skriefal on Tue Aug 25, 2015 10:59 pm

    That is not the impedance.  The speaker's impedance varies with frequency and cannot be measured with a multimeter.

    ArlanB

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    Re: hooking up 6ohm speakers into an m-125

    Post by ArlanB on Wed Aug 26, 2015 12:07 am

    I have been running ESS Heil AMT-10b 6 ohm speakers on the 4 ohm output of my VTA ST120 for over 7 years and have had no problems.  I believe that the ohms of the speaker must be equal to or higher than the selected terminal connection from the output transformer.  It is when the speaker ohms rating is below the ohms selected on the output transformer that sets up the situation that gets you in trouble.

    Tubes4ever

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    Location : Star, Idaho

    Re: hooking up 6ohm speakers into an m-125

    Post by Tubes4ever on Wed Aug 26, 2015 12:22 am

    I too have 6 ohm speakers connected to my ST70s 8 ohm taps. Will this cause any harm or degradation in audio quality? Anyone have any test results.

    Also, what's with the production of 6 ohm speakers? Why can't they stick with the 8 ohm standard?

    skriefal

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    Location : Utah, USA

    Re: hooking up 6ohm speakers into an m-125

    Post by skriefal on Wed Aug 26, 2015 12:29 am

    Tubes4ever wrote:Also, what's with the production of 6 ohm speakers?  Why can't they stick with the 8 ohm standard?

    It's not that simple. The impedance curve is a result of the combination of woofer, tweeter, crossover, etc. And it varies by frequency, with the number printed in the specs being little more than an average or approximation.

    Kentley

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    Re: hooking up 6ohm speakers into an m-125

    Post by Kentley on Wed Aug 26, 2015 1:16 am

    Impedance is measurured in ohms for convenience. It does indeed vary over the frequency drastically. My own experience, though not extensive, is that you are more than likely going to get best results when the taps you use are LOWER than the rating of the speaks, though this is highly relative to your whole setup. The rationale for this is that the relative "ohms" tax your amp less when this is the case. For a detailed analysis of this, you may refer to.........some other Einstein.


    Last edited by Kentley on Wed Aug 26, 2015 1:17 am; edited 1 time in total (Reason for editing : speeling)

    Bob Latino
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    Re: hooking up 6ohm speakers into an m-125

    Post by Bob Latino on Wed Aug 26, 2015 8:08 am



    Speakers tend to have wide fluctuations in their impedance which varies with frequency. How would you rate the speaker in the impedance graph above ? 6 ohms? 8 ohms ? Which transformer tap would you use ?

    Your use of the 8 ohm tap with the 6 ohm rated speakers is probably a good choice? Most speakers have a higher impedance than their rated impedance at one or more frequencies ..

    In your case with 6 ohm rated speakers, you could try BOTH the 4 and the 8 ohms taps and see if you can hear any difference ? Personally though, I don't think that you would hear any difference in the sound of the amp between the two taps.

    Bob

    GP49

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    Re: hooking up 6ohm speakers into an m-125

    Post by GP49 on Wed Aug 26, 2015 8:24 pm

    It will make virtually no difference to a TUBE amplifier and with a nominal 6Ω speaker you may as well choose by what your ears say.

    With a TRANSISTOR amplifier it is important that impedance not go below what the amplifier is rated for. A loudspeaker which goes down to 2Ω could be hazardous to a TRANSISTOR amplifier that is rated for a minimum impedance of 4Ω, because at 2Ω the current in the output stage is DOUBLE what it would be at 4Ω and could exceed what the output transistors are designed to handle.

    bluemeanies

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    Re: hooking up 6ohm speakers into an m-125

    Post by bluemeanies on Thu Sep 03, 2015 8:54 am

    I have been breaking in some new Warfardale Jade3 monitors for a friend of mine using my m125's wired to 8ohm taps.
    Naturally I cannot compare sound differences which IMHO I think would be minimal and only visible on a meter and not to my 65 year old EARS. Sound quality to me is measured by what my ears hear, not some graph.
    My concern was if there would be damage to my m125's and contacting Bob Latino who responded expediously answered my question which was a GO.

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