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Receiver and Amplifier Impedance Switches are a bad idea

Discussion in 'General Hardware' started by SabreWulf69, Sep 12, 2010.

  1. SabreWulf69

    SabreWulf69 New Member

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    Not sure if this has been brought up before but thought I'd give people a little heads up on my interpretation of the impedance switch/selector on a fair few varieties of Receivers and Amplifiers of home theater and why it is a bad idea to use. -->

    Oooh this one IS IMPORTANT. At anytime I have just discovered, do NOT set the impedance selector on the back of the amp to 4 Ohms, make sure it is always set as high as it will go (usually 8Ohms), all that switch there is for, is for the receiver and amp company's to cover their ass, and with it turned on you can possibly damage your speakers, with it in the lower position you almost half the power output of the amplifier, and reduces the sound quality incredibly as it just reduces voltage, hence you would then be underpowering your speakers, hence introducing amplifier clipping overall a lot earlier than rather if the impedance switch was in the highest position. Most receivers if not all within the last 20-30 years have overheating protection to stop things from dying anyway, so this impedance switch really serves as a backup system, which lowers the overall fidelity. With the amplifier that I have the clipping protector that I have is turned off, but that option on my amp is for when speakers are overdriven and as my amp is matched power wise (wattage) well just under actually with both large and small speakerd connected, my fidelity of the system is improved with it off, as well as turning off the short detection which could also activate prematurely with driving difficult speakers or when the speakers could blow yet again from being overdriven power wise which they aren't, yet again increasing fidelity, and seeing as how I have a slight low load at a slightly lower wattage rating having lower impedance options could theoretically kill my speakers which have no overheat protection of there own.

    Unlike my amp as we have (well I have) seen in the past, my single 2 channel amplifier is $1300 worth of just pure amp, has overheated twice now, shutting it'self off for protection in the process. Having it's remaining 3 protection circuits still active (which are unable to be disabled for good reason), has been far and enough to protect itself, and keep it's intended awesome high quality sound. So in short, disable the impedance switch no matter the speakers you use (set it back to 8Ohms from 4Ohms and keep it at 8Ohms if not done so already).

    Loosely what I managed to interpret from this very well described article located here --> http://www.audioholics.com/education/amplifier-technology/impedance-selector-switch-1
     
  2. AsRock

    AsRock TPU addict

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    Well i have always thought 4Ohm was for 4Ohm speakers. As the speakers with either be under powered or over powered.

    As you proberly know already most house speakers come as 8Ohm..

    Although last time i had seen a switch on one was with a amp from the 80's lol. Ya gotta love those days a lot of 80's 90's stuff had easy replaceable fuses
     
  3. SabreWulf69

    SabreWulf69 New Member

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    As mentioned this is not the case. A lot of Yamaha's receivers still to this have this antiquated option and as the article describes, the fact that they even put it in the flagship model of Yamaha's range is kind of self defeating, as it would seem from measurements and technical data to not make any difference. A pure ass-covering tactic in the products it's featured in I would believe.
     
  4. AsRock

    AsRock TPU addict

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    Well that explains that i have never had a Yamaha Amp or A/V. Maybe email them and ask them about it and why it's on their cheaper models.
     
  5. SabreWulf69

    SabreWulf69 New Member

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    According to the article, their excuse is they don't have very big transformers, and under full 100% constant load for ages on end may heat up to inappropriate levels for the consumer (burns and stuff) but yet they still have overheat protection to prevent fires and damage to the components of the receiver itself.
     
  6. cadaveca

    cadaveca My name is Dave

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    V/R=A

    VxA=W

    Apply the math.


    (V=Volts, R=resistance, A=Amps, W= Watts)
     
  7. SabreWulf69

    SabreWulf69 New Member

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    Eh I say if your gonna make a 4 Ohm amp, do it properly or don't do it at all.
     
  8. cadaveca

    cadaveca My name is Dave

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    It's been that way for years though. You really get what you pay for, when it comes to home audio. There truly is a reason that people spend so much for that high-end gear.

    Question is, how often do you crank your stereo.
     
  9. SabreWulf69

    SabreWulf69 New Member

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    I crank my stereo all the time.
     

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