Sub - Powersave feature question

Discussion in 'Archived Threads 2001-2004' started by Kevin Cagle, Feb 26, 2002.

  1. Kevin Cagle

    Kevin Cagle Agent

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    I just bought a SA-WM40 after much agonizing. I ended up splurging on the Bookshelves and the center. And saving on the sub. I will upgrade later when I can afford more.

    Anyway, enough of I have this and this and this.

    The Sony sub has an energy-saver switch on the back. I tried with it on for a couple of days but I found that at our normal listening volume (90% of the time). It will often shut itself off while we are watching TV and then turn back on later during brief loud periods. Overall I am very satisfied with this sub since I did the polyfill mod, but the shut-off is frustrating.

    I have now switched it to always on. Here are my 2 questions:

    1. Is it harmful to the sub to always leave it on, since its behind the tv and too hard to shut it off every time?

    2. Is it dangerous to use the switched plug on the back of my receiver to connect the sub or is it even worth it to shut the sub off(question 1)?

    Any input will be valued.

    Thanks,

    Kevin
     
  2. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    1. Its okay to leave the sub on all the time. Just costs you a tad more electricity.

    2. You do not want to plug the sub's power cord into the back of your receiver. The outlets on the back of the receiver specifically state a maximum power output (usually around 100 watts max, total) which is lower than what is necessary to drive the majority of powered subwoofers including the SA-WM40.

    Now here's the question you didn't ask:

    3. Can I do anything to make the energy-saver feature work better?

    Maybe. This feature works by sensing the voltage on the audio input signal. When the voltage goes above a specified threshold the subwoofer turns on. If the voltage remains below the threshold for a specified amount of time (usually 10 to 30 minutes) then the subwoofer turns off.

    If you turn up the subwoofer level on the receiver then the voltage on the audio signal to the sub will be some percentage larger. You may be able to turn this up until the sub doesn't shut off mid-program anymore. Of course now your sub is much louder than before and no longer calibrated. So turn down the input gain on the subwoofer to compensate.

    This may not completely fix the problem since its possible for a program to have no bass at all for 10-30 minutes and no amount of gain can help you there. The real problem is that the SA-WM40 doesn't turn on fast enough and also emits an audible thump when it turns on mid-program (I've heard it). Some of the higher quality plate amps like those on the SVS PC subs turn on almost instantly and with no thump.
     
  3. Kevin Cagle

    Kevin Cagle Agent

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    Thank you very much. I seriously doubt that power consumption can be that high when its not being used, so I won't worry about it.
     

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