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15Kwt stereo system in a Prius :)

Discussion in 'Gen 4 Prius Main Forum' started by Chris Wolfgram, Mar 3, 2021.

  1. Chris Wolfgram

    Chris Wolfgram Active Member

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    It always seemed to me that a HUGE stereo system could be ran in a Prius. But apparently, the computer has a problem with huge electrical draws. I heard when setting up my system, 100 amps was the safe maximum, before you start getting warning messages. This was Okay for me, and my purposes, as I wasn't really trying to build anything ridiculous in my Prius anyway. {That's in my truck ;)} But in the back of my mind I had always figured, "Surely their must be a way to get around computer warnings... And what the hey, if this electrical system can shove a 3000 lb car down the road, it should be able to shove on some big subwoofers pretty hard, too :)
    Well sure enough ;) Check the part @2:00 minutes when Jacob asks him about his alternator :) lol This is a Prius... It doesn't have an alternator :) lol



    PS, I've heard that all electric cars, such as Tesla's, have the "potential" to push a ridiculous stereo system (like 10's of thousands of wts) for hours at a time, also.

    Oh and for any of you that don't already know this, this system "might" sound pretty good in person, but you would never know it, by listening to a system like this, being recorded by the tiny mic in a phone, which can never handle this kind of sound pressure. This sub woofer setup is tuned to 39hz though, which is a little high for my tastes. That kind of bass hurts my ears. I prefer 30'ish, or even lower.
     
    #1 Chris Wolfgram, Mar 3, 2021
    Last edited: Mar 3, 2021
  2. jdenenberg

    jdenenberg EE Professor

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    There is an alternative to running a stereo off the 12v bus in a Prius. You can use a buck converter connected to the HV battery that creates a separate 12v bus for the stereo.

    JeffD
     
    #2 jdenenberg, Mar 3, 2021
    Last edited: Mar 3, 2021
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  3. Chris Wolfgram

    Chris Wolfgram Active Member

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    I wonder if that's what he did ? But then he did say something about 150 amps.... Which would be pretty light for a 15Kwt system ? Hmmm.
     
  4. Chris Wolfgram

    Chris Wolfgram Active Member

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    But then, no matter how you slice it, the guy said it metered at 153 db's. No matter the SQ or anything else, that's LOUD !
     
  5. CooCooCaChoo

    CooCooCaChoo Active Member

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    You can only listen to the radio on full blast once.
     
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  6. Chris Wolfgram

    Chris Wolfgram Active Member

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    Lol I've sat in a vehicle (SMD's Tahoe) that did 159 !
    It's pretty surprising what our ears can take, without being completely destroyed.
     
  7. jdenenberg

    jdenenberg EE Professor

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    It's cumulative exposure that damages hearing.

    JeffD
     
  8. Chris Wolfgram

    Chris Wolfgram Active Member

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    Well, to some degree. A close range explosion can destroy your hearing in a micro second.
    On the other hand, guys like SMD have been subjecting themselves to crazy loud systems for decades, and can still hear well enough to communicate.
    Also, the frequency in question, matters. Deep bass doesn't seem to hurt human hearing as much, but mids / highs, can mess up our hearing a lot easier / quicker.
     
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  9. fuzzy1

    fuzzy1 Senior Member

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    15kW audio output from a 1kW electrical system? Ratings standards must have changed a bit since I was buying audio equipment back sometime in the previous century. Either that, or I missed the Nobel Prize for overturning the First Law of Thermo.

    That's what my dad used to think, until his then-gf ordered him to get hearing aids. Now I can hear the TV just fine through his Bluetooth-linked hearing aids, with the actual TV speakers turned off.

    For a couple decades he really didn't understand why his adult children put on hearing protection around much of the farm equipment. That machinery didn't seem all that loud to him. After knocking the muffler off a tractor exhaust stack, he replaced only because we demanded it.

    His ears are not completely destroyed. When his hearing aids are out for bedtime and the situation doesn't allow lip reading, he can still hear me if I SCREAM! Ordinary yelling isn't loud enough.

    Now I wish that I'd started using protection much earlier.

    Another story came from indoor target ranges, where hearing protection was already mandatory when I joined an indoor team during college. Old geezers had begun their indoor years without hearing protection, at least for .22s:

    "Didn't that hurt in your ears"

    "It did at first, but not anymore."
    :rolleyes:

    ===========================
    SciAm, April 2014: Just 1 Rock Concert or Football Game May Cause Permanent Hearing Damage

    "A single exposure to loud but not deafening noise may be enough to precipitate irreparable harm to nerves in the auditory system. This is the take-home from a new line of research that may help explain why many people, particularly as they age, have difficulty in picking out a conversation from the wall of background noise that is a requisite accompaniment to any football game or meal at a family-style restaurant."

    "There are up to 25 nerve fibers for each of the up to 4,000 signal-converting hair cells in humans. When a few of them die, it may at first produce a minimal impact on the ability to hear but, if the losses continue with repeated exposures, there is a slow decline in the acuity of what your ears can pick up. “You can create a visual analogy that if you downsample the pixels in an image, you can tell if there’s something there but you can’t tell what it is,” Liberman says.

    The loss in auditory resolution doesn’t turn up on the traditional audiogram that measures the functioning of hair cells by determining whether they can detect a sound of a particular loudness and frequency. The threshold at which a sound can be discerned goes up after exposure to loud sounds but then, given a few hours or days, often returns to where it was. Some 90 percent of the nerve cells may have died but an audiogram can still be completely normal. At this point, you might be able to still hear sounds emanating from a dinner partner across the table, but have no capacity to distinguish individual words."

    From that article, I would compare initial youth hearing a multi-megapixel picture. For most ordinary viewing, one can downsample it a very long way, very sharply reducing the pixel count, before the pixelation gets coarse enough to really notice and significantly interfere with reading. But from there, any further losses are noticed very quickly.
     
  10. ChapmanF

    ChapmanF Senior Member

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    Could work, and might even earn some of the installers Darwin awards while they're young and their hearing's still good.

    Doesn't seem to be. What I could gather from the video was he used the 12 volt system (with its 120-ish amps available) to keep a lithium battery charged, and drew the power off that for the amp. So there was really nothing Prius-specific about the install; you could do the same in any 12-volt auto to buffer some power for transient power demands above what the car's system can provide.

    The amp he's using sure 'nuff will draw 1,300 amps on its 9 to 17 VDC supply at full output for a sine input. That's a shade under 12 kW at the low end of the supply range, 22 kW at the other end,

    The specs give only 651 amps as its maximum consumption reproducing music, so not quite 6 kW at the low end of supply range, 11 kW at the high end, just under 9 kW at the 13.8-ish READY voltage of a Gen 2 Prius. That's power in; it claims 80% efficiency, so maybe 7.2 kW out to the drivers.

    Mind, those amps are coming (if they're coming at all) out of the guy's added Li-ion buffer battery, which is getting replenished no faster than the 120 amps or so that it might be getting from the Prius on a good day. So these are going to be transients in the music that it's handling; as sustained output, it's not going to happen.
     
  11. Chris Wolfgram

    Chris Wolfgram Active Member

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    Most any typical 15Kwt system (which is to say, a system in which the rated power of the amps added up, equal 15Kwts, is likely only going to out out 7 or 8Kwts, after impedance drop among other things.
    I'd like to say the system in my truck was 3500 wts RMS.... But in reality, the actual wattage is probably closer to 2Kwts.

    As for hearing loss, it's different for different people. I've beat on my hearing fir 3 decades. A few years ago, I went and had a professional hearing test, and surprisingly, my hearing was quite good. Just about normal for a 50 yo male. Even the hearing Dr. was surprised after I had told her how hard I was on my hearing for so many years.
     
  12. fuzzy1

    fuzzy1 Senior Member

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    There is some form of bass, sometimes even from nearby booming cars, that sends something inside my ears into convulsions. On the current household cars with somewhat 'enhanced' factory OEM audio, I had to turn the default bass settings down to stop the ear problem from being triggered by some media that wasn't a problem on any prior cars.
    Note the portion in that SciAm article about being able to lose 90% of the nerve cells and still being able to pass common hearing tests with normal readings.
    I still use my primary audio receiver / amp / speaker set purchased in the 1970s, though items connected to it have changed. 20W rating, highest peak LED at 35W, I never listen inside with even the 1W light flashing.

    I feel like a dinosaur now ...
     
  13. tucatz

    tucatz Active Member

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    Glad he doesn’t live across the street from my house!