15Kwt stereo system in a Prius :)

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

 

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

 

It's cumulative exposure that damages hearing.

JeffD

 

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."

===========================
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.

 

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.

 

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 ...

 

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