Simple reversible "UFO noise" killer

From all of the responses from various members about the NOISE factor in the Prius I doubt if any of them have actually been in the cars to hear them firsthand. The fact that the Prius has this one speaker in the front of the car for both noise making while going forward as well as in reverse is just plain stupid. Going in reverse is twice as loud as forward. Why??? Because they are too cheap to put a speaker in the back of the car and one in the front. for their noise making. ALL of these cars should have these speakers in the proper places and for the proper noises.

 

um....

No Comment.

 

You could run over and kill cats sitting/sleeping under your car and not to mention hit people.

 

i don't mind having an option to toggle between the 'ufo' sound and an 'ice cream truck.'

 

Hhmmm. Mine doesn't make any sound like described

 

I did some research as I have a friend that would prefer an in between solution if possible. While my friend does find the noise annoying, they wanted to try and reduce it a bit rather than kill it entirely. Enter the "L Pad" circuit. This will let us reduce the volume of the speaker while still presenting a similar 8 ohm load to the amplifier. Here's a calculator that let's you work out resistance values based on how much attenuation you desire. For reference, -6dB "sounds" roughly about half as loud to most people.

For example, an 8 ohm speaker attenuated 6dB will require a 4 ohm series resistor and an 8 ohm parallel resistor. A package of 3.9 ohm resistors is close enough to make this combination fairly easily. HINT - 2 of the 3.9 ohm resistors in series makes 7.8 ohms which is close enough to 8 ohms for our purposes.

I'll report back on how my friend likes the results.

 

Trying the silent life for a bit. Since I like to overcomplicate things I made a box for my resistor. Here's the files so you can make your own. Printables

 

@planetarian, thanks for sharing this. After I read this thread, I could not unhear the ufo sound lol It is loud and I remember doing a similar mod to my F150 hybrid as well.

I ordered the Toyota 90980-11162 harness and 8.2 ohm / 2W resistors to tackle this project (amazon didn't have 3W readily available). 90980-11162 is the male that plugs into speaker and it turns out we need the female that plugs into engine side wire. Instead of chasing that part number and waiting, I just cut the tip off the factory harness and soldered the resistor in and removed the speaker altogether from the car.

FYI - I had to disconnect battery terminal for the error on dash to go away as it stayed on even after soldering in the resistor.

No more UFO sound and pedestrians will never hear me coming (we have had a Tesla for 3 years and never have we felt the need to have a UFO sound to increase safety).

 

Decided while driving today I need to do this mod. Toyota shouldn't have made it sound like sheet metal being dragged in the sand with an audio filter.

I was also slowing down to stop at a crosswalk when I saw a pedestrian become alerted by the sound, who then started looking around in a confused manner like they were trying to find a car backing up.

Is it at least possible to stop the sound while driving forward, keeping the reverse one?

 

Actually nevermind. I read through this thread and realized the speaker has other uses beside the ufo sound

 

I would just like to add a resistor to the entire circuit to attenuate some of the UFO sounds, and I can manually turn up the door chimes because I don’t mind them.

Has anyone done this and have any photos, and what resistors you used?

Thanks

 

...and think of the downsides!

j/k

Someone must make a reflash that plays the sound of a lopey v8 or the clippity-clop of horse hooves.

 

why we can not just do these setting in the Toyota Techstream software? I have an techstream and I can see every single sensors in the car, but customize options are very limited. Why we can't just tune the car and put some software and play with these setting on our responsibility.

 

The sound is a safety feature required by law.
If Toyota, or any company made a tool to allow you to defeat it, they open themselves up to liability.

 

But it would be good to modify the car maybe overclock it

 

Sorry, just wanted to ask, what are the two white things that the OP used on both sides of the resistor? Are they heat-shrink tubes, too?

Also, has anyone met any issues with this setup?

 

Just wanted to post an update from my friend who used an L Pad circuit to cut the volume in half. It's been working great and seems to be a good middle ground. It's still loud enough to be easily heard outside, but minimally audible while inside the car.

 

Curious where you ended up on this. I mainly want to silence the forward drive sound and leave everything else intact.

 

On a Gen 4, I simply put a paper clip inside the engine-side harness connector (I’m guessing it closed the circuit? I don’t know electrical terminology at all.) anyway, it worked. Would that same solution work on Gen 5?

 

How about a rheostat on the dash to control the volume.