Horn replacement: IASOD Reports

[Gruber]

Some important questions.

When was the lASOD founded? Where is it located? How many employees? Is it accredited by the lCHWA (International Car Horn Wiring Association)?

Thanks for your assistance on this matter.

The IASOD is a world class research facitlity located not far from one of the US DOE National Laboratories. Its founding in spring 2018 was precipitated by early reports of the oil dilution phenomenon interfering with Earthly Dreams.

The early work focused on novel dipstick handling techniques, modern dipstick metrology, and precise dipstick science. The IASOD collaborates closely with the Oil Dilution Anxiety Section of the American Psychiatric Society and is a member of the World Federation of National and Regional Engine Oil Discussion Associations.

As a leader in free exploration at the leading/bleeding edge of original science and discovery, the IASOD is not overly concerned with engineering or commercial accreditations and certifications.

Human resources issues at the IASOD are not publicly discussed.

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[shoegazer]

One variable, if I may, is the difference in actual sound pressure measurements vs. how loud it *seems* to our ears. Honda's meeper isn't that impressive to me. But the frequency seems to be closer to the magical 1KHz where our ears are most sensitive.

The meeper certainly doesn't command respect or adequately express the rage that we'd like during those situations when we may use it. But it might actually "cut through" and *appear* louder to our ears at a lower volume than the Blasters.

My next step will be to find a place in the engine compartment for my PIAA's to live. I feel like they are muffled in their current location.

Not trying to steer off topic of anything. Carry on.

 

[gtman]

The IASOD is a world class research facitlity located not far from one of the US DOE National Laboratories. Its founding in spring 2018 was precipitated by early reports of the oil dilution phenomenon interfering with Earthly Dreams.

The early work focused on novel dipstick handling techniques, modern dipstick metrology, and precise dipstick science. The IASOD collaborates closely with the Oil Dilution Anxiety Section of the American Psychiatric Society and is a member of the World Federation of National and Regional Engine Oil Discussion Associations.

As a leader in free exploration at the leading/bleeding edge of original science and discovery, the IASOD is not overly concerned with engineering or commercial accreditations and certifications.

Human resources issues at the IASOD are not publicly discussed.

Good to know just surprised it isn't ICHWA certified.

 

[Gruber]

Good to know just surprised it isn't ICHWA certified.

You mentioning it again.... made me rethink this situation. It occurred to me that many people may speculate as to exactly why the IASOD is not ICHWA certified, and naturally subscribe to conspiracy theories.
We just felt that ICHWA certification would impose strict limitations on our brilliant ideas and straightjacket free unbriddled scientific inquiry that we hold so dear and cherish here at IASOD.

Anyone who believes in Amsoil will understand....

" Full API licensing, or certification, would impose strict phosphorous limitations on AMSOIL motor oils. This limitation is the main reason most AMSOIL motor oils are not API licensed. "

 

[Gruber]

Here is the next part of the IASOD Report. This is mostly about loudness.

This is the sound of my twin (Wolo low, FIAMM high snails) horn powered by my slightly discharged battery. Of course a telephone recording won't tell you anything about the loudness, just the approximate tone, but it's much louder and slightly better tone when the car is running.

[First a digression on the OEM battery:
In the video the voltmeter is connected across the battery, which apparently shows some signs of aging. The voltage was only about 12.10 V (this particular CEN-TECH voltmeter (Harbor Freight) shows about 0.09 V too high voltage, according to IASOD testing). The open battery voltage drops to some 12.3 -12.4 V after just a couple days of sitting in the garage. It still doesn't show any apparent problems and starts the car fine, but seems to be not so fresh after about 3 years out of the factory (33 months since bought). Btw. FIAMM started as a manufacturer of automotive batteries. ]

So the principal problem with car horns is that according to the pseudoscience of psychoacoustics, to increase the perceived loudness of a sound by the factor of 2 (to make it sound "twice as loud") the sound level needs to increase by 10 dB, and this means the acoustic power needs to increase by a factor of 10. Of course, the acoustic power depends on electric power, so assuming about the same efficiency of good electric horns, the current needs to increase by a factor of 10x too. What this all means is that to replace the civic's 3.5 A nominal horn with a horn that's twice as loud, we would need a 35 A nominal horn. That's a lot of juice and 420 W of nominal power just for the stupid horn.

How much power would then an electric horn require that could continuously make the train horn noise level (150 dB for 5 s, as advertised for air horns, powered from a compressed air accumulator)? Well, that's 40 dB more than the civic OEM horn, so the perceived sound would be 16 times the OEM "meep-meep" horn. But the power needed for a 150 dB version of it would be 10,000 times more. 35,000 A....... That's 4.2 MW, the nominal power of a big windmill turbine.....




Or, instaed of one gigantic 150 dB electric horn, ten thousand OEM horns would need to be installed in the car for a sound as loud as this kind of train horn..... Btw. this kind of windmill turbine, which can power ten thousand civic OEM horns, according to its specs produces 106 db sound level continuously when operating. Talk about noise polution. That's almost as loud as my FIAMM horn (rated 107 dB @ 2 m)

Sounds like BS? Well, that's because the 150 dB number is obviously BS. Maybe from a foot distance. Not comparable at all with the 110 dB f@ 2 m for the "meep-meep" horn. So again, take the advertised dB numbers (and maybe some of the psychoacoustics too) with a tablespoon of kosher salt.

This also means that if you think you found a electric horn that makes about 120 dB according to advertising, but it is not rated at almost 40 A, that's not true, because that's roughly what would be required to make 10 dB more and be roughly twice as loud as a regular horn. The electric car horns offered by various leading manufacturers seem to have similar efficiencies. Reputable manufacturers don't make bad horns that take a lot of power and produce little sound. The sound efficiencies of electric horns of similar size are similar, and can't be easily improved. At least this is the expert opinion of the IASOD.

So again, increasing the sound level by 10 dB means only twice the "loudness" feeling, 3.16 (square root of 10) larger air pressure wave amplitude that hits the ears, and 10 times the power.

Increasing the sound level by 3 dB means only 1.23 times more loudness, 1.41 times the air pressure amplitude, and twice the power. So, you can only expect the horn to sound "23 % louder" by doubling the amperage or adding another horn.

But is this all true? In a sense only. What does it mean that one sound is twice as loud than another sound? In the rigorous sense, it means nothing. The only way to determine this is to ask people how they feel. It's easy to define what it means to seem twice as long, or twice as heavy. But "twice as hot" or "twice as loud" means nothing. Different people will have different opinions. In addition, it seems like this theory was developed using much quieter sounds, and it holds better for very quiet sounds. For very loud sounds, I have impression that people will increasingly hear more the "power" of a sound than its "loudness." A least, such is the opinion of the IASOD.

The bottom line is that you will not find on the market a car electric horn that's "twice as loud" as the OEM. Two horns vs. one will also increase the loudness just by a factor of about 1.23. You would need 10 horns to get twice as loud sound. But still, the tone is another part of "psychoacoustics." I'm very happy with my new twin horns, regardless of dB and how they should feel, they sound much more awesome than the single OEM.

 

[Deleted member 40923]

Indeed, so much fun for so little money . It's not like installing a bigger turbo....

So here are some fresh new hard experimental data, just completed late today. (I guess it's now yesterday.)

Experimental: Of course I was going to eventually measure the current my two horns are drawing. But it's not easy to stick the probes in the tiny fuse socket, and all my nicer multimeters only go to 10 A and they are fused, so if I had 11 A as I thought, I could blow the multimeter fuse. (This is one of those cases when putting in a bigger fuse would not be a good idea....). I didn't want to fiddle with jaw current measurements either. So I found this cheap big multimeter from HF, which measures to 20 A, not fused.

I also don't want to radicalize the IASOD neighbors with too much loud honking, and I work alone (my research assistant was unavailable) so it had to be reliable and quick, no hands (except on the steering wheel air bag).

So I used one of these piggyback fuse conectors I bought earlier to power dash cameras etc. interior devices from the under dashboard fuse box. It wouldn't fit in the tight space around the horn fuse socket, so I also had to hack it a little with a Dremel.

Here is my honkin' current measurement setup:

My first estimate was 11 A based on the Wolo specs, and the FIAMM specs from the box. Then it turned out FIAMM is really 4.5 A, so it would be now 9.5 A.

Results:
And the survey says....

From the battery, engine off, I measured 6.96 A honking current.
From the alternator while idling, I measured 7.55 A honking current.

The sound level at 165 cm (5 ft 5") from the front badge was
100.2 dB from the battery and 104.0 dB from the alternator.

It also sounded much louder by ear, and the same result was obtained on a couple of tests.

The increase of the sound level was more than expected from this modest increase of electric power estimated as 25%. The reason for this has not been established yet. The working hypothesis is that the efficiency of the horn(s) (the ratio of the sound power output to the electric power input) is not constant but increases quite quickly with increasing voltage.

Conclusions:
1. two nominally 6 A (in the US) or 4.5 A (elsewhere) FIAMM horns will not blow the 10 A fuse. The 5 A Wolo also must be drawing significantly less current than nominal. Even taking into account possible variations between copies, and aging, it seems unlikely they would ever reach 10 A.

2. If replacing the OEM civic horn(s) I strongly recommend installing two. While it's easier to just install one, the effect is much much better with two-tone horns, and no circuit modifications are necessary for the typical electric horns available on the market.

As per your conclusion, I've ordered a PIAA dual horn (400/500Hz). Do you have instructions on how to get the two horns working where there was only one before?

 

[Gruber]

As per your conclusion, I've ordered a PIAA dual horn (400/500Hz). Do you have instructions on how to get the two horns working where there was only one before?

These PIAA horns are specified at 2.7 A (unless they are some other PIAA horns that I haven't seen). Probably also a bit smaller size than some other snail type horns, which could make installation just a tad easier.

There are two bolts inside the HB civic fake vent cavity for supporting horns. The lower one has the OEM horn attached, and the upper one is free. The upper bolt holds the plastic support box thing to which the lower bolt is attached. The upper bolt goes into a thread in the aluminum bumper bar structure; the lower bolt has a nut. So the upper one is connected to the chassis and the negative electrode of the battery; the lower one is attached to plastic and so it's insulated. The horns that I used have their mounting screw insulated from horn terminals, so they need two wires. If you use a horn that has the mounting screw connected, you have to take it into account.

So I decided to not touch the lower bolt because its nut was a bit hard to access. I don't know if that nut is free or attached to the plastic support. Instead, I reused the OEM horn support and unscrewed only the horn nut. This may be not advisable, if you want to reuse the OEM horn. At least theoretically, you should not remove this horn's dedicated support. It's tightened quite hard, with a barbed locking nut. But it's easily accessible and can be undone no problem.

So after removing the OEM horn, I attached the Wolo low tone to the upper screw, using the Wolo's own support. This Wolo support is made of two separate very thin parts that are supposed to be stacked together. It's still pretty flimsy and bends easily. I attached the Wolo facing almost straight down, with the suport bent toward the rear of the car. Later I noticed it almost touched the intercooler inlet tube. So I made a small cutout on the edge of the plastic snail mouth to prevent any rubbing... I probably could have positioned it better to avoid touching, but I had already installed the high tone horn, and didn't want to undo it.

The high tone FIAMM directly replaced the OEM horn on the lower bolt with the existing OEM horn support. The FIAMM also had its own support, very thick and rigid (more so than the OEM support). I didn't use it. The FIAMM was installed also with the mouth facing almost straight down.

I made two leads for the second horn using female quick-connect spade connectors, with piggyback male connectors on one end. I used 18 AWG silicone insulated wire, maybe 10 inch long each. I crimped the connectors and also soldered the very tips of the wire for good measure. The wires connect the two horns in parallel, then the female connectors of the College-Hills Honda horn harness adapter are connected to the piggybacks on one horn. And that's all.

 

[Yoda]

After setting off the alarm on my Civic I realized it is a meep-meep horn. Only my Honda Fit sounded more pathetic. The cure for the Fit was to get a later model pair Honda horns, either Element or Odyssey from the local salvage yard. Take the wiring too, they won't you charge extra. It is possible to take the connector and terminals apart to add in the wires for the second horn.

I was considering some 1970's Delco trumpet horns I have laying around, but they drew 10 amps each!

 

[bcrichster]

After setting off the alarm on my Civic I realized it is a meep-meep horn. Only my Honda Fit sounded more pathetic. The cure for the Fit was to get a later model pair Honda horns, either Element or Odyssey from the local salvage yard. Take the wiring too, they won't you charge extra. It is possible to take the connector and terminals apart to add in the wires for the second horn.

I was considering some 1970's Delco trumpet horns I have laying around, but they drew 10 amps each!

Oof.. 12awg wire would be needed for them, then (FYI)

 

[Gruber]

Another experimental data point from IASOD:

Compared the horn loudness of my CR-V with my new civic horns. The 2009 CR-V has exactly the same Mitsuba low-tone 370 Hz (F4 flat/G4 sharp note) horn as the 2018 HB: UCL-202. But it also has its high-tone 440 Hz (A4 note) brother: UCH-201.

The CR-V's horns are placed symmetrically on each side of the H logo, significantly higher than in the civic and are visible through the grille. It seems like the sound will be coming forward quite unobstructed compared to the civic.

The test was done in an open garage with the cars side by side, not running. The voltage on each battery was 12.4 V.* For this quick test the sound meter was placed on the floor in the middle between the rear wheels of the cars. The meter was turned off and on after the first measurement.

Remarkably, the readings were identical! 100.9 dB in each case.

When standing outside the car and pressing the air bag, the CR-V horns sounded more buzzy and a bit more loud (annoying). The civic sounded more Trump-ety (presidential). The fact that the meter was on the floor might have been an advantage for the civic, because its horns almost face the floor.

* Footnotes: while the open voltages on both batteries were almost identical, my CR-V's battery is almost new, while my civic has its original 3-years-old battery, which may be producing a larger voltage drop under load. This might have given an advantage to the CR-V.

At this point, the funding for this project has been practically exhausted.

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