WOW, that looks great. I'm in the same boat re. removal of bumper, etc. I believe you could make those and sell them. Wanna come to VA and help me do mine. Got some good bourbon on hand that will help.

 

That sir is tempting! That said, pour a glass and build your own. It's really easy and I'd be happy to add clarification to help.

 

I forgot to mention, nice write up and great pics to go along w/.

 

Nice! I imagine so many people would want to do this, the first thing me an guys at work thought when we heard the new horn was like the noise Side Show Bob made when he stood on all those rakes!

As for the noise, it sounds like the throat cancer guy who calls out the score after a darts player takes his turn! It's contagious and makes you want to clear your throat each time lol ("Ahem Ahem Ahem... let me clear my... horn?) 🤣

 

stop messing about and fit some proper horns Chrome & Stainless Accessories :: Air & Electrical Horns :: ELECTRIC DUAL TRUMPET HORN 12V 460MM

 

stop messing about and fit some proper horns Chrome & Stainless Accessories :: Air & Electrical Horns :: ELECTRIC DUAL TRUMPET HORN 12V 460MM

Great Idea! Why don't you install them and document the process to share with all of us.

 

this is brilliant, thank you for all your efforts in posting this. I am going to do a very similar thing, but I think I can slide the assembly in where the old horns are and get at the bolts thru the grill. I took the front bumper off on my 2017 Outback, but I really didn't want to do that again on the new Onyx. I had never seen those fuse taps, that's very cool. I think one relay will be plenty (though they are cheap enough maybe I'll use 2 like you did). Thank you!

 

Thanks. One relay would be fine and even simplify things. These horns only draw something like 3.5A each and the relay is rated at 30A. I used two mainly because my initial design had two independent circuits feeding the two horns. It wasn't until the initial install that I realized that there just wasn't room to put the two fuse taps back to back into the box (due to the orientation and location of the two horn fuses ). It was at that point, I just tied the two switch wires together into the one tap (vs rewire everything). Keep us posted if you are able to get at those factory horns!

 

Update: I'm building a simplified (one relay) assembly for my son's new Crosstrek Sport now. It seems that vehicle has just as an anemic horn as the Outback. I'll post an update when done.
Update: I prebuilt the Horn bar to similar pecs as the one posted above but with a single relay. It dropped right into the 2021 Crosstreck Sport that it was intended for. BIG improvement in horn levels on that vehicle too!

 

Just curious, what's the point of bothering with relays at all? There are two 7.5A fuses for the horns in the 6th Gen Outback, that should be enough to handle the draw of the new horns. I've swapped horns in two vehicles (including adding similar Hellas in a '14 Mazda3, which was replacing a single horn with two) and didn't touch a thing. I'd do the same here.

 

That may/may not be possible in this case. The new horns are only rated at something like 4.5 A draw so that may be possible IF you tapped the circuit for both horns at the box. I was unable to do that due to the design of the fuse taps and real-estate around those two adjacent 7.5A horn fuses. ( I just couldn't find two taps that could be put in side by side.). The relay is cheap and adds a level of safety in adding new loads to existing factory wiring.

 

Like many here, I think the factory horns in my new Outback are anemic at best. Comical at worst. Unlike some here, I refused to tear off the entire front of the car to get at those factory horns to replace them. Some would argue that taking the entire nose off is easy but in engineering terms, this is what I would rate to be a moderate probability, high consequence process for the DIY owner. In short, it just imposed too much risk for my constitution.

If you're going thru all of that, why not use something like Steibel's air horn? Or similar 'motorcycle' air horns?

 

I'm not sure what "all that" is. I just built a second system today. It took about an hour. Easy enough. Real estate under the hood is at a premium on my XT so when I was designing the system. I looked for smaller sized horns that would give me flexibility in mounting locations. ( These will even fit in the air duct intact path in the grill if I chose too.) I'm sure there are other horns that would work (including motorcycle horns) but I felt these Hellas were a safe bet. I'm happy with them and see no need to chase anything further. I'd be interested to see posts from others that do try different horns though.

 

Like many here, I think the factory horns in my new Outback are anemic at best. Comical at worst. Unlike some here, I refused to tear off the entire front of the car to get at those factory horns to replace them. Some would argue that taking the entire nose off is easy but in engineering terms, this is what I would rate to be a moderate probability, high consequence process for the DIY owner. In short, it just imposed too much risk for my constitution.

So while I’m sure there are allot of other approach’s that could be tried, I poked around at different ideas until I down selected to this solution. I.e. Which was to build a horn bar assembly that could be mounted in the engine compartment with minimal wire runs/mods. I’ve installed horns in the engine compartments of past cars and results were good. I figured this one would be no different.

Design Details:

- 2 horns, 2 relays, wiring and mounting bracket attaches to the car as a single compact assembly via the battery hold down bolt in the engine compartment.

- No disassembly or alteration of the vehicle is required .

-Installation is 100% reversible in 10 min.

- Both new horns are switched from factory fuse location but powered and grounded directly to the battery for max sound output.

-Leaves factory horns in place and operational to create a functioning 4 horn set

Materials list:

8” of 1x1x1/16” Aluminum Angle stock

(2) , 6mm nuts

(1), 8mm nut

(4), ¼-20 x1/2” bolts with nuts and lock washers

6-10’ , 14 ga wire

(4)Butt ,(2) ring and (4)spade connectors,

(3) fuses (1 5amp Mini, 2, 7.5 amp Standard)

heat shrink tubing/electrical tape

Hella Disk Horn set (hi lo) Amazon.com: HELLA 011225802 Black 77mm 12V BX Disc Horn Kit (Universal Fit) : Everything Else

Low Profile mini fuse taps (1) https://www.amazon.com/gp/product/B082GFVCQ1/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1

Fused Horn Relay (2) Amazon.com: ONLINE LED STORE 6 Pack 4-Pin 12V Bosch Style Fused Relay Switch Kit [Interlocking Harness Socket Holder] [14 AWG Hot Wires] [SPST] [30 Amp] 12 Volt Automotive relays with Fuse for Auto Cars: Automotive

Tools needed:

Drill with ¼” bit

Lighter/heat gun

10mm wrench

13mm wrench

(2) 7/16” wrench’s

Wire stripping/crimping tool

Process:

Basically, I did some test fitting and measuring out wire lengths until I had a prototype design that fit into the space selected.. Then I assembled wire harness’s to drive each horn per general wiring schematics given with the relays. . The fuse/switch wire is 28” and is connected to both (white wires of the )relays, the battery power wire is 18” and is connected to both (red wires of the )relays, the negative wire is 18” (with a 4” pigtail from relay to horn via spade connector)

The 1x1 angle stock was drilled with a ¼” hole centered along the length across it’s top surface and 4 holes across it’s face ( about 1” from each end and 2” apart) to mount the horns and relays. Then the ¼” bolts were used to mount the horns and relays to the face of the bar (with terminals facing each other) Once assembled with the wiring harness, the assembly was slid down over to the battery hold down bolt and secured via a 6mm nut and lock washer. Wire connections ( external to the assembly) were limited to: a) the Positive battery terminal, b) Negative battery terminal ( using 6mm nuts) and c) the horn fuse circuit in the under hood fuse box via a fuse tap. Note: My original design was a bit of overkill with two completely independent harnesses but I found out there is only room for one fuse tap in the box due to the location of those fuses. Using a single wire run for each of these three connections does nothing to hurt the operation or reliability of the system.



Relay wiring:

Black – Ground at battery. Connect BLK wire to a tab on Horn with spade connector , then continue with 18” total Length from horn to battery, (2 wires coming out of the spade connector.)
White - positive trigger source. Connect to Horn Fuse circuit in under hood fuse box via Fuse Tap. Single wire of 28” total length from relay to tap. ( Both relays run off one wire tap at box.)
Red - Positive post of the battery- 18” total length from relays to Ring terminal at battery. Single wire between both relays and battery.
Blue – Connect BLU pigtail to Horn input via spade connector
Summary: Black, Red and white wires are combined from each of the 2 relays and "T"'d to a single wire going to Ground, Power and Fusebox respectively. (See diagram below)



Results:

I’m pretty happy with the outcome. For $50+/- and a couple of hours of experimentation/ fabrication, I now have a respectable horn set (totaling 4 horns) in my Outback. The assembly was easy to build, easy to install , is protected from the weather and resonates loudly in the engine compartment. It even disappears pretty well after application of some paint and tape . How loud is it? I have not done DB level measurements (yet) but I’d say that the horn set is at least 25-30% louder. Overall tone is deeper/raspier as well. ( No more "Meep-Meep" clown car tone) In short, I’m content and no longer embarrassed to lean on the horn!

Anyway, here are some pics taken along the way. Hope this helps someone here.
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I used these instructions and followed the build. I used PIAA horns in the 400 Hz and 350 Hz, and it took just over an hour from start to finish. I love the added bass sound to the factory horns treble. And it's loud without being obnoxious. Thanks for sharing your project details!

 

Heh, yeah, for a while I had swapped in supertones (~5A each, and without adding relay power) and they're most definitely louder than stock - if they're not, then something is wrong.

 

Just put in Piaa 85115 Superior Bass Horn set. Pulled the bumper using detailed instructions https://techinfo.subaru.com/stis/do...ack Front Bumper Under Guard Instructions.pdf It was an easier job than I expected. Removed OEM horns, connected horns with existing connectors and used PIAA provided ground wires. A definite improvement to sound level and quality. I'd have to say this project was even easier than doing speaker upgrades!

 

i wonder if maybe i have a defective set of sharptones. Hopefully someone else can chime in that has tried the same install successfully. As far as i know, i haven't seen any other report of success, or even attempt, with Sharptones with stock wiring.

 

i wonder if maybe i have a defective set of sharptones. Hopefully someone else can chime in that has tried the same install successfully. As far as i know, i haven't seen any other report of success, or even attempt, with Sharptones with stock wiring.

I’ll let you know. I’m hopefully going to get to my Sharptone install yet today.

I am also going to do some before and after testing.


Sent from my iPad using Tapatalk

 

Last week, my wife happened to complain about the new Hella Supertone horns being too quiet. I hit the button and found only the high tone was working.

Since I needed to open everything up again, I purchased enough items to experiment using the Hella-supplied relay: an inline fuse holder that was wired to the battery, and a fuse tap (aka add-a-circuit) for the fuse box so I could use the existing signal wiring to pull in the relay. I then ran a new signal wire from the relay to the horns, and ran a the final wire from the relay to a ground screw on the driver's side shock tower. All new wiring was 16 ga.

Using my wife's old iPhone and the NIOSH app, I held it in relatively the same location and took readings with several hookups. First, I fixed the low-tone's signal wire so it was working, and made new ground pigtails for each horn that used larger ring terminals to go between the top of the mounting bar and the mounting screw. I also threw the stock ones back on for a reading. Here's what I found:

Stock horns: 93.3 dB
Original Hella setup: 98.1 dB
New ground pigtails: 97.8 dB
With relay: 97.2 dB

I suspect the Hella readings dipped down as the battery voltage dropped slightly. But as I'd originally assumed, the stock wiring works well to power the horns; it uses its own relay which feeds two adequately-sized 7.5A fuses and 18 ga wire. It's simply not worth the effort of rewiring everything.

However, I do recommend replacing the inboard horn's connector (left side using standard automotive orientation, right side one as you're looking at them from the front). It fits fine on the stock horn, but just doesn't stay in place well enough on a normal quick connect terminal. I cut that one off and crimped on a standard insulated female quick connect plug. The outboard connector positively clicks in place and is fine.

All of that said, I'm not sure why the readings are low, for myself and others on here...they're definitely louder than stock, but not by much really. Bad batch of horns maybe? For S&G, I measured our Mazda3 last week and hit 114 dB no problem, using the same Hella Supertones on its stock wiring. We're getting ready to head out on a trip soon so I've no time to swap them out again, but I'm tempted to contact Hella to see what they think.

 

Nice job. You did not need any relays or the fuse tap. The factory horns are relay driven. You will not come close to drawing too much current even with 4 horns. Tap into existing horn wire. Thats what I did.

 

You think Subaru changed the horns and wiring from Gen5 to Gen6?

 

100% they didnt change the horns. Everything else, between two different generations...maybe?

from more and more experience that people are sharing, it seems likely that there may be some bad sharptones horns out there and/or there may be a benefit with a separate wiring harness. I'm still hoping to see the results from some of the folks from the earlier posts.

 

Here's my implementation of RocketMan's design. I cut 3/4" off an 8" angle stock bought on eBay to add clearance at the right (facing the car with the bracket installed) corner where there's a tab for the hood latch cable. The mounting hole is 5" from the left end. This way the left end sits against the corner of the battery (battery jacket, to be exact) and keeps the assembly from rotating. Relative to the bracket mounting hole, the holes for the horns are centered 3" to the left and 1 7/8" to the right. Relative to the long edge, all three holes are centered at 3/8" distance. The blue tape covers a redundant hole drilled in the process.
Added: in the end, the mounting holes for the horns were drilled 5/16" as the horn brackets are designed to be held with 8 mm bolts. The hole for the battery tie-down rod is still 1/4" and in my version, the relay bracket also sits on the rod, sandwiched on top of the aluminum angle and its holding nut, held with another nut.

 

Great writeup! Saved me from removing my bumper/grill after my low-tone horn died. Found I had to move the center mounting hole an inch to the right (facing car) so new horns (Hella Supertones) would fit behind the washer fluid fill. I also used a premade horn wiring harness kit (~ $11 on Amazon) to save time

 

Thanks so much for the Master Class on an excellent option to address the deficient stock horn. Would be great if you could post an audio file that samples the actual sound of the installed horns

 

Sharptones sound very much like the stock horns, just louder, sort of a harsh meep-meep. I didn't care for them and ultimately swapped them with PIAA sports which I much prefer - they give a smooth honk, very different from stock.