Creating custom sirens for GTA 5 can be tedious, but with the right workflow, you can get perfectly looping, loud, and high-quality tones in-game. This guide covers everything from sourcing the audio to editing loops, maximizing volume, importing via OpenIV, and making it work for FiveM. Prerequisites & Golden Rules Tools Required: Audacity (for audio editing) OpenIV (for GTA 5 archive modding) ArchiveFix (only required if you are porting this to FiveM) Golden Rule: Always create backups of your game files and strictly use the mods folder in OpenIV. Make sure Edit Mode is clicked ON in OpenIV before starting. Organization: Create a dedicated project folder on your PC. Keep your original downloaded videos/audio separated from your edited files and final game-ready exports. Phase 1: Sourcing the Perfect Audio The foundation of a great siren is a clean source file. Find Clean Audio: Search YouTube (or other sources) for clips of the siren you want. Look for videos with the absolute minimum amount of background noise. Avoid the Doppler Effect: Find a clip where the emergency vehicle is stationary or moving very slowly. The Doppler effect alters both the pitch and speed of the sound as the vehicle passes, which is incredibly difficult to fix later. Download: Use an audio downloader website (like NoTube) to rip the audio from the video. Phase 2: Audacity - Creating the Perfect LoopThis is the most meticulous part of the process. You want the siren to loop seamlessly without any clicking or popping. Isolate the Tone: Right click on your downloaded sound and open with Audacity, go to Mix>Resample>Mix Stereo Down to Mono. Find the cleanest single cycle of the siren. Trim the Fat: Click and drag to highlight the section you want to keep. Copy, click on an empty area down and paste it there and delete the old one by selecting and pressing Backspace. The Zero-Crossing Method (Fixing Pops): If the start and end of your audio clip don't align perfectly, you will hear a "pop" every time it loops. Zoom all the way into the audio track usingCtrl + Mouse Wheel until you can see the individual dots on the waveform line. Let Audacity do the hard work for you: Highlight your clip and press Z on your keyboard (or go to Select > At Zero Crossings). This snaps your selection edges perfectly to the horizontal center line (zero amplitude). Test the Loop: Use Shift + Space to play the selection in a continuous loop. Save Your Project: Go to File > Save Project > Save Project. The hardest part is done, lock in this progress before altering the volume. Phase 3: Audacity - The "Flat Volume" Method To ensure your siren sounds consistently loud and powerful in-game without volume fluctuations, flatten its dynamic range. 1. Compression and Limiting Highlight your audio, then navigate to Effect > Volume and Compression > Compressor Threshold: -20 dB to -25 dB Make Up Target: 0 dB Knee Width: 0 dB Ratio: 10.1 Lookahead: 1.0 ms Attack/Release: 0.1 ms 2. Forced Amplification (Optional) If it still needs more punch, force it right to the edge of clipping: Go to Effect > Volume and Compression > Amplify... Check the box for "Allow clipping" and increase the New Peak Amplitude by a few dB. 3. Export the File: When you are done, go to File > Export Audio... * Format: WAV (Microsoft) Encoding: Signed 16-bit PCM 32000hz Name the file exactly as the siren you intend to replace (look into the box at the end of this guide to see the siren names). Phase 4: OpenIV - Injecting the Audio (vehicles.awc) Now you need to get your new .wav file into the game's audio archive. Locate the File: In OpenIV, navigate to mods/x64/audio/sfx/RESIDENT.rpf. Export to openFormats: Scroll down to find vehicles.awc. Right-click on it and select Export to openFormats (.oac). Choose a location on your desktop. Replace the Audio: Go to your desktop. You will now see a file named vehicles.oac and a folder paired with it named vehicles. Open that vehicles folder. Find the original siren .wav file, delete it, and drag in your new custom .wav file (ensure it has the exact same name as the one you deleted). Import Back to OpenIV: Go back to OpenIV. Either Right-click in empty space and select Import openFormats, or simply drag and drop the vehicles.oac file directly into the OpenIV window. It will automatically recompile the .awc file with your new siren inside. Tip: Keep your loops short! GTA 5 has a strict file size limit for the vehicles.awc archive. If you exceed it, your game will crash or audio will mute. If you need to save space, download "dead air" (silent) audio files to replace obscure, unused vehicle sounds in the archive. Phase 5: FiveM Specific Step (ArchiveFix)If you are only playing Single Player LCPDFR, skip this step. FiveM requires custom .rpf files to be encrypted properly, otherwise the server will crash or reject the files. After you have successfully imported your .oac back into OpenIV, close OpenIV. Locate the physical RESIDENT.rpf file on your computer (the one you just modified inside your mods/x64/audio/sfx/ folder). Drag and drop the entire RESIDENT.rpf file directly onto your ArchiveFix.exe application. A command prompt window will briefly pop up to confirm it has been encrypted/fixed. Your file is now ready to be streamed to your FiveM server. [TheHC09] ELS Siren Strings Reference After extensive research, I have finally found the siren strings for ELS, and all but two siren tones are now working in-game! They seem to correspond to the OpenIV assigned names, but they have the beginning part of the string added. These were all found by me personally through research and experimenting, so you're welcome (also would appreciate this being a pinned topic for others to find). From what I gather, the string is basically referring to the location of the siren file in the game's archive ('RESIDENT' being the RESIDENT.rpf and 'VEHICLES' being vehicles.awc, followed by the siren name). LSPD Main Police Siren: "VEHICLES_HORNS_SIREN_1" - Police Primary (Note: "RESIDENT_VEHICLES_SIREN_PA20A_WAIL" doesn't work for some reason) "VEHICLES_HORNS_SIREN_2" - Police Secondary (Note: "RESIDENT_VEHICLES_SIREN_2" doesn't work for some reason) Firetruck Siren: "RESIDENT_VEHICLES_SIREN_FIRETRUCK_WAIL_01" - Firetruck Primary "RESIDENT_VEHICLES_SIREN_FIRETRUCK_QUICK_01" - Firetruck Secondary Police Bike Siren: "RESIDENT_VEHICLES_SIREN_WAIL_03" - Police Bike Primary "RESIDENT_VEHICLES_SIREN_QUICK_03" - Police Bike Secondary FIB Siren: "RESIDENT_VEHICLES_SIREN_WAIL_02" - FIB Primary "RESIDENT_VEHICLES_SIREN_QUICK_02" - FIB Secondary Ambulance Siren: "RESIDENT_VEHICLES_SIREN_WAIL_01" - Ambulance Primary "RESIDENT_VEHICLES_SIREN_QUICK_01" - Ambulance Secondary Siren Warning/Priority Tones: "VEHICLES_HORNS_POLICE_WARNING" - Police Warning (Note: "RESIDENT_VEHICLES_POLICE_WARNING" doesn't work) "VEHICLES_HORNS_AMBULANCE_WARNING" - Ambulance Warning (Note: "RESIDENT_VEHICLES_AMBULANCE_WARNING" doesn't work) Siren Horns: "SIRENS_AIRHORN" - Airhorn (Note: "RESIDENT_VEHICLES_AIRHORN_EQD" doesn't work) "VEHICLES_HORNS_FIRETRUCK_WARNING" - Firetruck Horn (Note: "RESIDENT_VEHICLES_FIRE_TRUCK_HORN" doesn't work) [TastyFlavour] Update: Sheriff (Granger) Sirens FixWhile the standard Granger strings (RESIDENT_VEHICLES_SIREN_WAIL_04 and QUICK_04) do not work for some reason, I have found the Granger Sirens that DO work correctly with ELS: Granger Wail: sirens_slow_dir4 Granger Yelp: fast_9oghrv1 [Nazdravi412] Siren file names Airhorn AIRHORN_EQD - Generic Bullhorn Police Bike SIREN_WAIL_03 - PoliceB Main SIREN_QUICK_03 - PoliceB Secondary FIB SIREN_WAIL_02 - FIB Primary SIREN_QUICK_02 - FIB Secondary Police SIREN_PA20A_WAIL - Police Primary SIREN_2 - Police Secondary POLICE_WARNING - Police Warning Sheriff Granger SIREN_WAIL_03 - Sheriff Granger Primary SIREN_QUICK_03 - Sheriff Granger Secondary Ambulance SIREN_WAIL_01 - Ambulance Primary SIREN_QUICK_01 - Ambulance Secondary AMBULANCE_WARNING - Ambulance Warning Fire Trucks FIRE_TRUCK_HORN - Fire Horn SIREN_FIRETRUCK_WAIL_01 - Fire Primary SIREN_FIRETRUCK_QUICK_01 - Fire Secondary