Most people coming into vocal production for pop girl groups have never dealt with a setup where five distinct vocalists share a single arrangement space. Fifth Harmony's recordings are a case study in that kind of complexity. You have three lead voices cycling through verses, two or three doing harmonies on the chorus, and then ad-libs layered on top that sometimes clash. It's not glamorous when you're trying to remix or re-verb them individually.
I used to work at a small commercial studio in Orlando around 2015, right when "Worth It" was blowing up. We got a lot of requests to do remix versions of their tracks. The problem was that the label stems were far from clean. The double-tracked lead vocals, the gang vocals in the final chorus — everything was glued together with automation and saturation that made splitting them nearly impossible without serious artifacting.
Isolating Voices in Fifth Harmony Backing Tracks
The straightforward approach doesn't work here. You can't just route a stem through an iZotope RX module and expect Alchemy Seal to pull out Camila's vocal cleanly while leaving Ally's harmony underneath. What actually works is a multi-stage process.
First, run the stem through a vocal isolation tool like Ultimate Vocal Remover (open source, free) or Lalal.ai to get a rough pass. Both will give you a vocal-leaning stem and an instrumental-leaning stem. The vocal stem will still have bleed. That's normal.
Second, take that vocal stem and run it through an AI source separation model specifically trained for vocal frequencies. I've found that using both open-source RVC models and commercial plugins like GEM Audio in tandem gives better results than relying on one alone. RVC handles the mid-range lead vocals well. GEM picks up the airy high-end harmonies that RVC tends to smear.
Third, subtract the combined result from the original stem to get what's left. That residual contains the leaked instruments and any voices the AI missed. Use a spectral editor like iZotope RX to manually carve out the remaining vocal fragments. This step is where it gets tedious. A single song like "All In My Head (Flex)" with its layered gang vocals in the outro can take two to three hours of manual editing to clean up to a usable degree.
I once spent an entire week trying to isolate the three-part harmony on the bridge of "That's My Man" because the label provided a compressed MP3 instead of a WAV stem. Compressed files destroy the frequency information that source separation models need. The workaround was to use a convolution reverb irish from a similar-sounding recording to reconstruct some of the lost high-end, then run the rehydrated file through the separation chain. It's a hack, and it won't recover everything, but it got us from a total failure to a working pass.
Common Pitfalls People Miss
The biggest mistake I see is assuming that the vocal stem from a stem-splitting service is ready to use. It's not. The AI models will often misattribute backing vocals as instruments or vice versa, especially on tracks with heavy harmonies like anything Fifth Harmony released. You need to listen critically to every split result before using it in a project.
Another issue is phase cancellation. When you combine separately extracted vocal stems, the timing differences between what each model identified as "voice" can create comb filtering. Always check in mono. If the vocal disappears or sounds thin when summed to mono, you've got a phase problem. Flip the polarity on one stem and listen again. Usually one orientation sounds clearer than the other.
What Doesn't Work
Convolution reverb alone won't separate overlapping vocals. No amount of EQ will pull a voice out of a fully mixed stereo file without affecting the rest of the mix. Trying to manually phase-align stems from different sources is mostly guesswork. There's no shortcut that gets you studio-clean isolation from a commercial release without significant manual effort.
If you need clean stems for professional use, the only reliable path is obtaining them directly from the label or publisher. Everything else is a compromised workaround. I've done enough of these projects to know the difference between "good enough for a YouTube cover" and "broadcast ready." Most of what comes out of AI stem splitters falls into the first category for Fifth Harmony material, and honestly, that's probably all most people need.
