Logic splits stems

digitalDrummer looks to Apple’s Logic Pro in its pursuit of drums-free tracks.

Apple’s latest Logic Pro updates (iPad 2 and Logic Pro 11 for Mac) are the latest DAWs to add stem splitting capability – something we first saw in FL Studio late last year.

We checked out the Mac version because the iPad version only works on the latest tablets with M-series processors. And even the Mac version required an operating system update for my M2 MacBook.

There are plenty of bells and whistles in the new version of Logic Pro – most of them aimed at composers and producers, with features like an enhanced AI-powered ‘software drummer’. But our interest is limited to the stem separation tools, which form the basis of this review.

What’s in the box

Of course, there’s no box: Logic Pro 11 is a digital download from the App Store – free for existing Logic users and around $200 for new buyers.

For those unfamiliar, the program is a cross between a conventional DAW and GarageBand – a series of tools for composing, editing and mixing music which rivals the functionality of its major competitors and adds Apple’s characteristic easy-to-use interface. Logic Pro also has a large sample library, including some excellent drum sounds.

The update is heavy on artificial intelligence-powered tools such as Session Players (virtual bass and keyboard players), in the same vein as the virtual Drummer introduced many years ago and which is itself further enhanced in this version.

Stem splitting

For some time, drummers (all musicians, actually) have had the ability to ‘unmix’ full songs and extract their constituent parts.

Since 2019, a number of vendors have been offering versions of the Spleeter online separation tool, which has continued to evolve. The technology was highlighted last year when movie producer Peter Jackson and his team of engineers used it to extract John Lennon’s vocal from the demo tape and used that as the basis of the ‘new’ Beatles’ song,

Now And Then.

Apple is touting its Stem Splitter as a tool with which “an artist can recover moments of inspiration from any audio file and separate nearly any mixed audio recording into four distinct parts: drums, bass, vocals, and other instruments, right on the device”.

For drummers, stem separation is particularly useful for creating drum-free playalong tracks. In theory, the drums should be the easiest stem to isolate and mute, leaving the rest of the song more or less intact.

That’s the theory – so how does Logic Pro perform in reality?

In action

To split a track, one simply imports a song into Logic. You can use almost any audio format, but obviously, the higher the resolution of the audio – and the ‘cleaner’ the sound, the more you are giving the tool to work with.

Click on the new Functions tab, select Stem Splitter, choose how many stems you want (the default is four) and hit ‘split’. That’s it! It is one of the simplest and quickest splitters we have tried – significantly quicker than the online tools that require uploading and then downloading and much easier to navigate than options like FL Studio. After months of use, I still struggle to remember where the conversion button is hidden in that DAW!

Not only is Logic easy, but it is lightning fast. A three-minute song is completed in seconds rather than minutes. One of my reference songs, The Shadows’ Apache, took less than 10 seconds to generate four stems – drums, bass, other (guitars) and an empty voice track.

But, it’s not just about getting it done quickly.

The results

While other artists may be looking for pristine, clean individual instrument stems, drummers will probably only be interested in how well any splitter isolates the drum track.

As it turns out, Logic is among the most successful of the tools we have tried in isolating and removing percussion.

I chose Apache as a reference song because the snare is so closely linked to the rhythm guitar, with the two seemingly merging for much of the track.

When I checked the stems, the drums were almost completely isolated with no guitar tones in the track. Similarly, the ‘other’ stem (guitar) was virtually uncontaminated by drums. The bass stem was the most ‘degraded’, missing some tones and a bit distorted. It was the only track that would need some artificial remediation if you wanted to solo it. But combined with the guitars, it worked really well. So, overall, as a drum remover, Logic gets an A+ for this track.

My second reference track is Elle King’s Exes and Ohs, a song I chose because there’s a lot of floor tom played on top of the bass guitar.

With the aid of Logic, I got vocals, drums, bass and guitar stems. Unlike the drums, which emerged fairly clean and full-sounding, the other stems actually sound quite messy and distorted when auditioned one by one. But together, they somehow filled the sonic gaps for a full-sounding rendition. Because of the overlap of bass and floor toms/kick drum, I found the best drumless track actually needed a tiny bit of drum stem in the mix rather than simply muting the track. I wouldn’t recommend it for splitting the tracks to grab a bass stem, guitar track or a cappella vocal, but for drumless tracks, I’d give it a B.

I tried an MP3 version of The Beatles’ When I’m Sixty Four (remastered) and got four pristine stems – delicate brushes, crystal-clear strings/piano/guitar in the ‘other’ track, detailed vocals and a pretty good bass (with slight deterioration and distortion). I was impressed that the bell sounds were captured in the ‘other’ track, so they were present in the sans drums version. As a drumless track, it’s an A+.

Toto’s Africa is another song that’s difficult to split because there is so much happening – drums, percussion, keys, guitars and multi-part vocals. Separation produced somewhat ‘iffy’ individual stems – nothing you could really use as a solo, besides the drum track that combined the kit and the percussion. While the song wouldn’t make the cut for any of the component stems, muting the drums produced an excellent drumless track – certainly a B+ or better.

Another tricky splitting song, Santana’s Smooth, was not overly problematic for Logic. The drum/percussion track was clear and clean; the ‘other’ stem neatly combined the horns, guitar and keys and the bass track was one of the cleanest and most intact I have encountered in Logic. The vocals, however, were quite ‘damaged’ with heavy phasing and some interference from Carlos’ screaming lead guitar riffs. But again, turn everything on, mute the drums and you have an almost perfect drum-free track. The score here: a clear A.

Overall

It’s worth noting that unlike some other apps that have some tweaking tools to refine the stems, Logic doesn’t really allow you to “edit” the separation. You can’t dial back the filters. Logic, of course, does have all the usual audio editing tools like effects and level adjusters. But at the end of the day, what you get is what you’re stuck with.

If you already have Logic, the upgrade would be a no-brainer, even if it didn’t contain the stem separation tool. But its inclusion makes this a serious contender for the supreme separator. It is fast, easy and logical and doesn’t require an Internet connection to perform the separations.

The output is slightly limited – four stems compared to five or more in some solutions, and some of the stems may not be totally up to scratch as solo tracks. But mute the drums and you get an almost-perfect drumless track every time.

Of course, the usual caveats apply: the original mix and the production complexity play a significant part in determining the final separation. The better the quality of the original, the cleaner the individual tracks. Also, less ‘cluttered’ songs produce better discrete stems.

If you’re not already an owner and need to buy Logic Pro, it’s worth putting the price into perspective, even if you ignore the DAW capabilities and just look on it as an advanced splitter.

Yes, there are free stem splitter apps, but most are fairly limited and tedious for regular users. An online app like Lalal.ai will set you back $35 for 500 minutes of conversion (using the current 50% off offer); the popular Moises online app costs $40 per year; Xtrax Stems costs $60 per year and RipX DAW Pro will set you back just under $200.

So, the one-off Logic purchase price is not unreasonable for a tool that does everything you need for drumless track brewing – and a whole lot more, if you are so inclined.

Logic Pro requires macOS 13.5 or later and 6 GB of storage space for minimum install (up to 75 GB storage space for full Sound Library installation – but you won’t need that if you’re only using the stem splitter functionality).

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