Case Study: Saving the Las Chollas Peligrosas record
A ways back, I got the call no mastering engineer ever wants to get:
“We just finished mastering our record, and it sounds really bad, can you fix it?”
There’s a great band out here in Phoenix, AZ called Las Chollas Peligrosas, they were coming out with their first big self-titled debut album, and had just done a bunch of old-school analog recording sessions to magnetic tape for their record.
Once their recordings were complete, they sent their mixes off to be mastered, and when they got their masters back, something was very obviously wrong, but they didn’t know what.
The diagnosis
So, I took a look, and found the problem straightaway: massive amounts of digital clipping baked into their masters, from their previous engineer not having their limiter set up properly.
Here’s the clipping report:
A digital clipping report made with the afclip tool.
And what that same report should look like if mastered correctly:
An afclip report showing no clipping.
This is a big deal, and sadly some really bad news, especially if you paid somebody to do these masters.
Checking for clipping yourself
The tool I used to check for clipping in this case study is a free command-line tool available on Apple computers called “afclip”. It’s one of the tools mastering engineers use to be sure their work meets the official “Mastered for iTunes/Apple Digital Masters” specifications.
Instructions on how to run a clip report using the afclip tool on a Mac can be found here (scroll all the way down to the final section), and a video showing this technique can be found here.
Rules of mastering
One of the first rules of proper mastering is to “do no harm”: a track should always sound better when it leaves your studio, never worse.
Adding any kind of digital clipping onto a track during the mastering process should never, ever happen. It’s the musical equivalent of keying the paint job on a brand-new car that you just drove off the lot.
The original mastering engineer here got it very wrong on this one, likely due to a lack of experience. The band, in this case, had been enticed by a low-priced budget provider, only to have to spend twice as much in the end, because they had to do the job twice. Such a shame.
The solution
Unfortunately, the only solution here was to do a complete remaster of the entire record. When there’s clipping baked onto the audio and it’s this bad, you’ve lost so much sonic information that there’s really no repairing the existing masters in a way that would justify the costs to make the repair.
Once I was able to work off of the original mix files (which were fine and undamaged), I did a new set of masters and everything worked out great.
The self-titled Las Chollas Peligrosas album ended up being voted some of Arizona’s best music for that year, so a happy ending that worked out for everyone!
How to avoid the clipping trap
It’s helpful for all artists to have a basic idea of how to check for the technical problems seen in this case study, on their own, and it’s actually something very easy to do (see my directions below).
Had this particular band had that knowledge before they called me, they could have spoken with their original engineer, told them they were seeing clipping on their masters, and just had that person fix it when they did the original job, or gotten a refund.
Knowing how to diagnose this problem is also a great way to double-check that your mastering engineer is competent, qualified, and knows what they’re doing.
You can save yourself a lot of headaches this way, especially if you’re working with low-cost providers, students who are still building their experience, or mixers who offer to throw in cheap mastering just to get you to say yes to a mixing job.
Had this been my band, I would have immediately asked for a refund had I received finished masters in this kind of condition.
Using the afclip tool
It’s quite easy to check for clipping using the afclip tool:
type a one-word command into the Terminal application.
drag/drop your audio file into the Terminal window
hit enter.
If you don’t have an Apple computer, you can check this by loading your master file into any DAW (free ones included).
Then, make sure the loudest parts of your finished masters are peaking at no higher than -1 dBTP, and -2dBTP is just fine if it’s a very loud master. You’ll need a True Peak loudness metering system to check this, but there’s a bunch of free ones out there.
All of my different practical creative case studies can be found here.
