Have you ever sent your mixes to a good mastering engineer, but were disappointed in the sound of those mixes after mastering? For example, the mastered mixes might sound too thin (weak in the bass or midbass) compared to your mixes.

That mastering engineer might be incompetent. But maybe your monitor speakers are the problem. Let’s explain using a real-world example.

An engineer sent me his mixes to master into an album. On first listen, all his mixes sounded bloated and puffy, with way more midbass than commercial mixes – especially in the lead vocal. So I EQ’d out a broad region centered at 250 Hz. Immediately the sound became more clear and open, less congested. The tonal balance sounded more like commercial CDs, and the measured spectrum (level vs. frequency) better matched the spectrum of commercial CDs of the same genre.

I sent the mastered mixes to the engineer for approval. He said that the mastered mixes sounded too thin compared to his original mixes. He wanted more lower mids.

So is the problem in the mastering, or in his monitor speakers?

Here’s what I wrote to the engineer:

Suppose you measured your monitors and found a significant dip around 250 Hz. It might be caused by a reflection from surfaces near the monitors, such as the wall behind them or the desk below them. So you’d put a bunch of acoustic absorption on the wall, space the speakers a few feet from the wall, put them vertically on stands so the tweeters are at ear level, and put them on foam isolators such as Auralex.

Suppose you re-measure them, and now they are flat. You’ll still create mixes that sound good on those monitors. But you won’t be boosting the 250 Hz area to compensate for the monitors anymore. So your mixes won’t have that emphasis, and they’ll sound better on other speakers and headphones. Everything will be easier to mix, too, because you’ll hear what you’re recording and mixing more accurately.

In other words, if you listen to the mastered album on your current monitors, it might sound weak in the 250 Hz area, but that’s because you’re listening with a dip in that region.

Something else to do: Compare your mixes to commercial albums of the same genre, both before and after mastering. You’ll hear that the mastered versions are closer to the sound of commercial CDs. Also, your studio monitors are probably weak around 250 Hz and are not telling you the truth. But if you want some 250 Hz put back, I will. The problem is, an emphasis in that region makes everything kind of puffy and muddy, not open. But whatever you want is what’s important – it’s your album!

If 250 Hz sounds weak in the mastered album, that might mean you need to turn up 250 Hz in your monitors, not in the recording.

As an analogy, suppose you’re looking at the world through blue sunglasses. Should the world around you be painted more red to compensate for your glasses? Or should you take off your glasses?



Or suppose you’re listening to CDs on a laptop computer, whose speakers have no bass. Should you tell all the record companies to turn up the bass on their recordings until they sound real on the tiny laptop speakers? Or should you get some good headphones or monitors to listen on?

I’d humbly suggest that you work on the speaker placement, or get better speakers, or insert a graphic equalizer between your audio interface output and your monitor inputs, and turn up a broad region centered around 250 Hz until it sounds right to you. Then do all your future mixes through the corrected monitors.

I’m here to help you get what you want, but also to make your album sound more like hit records. Of course, you might not want to sound like commercial recordings… you might like your recorded vocals to sound warmer than the vocals on hit records. That’s a legitimate point of view. It’s a matter of taste.

Just sayin’, if you need more lower mid in your mixes, try adding more lower mid to your monitor speakers, not your mixes. Or work on your monitor placement and room acoustics.

– Bruce Bartlett

AES member Bruce Bartlett is a recording engineer, mastering engineer, audio journalist and microphone engineer (www.bartlettaudio.com). His latest books are “Practical Recording Techniques 6th edition” and “Recording Music On Location”.