Digital and analogue drum machines have become staples in dance music with tremendous staying power over the decades. However, many of these classic sounds (including 909 and 808) are very raw and contain less than ideal “sonic gremlins” that hide in your mix. Today professional mixing engineer Hannes Bieger – who specializes in house and techno music – is going to show you how to clean up the high-end in your dance tracks by isolating and removing nasty frequencies.

Here is a look at frequency response curve of Pink Noise, which has a very even sound picture. All the frequencies have a nice even decay, which is very similar to our natural hearing response, and is there-fore easy on the ears.

Contrast that with instruments like the TR-909 drum machine, and you will find the hi hat and ride cymbal have very noticeable resonances in the upper end of frequency spectrum. Notice there are some significant peaks, and how flat the 3-8k range is.

While these drum sounds work very well for energy, and this shape gives the 909 hat it’s distinctive character – those more extreme resonances can really clutter up a mix if left un-treated.

Often these resonate frequencies sit between 3k and 5k, which is our most sensitive hearing range. In fact, we are most sensitive to sounds in this region because of our historical evolution towards picking the sound of birds. Ironically, the resonance of a 909 ride sounds like a whistle, which can be extremely distracting for our brains.

Not only do these “nasty whistling gremlins” occupy our attention, but they also take up a big amount of the frequency spectrum so removing them for good will create a lot of space in the mix.

Finding Those Nasty Frequencies

It’s best to use a sharp notching filter on an EQ to isolate the frequency. In the case of the 909 hi hat that frequency usually resides in the 3-4 kHz range depending on tuning. Reducing that frequency by about 3-4db, with a sharp Q, will keep the nasty whistling sound in check and open up the mix to other elements.

The same applies to the 909 ride. which has a similar whistling sound that draws the listeners attention even more. By taking out these annoying frequencies you create more room in mix and achieve more clarity to make your productions stand out.

Big thanks to Hannes Bieger, a fantastic mixing engineer, for sitting down with Ean Golden and shooting this great tutorial. Look for episode 2 in a few weeks time.