First Steps when mixing sound at a small bar

What I would recommend for your band

Before plugging in or soundchecking the band:

1. Set up the main speakers exactly where they’ll be during the show.
2. Set the mixer Main EQ flat.
3. Set your speaker/sub crossover correctly.
4. Play a high-quality song you know really well through the PA.
5. Walk around the audience area.
6. Listen for major boominess, muddiness or harshness.
7. Make small cuts on the Main EQ.
8. Then soundcheck the actual band.

The word small is important. If you’re making 8–10 dB EQ changes to get the room sounding acceptable, I’d start questioning speaker placement, crossover settings, polarity, or gain structure before continuing to carve up the EQ.

Reference music vs measurement microphone using the DBX Drive Rack PA2

Using an iPhone, plugged into the mixer, is essentially doing room/system EQ by ear. That’s perfectly legitimate. A measurement microphone and Smaart/DriveRack simply adds objective information:

Reference music tells your ears: “This room sounds really boomy.”

Measurement system tells you: “There is a strong buildup around 125 Hz and another around 250 Hz.”

The best approach combines the two:

Measurement → identify the problem → small EQ adjustment → reference music → verify with your ears

I would not use the DriveRack AutoEQ and then assume you’re finished. I’d still play a familiar reference song afterward.

Pick the right reference song

Don’t choose a song just because you like it.

Choose one that is:

• professionally recorded and mixed
• not excessively bass-heavy
• has a strong, natural vocal
• contains bass and kick
• has guitars/keys through the midrange
• has cymbals/high-frequency content
• something you’ve heard hundreds of times
• Something in the same genre as the band you are mixing

Ideally keep 2 or 3 reference tracks on your phone.

One with a strong male vocal (and female vocalist, if in the band) would be particularly useful for your band because you’ll immediately notice if the PA is making the vocal muddy, nasal, or harsh.

One distinction that will save you headaches

Use the Main EQ to make the PA sound right in the room.

Then use channel EQ to make the individual performers sound right.

So:

Before band:
Reference music → Main/System EQ

During soundcheck:
vocalist(s) → vocal channel EQ
Acoustic → acoustic channel EQ
Bass → bass channel EQ
etc.

You don’t want to fix a boomy room by cutting bass out of every channel individually.

For your small-bar gigs, I would absolutely use the reference-song method even if you buy the PA2. It takes only a few minutes and gives you a very good reality check before the band starts playing.

Here’s the basic path on the CS18AI:

1. Press the MAIN Select button so the Main mix is selected.
2. Press the GEQ button on the CS18AI.
3. The Fat Channel encoders/meters now control the 31-band graphic EQ for the selected Main bus. PreSonus added direct GEQ control from the CS18AI Fat Channel encoders, so you can adjust the frequency bands right from the surface.
4. Make sure you are looking at the Main L/R GEQ, not an Aux GEQ.
5. Start with the GEQ flat before tuning the room.

Setting up on a StudioLive CS18 AI console

The 31 bands cover roughly 20 Hz to 20 kHz, with fixed center frequencies. You change only how much each frequency is boosted or cut.

So when you play your reference song, you might do something like:

63 Hz     0
80 Hz    -1
100 Hz   -2
125 Hz   -2
160 Hz   -1
250 Hz   -2
500 Hz    0
1 kHz     0
2 kHz    -1
4 kHz    -1
8 kHz     0

That is just an example—not a preset I’d recommend using blindly.

The idea is:

• If the room is boomy, gently cut low/low-mid bands.
• If it sounds boxy, reduce some 200–400 Hz.
• If it sounds harsh, slightly reduce 2–4 kHz.
• If it sounds overly bright, trim upper frequencies.

PreSonus specifically cautions against making drastic changes; smaller, broader corrections are generally better for room tuning.