How to Connect Multiple Instruments to a Mixer

You've got your guitar, maybe a keyboard, mic stand, and this shiny mixer staring back at you. Now what? One wrong cable and nothing works. Wrong gain staging and everything clips. We've all been there—hours lost to "why is my bass silent?" Multi-instrument setups aren't magic; they're cables + levels + routing.

According to the technical guidelines from Yamaha’s Professional Audio division, microphones should be connected via XLR inputs to utilize the mixer's built-in preamplifiers, while high-output devices like keyboards and drum machines are plugged into Line inputs to prevent signal distortion. 

For electric guitars and basses, using a Direct Injection (DI) box is recommended to convert their high-impedance signal into a balanced format, which maintains tone clarity over long cable runs. Once connected, the critical step is setting the "Gain" for each channel individually so the signal is strong enough for the mixer to process without "peaking" or clipping.

This guide assumes you know nothing beyond "plug it in"—we'll cover every cable type, input choice, beginner mistakes, and troubleshooting so your first jam session actually sounds like music.

The Cable Cheat Sheet (No More Guessing)

Guitar/Bass (instrument level, high impedance): Black TS 1/4" cables (tip-sleeve) to combo jacks. Never use XLR—kills signal.

• Microphones: Silver XLR cables (3 pins) to XLR inputs only.

• Keyboards: Dual red/black TRS 1/4" stereo cables to stereo line inputs.

• Drum machines/E-drums: 1/8" headphone jack to 1/8" aux input (adapter).

• Phones/laptops: 1/8" to dual 1/4" or Bluetooth pairing.

Pro tip: Color-code cables (red guitar, blue keys). Label ends.

Step 1: Power Up Safe (Phantom + Ground First)

Mixer off. Plug power cord. Phantom +48V OFF (switch usually top-left). Master fader down, all channels zeroed. Power on. Check no hum/buzz.

Step 2: Guitars and Bass (Hi-Z Inputs)

Channel 1-4 (mono combo jacks): Guitar cable TS end into 1/4" hole. Engage "Hi-Z" or "Inst" switch if present (Harbinger CH1-6). Play hard riff—trim/gain knob till meter yellow peaks, no red.

Fader up to 12 o'clock. HPF on (80Hz kills cable rumble).

Step 3: Vocals (XLR Mic Preamp)

Channel 5: XLR mic cable into XLR hole. Phantom OFF (SM58s don't need). Gain till vocals peak yellow. Pop filter 2" from lips.

Pad button if meter slams immediately.

Step 4: Keyboards (Stereo Line Level)

Channels 7-8 (stereo pair): Left TRS cable to L/Mono, right TRS to R. Play pads—both meters move. Balance L/R faders equal.

No Hi-Z needed—keys are line level.

Step 5: Drums (Mic or Direct)

Acoustic kick: Channel 9, Beta52 XLR. Gain till foot hits register.
Electronic kit: 1/8" headphone out → 1/8"-1/4" adapter → Channel 10 mono.

Step 6: Bluetooth/Phone Backing Tracks

Harbinger CH13/14 Bluetooth: Pair phone (hold BT button). Play Spotify playlist.
5 Core: Dedicated BT input—stable 30ft range.

Gain Staging (The Real Secret)

1. Solo channel 1 (guitar). Play loudest. Gain till 0dB peaks.

2. Fader to unity (marked "U" or 0dB).

3. Un-solo, repeat every channel.

4. Master up slow—no red lights.

Common Beginner Disasters + Fixes

Dead guitar: TS cable? Hi-Z on? Gain up?
Mic hum: XLR fully seated? Phantom off? Ground lift?
Keys only left: Both TRS cables plugged?
Everything quiet: Master fader up? Power on?

Product Highlights

Harbinger LV14 14-Channel Analog Mixer

This compact rackmount mixer handles live performances with 6 XLR/¼" combo mic/line inputs (CH1-6) featuring 48V phantom power, 80Hz high-pass filters, and 26dB pads, plus 3 stereo ¼" line channels, Hi-Z on CH6 for guitars, stereo 1/8" aux, and Bluetooth audio pairing. Onboard 24-bit digital FX includes 16 lush presets (reverb, delay, chorus) with parameter control and footswitch jack, while 3-band EQ (±12dB high/low shelving, ±15dB mid peaking) per channel shapes vocals/instruments precisely. Outputs feature balanced XLR mains, ¼" monitor/control room, 1/8" record out, aux send/return for effects/monitors, USB for DAW recording/playback, and headphone jack with 6-segment LED meters for clip-free mixes.