How to Get Two Mono Headphone Feeds from a Stereo Headphone Amp

The current trend among bands is to use in-ear monitors rather than stage wedges. Furthermore, developments in wireless technology have made in-ear wireless monitors more reliable, lighter in weight, and easier to set up.

The downside is that a quality in-ear pack will cost $500 to $1,000, which may be beyond a band/s budget. However, band members that are more or less tethered to their instruments, like drummers and keyboard players (and often bassists) should consider using wired in-ear monitors. The savings are considerable, and of course, you have the reliability and easy setup of a wired connection.

Typically, each player would need their own headphone amp, because headphone amps generally send one input to multiple outputs—but for those on a tight budget, there’s a simple way to use one stereo headphone amp to obtain two mono headphone feeds.

ART’s HeadAmp4 is a rugged, compact, affordable headphone amp. The front has individual volume controls for the four outputs (Fig. 1).

Figure 1: The HeadAmp4 front panel includes four volume controls and a power indicator.

The rear panel has one stereo input and four stereo outputs (Fig. 2). The 1/4″ and 1/8″ jacks are wired in parallel.

Figure 2: The stereo input is on the right; it’s distributed to the four stereo outputs.


 To connect the headphone amp to the mixing board, you’ll need an insert-type cable with a stereo male 1/4″ plug, and two mono male 1/4″ plugs (Fig. 3), like Hosa’s STP-203.

Figure 3: Hosa’s STP-200 series of insert cables have a stereo male plug and two mono male plugs.


The STP-203 is 9.8 feet long. However, shorter versions are available; the STP-201 is 3.3 feet, and the STP-202, 6.6 feet.

Next, you need to dedicate two sends from the mixer—one for Singer A, and the other for Singer B.  The two mono plugs (tip plug and ring plug) from the insert cable plug into two 1/4″ send outputs on the board (Fig. 4).

3_Back of Mixer
Figure 4: The aux outs circled in orange can provide the two needed send outputs (one for each singer). Of course, these could be any two available sends.

Plug the stereo plug into the headphone amp’s stereo input, and you’re almost ready to go.


The final step is wiring up two adapters so that the wired in-ear monitors can connect to the headphone amp’s outputs. For this, you’ll need two stereo male 1/4″ plugs, and two female 1/4″ jacks. The easiest way to wire these adapters is to take a stereo cable with two male 1/4″ plugs, cut it in half, then strip the two ends so you can wire them to the female jacks. If you need a long stereo cable, the Cable Up PM3-PM3-ES-25 is 25 feet long, so when cut in half, you’ll have two 12.5 foot cables. For something shorter, cut the Hosa HSS-010 in half, and you’ll have two 5 foot cables.

For the stereo 1/4″ jacks, Neutrik’s NYS2203P uses all-metal construction instead of having a plastic outer cover, so it’s a good choice for the rigors of the road. Wire the adapters as shown in Fig. 5.

5_Adapter wiring
Figure 5: Wiring for the two adapters that convert the stereo outs into separate mono outs.


Now all that’s left is to plug each adapter into its own headphone amp output, and each musician’s wired in-ear monitor into their respective jacks. Note that because each musician plugs into their own headphone amp output, they each have their own master volume control on the headphone amp.

That’s all there is to it—an easy way to get two mono headphone feeds from a stereo headphone amp. I hope it serves you well on your gigs!


bio: Gold/Platinum record-winning recording/mixing engineer Marius Perron is director of the Audio EnginEARing Institute in San Antonio, Texas.

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