Side-by-Side Training with USB Headsets: Updated for 2025
Published: January 2023 | Updated: January 2025
What is Side-by-Side Training and How is it Implemented Today?
Side-by-side training is a common practice in call centers where a trainee or a coach sits beside an agent to listen in on a live customer call. It helps trainees learn in real time and enables supervisors to provide live coaching.
Traditionally, this is done using headset solutions that allow two headsets to be daisy-chained together using a Y-splitter cable. One headset handles both mic and audio input/output, while the second listens in.
Why Double-Jacking Two USB Headsets Does Not Work
It’s a common assumption that you can simply plug two USB headsets into a PC using different USB ports. Unfortunately, it doesn’t work that way.
Operating systems like Windows only allow one audio input and one audio output device to be active at a time. Each USB headset has its own internal sound card (audio processor), so the computer treats them as entirely separate audio systems.
Even if you use a USB hub, the system won’t mix or combine both devices. You’ll still have to manually choose one device at a time for input/output—and only that headset will work.
Alternate Approaches to Side-by-Side Training with Corded Headsets
Many contact center platforms support remote conferencing features. A supervisor can join the call remotely using using a feature called call barging, which is enabled through the call center software or telephony system. After monitoring calls and deciding intervention is needed, the supervisor selects the option to barge in from their dashboard, which creates a three-way conference call between the supervisor, agent, and customer. The supervisor can then actively participate in the conversation or provide real-time assistance through “whispering” to the agent.
While it sounds convenient, this requires elevated permissions, and doesn’t allow the same proximity benefits that physical side-by-side training provides.
If you’re still using Quick Disconnect (QD) headsets, then good news: you still have several reliable options for side-by-side training using Y-splitter cables designed for this purpose.
Most QD headsets consist of:
- A headset with QD connector
- A bottom cable or USB adapter (DA series)
Leading manufacturers like Poly and Jabra offer Y-splitter solutions for their QD headsets. These allow:
- Two people to hear the same call simultaneously
- One person (typically the agent) to speak
- The other (coach or trainee) to listen only
However, as more call centers adopt platforms like Zoom, Teams, Genesys, NICE, Five9, Cisco Jabber, Avaya, RingCentral, and more, USB headsets have taken over. That’s where the problem arises—USB-based solutions don’t natively support dual-headset training.
Real-world example: One of the nation’s largest wireless carriers transitioned over 10,000 agents from QD to USB headsets, only to later realize side-by-side training was no longer possible. BTP worked closely with engineering teams to help build a viable workaround, covered in detail below.
Supported QD Headsets for Side-by-Side Training
If you’re using Poly EncorePro HW520 QD headsets, here’s your setup:
- Use a DA75 or DA85 USB adapter
- Plug the tail of a Y-training adapter cable (PL-27019-03) into the DA75/DA85
- Connect two HW520 headsets to the Y cable
This setup allows both users to hear the conversation, but only one user can speak using the mute toggle switch. The PC communicates with only one processor, ensuring seamless audio handling.
[SHOP NOW] Buy the full EncorePro 520 Training Bundle that includes the HW520 headset, DA85 adapter, and Y-training cable.
DA85 USB Audio Processor
DA75 USB Audio Processor
Poly EncorePro HW520 QD Headset
HW520 Training Bundle
Which USB Headsets Can Support Side-by-Side Training
We explained earlier how USB protocol does not support double jacking? Well, there are two brands that have worked around this problem. Poly leveraged the 3.5mm connection with their Blackwire 5220 headsets and developed a 3.5mm Y-splitter (a.k.a. Y-adapter) that allows two 5220s to be daisy chained for training. Poly product team smartly designed this solution so that you MUST purchase both headsets and the Y-splitter from Poly and Poly only. Nucleon Audio took a step further and integrated 3.5mm Y-splitter on the circuit board so you can directly double jack another 3.5mm headset into it. What’s more interesting is that you can insert just about any 3.5mm headset (you don’t have to stick to Nucleon Audio S2521). Let’s look at two bundles – one with Poly headsets and one with Nucleon Audio (roughly half the price) next.
Option 1: Poly Blackwire C5200 Series – Separate Y-splitter cord required
The Blackwire C5220 comes with:
- A USB inline controller
- A 3.5mm jack for daisy chaining another headset
To implement training:
- Plug two Blackwire 5200 series headsets into a Y-training adapter (PL-217008-01)
- Connect Y-adapter to the 3.5mm ports on each headset
- Plug USB end into PC
The “Supervisor” side of the Y adapter is muted by default, enabling one-way monitoring.
[SHOP NOW] Purchase the full Blackwire 5220 Training Bundle including two headsets and training adapter.
Blackwire 5220 USB Headset
Blackwire 5220 Training Bundle
Option 2: Nucleon Agent USB Headset – Built-in Y-splitter port (separate cord NOT not required)
The Nucleon Audio brand is revolutionizing USB headset training:
- ✓ Built-in 3.5mm jack in inline controller
- ✓ Supports any 3.5mm headset—even basic earbuds
- ✓ Proprietary dual ANC processors eliminate 99% background noise
- ✓ Mic Boom RED indicator ensures optimal placement
- ✓ Plug-and-play, no proprietary cables needed
[SHOP NOW]Nucleon Agent USB Headset training bundle (U2521+S2521)
Nucleon Agent U2521 USB Headset
Nucleon Agent U2521+S2521 Training Bundle
Need Help Choosing the Right Setup?
We’ve tested and curated these bundles to make training easier for IT teams and trainers alike.
[CONTACT US] Email us with your requirements
[EXPLORE] Explore more options at www.btpi.com
Need Help with Your USB Training Headset Splitter Setup?
Contact our experts at info@btpi.com for personalized assistance with your USB training headset splitter requirements, including solutions for Polycom Blackwire 5220 and other popular USB training headsets.
See our OLD 2023 post: Side-By-Side Training for USB Headsets here!
Training a new agent side-by-side? There's a simpler way.
The Nucleon U2521 + S2521 Training Bundle gives the agent a USB headset and the trainer a plug-in listening headset — the training adapter is built in, so there's no Y-cord and no extra adapter to buy. Works with Genesys, Five9, NICE CXone, Teams and any softphone. Ships from BTP's own stock.
Samples go to business addresses with a work email. Volume pricing is by account — ask us.
Need just one or two? Buy the Nucleon U2521 on Amazon →
Good afternoon,
Our Client Erste Banka conducts training for contact center agents.
The person in training should hear the conversation between the agent and the client. Headphone models currently in use are: Poly Blackwire BW3310 USB-A and Blackwire C3210 USB-A.
Please let me know if there is a Y training adapter for connecting 2 usb headphones, or if you have another solution.
Good morning! While I’d love to give you better news, unfortunately there is no easy way to split USB audio transmit and receive for two headsets. USB connections aren’t meant to be split. However, depending on what softphone or hard phone you’re using, there may be an easier way to conference two callers together than using a physical connector! The available types of conferencing within the phone or softphone are generally the best way to connect two users to a single call, when both are using USB headsets. Hope that helps!
-Headset Help Desk
I have 2 USB headsets with mics. I understand that I can connect them to your “Y” cable and both people can hear the audio. However, will both of the mics work? If not, is there a product that will allow this?
Good afternoon Hoss. The recommendation is two (2) Poly Quick Disconnect Headsets, a Y Training Adapter and a DA Series Audio Processor. Two USB headsets cannot be used.
If I am playing a video, can two people both hear the audio using USB headphones?
Thanks!
Good afternoon Bob, thank you for your inquiry.
If you are using the setup advised in this post, yes, both users will be able to hear the PC audio.
Please let us know if we may be of further assistance.