Tested: Do Audio Interfaces Really Sound Different?

Summary

The video tests whether audio interfaces have clearly audible sound-quality differences, rather than relying only on online claims or measurements. The presenter says his measurements found differences in noise floor, distortion, dynamic range, and frequency response, but notes that those figures do not necessarily predict whether listeners can hear a difference.

Listening Tests and Findings

• Blind headphone comparisons: The presenter level-matched identical recordings from different interfaces and switched between them using a custom headphone-switching device. Across multiple headphones and sessions, he could not identify a definitive difference. Producer and engineer Dana, using Hifiman Sundara headphones, and an unnamed live-sound professional also reported no audible difference.
• Repeated “regeneration” tests: To make small differences accumulate, the presenter repeatedly sent a signal through an interface’s line output and recorded it through its microphone preamp.
  • After 10 generations, differences were difficult to hear. The presenter says the Scarlett 2i2 Gen 4 and better-performing interfaces were faintly different or effectively indistinguishable.
  • After 50 generations, differences became audible. Across more than 20 interfaces, he ranked the Universal Audio Volt 476 highest and a very inexpensive four-channel interface—whose name is inconsistently captioned as “Depang” or similar—lowest.
• Line input/output loopback: The presenter describes line inputs and outputs as more transparent than preamps. In a blind comparison after 20 generations, he says he could not draw a firm conclusion from listening. For this group, the SSL 2 Mk II ranked highest and the M-Audio Air 192|6 lowest in his measurements.

His overall interpretation is that measurable differences can exist, but when a signal passes through an interface once during ordinary recording, those differences are generally much smaller than online discussions suggest.

Recording-Chain Comparisons

The presenter recorded the same performance simultaneously through an SSL 2 Mk II and a very inexpensive interface, using closely placed, factory-matched AKG C414 microphones. He heard little difference between the recordings. When he substituted a cheaper ISK microphone, he says the better microphone made a more noticeable difference than the interface.

He also compared recordings made with different combinations of microphones, interfaces, and room treatment. In these demonstrations, he judged room treatment to matter more than the interface, and room acoustics to matter more than microphone price. He recorded a full song using the inexpensive interface and a microphone costing roughly $60 to demonstrate that low-cost equipment can produce strong results.

Advice and Other Interface Benefits

The presenter’s suggested priorities for home recording are:

1. Room acoustics
2. Monitoring
3. Microphone
4. Audio interface

He also emphasizes recording skills and microphone placement. In his view, many home studios prioritize microphones, interfaces, and preamps before treating the room.

The video discusses low-frequency room buildup as a major source of muddy recordings. The presenter contends that common wall panels often address higher frequencies more than troublesome bass, and that effective bass trapping and room design are important. These acoustics points are his advice and explanations, not findings from the interface blind tests.

The presenter does not claim that expensive interfaces are pointless. He notes potential benefits such as lower latency, better drivers, DSP, flexible routing, more inputs and outputs, stronger headphone outputs, expandability, reliability, build quality, and customer support. He also says preamp noise and distortion can matter, particularly distortion affecting preamps when headphone output is turned up. He refers viewers to a separate interface-comparison video for more detail.

Tests, Demonstrations, and Resources

The video features:

• Measurements of noise floor, distortion, dynamic range, and frequency response
• Blind headphone comparisons and repeated regeneration tests
• A line-input/output loopback comparison
• Simultaneous vocal-recording comparisons using different interfaces and microphones
• Comparisons of untreated and treated recording spaces
• A full song recorded with inexpensive equipment
• An offer to download the song’s raw tracks for mix practice
• References to a separate detailed interface-comparison video and a room-acoustics course

Interfaces Mentioned

The video names the Lewitt Connect 6, PreSonus Quantum ES2, MOTU M2, Arturia MiniFuse 4, Focusrite Scarlett 2i2 Gen 4, Universal Audio Volt 476, SSL 2 Mk II, Audient iD24, and M-Audio Air 192|6. It also mentions a low-cost interface whose name is inconsistently rendered in the subtitles as “Depang,” “Depuchen,” or similar.

Main Speakers and Sources

• Chris: Presenter who conducts the interface tests and explains the results.
• Dana: Producer and engineer who participates in the blind listening test.
• Unnamed live-sound professional: Provides a brief listening-test assessment.
• Other sources: The presenter’s measurements, blind listening comparisons, recorded-song demonstrations, and references to a separate interface-comparison video and room-acoustics course.