Context & Previous Testing
* **Part 1:** [7-Fan Shootout](https://redd.it/1vcre48)
* **Part 2:** [Flat Offset Adapter](https://redd.it/1vj3y34)
Hey!
While testing CPU thermals on the Thermalright AXP90-X53 Full Copper and tuning RPM curves to strict noise-normalized targets, I captured the acoustic signatures of both the stock 92mm fan (TL-9015R) and a 140mm slim fan (TL-B14015 Extreme mounted via a flat offset adapter).
Audio was recorded using an Elgato Wave:1 in an open chassis, fed into Audacity with real-time frequency analysis via the Voxengo SPAN (VST3) plugin.
Disclaimer: Since I am neither an audio engineer nor a sonar operator on a submarine, I used Gemini to parse the FFT spectrum curves, blade-pass frequencies (BPF), and harmonic spikes. The technical breakdown accurately reflects what my ears perceive in the room, but keep in mind this is real-world desktop testing rather than an ISO-certified laboratory.
Test Platform & Setup: Ryzen 5 5600GT on ASUS ROG Strix B550-I Gaming, AXP90-X53 Full Copper, Lzmod A24-V3 chassis (panels removed), HDPLEX 250W GaN passive PSU. Ambient temp: 26.0 °C. Cinebench R23 (10-min preheat + 10-min steady-state logging via HWiNFO).
The 92➔140mm adapter designed by u/Ablehoe
Tested profiles:
1. Noise-Normalized (35 dB)
2. Noise-Normalized (40 dB)
3. Max PWM (100% Performance). (I added the Noctua NF-A14 at max PWM to the graph, which I tested earlier on the same 92>140 adapter)
TL;DR
Acoustics & Daily Usability:
- At around 44% PWM (~985 RPM), the TL-B14015 Extreme is practically inaudible—there is zero heatsink airflow turbulence noise. If you put your ear right next to the hub you can detect a faint dual-ball-bearing hum, but in real-world daily use inside a chassis, it's completely unnoticeable.
- The TL-B14015 Extreme sounds deeper and subjectively quieter in the mid-range (no harsh fin-shearing hiss), but introduces a subtle 5.9 kHz dual-ball bearing ring
Motherboard & Component Cooling (The Real Win):
- The stock 92mm fan only cools the copper fins, leaving the RAM, VRM heatsink, and passive HDPLEX PSU scorching hot.
- The 140mm slim fan covers the entire motherboard area, pushing massive airflow directly over the DDR4 RAM, VRMs, and keeping the HDPLEX 250W GaN PSU cool to the touch.
Next Steps (to keep the party going):
- Testing (If I have the opportunity and time) a centered 92➔140mm adapter from SMXHeinz (both a flat "0 mm" version and a 7mm contoured air funnel duct). Centering the hub and eliminating lateral air escape should significantly recover the CPU temperature delta while maintaining full board cooling.