Just received my Cq-20b and have to add to this list, fan noise, while not loud, is rather annoying. It’s winter here in Boston and my studio is cool, shouldn’t even need a fan.
The device is generating it’s own heat. Therefore while the ambient temperatures can plan a small role in heat mitigation, it doesn’t change the fact that the chips are generating heat that needs to be mitigated/managed. In other words, just because your studio is only 60 deg Fahrenheit doesn’t change the fact that the chip might be outputting heat measured at 200+ deg Fahrenheit which needs to be managed properly.
Here as a comparison the Info from my CQ20B. Environment is at 20°C. Device ruining ideale for about 15 Minutes
Allen & Heath CQ Mixpad V1.1.3 - Rev. 80777 1.1.3.80777
Unit Type: CQ-20B
DDR Calibration: RU:0 RO:0 FF:0 FE:1 C1:1 C0:1 PASS
Core Temp: 75.79C (Max: 76.29C, Min: 26.45C)
Core Voltage: 0.998V (Max: 1.004V, Min: 0.996V)
DAC Temp: 38.00C (Max: 39.00C, Min: 22.00C)
FX Temp: 72.72C (Max: 73.33C, Min: 26.09C)
Fan Speed: Fan 1: 1052rpm
Fan PWM: Fan 1: 34
TFT PWM: 90
MAC Address 1: 00:04:c4:0f:37:e0
MAC Address 2:
Firmware Version: 1.1.1 r3684
IP Address 1: 192.168.2.1
Active Image: 0
Bootloader Version: 2151
FPGA: 1/12/22/ 10:35:23
OS State: 1
Audio Board: Type 2
DNA Valid: true
DNA: 100E-75CC-5C73-30
Fan between 1050 and 1100 RPM and not loud at all….
I guess my ambient temperature is by about 5°C lower (you can see it at the mininmum temparerture readings).
I would expect that the fan is running faster if the ambient temperature is higher, but 2500 RPM at a slightly higher ambient temp. Doesn‘t sound logical.
My CQ20 fan is quieter than ambient, so I suspect inside the level A&H quote. Of course I have no experience with the CQ18 .
I have looked a fan noise reduction on amps before and there are two types of noise. The first turbulence, the noise generated by the rotation or the fan blades. It is hard to reduce this as it is proportional to fan speed. Slowing the fan speed will improve it BUT reduce cooling.
The second is transmitted vibration, where the mechanical vibrations are conducted through the metalwork.
Finally the fans could be out of spec noise wise. There is nothing that can be done on a forum to decide that so you will have to get back to the Distributor/AH.
@Nicola A&H are there certain FX or processing features that tend to cause the unit to run hotter or is it primarily dependant on ambient temperature? Can switching to ethernet or turning off bluetooth help? Clearing unused FX racks? If so I could make a “Quiet Recording” Show and use that for recording in quiet environments. Did some very preliminary testing. Base was around 1200 rpm. Loading all empty effects racks, switching to Ethernet and turning of bluetooth brought it down to between 950 and 1150 rpm. Changing brightness levels had no effect.