PC case fan pins

[another random person]

I was wondering why my fans were loud which was when I realised my mobo didn't have fan speed controller properties, so my question is : how many types of fan connectors are there and what are their purposes? (eg, 3 pins) Also, how does DBA work because my PC fan, rated at 30 dba runs at 50- 60 decibels on a DB meter.

 

Any help is greatly appreciated.

 

[SinisterPat]

Well there are 2 types. One is 3 pin and another is 4 pin. 
The two pins (power and ground) can go by themselves (as a result you can make a usb case fan)

The third pin is for RPM measurement. All computer fans have it these days.

And the fourth pin is for PWM fan control. This is used to let the motherboard control the fans based on temperature, etc.

 

For the last one, I'll let somebody answer.

[another random person]

1 minute ago, SinisterPat said:

Well there are 2 types. One is 3 pin and another is 4 pin. 
The two pins (power and ground) can go by themselves (as a result you can make a usb case fan)

The third pin is for RPM measurement. All computer fans have it these days.

And the fourth pin is for PWM fan control. This is used to let the motherboard control the fans based on temperature, etc.

 

For the last one, I'll let somebody answer.

 

ok thanks, so would that mean that my 3 pin fans would work with a fan controller?

[SinisterPat]

Just now, another random person said:

ok thanks, so would that mean that my 3 pin fans would work with a fan controller?

Does your fan controller have 4 pins for each fan?

[another random person]

2 minutes ago, SinisterPat said:

Does your fan controller have 4 pins for each fan?

my fan controller has 4 pins but it says i works with 3 pins, i havent tried it yet.

[SinisterPat]

Just now, another random person said:

my fan controller has 4 pins but it says i works with 3 pins, i havent tried it yet.

Try it first. Then report back if it works. Or not...

[another random person]

1 minute ago, SinisterPat said:

Try it first. Then report back if it works. Or not...

ok thanks, ill try it out later

[Naeaes]

14 minutes ago, another random person said:

my fan controller has 4 pins but it says i works with 3 pins, i havent tried it yet.

In that case it's dual-function. It's able to control the speed of 3-wire fans by reducing the voltage it gives them (Direct Current or DC-control) and the speed of a 4-wire fan by keeping the voltage at max but cutting it rapidly on and off in sync with the operation of the magnetic motor (Pulse Width Modulation or PWM -control).

 

The question about dB(a). It's basically the same as dB. In therms of scale and whatnot. But dB is a measure of all the noise and dB(a) is only the noise an average human can hear. The noise that those fans make is probably such a low hum that it's ignored in the dB(a) measurement but since dB catches everything (within the scope of the monitor device), it'll give you a higher number.

[another random person]

7 minutes ago, Naeaes said:

In that case it's dual-function. It's able to control the speed of 3-wire fans by reducing the voltage it gives them (Direct Current or DC-control) and the speed of a 4-wire fan by keeping the voltage at max but cutting it rapidly on and off in sync with the operation of the magnetic motor (Pulse Width Modulation or PWM -control).

 

The question about dB(a). It's basically the same as dB. In therms of scale and whatnot. But dB is a measure of all the noise and dB(a) is only the noise an average human can hear. The noise that those fans make is probably such a low hum that it's ignored in the dB(a) measurement but since dB catches everything (within the scope of the monitor device), it'll give you a higher number.

 

ok, thanks heaps- (phew i didnt buy a pc front panel decorator)

[LogicalDrm]

Another note on decibels. The scale for them is logarithmic and how high number you see will be different if you measure right next to fan and where you usually sit. I tested this once with phone app (very inaccurate). Difference between table top and chair next to case was 5-7db. And only my PSU fan and HDDs really do bother me.

[another random person]

1 minute ago, LoGiCalDrm said:

Another note on decibels. The scale for them is logarithmic and how high number you see will be different if you measure right next to fan and where you usually sit. I tested this once with phone app (very inaccurate). Difference between table top and chair next to case was 5-7db. And only my PSU fan and HDDs really do bother me.

 

ok thanks, my hdds are mostly quiet so they dont bother me and sapphire has good cooling fans so they are silent most the time. just the case fans are annoying. but when i attach the fan controller it should be better

[LogicalDrm]

3 minutes ago, another random person said:

ok thanks, my hdds are mostly quiet so they dont bother me and sapphire has good cooling fans so they are silent most the time. just the case fans are annoying. but when i attach the fan controller it should be better

There's another note to how fans sound. Just pure numbers don't tell what kind of hum comes out from fans and does your case resonate with them. So just looking at fan specs doesn't really tell you that much of what they do sound like.