Where is my noise coming from?

blahblahbloo · Post by **blahblahbloo** » Sun Jul 27, 2003 6:30 pm

My system is a lot quieter with some new heatsinks I just put in, but it's still kinda loud, and now I can't really tell where the noise is coming from. Here are the noise-generating components:

- 3 stock Lian-Li 80mm case fans (two in front set to medium speed)
- Fujitsu MAN series 10,000 RPM SCSI hard drive, mounted to the case (which is a longer version of the Lian-Li PC-60)
- PC Power and Cooling Silencer 400 ATX
- 2 Panaflo L1A 80mm fans, each mounted on a SLK-800A heatsink
- Visiontek GeForce 4 Ti 4600

Where is my noise coming from? Or could it be case resonance, preventing me from telling where it's coming from by putting my ear up to different things?

blahblahbloo · Post by **blahblahbloo** » Sun Jul 27, 2003 6:50 pm

Oh, forgot one thing: there's a 120mm Panaflo low fan in a hole cut out of the top of the case.

Post by **Rusty075** » Sun Jul 27, 2003 7:29 pm

describe the noise.

Most likely suspects:

1. the SCSI drive is vibrating the heck outta the case.
2. the 4600 is whining like a fat kid in an ice cream parlor

GamingGod · Post by **GamingGod** » Sun Jul 27, 2003 7:46 pm

The hole in the top of the case is letting out all the noise.

starsky · Post by **starsky** » Sun Jul 27, 2003 8:00 pm

I would lay the case on its side, and start by removing the HDD and sitting it on some foam. If the HDD is not it....

Then Disconnect the case fans one by one. After disconnecting each case fan, don't reconnect it.

Then the TI4600. It is the most likely culprit, but could be a bitch to disconnect . If it is still noisy it is only CPU and PSU left...

With the case on it's side and open you should be able to hear if it is the CPU fans or PSU fans ... or PSU electrical noise.

Once you have narrowed that down, If it is the CPU fans (Panaflo's), then you can replace them easy. If it is the PSU or 120mm top of case fan, it is a little harder, but still achievable.

Zhentar · Post by **Zhentar** » Sun Jul 27, 2003 8:36 pm

Stop everything one at a time and see what makes the biggest difference.

blahblahbloo · Post by **blahblahbloo** » Sun Jul 27, 2003 10:10 pm

Rusty075 wrote:describe the noise.

Most likely suspects:

1. the SCSI drive is vibrating the heck outta the case.
2. the 4600 is whining like a fat kid in an ice cream parlor

Well, I'm not sure how to describe it except that it's fairly low pitch, like how a jet engine sounds when it first starts up and hasn't nearly gotten up to speed yet.

starsky wrote:I would lay the case on its side, and start by removing the HDD and sitting it on some foam. If the HDD is not it....

Then Disconnect the case fans one by one. After disconnecting each case fan, don't reconnect it.

Then the TI4600. It is the most likely culprit, but could be a bitch to disconnect . If it is still noisy it is only CPU and PSU left...

With the case on it's side and open you should be able to hear if it is the CPU fans or PSU fans ... or PSU electrical noise.

Once you have narrowed that down, If it is the CPU fans (Panaflo's), then you can replace them easy. If it is the PSU or 120mm top of case fan, it is a little harder, but still achievable.

I started by just unplugging the HDD altogether. (The machine makes most of its noise even at idle, so it was OK that the OS couldn't get loaded.) This didn't significantly impact the noise. Neither did unplugging any of the 80mm case fans or the Ti 4600.

The Panaflo 120 mm on top made a BIG difference.

WIth the 120mm unplugged, I could hear the high pitch whine coming from the HDD. Putting that in a Smart Drive enclosure just about made that noise go away. Now it sounds like the PSU is the loudest component.

blahblahbloo · Post by **blahblahbloo** » Sun Jul 27, 2003 10:21 pm

starsky wrote:Once you have narrowed that down, If it is the CPU fans (Panaflo's), then you can replace them easy. If it is the PSU or 120mm top of case fan, it is a little harder, but still achievable.

Actually, the 120mm top of case fan is very easy to replace. Should I replace it with a Papst, undervolt it, or do without?

GamingGod · Post by **GamingGod** » Sun Jul 27, 2003 11:08 pm

you probably dotn need it. But since you already have a gapping hole in the top of the case then you should undervolt it. It would be best if there was no hole there in the first place though.

blahblahbloo · Post by **blahblahbloo** » Mon Jul 28, 2003 12:02 am

GamingGod wrote:you probably dotn need it. But since you already have a gapping hole in the top of the case then you should undervolt it. It would be best if there was no hole there in the first place though.

Covering the hole with a pillow has no significant impact on the noise level.

blahblahbloo · Post by **blahblahbloo** » Mon Jul 28, 2003 12:42 am

I'm pretty sure the noise I hear now is just turbulence noise from the PSU.

Post by **Ralf Hutter** » Mon Jul 28, 2003 3:56 am

blahblahbloo wrote:I'm pretty sure the noise I hear now is just turbulence noise from the PSU.

That's not suprising, those PP&C "Silencers" are far from silent.

ez2remember · Post by **ez2remember** » Mon Jul 28, 2003 4:43 am

blahblahbloo wrote:
starsky wrote:Once you have narrowed that down, If it is the CPU fans (Panaflo's), then you can replace them easy. If it is the PSU or 120mm top of case fan, it is a little harder, but still achievable.
Actually, the 120mm top of case fan is very easy to replace. Should I replace it with a Papst, undervolt it, or do without?

You should definetely undervolt any 120mm fan. At 12v any 120mm fan will shift too much air and cause a lot of turbulance noise. I would recommend undervolting the fan to 5v. This will still shift plenty of air at this voltage, just make sure it starts at this voltage all the time, if not increase a little.

If your noisiest component is your PSU when the 120mm fan is disabled and your HD is in a Smart Drive enclosure. I would recommend modding with a quieter fan OR getting a new PSU that is quiet.

Even 80mm Panaflo 'L1a' is not quiet at 12v, they whine. Consider reducing the voltage to about ~9v where the whine seems to dissapear at this voltage.

pingu666 · Post by **pingu666** » Mon Jul 28, 2003 5:09 am

stick the fan on the outside of the psu, hey it works

. also remove any grills as they add to the noise

POLIST8 · Post by **POLIST8** » Mon Jul 28, 2003 5:30 am

Hahahaha

Fat kid at an ice cream parlor.

Yeah dude, you've got a ton of fans, a 120mm hole letting that Gforce card and your SCSI HDD's noise out.

Try decoupling your hard drive and putting it at the bottom of the case w/foam and cover up that 120mm hole.

starsky · Post by **starsky** » Tue Jul 29, 2003 5:32 pm

I would definitely undervolt the 120mm fan to 5v. Given natural convection, it won't need much speed to add decent exhaust. At 5v it should be inaudible if it is an L series.