Gearslutz.com

All Advertisers
Go Back   Gearslutz.com > The Forums > Geekslutz forum


New Reply New Reply Thread Tools Search this Thread
Old 10th November 2008   #1
Gear Head
 
Join Date: Nov 2007
Posts: 40

Thread Starter
Red face Monitor Hum!!!

Hello Slutz!!!

Can anyone be kind enough to enlighten me as to why this is happening????

So I sit in my room where there is only one power outlet. The only thing I plug into it is my powered monitor (Event ALP5) with no signal cable connected or anything. Just the power cable. No other things in the room are running.

There is an annoying hum in my speaker and when I moved the power cable around in different positions the hum decreases in certain spots. Almost disappears sometimes...

Any ideas what's going on?

Thanks.


I love Slutz!!!!
pinklesson is offline   Reply With Quote
Old 10th November 2008   #2
Moderator
 
EveAnna Manley's Avatar
 
Join Date: Jul 2002
Location: Chino, CA (cowtown)
Posts: 671

Send a message via Skype™ to EveAnna Manley
Does it hum also with something connected to the input? It is not unusual for something to hum or buzz with an open input. Go ahead and find the quietest place for that power cord while you're at it though.
__________________
Cheers, EveAnna Manley, Manley Laboratories, Inc.
www.manleylabs.com
EveAnna Manley is offline   Reply With Quote
Old 11th November 2008   #3
Gear Head
 
Join Date: Nov 2007
Posts: 40

Thread Starter
Yeh it does still hum when something's connected...
Also the the amount of gain on the speaker has no effect on the hum. It's exactly the same whether it's cranked right up or turned right down...
pinklesson is offline   Reply With Quote
Old 11th November 2008   #4
Gear Guru
 
tINY's Avatar
 
Join Date: Jul 2004
Location: Orygun
Posts: 10,198



Powered monitors....

Are there florecent lights or motors (AC, pumps, heater blowers, conveyor belts) nearby?



-tINY

tINY is offline   Reply With Quote
Old 11th November 2008   #5
Lives for gear
 
Join Date: Sep 2004
Location: UK
Posts: 4,547

Hi
I presume that your mains settings are correct and that your mains supply is not too high, as this could cause the transformer to start to saturate. Is the hum mechanical (the box vibration) or 'audible through the speaker cone'?
Is your mains quite 'clean' and non distorted. If you have a supplty conditioner available does it make any difference?
Matt S
__________________
Matt S
www.mseaudio.co.uk
Matt Syson is offline   Reply With Quote
Old 12th November 2008   #6
Gear Head
 
Join Date: Nov 2007
Posts: 40

Thread Starter
Thanks for the replies.

I'm in Australia by the way... so my outlet is constantly delivering 246-248V. So that all seems fine.

The hum is audible through the speaker cone. There is a buzz along with the hum also. Putting my finger on the cone eliminates some of the hum. Sometimes just grabbing the cable eliminates the hum.
I can also hear some radio through the speaker.

Trying to vomit out as much info here....

No conditioner to try out.
There's obviously some kind of interference, but I'm dying to know why it is happening. And why it disappears when I just lift the cable slightly...



Should I be looking at getting a shielded IEC power cord?
pinklesson is offline   Reply With Quote
Old 12th November 2008   #7
Gear maniac
 
Radioman's Avatar
 
Join Date: May 2008
Location: Roma - Italy
Posts: 188

Quote:
Originally Posted by pinklesson View Post
I can also hear some radio through the speaker.

Should I be looking at getting a shielded IEC power cord?
Maybe RF interference from a local broadcaster intermodulating with AC mains.
A shielded IEC power cord could help you.
Try putting a EMI filter on the AC mains cords and/or wounding mains and audio cable into a ferrite ring.
You can add a ferrite bead on AC and audio cables too.
Radioman is offline   Reply With Quote
Old 12th November 2008   #8
Lives for gear
 
Join Date: Sep 2004
Location: UK
Posts: 4,547

Hi
Physically moving cables around can reduce or even eliminate hum and or interference as you can often 'cancel' it out by having the 'interferance' out of phase. The root cause should be sought really because you don't want to have to tinker with wiring position every time you change ANYTHING!
The fact you have some radio in there is a clue as this should not be happening at anything like a level that interferes with line level monitor signals. Find out which station is broadcast and get technical details from them. A 100KW transmitter 500 Metres down the road will upset things.
Ferrite beads, rings, filters, foil on walls, metal plate the room, pull the nearby transmitter down, move house (studio), the list starts off cheap!
Actually, contact the monitor manufacturers as they should not be so sensitive to 'airborne' interference.
Good luck
Matt S
Matt Syson is offline   Reply With Quote
New Reply New Reply Submit Thread to Facebook Facebook  Submit Thread to Twitter Twitter  Submit Thread to LinkedIn LinkedIn 



Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread starter Forum Replies Last Post
Dynaudio BM15A hum - active monitor hum due to cheap TC Elec amplifier inside? Mitch Manger High end 6 1 Week Ago 02:42 AM
Yamaha monitor hum -Noodles- Geekslutz forum 5 2 Weeks Ago 02:16 AM
Dual monitor set-up with 3rd monitor for video reference. seangp Music computers 5 29th April 2007 01:40 PM
monitor hum? richMOE Low End Theory 10 18th December 2006 02:03 PM
monitor levels changing while in low latencey monitor mode Pro Tools LE turk sanchez Music computers 0 6th August 2006 07:44 PM


All times are GMT +1. The time now is 10:10 AM.

 
 
Powered by vBulletin®
Gearslutz.com Limited - UK Company Number 7597610.
Registered Office: 35 Ballards Lane, London, N3 1XW.

SEO by vBSEO ©2010, Crawlability, Inc.