Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 21-12-2013, 05:04   #1
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 3,585
Speaker magnetic inteference?

Hello Cruisers,

A while ago I pulled out the very tired old set of massive speaker boxes in the cabin, and consigned them to land fill. Chipboard boxes do NOT look good after 20 or so years.

Now I am about to replace them with something a lot smaller, but I am worried about interfering with the compass or either of the fluxgate sensors on the boat.

Is there a rule of thumb for how far away these should be from the speakers, if the speakers do not have any special shielding?

Matt
__________________

__________________
GILow is offline   Reply With Quote
Old 22-12-2013, 09:45   #2
Registered User

Join Date: May 2011
Location: Toronto
Boat: Sandpiper 565
Posts: 2,943
Re: Speaker magnetic inteference?

I would aim to have speakers at least 2 m (6.5 feet) away from the helm compass and fluxgate compass sensor.

But it's easy to confirm whether you're getting interference... make note of your compass readings, then bring the speakers aboard and check for changes. You can also try moving the speakers toward the compass to see how much influence the speaker has and at what distance. Or test with a pocket compass.

Does anyone still "swing" their compass, or pay a pro to do so? That's the gold standard for detecting and factoring out any remaining magnetic influence.

Good "shielded" speakers are still available - look at some of the small monitor speakers sold for home studios, for example.
__________________

__________________
Lake-Effect is offline   Reply With Quote
Old 22-12-2013, 10:02   #3
Registered User

Join Date: May 2008
Location: British Columbia, Mexico
Boat: S&S Hughes 38
Posts: 837
Images: 23
Re: Speaker magnetic inteference?

I had shielded marine speakers mounted in cockpit(bad idea,PO).I routed my longwire GTO cable near speakers ,as was nowhere else to run it.When I removed speakers ,my SSB reception improved dramatically.
__________________
highseas is offline   Reply With Quote
Old 23-12-2013, 12:33   #4
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 3,585
Quote:
Originally Posted by Lake-Effect View Post
I would aim to have speakers at least 2 m (6.5 feet) away from the helm compass and fluxgate compass sensor. But it's easy to confirm whether you're getting interference... make note of your compass readings, then bring the speakers aboard and check for changes. You can also try moving the speakers toward the compass to see how much influence the speaker has and at what distance. Or test with a pocket compass. Does anyone still "swing" their compass, or pay a pro to do so? That's the gold standard for detecting and factoring out any remaining magnetic influence. Good "shielded" speakers are still available - look at some of the small monitor speakers sold for home studios, for example.
sounds like a sensible approach. Certainly easy to do in the marina too. Our main compass was last calibrated about 10 years ago but before that it was done every couple of years by the original owner. I guess gps has changed how much importance people attach to the compass.
__________________
Very funny Scotty, now beam down my clothes.
http://www.swansonsailor.id.au
GILow is offline   Reply With Quote
Reply

Tags
enc

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 05:48.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.