Hi all

Please check out this thread: http://forum.rscnet.org/showthread.php?t=290322

in the beginning is a couple pics of a pc in a box with a subwoofer. Will I experience any problems from the magnet of the subwoofer? Erased harddrive? anything like that?

If so, is there some sort of sheild I can put in there? Something easy to find, and cheap?

tnx

 

hi ryan,
At one time you could buy 'mu-metal' sheet for magnetic screening, not sure if its still around.

If you can keep the woofer and HDrive as far apart as possible, I wouldn't expect any problems with the HD.

You may have to do some 'airflow' work around the fan, else the noise will be irratating.
Ventilation/cooling may be a problem, wood is a good thermal insulator.

EDIT:
Quick Google!

http://www.lessemf.com/mag-shld.html

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For me it looks like its not enough with the ventilation INLET & EXHAUST.
For the VIBRATION matters you must use a laptop hard disk for long life.

Your subwoofer controllers are inside the box how you going to control it?

What about the display? Or did you configured as a character LCD panel?

How was the sound?

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Eric: I cant find anything like that mag-sheild stuff in South Africa, but I should imagine if I make a small box out of 1mm galvanised sheet metal to cover the subbox, this should help?

Harddrive is about 30cm away.

What do you mean airflow work... and the noise? You mean I should put some ducting in or something? I dont think I will hear any noise, the 5.1 surround sound should drain any fan noise from within the box?

Gayan:

You think I should add another fan?
I will look into the laptop drive if this one dies.
I dont really plan on changing the settings on the sub, all it is a gain pot, which I will leave at like 3/4, and operate the bass settings via the software. I have considered remote mounting the gain knob though.

This sim is still work in progress, I am mounting a steel arm just behind the steering wheel which will hold up a 22" widescreen LCD. (Dont understand what you mean about a character LCD panel.

Havent tested the sound yet, will let you know.

thanks all.

EDIT: btw, I dont know if you saw, but there is a fairly large (+- 10cmx18cm) exhaust port directly opposite the fan, difficult to see in pic, but if you look, its there.... Surely that should be sufficient?

 

What you need is mu-metal, I can't say I've ever seen it for sale anywhere?, but it was used to make shields for oscilloscope tubes.

Normal metal won't help at all.

But, like the others, I don't consider the magnetic field likely to be a problem?, the massive vibration caused by the sub-woofer is more likely to be a concern though. Even laptop drives aren't designed to used in such a rough environment - I would suggest using a solid-state drive might be a FAR better idea!.

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you can order mu metal online, its extreemly effective at deflecting magnetic fields, however, I hope you have some money to spend, because it costs ALOT!

 

hi ryan,

What do you mean airflow work... and the noise? You mean I should put some ducting in or something? I dont think I will hear any noise, the 5.1 surround sound should drain any fan noise from within the box?

The cooling air must flow around the modules in the box for best effect, just don't blow/suck air thru the box.
Drives do get hot so pay special attention to their cooling.

The galvanised steel will have little effect on the magnetic fields.
If you do find some mu-metal its expensive, try a local scrap merchant, he may be able to source some for you.

Sorry about delay in reply, picked up a damned virus from the web.
It got thru all the Firewalls, Norton and the Sky blockers and I cannot shift the bl**dy thing.

Intend reformatting the HD tomorrow and reloading XP.

Anyone reading this any cures for the woso.exe????
Ive tried all the usual web advice, no avail, running in 'Selective startup mode' with woso disabled, I hope.

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Well, did the display of my simulator at the show, was a great success.

I found that with the lid off, the internals definately overheated, I experienced a system lock up. So I removed the lid, and the system ran perfect the whole day. Seems the heat was a problem. I think I will make a new lid out of steel mesh, much like speaker mesh, should be the best solution.. right?

After that system lockup, windows restarted and ran a checkdisk, and subsequently found 8kb in bad sectors. Do you think this is a result of the overheating, or magnetic problems? I never managed to sheild the sub, had no time.

Thanks.
Ryan

 

It shouldn't be magnetic problems in my experience. One way to fix this is to glue a smaller magnet to the back of the speaker in reverse polarity. This will cancel out a fair amount of the external magnetic field and increase the motor strength of the speaker at the same time by forcing more of the flux from the speaker magnet through the motor structure. Partsexpress.com sells them. They are called bucking magnets and are pretty cheap. Their shipping is on the high side though. Experiment with a couple sizes for the best solution.

 

hi Ryan,
The disk corruption IMO would be due to overheating, is it possible you had these bad sectors before the crash???,
Did you do a disc check sometime before and find it OK?

Its also possible that some disc damage occurred in transit to the show?

A remote possibility is if the sub woofer is causing strong vibrations in the box, which are transferred to the drive???

Pleased the show went A OK.

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Eric
"Good enough is Perfect"

PIC tutorials:
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Bill's: www.blueroomelectronics.com/

 

SpeakerGuy: I will look into your solution, sounds cheaper and fairly promising.

Eric: No ways I had the bad sectors before,... brand new harddrive, never used.... unless it came from the supplier like that.

I suppose the disc damage could have been caused in transit, although I transported it myself, and never dropped it or anything, and it rode the whole way in my BMW which has a great ride quality

The sub isn't so strong, but its a possibility. I will check to see how much vibration the hdd gets whilst the sound is on.

Thanks again for your input Eric, you're a legend!

btw. I will have some time soon again, maybe this week to begin work on the new circuit for the gear display. will keep you posted.

l8r's

 

I would agree that the magnetic field is the problem. I've damaged an old 39MB drive before by sticking a magnet to it.

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Harddrive itself is vibrated and containing many magnetic component inside.
I think that small magnetic field isn't harmfull to your drive.
My dec-2000 40GB drive is near PC speaker, and still health now.

 

May be temperature is more danger than subwoofer.

 

Another problem the fan holes can effect the quality of the sound it means the holes acting like a BASS holes.

If you can divide the subwoofer & the Motherboard separately it will be quite ok. But More work.

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