Monitor distortion caused by speakers?

[Shoegazer]

Hello:

Recently I purchased and assembled a SlikStik Classic cabinet - which is quite the bomb for anyone interested in top quality cabinets.  There are a few small issues I'm addressing, one of them being some distortion that appears on my monitor, which is the new Wells Gardner D9400.  The top-center of the screen "sags" as the screen is maybe 1/4-inch higher on the left and right sides than the center.  Also, the screen resolution is slightly fuzzier on the left and right-hand sides of the screen until maybe 3-4 inches inward (though it extends from top to bottom).

I believe this is being caused by intereference from the two Sony Xplod 5.25" speakers that are immediately above the monitor.  I've tried several DIY options to remove the intereference, such as putting two empty tuna-fish cans immediately over the top of the magnets, but it didn't seem to do much.  So I found this online:

http://www.lessemf.com/faq-shie.html#speakers

MagnetShield/JointShield seems to be a decent (though more costly) option to fix the problem, but I'm not quite sure if the monitor distortion is really related to EMI from the speakers or something else (a bad monitor?).  I'm interested in hearing if any of you have had this sort of problem before and what you are doing to address it.

Thanks,
Darren

http://nonmame.retrogames.com

[BamBam]

Have you considered shielded replacement speakers.  I got a set of Klipcsh Pro media speakers in my cab and they only cost $70.00 (CDN)
I don't think I would want to leave the speakers near that nice monitor for long, or you may damage the monitor.

John

[NightGod]

Have you tried moving the speakers to confirm that they are the source of the problem? I'd personally start there.

[somunny]

Follow nightgod's advice and if that is your problem, I'd suggest picking up a pair of bucking magnets from Parts Express.  I have similar speakers to yours and the magnets fixed my problem.

Steve

[AMDman13]

Yes bag those bucking magnets before you do major damage! It's well worth it!

[Shoegazer]

Hey thanks, guys - at just a few dollars, these magnets are definitely a lot less than the $60 or so I was going to pay for the other stuff.

A quick Google search pulled up this:

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=329-212

Given that the bucking magnet's dimensions are 75mm x 32mm, I'm assuming 32mm is the measurement for the inner ring - I guess that makes sense, right?  I just want to be sure I get the ones that are the closest fit for my 5.25-inch Sony Xplod speakers..

Thanks again,
Darren

http://nonmame.retrogames.com

[somunny]

You Don't want them to match up exactly.  You're looking for a bucking magnet that is roughly 1/2 to 2/3 the size of the magnet on your speakers.  Try checking the specs for your particular model.  There should be an ounce value in there somewhere.  Use that to determine the size of the magnet you need to purchase.

Or guess. 

[Shoegazer]

Somunny:

Thanks for the tip.  The speakers didn't come with very good documentation but at least the website posts the following dimensions for my speakers:

Frequency Response (Hz): 40-30,000
RMS Power (W): 45
Nominal Imp (Ohms): 4
Sensitivity 1W/1M (dB): 90
Max Power (W): 220
Cone Material: HOP/paper/PEI
Mounting Diameter (inch): 4-1/2
Diameter (inch): 4-1/2
Mounting Depth (inch): 1-13/16

I got that here:  http://xplodsony.com/xplod/speakers/XS-V1342A

So it looks like the only useful information is the "4-1/2 inch" diameter measurement.  I'm going to have to do some more digging to figure out what's best - I just expanded my search on Parts Express and found *seven* bucking magnets of various sizes and weights!

Thanks,
Darren

[somunny]

Well, the magnets are cheap enough that you could use the dimensions from those found on you speakers, calculate approximately what size you will need and buy several pairs in the general range.

Steve

[Shoegazer]

Yup - that's exactly what I did.   

Can't wait to try them out.  I hope they are better than my tuna fish can solution, which barely works at all!   

Darren

http://nonmame.retrogames.com

[Shoegazer]

Ok, I tried the bucking magnets previously suggested but they didn't work - in fact they actually made the problem WORSE (discoloration on the sides, even fuzzier resolution, etc).  I'm wondering if there's something I need to be doing with them besides placing them over the top of the speaker magnets?  It doesn't look like I have too many options!

What are other people doing to combat monitor distortion from speakers?  Are there shielded speakers anyone recommends?  These Sony Xplods seem to cause really serious distortion on my Wells Gardner D9400 - so much so, I'm surprised other people haven't mentioned the same problem.

Darren

[NightGod]

You sure you are putting them on the right way? They have to be in reverse polarity-try flipping them over, if you haven't already.

[Shoegazer]

Yep, tried that - and even degaussed the monitor again.  No dice.  Good suggestion though.  It's REALLY bad when the polarity isn't reversed, so you definitely know which direction is correct.

[Quarters]

Sounds like you should take this up with SlikStik. After paying $$ for a complete cab you should not be paying $$ to fix it. 

[divemaster127]

That is not a slikstik issue thats a speaker/monitor issue which you add on yourself, I also had this issue but the bucking magnets solved it
dm

[somunny]

That's strange.  Like I said before, I have a similar setup and the magnets worked perfectly.  Maybe they're too big?  You should have to hold or clamp them on when poles are facing like/like.

I had a set of smaller speakers that I was trying to use magnets on  The magnets I had were too large (I believe) and would hold regardless of pole orientation.

Steve

[Kevin Mullins]

Have you removed the speakers and done a clean degauss just to verify the problem is fixable without the speakers present?

It is very hard to battle earth magnetics even with these "bucking magnets". The strength and purity of the speaker magnet can be hard to compensate for.

[_) (V) (-)]

Just a tip from my past experiences...

If you've had these speakers in close proximity to your monitor for any length of time (say a day or more) you may have already magnitized the screen in the monitor. This is usually noticed as strange discoloration or rainbow paterns on the screen while displaying a white image. It may take a few days and/or several degausings (sp?) to clean up.

Do as Kevin (and Nightgod) suggested, and remove those speakers for a couple days. Then check the monotor and see if the distortion is still there before you waste anymore $$$.

Just my $0.02. 

[NightGod]

Just a tip from my past experiences...

If you've had these speakers in close proximity to your monitor for any length of time (say a day or more) you may have already magnitized the screen in the monitor. This is usually noticed as strange discoloration or rainbow paterns on the screen while displaying a white image. It may take a few days and/or several degausings (sp?) to clean up.

Do as Kevin (and Nightgod) suggested, and remove those speakers for a couple days. Then check the monotor and see if the distortion is still there before you waste anymore $$$.

Just my $0.02. 

Good point on that-about a year ago I bought a bunch of Neodymium magnets off Ebay and my kid *ran* past the TV holding them and I had a rainbow pattern for most of a week. I imagine having them sitting there causing distortion for an extended period of time would have only made it worse.

[NIVO]

just for kicks.....hows the marquee lighting in there? how close to the monitor? Certain lighting transformers and monitors dont mix(in other words its noticeable, and then not so noticeable, depending on given situation, spacing, wattage etc etc). Try without light on? Just some ideas for you that dont cost a nickel

[postalp123]

Just a suggestion, but most CRT tubes don't like being tilted, see if maybe leveling the monitor might help.

[Shoegazer]

Okay, folks - time for an update on this.

Several of you have had some great suggestions, all of which I tried:

1) I removed the speakers completely and did a degauss with them being nowhere near the monitor for several hours.  No dice - I get the same problem. 

2) I turned the flourescent light off and left it off for several days.   I mounted it a bit further to the back of the cabinet than I believe most folks do.  Still same problem.

3) I tried plugging into a different computer, thinking it might be the video card or drivers.  Same problem.

A few clarifications - I bought all the bucking magnets in the general size I was looking for (3-4 sets) and in all cases, they are almost exactly the same size as the Sony Xplod magnets, i.e. within a millimeter or two.  So, they fit like/like poles without clamps or anything - they just stick on there.

About the only thing I haven't tried is leaving the speakers out of the cabinet for several days (I've had them out for several hours, but that's about it). 

I'm starting to wonder if this was maybe a bad monitor issue to begin with?  Again, I'm not having discoloration issues or rainbow patterns - rather, a "bowing" effect where the screen appears to sag just a little in the top-center, along with a 4-5 inch wide fuzzy resolution down the left and right sides.  For example, the WinXP clock numbers at the bottom-right are barely readable.  Does that sound to any of you like a magnet would be the cause?  As far as I know, the monitor doesn't go higher than 800x600, but it is definitely slightly clearer towards the center, so I doubt it's purely a resolution thing.

Anyway, thanks again to all of you for your help and suggestions.

Darren

http://nonmame.retrogames.com

[grantspain]

its best to post a pic of the problem,the only way your tube could be bad is if the shadow mask is damaged and that is unlikely unless the tube had some sort of impact-more than likely your fault is the ptc component which is basically the switch for the degauss coil

[Wade]

its best to post a pic of the problem,the only way your tube could be bad is if the shadow mask is damaged and that is unlikely unless the tube had some sort of impact-more than likely your fault is the ptc component which is basically the switch for the degauss coil

I think that what he is seeing is normal for a monitor of this type.  He is probably expecting it to look "too good".

The dip in the top could probably be adjusted out with the controls?  You could also try tweaking the focus knob on the flyback carefully, you might be able to improve the sharpness on the sides a bit.

Wade

[Shoegazer]

Wade:

What you say makes complete sense, and in fact, I thought for sure the monitor settings would fix at least the "bowing" in the top center.  However, the WG D9400's internal controls do not allow you to adjust that particular aspect (though it provides settings for just about everything else!)  So I'm struck out there.

As far as the focus knob on the flyback, do you know where generally that would be located on a digital monitor of this type?  I realize this sounds newbish but I don't really know where that is.  I had a brief discussion with a WG engineer a while ago who did not mention this as being a solution, but I guess it's worth a shot, right?

Thanks,
Darren

http://nonmame.retrogames.com

[Wade]

I have a D9200 which is almost the same monitor, and I didn't know if it had an adjustment for that bow on top but I know it has a lot more adjustments than any other arcade monitor I've seen.  It was worth mentioning.

The flyback is a large (roughly 3" wide) black plastic thing mounted to the chassis boards with two small knobs on the side, and a big red cable coming out of the top.  One knob is labelled Screen, one Focus.  (this is common to all CRT monitors).  Use a small screwdriver to very slightly tweak the Focus knob.  If you are uncomfortable, do it with the monitor OFF.  Just go a little bit one way, and then a little bit the other way, and see if the sharpness improves.

It is hard to judge whether what you are seeing is "normal" or not, by your description, and since you don't know exactly what to expect.  And a photo probably wouldn't show it either, but you could try getting some pics if you have a good camera.

Wade

[headkaze]

Shoegazer: I have the same problem with my cab, but international orders from parts express require a minimum order of $50 (US)! If you don't have any use for the magnets I'll be more than happy to pay for postage and the magnets. I have PayPal if you can accept payments that way.

Let me know if it's possible, you can email me at headkaze [at] gmail.com