Cavity shielding?

[LushTone]

So I have a Warmoth strat body that I'll be shielding soon. It's been top routed H-S-H and has a battery box rout. I'm hoping to get some recommendations on shielding it all. Is copper tape or shielding paint better? Should I shield the entire cavity or just where the controls go? I'm just trying to get some opinions, any feedback is appreciated!

 

[pabloman]

IME shielding isn't all that important. Solid wiring is far more beneficial. Good solder joints and proper grounding are key. You have a battery box, does this mean you're using active electronics? If so then shielding is absolutely not necessary. In all honesty I've never shielded a guitar. My production guitars came that way but nothing I've built is.

 

[gjacob]

I've used both.  I think the paint looks better, but is more expensive.  Good wiring with shielded wire for long runs will go a long way, but cavity shielding will not hurt at all.  If you do a good job, you can have the gain on 11, your hands off the guitar and not a peep from the amp - try doing that with a guitar on the wall at GC.

The foil is cheap, easy to find on eBay, and just as effective.

 

[line6man]

Copper is superior to paint. Paint is not as continuous as copper.

 

[LushTone]

Yea I have Emgs in my current wired pickguard, but I'm going to wire a passive setup for the same guitar while using the Emgs in the meantime. But I want to take care of any shielding first. If I go with the copper, where are the most critical areas of the cavity to shield?

 

[line6man]

where are the most critical areas of the cavity to shield?

It doesn't work that way. If you miss anything, the shielding is not effective. It is like waterproofing a submarine. One leak is all it takes to defeat all of your hard work.

 

[LushTone]

Hmm so ideally you would copper tape the pickguard underside, pickup routs, and control cavity completely?

Leaning towards no shielding at this point...:laughing7:

 

[bagman67]

Trouble is, if you have a hole in your cage - like, for the top of the pickup to stick through, for example - it ain't a completely shielded system, which is to say, it's not shielded.  You have these antennae sticking out of the so-called shielded space, and they consist of a few miles each of wire.  So use shielded wire for your runs inside the axe, because that will tend to have a useful effect - but beyond that, there is profound disagreement on whether you'll get any benefit at all.


That said - some folks report improvements anyway, and maybe they are really experiencing improvements due to the presence of he copper foil tape all over the place.  Or maybe they're taking extra special care to solder really well.  I dunno.  A shielded cavity can look really nifty, and that alone can be gratifying for a lot of folks. 

 

[line6man]

Hmm so ideally you would copper tape the pickguard underside, pickup routs, and control cavity completely?

Leaning towards no shielding at this point...:laughing7:

Yes, that's how it's done.

Why skip such an easy step? Just treat it as part of the building process. You have nothing to lose.

 

[Cederick]

It doesn't work that way. If you miss anything, the shielding is not effective. It is like waterproofing a submarine. One leak is all it takes to defeat all of your hard work.

So... How do you go about with the gap between pickup and pickguard? That should make the "submarine" sink pretty quickly...

Personally I've never shielded a guitar and don't have much problem with noise, but I play humbuckers 95% of the time anyway. Passive that is. I like EMGs but I don't have them in any guitars now, but they are very quiet and nice.

 

[Cagey]

So... How do you go about with the gap between pickup and pickguard? That should make the "submarine" sink pretty quickly...

It's not the gap that's the problem, it's the pickup itself and that entire hole the pickup sticks up through. The pickup acts as very long antenna listening for very slight variations in the electromagnetic spectrum (EMI), and the hole is a leak to the internal wiring as well. You could shield the internals as aggressively as you'd like, and you'd still have the antenna sticking out.

But, that's generally only a problem with single coil pickups. Noiseless pickups generally use two coils wired out of phase with each other so that any EMI they pick up is cancelled out. Unfortunately, that would also prevent them from picking up the strings, so they reverse the magnetic field on one of them. This has the effect of reversing the magnetic polarity of one of the coils, so if you tickle the field (by vibrating a string, for instance), you create a signal in one coil that's out of phase with the other. Since the coils are wired out of phase, the two signals now add rather than subtract, while external influences on the coils subtract. Now all you hear is string and no noise. You don't need to shield against noise, it's simply cancelled. You also end up with a higher output, so you can wind smaller coils. Which, incidentally, is why split humbuckers often sound wimpy and noisy.

Now, even with noiseless pickups, you can still get noise just from the internal wiring. The run to the output jack is the most common culprit, but pickup switch wiring can be problematic as well. There, you'd think shielding the cavities would be helpful, but it usually isn't. What you need to do is use shielded cable. Works a million times better. Still not 100%, but it's as close as you can practically get.

Of course, you can paint/plate/foil/etc. the cavities if you want to and it won't hurt anything - might even look kinda cool if you're of a mind to run around with your pickguards and covers hanging off or missing - but it doesn't help anything either except StewMac's and their supplier's bottom lines. It's just one of those things that seems like a good idea from a theoretical POV, but has no practical value.

 

[LushTone]

So... How do you go about with the gap between pickup and pickguard? That should make the "submarine" sink pretty quickly...

It's not the gap that's the problem, it's the pickup itself and that entire hole the pickup sticks up through. The pickup acts as very long antenna listening for very slight variations in the electromagnetic spectrum (EMI), and the hole is a leak to the internal wiring as well. You could shield the internals as aggressively as you'd like, and you'd still have the antenna sticking out.

But, that's generally only a problem with single coil pickups. Noiseless pickups generally use two coils wired out of phase with each other so that any EMI they pick up is cancelled out. Unfortunately, that would also prevent them from picking up the strings, so they reverse the magnetic field on one of them. This has the effect of reversing the magnetic polarity of one of the coils, so if you tickle the field (by vibrating a string, for instance), you create a signal in one coil that's out of phase with the other. Since the coils are wired out of phase, the two signals now add rather than subtract, while external influences on the coils subtract. Now all you hear is string and no noise. You don't need to shield against noise, it's simply cancelled. You also end up with a higher output, so you can wind smaller coils. Which, incidentally, is why split humbuckers often sound wimpy and noisy.

Now, even with noiseless pickups, you can still get noise just from the internal wiring. The run to the output jack is the most common culprit, but pickup switch wiring can be problematic as well. There, you'd think shielding the cavities would be helpful, but it usually isn't. What you need to do is use shielded cable. Works a million times better. Still not 100%, but it's as close as you can practically get.

Of course, you can paint/plate/foil/etc. the cavities if you want to and it won't hurt anything - might even look kinda cool if you're of a mind to run around with your pickguards and covers hanging off or missing - but it doesn't help anything either except StewMac's and their supplier's bottom lines. It's just one of those things that seems like a good idea from a theoretical POV, but has no practical value.

This makes a lot of sense. Thank you

 

[line6man]

So... How do you go about with the gap between pickup and pickguard? That should make the "submarine" sink pretty quickly...

And that's why shielding is usually ineffective. It's almost always an incomplete job, so it does nothing.

 

[Strat Avenger]

Shielding is 100% UNnecessary if you run humbuckers and/or hum-canceling single coils (which you should be).

Just make sure the back of your plastic pickguard has aluminum tape on the back of it to eliminate static.

 

[sixstringsamurai]

Shielding is 100$% UNnecessary if you run humbuckers and/or hum-canceling single coils (which you should be).

Just make sure the back of your plastic pickguard has aluminum tape on the back of it to eliminate static.

I had an SG with that issue, so I did the inside of the cavity cover, Backside of the Pick guard, that should've dealt with the issue, right?

Nope, no matter what I did, that SOB would pop and crackle with the slightest bit of friction, and it was worse in the winter.

Great looking and sounding guitar, and the dude I sold it to hasn't had a bit of issue with it...... :icon_scratch:

 

[LushTone]

Shielding is 100$% UNnecessary if you run humbuckers and/or hum-canceling single coils (which you should be).

Just make sure the back of your plastic pickguard has aluminum tape on the back of it to eliminate static.

I had an SG with that issue, so I did the inside of the cavity cover, Backside of the Pick guard, that should've dealt with the issue, right?

Nope, no matter what I did, that SOB would pop and crackle with the slightest bit of friction, and it was worse in the winter.

Great looking and sounding guitar, and the dude I sold it to hasn't had a bit of issue with it...... :icon_scratch:

Hmm I smell more hocus pocus in the guitar industry.. :laughing7:

 

[Cagey]

Hmm I smell more hocus pocus in the guitar industry.. :laughing7:

Actually, it's not the guitar industry that's at fault as much as their market. Most manufacturers know a lot more about building guitars than their customers do. It's not rocket science. But, there's a huge percentage of the market that demands things that don't make much, if any, sense. Lotta junk parts, bad designs and poor practices still being propagated simply because people demand to have the same gear their heroes used, or as close to it as possible. If you wanna be in the business, it's like any other - you gotta give the people what they want.

It doesn't always happen. In the case of cavity shielding, since that's the topic at hand, you'll notice almost nobody does it but DIY builders. The OEMs know it's not only worthless, it's labor intensive to apply. So, they'd have to raise their prices a noticeable amount to compensate, which would make them uncompetitive. On the other hand, junk bridges and tuners are easy to supply at substantial markup, so why not? Jimi Hendrix and Eric Clapton used them, and they're no slouches. That's why we still see 6 point Strat vibratos, string trees, and sloppy-assed Kluson tuners.

 

[GoDrex]

I had an SG with that issue, so I did the inside of the cavity cover, Backside of the Pick guard, that should've dealt with the issue, right?

Nope, no matter what I did, that SOB would pop and crackle with the slightest bit of friction, and it was worse in the winter.

Great looking and sounding guitar, and the dude I sold it to hasn't had a bit of issue with it...... :icon_scratch:

just curious - did you connect the shielding to ground?

 

[gjacob]

There are some compelling arguments, but from personal experience it makes a difference.

I had a MIM strat that would pick up the local AM radio station as well as 60-cycle hum from virtually anything nearby.  Taped the cavity and pickguard, and it was dead quiet even with the crappy pickups.

I think Fender uses shielding paint on some of their newer guitars, Carvin uses foil.

 

[sixstringsamurai]

I had an SG with that issue, so I did the inside of the cavity cover, Backside of the Pick guard, that should've dealt with the issue, right?

Nope, no matter what I did, that SOB would pop and crackle with the slightest bit of friction, and it was worse in the winter.

Great looking and sounding guitar, and the dude I sold it to hasn't had a bit of issue with it...... :icon_scratch:

just curious - did you connect the shielding to ground?

Yeah and it got worse...