Shim = Bogus Neck?

[Canadian APII]

The problem I have is with what you are calling "preferred". The obvious questions are "preferred by whom?" and "preferred over what?". And for you it seems that it is your preference over other solutions. I have no argument that those are your preferences.

Oh yes. This is all my preference. This is a great forum to trade opinions and techniques. Even though I am an old dog I am always open to learn new things. I also hope I can pass on my knowledge.

 

[Canadian APII]

It's guitar geometry. That is established at the point where the neck and the body meet. That's how it's done on set necks. That's how it's done in neck through construction. It is no different for bolt-on construction.

I agree that the geometry needs to be corrected. I believe it should ultimately be at the manufacturer level and their build process should be tweeked to eliminate shims. I have a formal education in sound propegation through different materials so I disagree that card shims are the way to go since they act as a tone damper. Yes you will still hear your bass but the quality of tone will suffer by using shims like card or plastic. Sometimes that decreased sustain is desired, sometimes you just want a bass thump instead of it singing, so what it all comes down to is preference.

 

[Turnaround]

I believe it should ultimately be at the manufacturer level and their build process should be tweeked to eliminate shims.

They would if it made sense to do so economically. I doubt that any manufacturer deliberately cuts a bass so that it will require a shim. Putting in a shim is an extra step that costs time/money, and if that step could be eliminated in a cost-effective way, the manufacturers would be all over it.

I disagree that the tone or the sustain of the instrument will suffer by using a card or plastic shim. As I pointed out, analysis of an oscilloscope trace of the signal going to the amp before and after a shim revealed no difference (the shim was plastic, BTW). Though I must admit a poorly-installed shim will have an effect.

 

[Doner Designs]

I was a little skeptical about shimming a neck to get correct uniform string height etc etc . I figured that adding a shim to a neck puts a weird angle on it that is in opposition to relief, bridge saddle height and so forth.

So it was off to my pro-luthier...who promptly informed that Fender and just about everybody other bass with a bolt on neck, the shim factor was already built into the bass and that even back in the day Leo Fender had made allowances for this in the design.
He assured me that shimming a neck is absolutely not an issue at all and it certainly doesn't mean the neck is "messed up".

Are you saying that neck pocket routing typically errs on the side of putting a slight reverse angle on the neck so that adding a shim at the heel will bring it closer to dead straight?

 

[JustForSport]

I doubt that any manufacturer deliberately cuts a bass so that it will require a shim. Putting in a shim is an extra step that costs time/money, and if that step could be eliminated in a cost-effective way, the manufacturers would be all over it.

I certainly don't think they go to the effort of designing/routing a bass to require a shim, tho some DO design and build to Not require one.
It's like 'not seeing anyone coming', and just pulling out into the road
vs Looking AND ENSURING no one is coming before pulling out into the road.
Significant difference, altho many don't see the distinction.

 

[Martin Beer]

Are you saying that neck pocket routing typically errs on the side of putting a slight reverse angle on the neck so that adding a shim at the heel will bring it closer to dead straight?

I had also heard it suggested that Fender originally designed around the use of a shim, though I would be surprised if the neck pocket was ever angled as that would make the routing jig more complex, and Fender was all about simplifying things.
Since there is always a +/- tolerance in the measurements used in manufacturing processes, it would actually be kind of shrewd to design things so that an instrument manufactured absolutely to spec would require a small shim. That way, there would be room to adjust the neck/body geometry in either direction by using either no shim or a thicker shim as required. If they designed around using no shim, adjustment would only be possible in one direction and either smaller tolerances would be necessary or the rate of rejects would be higher, pushing up costs.
I don't know whether this is what they did, but it would seem consistent with Fender's approach back in the day if they valued manufacturing efficiency over "perfect" acoustic coupling.

 

[electracoyote]

I understand your desire for a super low action. Not everybody wants their bass exactly like yours. If you are happy with your set up that is great. We all have different experiences. In mine I have been able to set up all my basses without shims. Some super low. In my experience all have had an increase in sustain and an improvement in tone. IMHO

Same here. The basses I have had to shim over 38 years across all price points are few and far between, and were therefore a relatively rare and frustrating experience. I understand the geometry of a basic setup to taste; everyone who plays my basses is impressed with the setups, low action with little-to-no buzz, and overall playability. That's not a boast; a good setup is not rocket science. The shim doesn't change the basic geometry, which IMO is far more dependent upon level frets, properly adjusted truss/relief, properly cut and slotted nut, and saddle height. Shimming the pocket and re-angling the neck does not change those more vital variables--they all must still be in place. The only thing a shim can do is compensate for a poor relationship between the neck heel and pocket, or a poor or impeding bridge-to-body relationship. It might also give the illusion of alleviating un-level frets or a 14th-fret hump (though it certainly does not). Or, considering how often shims are used, perhaps it simply provides peace of mind, which is the most likely and reasonable explanation for so many people using them.

IME, IMO, YMMV

 

[electracoyote]

Sometimes that decreased sustain is desired, sometimes you just want a bass thump instead of it singing, so what it all comes down to is preference.

Agreed, it's a preference thing for sure. I can't engage the "coupling" debate too much because it's too close to the "wood matters" or "high mass bridge" debates, which are no-wins. I have my thoughts on the matters, and everyone has to come to their own conclusions.

I've played basses with a shim and I could hear a difference when I removed the shim, I've shimmed basses and heard no discernible difference.

 

[202dy]

I agree that the geometry needs to be corrected. I believe it should ultimately be at the manufacturer level and their build process should be tweeked to eliminate shims. I have a formal education in sound propegation through different materials so I disagree that card shims are the way to go since they act as a tone damper. Yes you will still hear your bass but the quality of tone will suffer by using shims like card or plastic. Sometimes that decreased sustain is desired, sometimes you just want a bass thump instead of it singing, so what it all comes down to is preference.

Please do not take my words out of context. I never said that the geometry "needs to be corrected." If you read the post again it is clear that I pointed out where adjustments to geometry are regulated. And further, that is the way the geometry is designed and regulated in both set neck and neck through construction.

Stating your formal education is what logicians refer to as an appeal to authority. It is a logical fallacy, designed to give more weight to an opinion. In other words, it carries no weight other than to possibly define the person behind the opinion.

However, since you do have a formal education in sound propagation, you should be willing and able to present scientific evidence of your assertion that placing a shim in the neck pocket of a bass guitar will cause a situation where "the quality of the tone will suffer."

 

[Canadian APII]

They would if it made sense to do so economically. I doubt that any manufacturer deliberately cuts a bass so that it will require a shim. Putting in a shim is an extra step that costs time/money, and if that step could be eliminated in a cost-effective way, the manufacturers would be all over it.

I disagree that the tone or the sustain of the instrument will suffer by using a card or plastic shim. As I pointed out, analysis of an oscilloscope trace of the signal going to the amp before and after a shim revealed no difference (the shim was plastic, BTW). Though I must admit a poorly-installed shim will have an effect.

Please do not take my words out of context. I never said that the geometry "needs to be corrected." If you read the post again it is clear that I pointed out where adjustments to geometry are regulated. And further, that is the way the geometry is designed and regulated in both set neck and neck through construction.

Stating your formal education is what logicians refer to as an appeal to authority. It is a logical fallacy, designed to give more weight to an opinion. In other words, it carries no weight other than to possibly define the person behind the opinion.

However, since you do have a formal education in sound propagation, you should be willing and able to present scientific evidence of your assertion that placing a shim in the neck pocket of a bass guitar will cause a situation where "the quality of the tone will suffer."

Lol. I brought that up just to show you I am not talking out of my a#$. Maybe I read more into your post because I was talking of neck pockets with an angle cut into them previously. I have two projects on the go right now. When they are finished I have a bass with the G saddle dropped to within a millimeter of the bridge. The body is also plywood which in my opinion really lessens sustain. Ultimately I have an alder blank that I plan to turn into a new body for this bass and I plan to get rid of the flat neck pocket and engineer an angle into it from the get go.

 

[musicman666]

Juat in case it has not been mentioned, the answer to the question is 'no'.

 

[202dy]

Lol. I brought that up just to show you I am not talking out of my a#$. Maybe I read more into your post because I was talking of neck pockets with an angle cut into them previously.

You brought it up because you have no data to back up your statements. You thought you could add weight to your statement by citing education.

 

[Canadian APII]

You brought it up because you have no data to back up your statements. You thought you could add weight to your statement by citing education.

Ha ha ha. We have been through this argument before on here for many different aspects of basses. Maybe I could back it up with NDT pictures but Data isn't what makes music. This is about personal taste. Talkbass is here to spread news, info, advice and opinions. These are my opinions and advice from experience and yes education. use them or don't. No skin off my a#$.

 

[Pilgrim]

To this humble person the answer is still as simple as it was when I commented on the first page.

If you need a shim, use it. If not, don't. No harm, no problem, and it's not an indictment of the instrument.

 

[202dy]

Ha ha ha. We have been through this argument before on here for many different aspects of basses. Maybe I could back it up with NDT pictures but Data isn't what makes music. This is about personal taste. Talkbass is here to spread news, info, advice and opinions. These are my opinions and advice from experience and yes education. use them or don't. No skin off my a#$.

You are right. TalkBass, especially this forum, is about spreading facts and dispelling myth.

If you have data publish it here so others may learn.

 

[202dy]

To this humble person the answer is still as simple as it was when I commented on the first page.

If you need a shim, use it. If not, don't. No harm, no problem, and it's not an indictment of the instrument.

Wisdom is often revealed early.

Unfortunately, it is often dismissed as quickly.

 

[Hillsidebass]

wow...this place has changed

 

[mongo2]

To me, if the bass was well made, it wouldn't need shim. Every time people talk about shimming, it is about a Fender bass, you never hear someone shimmed a Yamaha or a Peavy or a Ibanez ... no, it is a Fender.

Lots of Peaveys have a neck tilt adjustment instead of a shim.

 

[96tbird]

Really? Yeah peavey doesn't shim coz they have a neck tilt system that does the same thing.

http://assets.peavey.com/literature/manuals/80300018.pdf

I swear, you guys gotta quit making crap up to support your shoddy theses.

Quoted myself from page 2 to provide you with the proof, Mongo.

 

[mongo2]

To me, if the bass was well made, it wouldn't need shim. Every time people talk about shimming, it is about a Fender bass, you never hear someone shimmed a Yamaha or a Peavy or a Ibanez ... no, it is a Fender.

Quoted myself from page 2 to provide you with the proof, Mongo.

Thanks for the assist 96tbird.

But there's more...

Not only does Peavey use a neck tilt adjustment instead of shims...Yesterday, I removed the neck on a brand new, fresh out of the box Ibanez I had just purchased...Care to guess what I found...that's right, a factory installed neck shim. It consists of two stacked ~3/8" wide strips of about 100 grit sandpaper.