Getting rid of cabinet drop

Karlis Abolins · From: (near) Seattle, WA, USA

I recently began thinking about cabinet drop as an issue because my guitar experiences a lot of cabinet drop (about 3 to 4 times more than most other guitars). I started to look at what the guitar makers have done to address the issue and found some hints at what they have done. A couple of guitar makers, Emmons and Remington, have put compensators on the underside of the guitar to offset the deflection caused by the increased tension when a string is raised in pitch. GFI has lowered the string height relative to the neck and increased the strength of the neck resulting in very minimal cabinet drop. For the most part, the changer and nut have been strengthened so that they don't enter into the cabinet drop equation.
The main culprit is tension. Most guitar strings are up to pitch at about 22 to 27 pounds of tension. If you assume an average tension of 25 pounds for each string, a 10 string steel guitar has 250 pounds of tension on the strings between the tuners and the changers. The force is transmitted into the body of the guitar at the changer and the nut. The typical string height above the body of the guitar is 1 1/2".

You can think of the steel guitar in this configuration as a kind of bow. Because of the strength of the body, the bowing effect is not visible but is measurable with a deflection gauge. Using the bow paradigm, if you pull on the string (raise the pitch of the string with a pedal) the bow bends. This is the root cause of cabinet drop.

A novel idea occurred to me as I thought about this problem. Change the force. Instead of tension on the guitar body, make the force compression. How? Modify the changer and the nut. Instead of mounting these on the surface of the body, make the frame of the changer extend through the body and make the frame of the nut extend through the body as well. Attach tensioning rods between the nut and changer to counter the tension of the strings. Also attach tensioning rods between the nut and the tuner frame. The idea is to make the tension of the strings and the tensioning rods equal. So now the body is not in tension anymore rather it is in compression.

If the tension of the top and bottom are equal the body of the guitar will be straight (provided it is strong enough to withstand the 500 pounds of compression). The force will be transmitted into the body evenly throughout the thickness of the guitar rather than on one side as is the case with current guitar designs.

I can see two major benefits of this approach. The first is the virtual elimination of cabinet drop making the guitar easier to tune and play. The second is increased sustain due to increased pressure on the body.

[This message was edited by Karlis Abolins on 27 June 2002 at 02:36 AM.]

[This message was edited by Karlis Abolins on 27 June 2002 at 06:01 AM.]

C Dixon · From: Duluth, GA USA

Karlis,

Brilliant post. ONlY one problem.

Sound!!!!

IF, you can retain that, I am with you all the way! NOT sure you can, but maybe.

God bless you with your ideas and willingness to number one, accept there IS a problem. And number two; to try and figure out a solution. I applaud your efforts,

carl

Jim Palenscar · From: Oceanside, Calif, USA

You bring up some interesting points, Karlis. There are a number of possibilities for the cause of cabinet drop- and each guitar is a bit different. One of the semi-popular thoughts is that changer axle flex contributes to it and, while this may be the case, due to the work I've done in this area my feeling is that it is negligible. On a 12 string the string pressure approaches 330#- a 14 string approaches 400#. I think that the counter force idea that you propose has merit but I wonder if the tension on the cabinet is responsible for some of the tonal characteristics of the guitar? Are you planning on implementing your idea? I'd like to hear what the results are.

Kyle Bennett · From: Dallas, TX USA

Or your could resolve it by making your cabinet out of Carbon Composite...

Kyle

Jim West · Posted 27 Jun 2002 6:52 am

I know Ed Packard has his hands full right now but it would be interesting to hear his take on this subject.

Donny Hinson · From: Glen Burnie, Md. U.S.A.

That's a good start, Karlis, but the body flex due to string tension is only one cause of what we term "cabinet drop". Also in the equation are changer-axle flex, cross-rod flex, body distortion due to pedal forces, and nut movement/axle flex. Presently used technologies permit minimum "cabinet drop" if the guitar is designed right. It's just my opinion that, at this time, we don't need more "mechanical intrusions and complications" in the instrument.

A two-to-three cent drop is both obtainable and acceptable (read...insignificant), IMHO.

[This message was edited by Donny Hinson on 27 June 2002 at 08:32 AM.]

Andy Greatrix · From: Edmonton Alberta

Keep on Looking karlis, and don't let the flat-earth society scare you off. (grin)
The steel is still evolving because of people with imagination, just like you.
Go for it!

Sage · From: Boulder, Colorado

Interesting thoughts, Karlis. Your analogy of a steel guitar as a bow is right on. In terms of compression and tension, like a bow the guitar has compressive forces close to the strings and tensile forces carried on the bottom. Equalizing the tension as you have suggested would change the forces on the body to all compression (the tension would not double though, just be distributed differently). If the changer pulled against an independent tension rod on the underside, the forces would theoretically be neutralized. But, since the total load is still being changed in a complex way as the strings are worked, you'll still have stability issues to contend with. The biggest problem I see with your design is how thick it is. Kind of hard to get your knees under there.
In a way, the space frame body of the guitars I'm making act like the system you describe. The continuous lateral struts on the top have pure compressive load, and the bottom ones have tensile loading. The ones in between distribute the difference in an equal way- it is inherent in the geometry.
On the pedal steel prototype I'm working on, The frame body is the same as the lap steel- it weighs 13 ounces between the ends- carrying a load of 13 strings. I don't have enough pulls hooked up yet to see what kind of cabinet drop problems it will have, but so far it is promising. And it sounds great, of course!

T. Sage Harmos
Harmos Steel Guitars http://www.harmosmusic.com

Rick Collins · From: Claremont , CA USA

Reinventing The Wheel:

Four pedal steel guitars have already eleminated cabinet drop: Fender 1000, 2000, 400, & 800.

Much, much easier to redesign the cable system and add knee-levers.

C Dixon · From: Duluth, GA USA

Donny,

"A two-to-three cent drop is both obtainable and acceptable (read...insignificant), IMHO"

With much Christian love and respect, a 3 cent drop is totally UNacceptable to me. ONLY Zero drop is acceptable to me.

I predict one day that WILL be standard. Without having to use a counterforce option like the LeGrande III.

When, I haven't a clue.

God bless you,

carl

Karlis Abolins · From: (near) Seattle, WA, USA

It is a pleasure to see such insightful and informative comments being posted in response to my suggestions.
Kyle, your solution about carbon composite necks will shortly be seen on your new guitars. I wish you the best.
Carl and Andy, Thank you for your kind words of encouragement.
Jim, I agree that the changer axle deflection on most current guitars is not a factor.
Sage, I am fascinated by your instruments. I hope you will share your pedal steel with us in the near future.

Karlis

[This message was edited by Karlis Abolins on 27 June 2002 at 12:03 PM.]

Jim Smith · From: Midlothian, TX, USA

Matt Steindl · From: New Orleans, LA, USA

Kyle,

Are you telling us that there will be zero cabinet drop on all of the ne MSA guitboxs?

------------------
Mattman in "The Big Sleazy"-:
S-10 Dekley, Suitcase Fender Rhodes, B-bender Les Paul

Tony Orth · From: Evansville, Indiana, USA

Cabinet Drop on my old Dekley SD-10 was 2 cents with A and B down.

With my brand new Emmons LLII SD-10 it is also 2 cents.

I guess you could say that's my 2 cents worth.

Tony

Kyle Bennett · From: Dallas, TX USA

Matt,
On the forth string E with the AB pedals depressed, Millennium now detunes less than 0.8 cents. We are working to reduce this detuning to near zero. Millennium uses no “crowbar” mechanism but simply has a strong body and an extremely stiff reinforced changer shaft.
Kyle

Donny Hinson · From: Glen Burnie, Md. U.S.A.

Carl, (likewise...no disrespect intended), I don't worry about "numbers"...just the "sound". I, personally, (in the context of playing in a band), cannot "hear" a 2-cent discrepancy, therefore, I choose not to concern myself with it. It is my own feeling that the time spent on these tiny intricacies of tone and tuning (that seem to seriously trouble so many players) would be better spent on learning to just play the thing! Your own feelings, however, are just as valid.

Neither of us is right or wrong, we just have different priorities!

Tony Orth · From: Evansville, Indiana, USA

Donny,

I, likewise, agree. I bet I'm often 2 cents off with my bar placement. Even with a good ear, it's not always easy, especially above the 12 fret.

Dang, this is a hard instrument. I really appreciate those who play it so well.
Tony

James Smith · Posted 27 Jun 2002 1:45 pm

I have a question. If you use tension rods to counteract the force above the body with forces below the body, wouldn't that be like making the changer, neck, & nut all one piece. Wouldn't it be hard to keep it in tune?

C Dixon · From: Duluth, GA USA

'Tis true that on a 10 string PSG, you have somewhere in the neighborhood of 250-300# of stress on the cabinet.

However, one must realize that this stress, once the open strings are tuned, is "ZERO" stress in relation to a given pedal(s) and/or knee lever(s)) additional stress.

In other words, WHEN the A pedal is engaged, and another string drops, it is NOT due to the 300# of static pull. That pull is already there!! And the opening tuning has NO strings that are in a dropped state. UNTIL some additonal pull(s) occurs.

Rather, it is ONLY the two pulls on the A pedal (in this instance) that has an affect on a string or strings dropping. So 300#'s suddenly becomes 50 pounds of pull. NOT 300.

Something that MOST cabinets can easily handle with OUT the problem we all face more or less.

So what we are looking at here in the case of the A pedal and the 6th string dropping as an example is: The root cause is promulgated by the two B strings ONLY being raised.

Now the 64 million dollar question is; WHAT is allowing that 6th string to drop?

WHEN you find this, the solution should be quite easy. The Problem is and has been all along, I have found NO one that can satisfy me that it is in fact the cabinet bowing that is causing MOST of the drop.

Ron Lashley said it was NOT! His words to me on 2 different occasions were,

"I KNOW what is causing it. AND, it is more than one thing".

I tried my best to get him to tell me. But that was never to be.

God rest his precious soul,

carl

Frank Parish · From: Nashville,Tn. USA

Kyle,
Are you saying the Carbon Composite design has zero cabinet drop? How would you compare the tone to a wood body guitar? Are there any sound files to hear the difference?

Henry Matthews · From: Texarkana, Ark USA

CARL, I'M GOING TO HAVE TO AGREE WITH YOU. I THINK THAT IT IS SIMPLY THE BOWING OF THE CABINET THAT CAUSES CABINET DROP. THERE MIGHT BE ANOTHER SMALL FACTOR INVOLVED BUT THE MAIN CAUSE IS THE BOWING OF THE CABINET. TRY TWO THINGS. PUT A GOOD TUNING METER ON THE STEEL OF YOUR CHOICE AND MASH THE A&B PEDALS AND OBSERVE THE DROP. NOW MASH TWO OF YOUR C6TH PEDALS AND YOU WILL SEE THE SAME DROP OR REALLY CLOSE. THE CLOSER YOU GET TO THE MIDDLE OF THE GUITAR AND THE HARDER YOU MASH THE PEDALS, THE MORE DROP YOU HAVE ON THE E 9TH NECK. DAY SETUP GUITARS HAVE MORE DROP THAN EMMONS SET UP BECAUSE YOUR MAIN A&B PEDALS ARE CLOSER TO THE MIDDLE OR CENTER OF THE GUITAR. THE L-LEGRAND III CABINET DROP ELIMINATOR AS INGENIUS AS IT IS, IS NOTHING MORE THAN A ADJUSTIBLE PRY DEVICE THAT BOWS THE CABINET THE OTHER WAY BY PUTTING TENSION ON THE CHANGER BAR AND IT WORKS VERY WELL, IN FACT GREAT.

I DON'T WORRY ABOUT DROP BECAUSE MY EARS CAN'T HEAR A 2 CENT DROP AND I ENVY YOU GUYS THAT CAN HEAR THAT.

TO ME IT ALL BOILS DOWN TO ONE THING. THE STRONGER YOUR GUITAR CABINET THE LESS DETUNING YOU HAVE.

Bobby Lee · From: Cloverdale, California, USA

Gil Berry · From: Westminster, CA, USA

You know, this is an interesting subject. And I have been thinking - maybe this is why one set of "numbers" for tuning pulls cannot work - for example, if on one guitar the 8th string drops 5 cents when AB is engaged, then the A and B pulls need to be LOWER so that the 3-4-5-6-8 strings would be more in tune with EACH OTHER. This would mean you would have to cheat a little in distance with the bar when going from open to AB, for example. (All this compared to a guitar with "zero" cabinet drop.) Since it seems EVERY guitar has a different drop, then the amount of raise (for A & B) would be different for the main groups to still be in tune WITH EACH OTHER with pedals engaged. Maybe this is why the real "pros" often tune only their open strings with a tuner and tune pedal pulls by ear?????

C Dixon · From: Duluth, GA USA

Gil,

You are correct.

The reason that the "Jeff Newman" tuning guideline* is so popular, is it takes into consideration just what you speak of.

Jeff would be the last player on earth to recommend we shapen our E's by a full two and one half cycles IF, it were NOT for cabinet drop. His ears are just too good for that. Few players on earth play MORE in tune than Jeff. Along with his awesome teaching attributes.

The reason the 442.5 works is because MOST players are always pulling toward the A chord rather than pulling toward the E chord. This is because that is what A and B do!!

Cabinet drop is creating an almost "false" situation. We WANT The 4th string to be 440. But dang it, when ya go down on A and/or B it aint 440 no MO!!!

(If you are from SHY-Cargo that means it is LESS than 440 hoss.

)

So we purposely raise the E's so that as one engages these pedals cabinet drop lowers the E's back to 440 where it belongs! (Or there abouts.)

*Note: NOT all guitars need 442.5. Some need less. Rarley do they need more. Experiment with yours, using Jeff's chart as a starting point, until you find one that will allow you to play OVER the fret. You will be suprised.

May Jesus bless you in your quest(s)

carl

Jim Smith · From: Midlothian, TX, USA

I wonder how much the E9 strings on a LeGrande with the anti-detuner drop when the C6 pedals are pushed?

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