Martin M36 Setup advice

david.j.barrie

I'm looking at lowering the action on my Martin M36 and was hoping for some sage advice.
I've had the instrument for 1yr and initially I had it set up which lowered the saddle a bit, but not much.

Here are some pics of it currently:

http://imgur.com/a/OANGT

I've measured:
6th string 3.25mm at 12th
1st string 2.25mm at 12th

As you can see there's still plenty of saddle sitting proud (about 3mm), creating a healthy break-angle.

I'm a finger-style player, and I'm starting to think that I'd benefit from an action on the 6th at more like 2.5mm. Is this achievable and if so how much saddle has to be filed away? Should I consider getting a blank saddle to experiment with?

I've also included a photo looking down the fingerboard, picking up the bow on the neck. From those with a trained eye, is this about right, or does that truss rod need a tighten?

As I'm sure many will understand, I'm torn between doing the work myself (in the spirit of learning how everything works) and handing it to a luthier to make the (rather expensive) adjustments.

I would, of course, be grateful for some opinions.

richardhomer

How old is the guitar?

It looks like the saddle is fairly low already - and the neck appears to have 'hinged' where it meets the body.

If I'm right, the cure is a neck reset - it's not something the truss rod will cure.

Lewy

Before you undertake any set up work, you should make sure the neck relief is set properly. Even seemingly experienced repair people have a habit of putting excess relief in necks for some reason. Martin specs are a maximum of .010" relief at 7th to 9th frets, and other manufacturers like Collings have .005" as their standard relief.

Excess relief makes the action slightly higher, but more importantly it really detracts from playability in the middle of the neck, getting you thinking about lowering the saddle when you maybe don't even need to.

Cant really tell from the pic, although it looks like a lot of relief. Measure it properly and go from there.

david.j.barrie

richard: the serial number puts it at 2015, but I bought it new in 2016. I'd be seriously disappointed if it needs any sort of neck work already!!

lewy: any top tips for measuring neck relief without a feeler gauge? I know it's capo on 1st & fret the string at neck/body join, but I don't have anything to stick in the gap!

Lewy

david.j.barrie said:

richard: the serial number puts it at 2015, but I bought it new in 2016. I'd be seriously disappointed if it needs any sort of neck work already!!

lewy: any top tips for measuring neck relief without a feeler gauge? I know it's capo on 1st & fret the string at neck/body join, but I don't have anything to stick in the gap!

People sometimes talk about comparing the gap to one of the strings which is a known quantity - so if your second string is a .017 then half that thickness would be .008 etc but I've never had a good enough eye for that method muself
and just use feeler gauges. They're cheap from Halfords. 

The other critical measurement is the distance between the string and the soundboard....right in front of the bridge it should generally be around 1/2". What is it on your guitar?

Moe_Zambeek

Other than the setup, how do you like the M36? It was recommended to me as a perfect compromise / all rounder that isn't as physically big as the dreads.

david.j.barrie

It's a wonderful guitar. Or at least, the one I chose is ideal for me.

In the process of choosing, I tried: 000-18, 000-28, 000-28EC, OM21, D18, HD28, D35....amongst a host of Gibsons (I previously thought the Hummingbird was what I'd go for) and all sorts. The M36 was the first one that felt right. It's a fairly hefty body, and on occasions I can see the merit in a more slender 000 shape. But the payoff is all in the tone. As many have commented on here, it strikes a delightful balance of bright & warm; present in the top end while remaining smoothly bassy without any boom. 

If you ever come to Bristol or the west country, feel free to have a strum.

In other news, feeler gauges and ridiculously long truss rod key on order...standby...

ICBM

david.j.barrie said:

lewy: any top tips for measuring neck relief without a feeler gauge? I know it's capo on 1st & fret the string at neck/body join, but I don't have anything to stick in the gap!

Very easy - hold the guitar in the playing position and fret the G string at the 1st fret with your left hand while also at the 15th with your right. Look at the gap between the string and the 7th-8th frets - if it's more than half the diameter of the string then there's too much relief. It doesn't actually have to be measured very accurately, just by eye like that is plenty accurate enough to see if it's likely there is a problem. (My guess is that there will be, from your pic.)

Check the nut height in the same sort of way - fret each string at the 3rd fret, and look at the gap between the string and the 1st fret. It should be tiny - definitely less than a quarter of the string diameter, and preferably even less, around 1/10th of it. Again, it doesn't have to be super-accurate - in the ballpark is fine. There are no absolutely 'right' measurements, just what feels right to you.

Once both of those things are right, check the action again. If it's still too high, the amount you need to shave off the bridge saddle is double the amount you want to remove, although it's good practice to err on the side of caution and only take off about one and a half times - because the bridge will move down slightly with less string leverage provided by the high saddle.

You should be able to achieve about 2mm (top E) and 2.5mm (bottom E) quite easily on a modern acoustic with a truss rod and good fretting.

ICBM

For what it's worth, a friend has just dropped off his nearly-new Gibson J-15, which currently has an action of *4mm* on the top E string! Not kidding. The relief is about right, the nut is about half a mm too high, and all the rest is the bridge saddle… which by my calculation makes it around 3mm too tall.

He says it was sold as 'unplayed', which is obviously true because its unplayable! Gibson's QC strikes again.

thermionic

I would ask what the humidity is where it's kept. On a stand or in its case?

The action on my Taylor crept up in the first couple of years and I could see noticeable "bellying up" of the top (using a steel rule). This raised the bridge and the action. Although I generally kept it in the case, my house is quite humid (currently 62%, and I wouldn't want to leave a solid wood acoustic out in that for any length of time). A slight sanding down of the bridge saddle and a hefty sachet of silica gel in the case has it under control.

Mine was nowhere near as bad as this, but it's an illustration of how string tension and swollen wood can raise the height of the bridge:

https://farm6.staticflickr.com/5554/15017043979_22a7919b6c_c.jpg

david.j.barrie

Hmm. My flat is a little humid, and I have a dehumidifier for battling this. However typically it stays 60-65%. I do store the guitar mostly in its case for this reason...however I've looked with a ruler and there is a little bow in the belly. Arse.

Lewy

david.j.barrie said:

Hmm. My flat is a little humid, and I have a dehumidifier for battling this. However typically it stays 60-65%. I do store the guitar mostly in its case for this reason...however I've looked with a ruler and there is a little bow in the belly. Arse.

A belly isn't the end of the world. Nearly all properly made (i.e. Not overbuilt) guitars get them to some extent or another.

But you should add getting the humidity under control to your list of things to take care of before assessing whether your guitar needs work. It doesn't just affect action. Over-humidified guitars don't sound their best either. Starting point for me would be to try and establish whether the humidity inside the case is any better than the room outside. All cases are definitely not equal when it comes to airtightness. If you're measuring your humidity with a small hygrometer then stick it in the case for a bit and see what's what.