Slab vs. Quarter, wide vs. fine

[John Delventhal]

Arnold, you mentioned that a slap-cut top would makes the bass vibrate more in the lower frequencies, generally resulting in a strong, boomy bottom end tonally.

What about combining the two types of cuts? Keep the quarter-sawn wood in the center of the top table for the bridge, neck block, and heel block. But, have the outer sides of the table be slap-cut. Would this help create a strong instrument that could still produce those incredible lows.

I am sure this has been done somewhere. Has anyone ever seen/played a bass like this. How was it structurally, and how was the sound?

[John Delventhal]

Found one! Ken's Martini. I have played this bass, its great! As Ken puts it "It's a Canon." Ken, have you seen others like this? Were they similar at all?

[Ken Smith]

Originally Posted by John Delventhal

Found one! Ken's Martini. I have played this bass, its great! As Ken puts it "It's a Canon." Ken, have you seen others like this? Were they similar at all?

The Martini top is a result of a small tree from what I can see. The grain is tight in the middle and fanning out to flat grain at the outer wings. The back and ribs are Oppio which is a local Italian soft maple. If the back and rib woods were the harder Bosnian type then it might be a brighter sound with the same top. Also, the deep arching of both the top and back has something to do with it as well. Also, Martini was a bass player first and then a violin-bass maker producing over 400 instruments in his lifetime with over 40 of them being basses. My Martini is the earliest known example of a bass from him made right after the 1st war. It's a real bass by a good maker. It deserves the sound it has.

I have played some very very deep sounding basses with quartered tops and backs and that had fairly hard maple in the backs and ribs. Why is that? Maybe it was just a good bass, made right, aged well, repaired well and luck was on its side.

A bass is the sound of the sum of its parts and how its designed, made and put together coupled with how it aged and how it's been played. I think!

[John Delventhal]

Slab-cut is on the left in the drawing. Quarter-sawn is on the right. Notice the four quarters in the log, hence the name quarter-sawn.

[Thomas Erickson]

The way I tend to think of it is that quartered wood is like what you get when you split firewood, whereas flat or slab-cut is what you get if you take a log and just saw it into boards. If that makes sense.

[Ken Smith]

[quote=Thomas Erickson;19642]The way I tend to think of it is that quartered wood is like what you get when you split firewood, whereas flat or slab-cut is what you get if you take a log and just saw it into boards. If that makes sense. [/quote

Do you mean commercial 'grade cutting' when you say "just saw it into boards"?

I have some experience with sawn logs. There is more than one way to cut a log. Here is some results from 'flitch cutting' walnut logs. I have a maple log or two that was cut the same way.

In commercial flat sawn lumber they cut a couple slices (or more depending on the log) off of one side and then turn the log a quarter of they way and continue as they cut most of the first grade all around it. This is called FAS meaning First and Seconds. This yeilds flatsawn lumber/boards. I have some experience watching some of my wood coming off the chain this way as well. I have probably bought more wood personally than most people in the wood business that is also hands on in the making process, not just the lumber buyer. This is in my KSB business but some of my wood has been used to make double basses as well, just not by me.

[Thomas Erickson]

Ken - yes, of course there is a lot more to "sawing boards" than how it sounds, I just posted the "firewood vs. sawn boards" thing because it's a crude little way of remembering it. Sometimes I get a little confused looking at lumber or discussing how to cut some wood, and that just helps me keep it simple.

[Matthew Tucker]

Originally Posted by John Delventhal

What about combining the two types of cuts? Keep the quarter-sawn wood in the center of the top table for the bridge, neck block, and heel block. But, have the outer sides of the table be slap-cut.

This is, in fact, what happens naturally with quartersawn tops; the tightest grain is in the middle, at the seam, and the grain tends to go wider at the flanks. Also, if the board is not EXACTLY quartersawn, the grain will run almost slab-like at the flanks. I'm not shy to use wood that is not exactly quartersawn for this reason; the way i see it, the most vertical grain in the middle will strengthen the arch and resist splitting, and the slabbier wood at the flanks adds flexibility at the edges where it is needed.

[Thomas Erickson]

Originally Posted by Matthew Tucker

the way i see it, the most vertical grain in the middle will strengthen the arch and resist splitting, and the slabbier wood at the flanks adds flexibility at the edges where it is needed.

I'm not so smart when it comes to the physics so I wonder if it's the center/top of the arch that contributes the most to stiffness, as opposed to the whole arch? Seems to me (the layman) like if the bottom of the arch is flexy, then making the top stiff isn't going to do so much good. And then the amount of top-plate area attached to the ribs/blocks inhibiting vibration, in terms of the number of grains... Like I say, I don't know...

[Arnold Schnitzer]

The recurve, an area of the vibrating plates just inside the perimeter, is carved thinner than the rest of the plate, in order to allow the plate to "uncouple" from the rib assembly and vibrate more freely. Some makers carve this area deep and wide, others make it barely noticeable. This has a noticeable affect on the depth and power of the bass, but when overdone can lead to sinkage and cracking.

[Thomas Erickson]

Ah, I was neglecting that.

So how wide and/or angled the grain gets toward the edge helps determine how much recurve makes for a good balance of support and vibration, while moving toward the center of the plate the arching height and thickness, assuming the grain is more vertical there, help to determine the longitudinal stiffness and actual acoustic properties, right?

So it would seems to me like a top with even, vertical grain all the way across isn't, as a rule going to sound better, but that it is going to be simpler to interpret and make a good top from. Conversely, a top with other sorts of grain orientation has the potential to sound just as good, perhaps even better, but is going to take more consideration (and perhaps luck?) in order to get the best performance from it. And then there are the health issues to consider.

[Ken McKay]

Sounds like you understand Thomas.

[Arnold Schnitzer]

Picture looking down on a tree trunk, where you can clearly see the growth ring circles. Now, slice down through the trunk, cutting it into quarters. Then, make thin pie slices out of each quarter. Take two adjacent ones and true up the wider sides of the pie slices. Glue them together and you have a "quarter-sawn" bass back or top. Cutting the tree trunk in any other fashion will result in a combination of slab, quartered, and rift-sawn stock. Bass bar stock is cut in a similar manner to top and back wood, then trued up to be rectangular, rather than pie-slice shaped. Is there somebody out ther, more computer savvy than me, who can diagram this?

[Arnold Schnitzer]

Originally Posted by wayne holmes

This is not about recurve.

Wayne, are you the subject matter police? The subject got on to quartered vs. slab grain around the edges, and that's where the recurve happens. Where's the problem?