Double Bass Thick Top or Thin?

[Hector Wolff]

I have read in several places here, that basses with thick or stiff top plates, often improve in volume and response with heavy or "stark" strings. The extra pressure apparently gets the thick plate moving. Conversely, it seems that a bass with a thin or flexible top plate may actually have it's volume and response inhibited, by the additional pressure of these strings.

Assuming this is all true, I would like to know from those who actually have experience with this instrument, if the Shen SB180 hybrid that I have, would be considered to have a thin top or a thick top.

I am considering a new set of strings for orchestra, and I am interested in the Pirastro Flexicore 92 "Starks" or the Jarger "Heavy" strings, but I am concerned that my bass may not resond well to these heavy strings.

Similarly would the New Standard "Cleveland" Hybrid, be considered to have a thick or stiff top?

 

[Nick Lloyd]

The graduations (thickness) of then Shen tops are fairly middle of the road. Not terribly thick, but not too thin, either. Arching also plays a role in the strength of the top. Flatter, lower arching requires a thicker top. Higher, more peaked arching likes thinner graduations. Again, the Shen arching is middle of the road. Bass bars tie into this strength-equation, but I wouldn't worry on the 180. Try whatever strings you like. Use your ear, your bow, and your hands to determine what works for you and your bass.

As far as the New Standards go, I'm sure Arnold could chime in...

 

[jmpiwonka]

i'm kinda glad to read that the shens are about middle of the road.
i have a shen sb200 willow and i'm going to get up early in the morning and make a big cup of coffee and put some spirocore mittels on it before work.

i thought i didn't like the dominants that are on it, i imagine they are old too and not a fair representation of what they normally sound like but the sound of them has started to grow on me. kinda reminds me of another bass i played that had some really old original flexocores on it, except with a raspy g string.

as for finding the right strings your gonna have to do some experimenting, thats where i'm headed....next up will be some superflexibles.

have fun.
if you read kensmith's thread in the strings forum you might want to try the regular flexocore set but use a stark E string instead of the regular E string.

 

[arnoldschnitzer]

I have read in several places here, that basses with thick or stiff top plates, often improve in volume and response with heavy or "stark" strings. The extra pressure apparently gets the thick plate moving. Conversely, it seems that a bass with a thin or flexible top plate may actually have it's volume and response inhibited, by the additional pressure of these strings.

Assuming this is all true, I would like to know from those who actually have experience with this instrument, if the Shen SB180 hybrid that I have, would be considered to have a thin top or a thick top.

I am considering a new set of strings for orchestra, and I am interested in the Pirastro Flexicore 92 "Starks" or the Jarger "Heavy" strings, but I am concerned that my bass may not resond well to these heavy strings.

Similarly would the New Standard "Cleveland" Hybrid, be considered to have a thick or stiff top?

I've measured the Shens and Nick is essentially correct, though the graduations around the edges are a bit on the thin side. This is one of the reasons they sound so good. The New Standard Cleveland hybrid has an average thickness top. The arching is slightly high, which works well with the bass' wide body. I agree with Wonka that the regular Flex's are the way to go; Ken is on to something with the heavy E string. That said, starks should not damage your bass, though I think you should lower the strings slightly (looser strings need more vibrating room).

 

[jallenbass]

I am considering a new set of strings for orchestra, and I am interested in the Pirastro Flexicore 92 "Starks" or the Jarger "Heavy" strings, but I am concerned that my bass may not resond well to these heavy strings.

I have the Jarger heavy guage strings on my bass and they are softer than original flexocors.

 

[Chasarms]

I have tried the following on my 180:

Obligatos, Spirocore Weichs, Flexocor 92s, Flat Chromsteel, SS Supremes and Dominants.

I've had better luck with the stiffer strings like the flexo and FCS. They definitely don't choke the bass and seem a little louder to me.

I am pretty much stuck on the FCS for a hybrid string. The Obligatos were a little flabby and really couldn't get the bass to resonate as well as some others. The Flexocors are excellent under the bow, but don't do much for pizz outside the classical application.


I may may also try Dominants again. The only ones I have tried on the Shen were used off my teacher's bass. If I ever do Spiros again on that bass, it'll be the mittels.

 

[B. Graham]

I've got a Shen SB80. Low price, great sounding bass. I'd love a solid top of course someday.

I've been using Flat Chromesteels. I think they sound great, and play great, but are kind of weak in volume. Superflexible's have worked pretty well on this bass as well.

At this time I've got Dominant's on it. The sound of the string at attack is a little different; kind of higher pitched "thwack" sound. Other than that, they are louder than the afore mentioned strings, and I think are equally good for pizz and arco. My only complaint is that the E is actually a little more growly than I would like. Not sure what to try for a different E as of yet.

 

[Mike Crumpton]

I've measured the Shens and Nick is essentially correct, though the graduations around the edges are a bit on the thin side. This is one of the reasons they sound so good.

Could you elaborate on this Arnold please. Now I have read all the caveats about making alterations to gradations of existing tops, but the implication here is that a thick topped bass can be improved by thinning the edges only, which presumably allows movement of the centre of the plate as one?? Just guessing and curious. My bass has a thick top BTW - or at least I think it does and was told by someone who should know that it does.

 

[Hector Wolff]

Thank you all for your quick and helpful replies. I am pleased that my top is middle of the road, actually. It allows me to experiment without worrying that one choice or the other will hurt the performance and sound of my bass. I will probably try the regular Flexicore 92s with the stark E.

 

[arnoldschnitzer]

Could you elaborate on this Arnold please. Now I have read all the caveats about making alterations to gradations of existing tops, but the implication here is that a thick topped bass can be improved by thinning the edges only, which presumably allows movement of the centre of the plate as one?? Just guessing and curious. My bass has a thick top BTW - or at least I think it does and was told by someone who should know that it does.

There's a tool called a Hacklinger gauge that allows measuring plate thicknesses accurately with the instrument together. It's about $10 worth of parts plus a patent, and sells for $400! Anyway I have one and use it regularly to measure basses in my shop. As far as thin edges, the theory amongst many makers is like that of a loudspeaker: keep the center thick so it can move more or less as a unit, and thin it near the edges so it can uncouple from the ribs and let the movement occur. This also involves a carefully executed recurve, though that's a whole other subject. BTW, I think too much fuss is made over the regraduation of commercial instruments. If a bass' top and back are too heavy, and you can improve it with some careful reworking, who loses?

 

[Mike Crumpton]

Thanks a lot for this Arnold - most helpful - I'll keep it in mind!

 

[Silversorcerer]

One way you can experiment with the tension/ gauge optimization is to gradually down-tune your instrument from full in-tune tension. This should be done gradually in quarter tones, matching all of the strings in tuning as you go down. If it appears that as you down tune that your bass becomes louder and more responsive, that is a good indicator that the string tension is choking the top. If you observe the opposite, that the bass becomes quieter, it is an indication that the gauge and tension could be increased to give more response. This is one of the things that makes string selection so tricky and why it is a good idea to compare manufacturers' tension numbers before you spend a load on strings.

As always it helps if we could give some dimensions as to what constitutes "thick" and "thin". Admittedly this can only apply most generally, because what is thick for one piece of wood might not be for another. The maker of my bass is reputed to make "thick" tops. Actually, I can easily observe a portion of the graduation at the edges of the f-holes. Along the vertical cut of the f-hole closest to the edge of the C bout the top is about 4-5mm thick and at the top portion of the f-hole closest to the centerline the top is about 9-10 mm. Looking at the edges of the f-holes could be misleading on some basses because there are makers who deliberately leave a little more wood around the f-holes, although mine certainly seems to reflect a normal graduation across the f-hole.

I have seen reports for instance at the Contrabasse shop of commercially made French basses (usually 1800's) that were as thick as 15 mm. in the center, which is definitely a case for regraduation. One theory is that the makers knew they were using new wood and were leaving more of it in the tops to prevent or minimize cracks. Thicker wood dries slower. As Arnold points out, on these basses there is little to be lost (except excess weight) and much to be gained by regraduation.

 

[Mike Crumpton]

Without seeing your post I recently did try detuning a semitone accross all strings and it made it easier to play and clearer high in thumb. A quick measre with calipers gives 7.5mm & 6.5 mm top thickness at the f holes as you describe. It was a couple of luthiers who said these basses had a good thick top. The detune test didn't seem to loose any volume so I may go for a little less tense string despite all. one thing i'm adamant about - it sounds stiff and choked if not dead when cold but when warm gives more or less a sound I think isn't bad at all. For the UK and curious its a zeller.