Double Bass Issue with Harley Benton Harley Benton DB02-BEM when bowing

[maneyro]

One of my students bought a Harley Benton DB02 Edb and I noticed that although on pizz the sound is decent, on arco the sound on A string mostly but also on D string is noticeably wicker than E and G string.
I don't know if it caused by the quality of the string or if it's a preamp issue.
To me seems like a preamp issue.
Does anyone has the same problem?

 

[DoubleMIDI]

This is a Stagg EDB with a DB pegbox/scroll and a thicker endpin rubber.

There is a piezo wire beneath each bridge foot which go to two pots on the preamp, close to the jacks where the piezo cables are connected. You might plug them both off and on to be sure they make good contact. You also could find out which cable goes to which bridge leg and which pot.
But just a weak D string cannot be solved that way.

Check the piezo wire position beneath the bridge feet and maybe rearrange them a bit, make sure that the bridge is perpendicular to the body when tuned up.

If the D feels looser than the G and A, it might be the wrong (or defective) string.
If you have a spare (old) steel core set, try that. Since the underlengths are large, a 4/4 set (Spiros) works well.

Anyway, the Staggs are bowable, but the low bridge and fingerboard curvature makes is difficult not to catch a neighbor string by accident. Even a bit worse than on my bowing angle optimized 5-string DB.

You can also enlarge the neck angle by unscrewing the neck and put a shim or cardboard into the inner side of the neck pocket and remount the neck. That will enlarge the pressure onto the pickup elements when you put the bridge a bit higher without changing string action height.
Try things as long as they are reversible.

The Staggs and relatives need a bit of tweaking, but not too much.
Some foam (cut sponge) beneath the underlengths helps to get rid of strong underlength resonances.

 

[maneyro]

This is a Stagg EDB with a DB pegbox/scroll and a thicker endpin rubber.

There is a piezo wire beneath each bridge foot which go to two pots on the preamp, close to the jacks where the piezo cables are connected. You might plug them both off and on to be sure they make good contact. You also could find out which cable goes to which bridge leg and which pot.
But just a weak D string cannot be solved that way.

Check the piezo wire position beneath the bridge feet and maybe rearrange them a bit, make sure that the bridge is perpendicular to the body when tuned up.

If the D feels looser than the G and A, it might be the wrong (or defective) string.
If you have a spare (old) steel core set, try that. Since the underlengths are large, a 4/4 set (Spiros) works well.

Anyway, the Staggs are bowable, but the low bridge and fingerboard curvature makes is difficult not to catch a neighbor string by accident. Even a bit worse than on my bowing angle optimized 5-string DB.

You can also enlarge the neck angle by unscrewing the neck and put a shim or cardboard into the inner side of the neck pocket and remount the neck. That will enlarge the pressure onto the pickup elements when you put the bridge a bit higher without changing string action height.
Try things as long as they are reversible.

The Staggs and relatives need a bit of tweaking, but not too much.
Some foam (cut sponge) beneath the underlengths helps to get rid of strong underlength resonances.

Thanks for your reply, the A string is the most wick (maybe I was not so clear) and he uses the factory strings.
The instrument is in warranty so I don't know if it is a good idea to try this with the piezo but thanks anyway for your advice

 

[DoubleMIDI]

I check my Stagg later amplified with the bow if I find anything unusual.

It is possible that this is a normal behavior as the vibrations of the inner strings might cancel each other out partly.
The NS EUBs have/had a polarity switch for pizz/arco for this reason.

But as I said, I will check it in a few hours and report.

 

[DoubleMIDI]

Just checked it out:

It’s the same with my Stagg EDB, the inner strings are weak when bowed compared to the outer ones, the D a bit more than the A if I remember correctly.
So this seems to be normal, not a damage of any part of it.

Beyond the bridge and fingerboard curvature the biggest design flaw of this instrument is the bridge. It is designed for equal string action height which is bad for a DB/EUB. Also the big metal parts for the adjusters put too much mass on the bridge. Reshaping the bridge will remove the black laquer and the light wood (visible from below the bridge feet) would shine through. But it would be is hard to remove the laquer only on a specific section and hard to do completely.
Also the low pressure on the bridge with the small bridge groove can let the E string jump off the bridge when played a bit harder.
I made a temporary fix by putting stripped microphone or instrument cable outer rubber isolation (or leather strips) between the D and A string and two of them below the E string and the bridge to lift the lower strings a bit up. But that reduces the bowing angle for the inner strings even a bit more.

If I hadn’t a better 5-string EUB, I would have made a purely wooden bridge without adjusters from scratch, but I hardly use the Stagg now.
I find it a bit strange that Thomann sells that instrument together with a bow now.

So this is normal the way the instrument is constructed.

A phase flip switch would help to avoid the phase dependent volume loss with arco, but I had to look into the schematic (reconstructed by another Talkbass member) to find out if it would be possible by a trace cut and rewiring to a switch or if it needs more electronics.
I won’t recommend that before the warranty period is over.

Why doesn’t be it happen with pizzicato?
Because the angle of vibration of the string is different with pizz and arco.

I would rather recommend a better EUB that is twice the price (without a bow) like a used Yamaha or a MK (Studio) EUB (Italian EUB).
But check with Mirko (MK Basses) if this might not happen on the Studio instrument too as all of them are solid body instruments where the bridge foot cannot move up and down as on a real DB. The higher bridge with long legs on the Yamaha and MK Studio might help to avoid that at least more than on the Stagg/HB EUB.

The Stagg is OK for Jazz, singer-songwriter and folk, but I css as not recommend it for practicing classical music or amplified bowing for more than a few long notes.