Uneven string volume troubleshooting (help needed)

[mr.noisy]

Hey guys,
I believe that I actually might started similar topic before, but for some reason I can't find it in my content and using search function, so here it is again.

I have a custom build bass, that is beautiful but it gives me some headache with the string volume, or maybe a presence or I don't know. Bass got Bartolini pickups, NOLL 3 band EQ and 16.5mm spacing. At first I had it strung E to C, and it sounded beautiful unless I had to play with a band, then D,G and C string would sound very weak. Currently I got in a common B to G tuning, I wanted to check if i was a string gauge problem, but it's still there and now D and G strings sound quite weak, and it is not only my perception but I had a feedback from other people that listened to me playing from audience perspective. I did some research, I asked some questions and I tried to work with EQ like some people suggest, I have tried pickup height and got it lower on the lower strings that sounds fine and a bit closer to the weaker sounding strings but these things did not sort out the problem. I have also had quite a few different sets of strings from different manufacturers so it is definitely not a bad set of strings problem too.

I guess that the only thing thats left is preamp or pickups. I was actually wondering if I don't have a wrong set of pickups for my bass, as it has 16.5 mm spacing. Pickups are Bartolini P25CBC dual coil soapbars. I was wondering that if those pickups have magnets similar to those like in jazz or other pickups with exposed poles, but just underneath the covers? If yes, maybe the strings are misaligned with those poles hidden under the cover? I tried to look there, but when I unscrewed the pickup and checked it out, I can't take the cover to have a look inside.
I am really running out of options, replacing the pickups isn't cheap so I wanted to ask first for some opinions and if anyone is running those pickups in a narrow spacing bass without any problems.

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[MoonBassAlpha]

It looks to me like Barts have bar magnets, so string spacing in your case shouldn't be an issue.
http://www.bartolini.net/pickups-faq/ section 12
Does it only do this when both pickups are on? The spacing between the two may be scooping those frequencies.

[HowieBass]

Have you run out of adjustment with the pickup height screws? I'd be tempted to bring the bass side down further if you've got little option with the string to pickup spacing on the treble side (typically a gap of about an 1/8" is recommended when the string is held down at the last fret) just to see how much influence the string to pickup distances have on the volume balance.

[Twincam]

Is the sound level on open strings?
Fret all strings one at a time at the 3rd, 5th and 7th etc etc till the last fret, is the fretted sound equal on some neck positions and not others?

Also sometimes instead of bringing the weaker strings closer, make the stronger sounding strings further away! Leaving the weaker strings where they are, equaling it that that.
This can effect tone and output slightly but as long as you have a strong pre amp or amp then it can be compensated for and its at least an equal sound.

[Ghost_Bass]

With E > C tuning you had weak D G and C and now with B > G tuning you have weak D and G strings! Have i got this right?

Don't think the problem is in the pickups. One way to find this for sure is to either rotate your pickups 180º (best way to do this but only if you have enough wire to do it) [b]OR [/b]put a G string on the E/B position and listen if it still sound weak. If the G string improves then try an A string in the D or G position (be carefull not to wreck the nut) and see if it's weak. If the A string gets dull and the G improves then your pickups are knackered, if it remains the same then the problem is elsewere.

It looks to me that this probably is a preamp problem. Does it have any internal trim pots to cut/boost low and highs?, the highs may be trimed a bit too far! It could be also a knackered component.

[mr.noisy]

Hey guys, thank you very much for your response and suggestions. I have now few more things to check. The worst thing is that actually I can't really tell any difference unles I play with the band, when I play it at home everything sounds just fine, so I don't know if I would be able to swap the strings to check if D or G would sound right if put in the E or A position.
I don't have any precise ruler to check the measurement between pickup and strings but I guess it should be a bit more than 1/8" on the higher side and the B, E and A side is maxed down, can't put it any lower
I will try on the rehearsal if this problem still exist with only a single pickup

Ah, and preamp does not have any internal boost or cut dials, just a little cube http://noll-electronic.de/bass-electronics/tcm-3/

Edited February 22, 2016 by mr.noisy

[Twincam]

That is a fairly extreme angle. Maybe try putting the treble side down just as much, sounds wrong but it can sometimes help capture more sound.
Of course then try new strings. If all this adjustment doesn't work nor different strings then it's the pickups or the nature of the bass.

[mr.noisy]

I have tried a lot of different brand of strings as well as stainless and nickel plated. So this is not the strings problem I guess. I'll bring the other side down too and see whats going to happen.

[bertbass]

It might not be the bass at all if it only happens at gigs. If your cab is between 2 and 8 feet from a wall you'll get cancellation. Might be worth placing your cab in a corner and seeing if you get the same problem.

[Ghost_Bass]

Only happens with the band? Well, that's another story. Opens a lot of questions.

How is your amp's EQ when you play with the band, are you cutting too much high mids/highs?

If you play your gear alone at home (at band volume) is the problem there? When you sondcheck is the problem there? Are you only feeling the loss when the other instruments kick in?

Are you going through FOH, who is the tech, have you tried talking to him to see if he's doing the standard "V" EQ on you bass cutting your mids?


It could pretty much be a problem with the band mix an the way you're EQing your instruments.

[mr.noisy]

This is definitely not the EQ thing, I have played it through many different amps, as I am at music uni at the moment, and we perform every week on stage and play rehearsals in different rooms, I used different bass as well as other students with different basses after or before me playing at exact same settings would not have any problems. That's why I thing that the only things left are pickups or the pre-amp, but I think I have replaced the preamp before when I had some other problems, but for exactly the same model. Now it is narrowing down to the pick ups I guess. But I am not sure what could go wrong with them.

[Ghost_Bass]

One more question i remembered, have you tried panning the pickups whilst on a gig? Are the strings weak no mather you're using neck/both/bridge pickups? If it happens no mather how you pan the pickups it should be a problem with the preamp, it would be very unlikely that both your pickups develop the same fault at the same time.

[mr.noisy]

I haven't tried it yet, but I will try it on next rehearsal or performance and let you know.

[Ghost_Bass]

And if the problem happens with only one of the pickups then is most likely that it's knackered.

[Chienmortbb]

The only way a pickup can go "wrong" is open circuit, that is no sound at all, or short circuit where the signal would be reduced to some degree. Clearly both those problems would affect all strings.

Having written this though I have thought that is the pickup is ceramic or another bar magnet and it has broken, with part falling away from the pickup. Them the poles would be come demagnetised and the volume level of those strings would be much lower. So go ahead restrung so that the strings seed opposite to the way you normally have them. This will tell you wether the PUPs are at fault,

[Ghost_Bass]

[quote name='Chienmortbb' timestamp='1456252167' post='2987133']
(...)

Having written this though I have thought that is the pickup is ceramic or another bar magnet and it has broken, with part falling away from the pickup. Them the poles would be come demagnetised and the volume level of those strings would be much lower. So go ahead restrung so that the strings seed opposite to the way you normally have them. This will tell you wether the PUPs are at fault,
[/quote]

Yep, it was my thought. I think that just getting a spare G string on the B position and use it in a band reharsall/gig and compare both G strings to see if both are dull or not should crack this mistery.

[RhysP]

If it only happens at gigs it sounds like somebody else in the band is stomping all over those frequencies.

[Ghost_Bass]

[quote name='RhysP' timestamp='1456319702' post='2987765']
If it only happens at gigs it sounds like somebody else in the band is stomping all over those frequencies.
[/quote]

It was my first thought but then the OP posted this:

[quote name='mr.noisy' timestamp='1456234087' post='2986843']
This is definitely not the EQ thing, I have played it through many different amps, as I am at music uni at the moment, and we perform every week on stage and play rehearsals in different rooms, I used different bass as well as other students with different basses after or before me playing at exact same settings would not have any problems. That's why I thing that the only things left are pickups or the pre-amp, but I think I have replaced the preamp before when I had some other problems, but for exactly the same model. Now it is narrowing down to the pick ups I guess. But I am not sure what could go wrong with them.
[/quote]

If this is true it must be some kind of problem with the bass. I still can't figure out why it only shows with band, if there's a problem on the pickup or preamp it should be even more noticeable when playing alone...