weak(ish) and muted E and B strings on bolt-on bass

OldogNewTrick · #1 03-08-2011, 07:52 AM

Looking for help from experienced luthiers:

I have been trying for a long while to track down the cause and possible remedies for a problem with my 5-string bolt-on fretted bass.
The E and B string sound weak and muted. Playing fingerstyle, this is not very noticeable, but slapping lacks a strong fundamental and notes do not ring out.
A-string and higher are fine. Especially in contrast to the E, the A has a solid heft and a clear ring.

At first I suspected maybe pickups and/or onboard electronics. After contacting Delano, this seems not to be the case. The A-string shares a coil with the E and B string in the inline humbuckers and there is not difference beween active and passive operation.

I have dismantled the neck and the 6 scews holding the neck were tight and the neck fitted the pocket tight, without preceptable play. The heel of the neck is lacquered (thin), as is the neck pocket (fairly thick). After reassembly no change.

Trying to escape any psycho-acoustic tricks my mind is possibly playing on me, I have tried to measure the effect by frequency analysis.

Bass with new Dunlop Nickel roundwounds. Bridge pickup solo-ed, pre-amp bypassed to passive, into Line6 AD converter to Audacity. Recorded both slapping the open strings as well as evenly tapping them with a small screwdriver (no contact of string to frets or fingerboard) to eleminate my flawed fingers.

Directly comparing the spectrum analysis charts between E and A string showed:
On the A-string the 2nd harmonic (= 1.st overtone above the fundamental) and 4th harmonic strongest with the fundamental at 55Hz app. 10dB down.
On the E-string was the 4th harmonic the strongest, with the 2nd down by 10dB and the fundamental down by 20 dB. Drastic difference.
The B-string shows the same behaviour.

The graphs show equally the clear ringing harmonics of the A and D strings and the quickly falling higher harmonics on the E and B strings.

All strings sustain well with similiar length. I can also not detect a single dead spot on any string between 1st. and 9th fret.

I am at a loss and your suggestions are greatly appreciated.

tjmdetroit · #2 03-09-2011, 12:28 AM

I'd look closely at the nut.... make sure the strings aren't being muted by an improperly cut nut. If your not sure how a nut should be slotted, do a search in here or you tube. Good luck.

OldogNewTrick · #3 03-09-2011, 05:33 AM

Quote:

Originally Posted by tjmdetroit

I'd look closely at the nut.... make sure the strings aren't being muted by an improperly cut nut. If your not sure how a nut should be slotted, do a search in here or you tube. Good luck.

Good point, theoretically.
I should have mentioned that the bass has a Zero fret and an 13° angled headstock. Combined with a 120 B and a 100 A, this seems pretty unlikely to be the problem area. More so as the problem is not only with open strings, but equally fretted, where the nut has no more influence.

TripleDouble · #4 03-09-2011, 05:57 AM

Subscribed. I have a nice quality 5 string that suffers the same thing, though mostly just on the low B. I've also tried using a much larger B string, which helps, but would not be my first choice as far as treating this.

mixamatchi · #5 03-09-2011, 06:15 AM

This may sound silly, and/or may have been tried already, but try the same test with your volume knob turned down to 1/2 or 3/4. You may find that the bass has so much output, that the electronics/rig/signal chain is compressing the output of your bass. The first thing to go when a bass signal is compressed is bottom. I know there isn't compression listed in your test rig, but the electronics in your bass could actually be doing this, as well as the A/D interface you used to record it.

OldogNewTrick · #6 03-09-2011, 06:49 AM

Thanks for your input !

The problem exists both in active mode as well as passive, that is the entire preamp bypassed.
Also, the recording setup was only as a means to quantify that what I heard in normal playing.
Again, the A string has more perceived volume output than the weak E and B strings...

mikezimmerman · #7 03-09-2011, 08:46 AM

You mentioned that you measured this with a new set of Dunlop nickels. Does this happen consistently with any set of strings you try, or is it just with Dunlops in this particular gauge? If you're looking for more sustain and stronger, clearer harmonics, it sometimes helps to go to a lighter gauge with a round core for more flexibility and truer harmonics.

Another thing I would try is to brace the back of the headstock against something solid (like a doorframe, for instance) to see if minimizing the neck vibration/resonance changes the behavior of the E and B strings.

Mike

JLS · #8 03-09-2011, 09:29 AM

You've got a lousy bass. Some are just bad.

Do you perceive this, unamplified? If so, it's a dog. Get rid of it.

OldogNewTrick · #9 03-09-2011, 10:23 AM

Quote:

Originally Posted by mikezimmerman

You mentioned that you measured this with a new set of Dunlop nickels. Does this happen consistently with any set of strings you try, or is it just with Dunlops in this particular gauge? If you're looking for more sustain and stronger, clearer harmonics, it sometimes helps to go to a lighter gauge with a round core for more flexibility and truer harmonics.

Another thing I would try is to brace the back of the headstock against something solid (like a doorframe, for instance) to see if minimizing the neck vibration/resonance changes the behavior of the E and B strings.

Mike

Interesting sugestion - I'll try that.
AS far as strings are concerned, its been consistently with a lot of strings like that. Intially I had thought that the strings were duds... tried D'Addario XL's, DR Low Beams, Elixirs, always hoping that its the strings......

OldogNewTrick · #10 03-09-2011, 10:46 AM

that's the spectrum analysis for the E-string
note the 4th harmonic peak and the rapidly dropping harmonics

this is the A-string, all equal to above
note the peak on the 2nd and 4th harmonic and the much more pronounced harmonics

I've tested all sorts of variations of the above, all boiling down to basically the same thing.

Mind, this a basically a quality instrument, not El-Cheapo, with excellent workmanship....

I would really like to get to the bottom of this in order to find out what to be on the lookout for in future.

Chuck Sylvester · #11 03-09-2011, 01:35 PM

OldDog,
I had the same problem with just the B string on a few 5-string bassess I've owned over the years. D'Addarios sounded weak on the .130 B string. I tried their tapered B-string. No good; too piano-like compared to the other 4 strings.

I thought it was the bass. Then I tried a set of these from Carvin: Carvin.com :: 5011. They're actually made by LaBella. They have a tapered B-string that has some bite, but it blends pretty well with the other 4 strings. They're only 14.99 USD. Might be worth the risk to check them out.

Good luck
Chuck

greenboy · #12 03-09-2011, 01:47 PM

Just looked at the graphs, didn't read much. But if you have construction details or wood that's especially resonant at the worng frequencies, it can cave an essential range out pretty bad. The particular wood pieces can actually suck vibratory energy away.

Usually with more limited dead spots the trick is to move the resonant frequency to a different range. That can be achieved several ways including a little chambering, or different lighter tuners, or the opposite, a bunch of weight on the peg head, or sometimes even some changing of string gauges, which then means different truss rod tension which can change the soak frequency and Q.

tjmdetroit · #13 03-09-2011, 02:21 PM

Quote:

Originally Posted by OldogNewTrick

Good point, theoretically.
I should have mentioned that the bass has a Zero fret and an 13° angled headstock. Combined with a 120 B and a 100 A, this seems pretty unlikely to be the problem area. More so as the problem is not only with open strings, but equally fretted, where the nut has no more influence.

It sounds like something is slightly muting those strings and if it displays the same symptoms fretted/unfretted, amplified/unamplified ... where else could it be dampened...... Ummm... the bridge.. Those strings should be vibrating freely between the fretted fret or zero fret and the bridge saddle, the end! I'd put an eyeball on that bridge, make sure it's tight etc. then check the saddles and then make sure the strings aren't just slightly touching the fretboard. Raise the strings up a taste to see if it still does it. What else could be dampening the vibrations? Gremlins?
Keep us posted... we're all counting on you....
Tim

OldogNewTrick · #14 03-09-2011, 02:54 PM

Thanks again for everyone's input, truely appreciated.

I will follow up on your suggestions and report back as soon as I can. My job is eating me alive at this moment....

Meanwhile, this what the slapped tone is like, Bridge humbucker to 70's SC, blend with neck p-up at centre, passive.

D-string:

A-string:

E-string:

B-string:

and for good measure, my neck-through fretless with Delano Xtender in SC mode, screwdriver tap without touching the fret board with fairly dead DR Sunbeams E-string:

OldogNewTrick · #15 03-09-2011, 02:58 PM

Quote:

Originally Posted by greenboy

Just looked at the graphs, didn't read much. But if you have construction details or wood that's especially resonant at the worng frequencies, it can cave an essential range out pretty bad. The particular wood pieces can actually suck vibratory energy away.

The bass is a light mohagony body with walnut top, quarter sawn maple neck with rosewood fingerboard.

JLS · #16 03-09-2011, 06:06 PM

Do. You. Perceive. This. With. The. Bass. Unplugged?

OldogNewTrick · #17 03-10-2011, 04:01 AM

Quote:

Originally Posted by JLS

You've got a lousy bass. Some are just bad.

Do you perceive this, unamplified? If so, it's a dog. Get rid of it.

Quote:

Originally Posted by JLS

Do. You. Perceive. This. With. The. Bass. Unplugged?

The muted ring / lack of highs, yes I do.
The weak fundamental on the E and B are acoustically difficult to detect.

But. I. Am. Not. Slow.....

and what makes a bass a(n incurable) dog? Sorry, trying not to appear defensive or unappreciative, I am indeed grateful for any help and idea I can get, as I am obviously unable to solve the problem without assistance....

mech · #18 03-10-2011, 05:57 AM

Try lowering the PUs on the BE side. Hard to tell from the pic but they look really close to the strings. Could be a classic case of coil saturation/magnetic muting or whatever mojological term may apply.

mech

JLS · #19 03-10-2011, 09:02 AM

Quote:

Originally Posted by OldogNewTrick

The muted ring / lack of highs, yes I do.
The weak fundamental on the E and B are acoustically difficult to detect.

But. I. Am. Not. Slow.....

and what makes a bass a(n incurable) dog? Sorry, trying not to appear defensive or unappreciative, I am indeed grateful for any help and idea I can get, as I am obviously unable to solve the problem without assistance....

Sometimes it's just a dead piece of wood. I remember a Les Paul that was so unresponsive, I didn't want to play it. New strings, didn't matter--it was just junk.

Also, listen to the good advice about lowering the pickups on that side. You might luck out

tubby.twins · #20 03-10-2011, 12:02 PM

Quote:

Originally Posted by mech

Try lowering the PUs on the BE side. Hard to tell from the pic but they look really close to the strings. Could be a classic case of coil saturation/magnetic muting or whatever mojological term may apply.

mech

I was going to suggest this as well. I've run into issues here. The B and E strings are especially susceptible to this, since they're so massive (relatively speaking).

The other thing you'd notice is that, when you play above the twelfth fret, the B and E strings sound muted, warbly and chorusy, almost as if they're off pitch (flat).

This is common with polepiece pickups which have strong magnetic fields and are too close to the strings. I've had generally good luck with Delano pickups (including the PMVC 5, which is not too dissimilar to your neck pickup) but then again I don't slap that much.