Not sure this is right?

bigweirdbeard · #1 02-19-2009, 05:21 PM

I am new to the upright or double bass.
I just bought a body off ebay and my friend and I built a neck, fingerboard and tail piece for it. We bought the bridge.
It plays and sounds great, but there is one problem.
The intonation is way off. I will try and explain... If I pluck E A D G opened and it is in tune..fine..... Now say I bar the third fret..or position.. If I bar it with my finger straight across then the notes get sharper and sharper.. I would have to bar it diagonally to have it in tune.
I guess I could learn to deal with this, but if it is not correct then I would like to fix it.. It is messing me up right now as it is.

What is the deal? Anybody? Oh also the nut is homemade.

**Chris Fitzgerald** · #2 02-19-2009, 06:06 PM

Do you have another commercially made/setup double bass nearby you can compare it with? The perception that notes are farther from the nut on the lower strings is a common one for beginners - I had that same feeling, way back when.

shadygrove · #3 02-19-2009, 06:21 PM

I was just talking about this with some fiddlers the other day. Our conclusion was the finger placement does change ever so slightly to compensate for the change in string diameter. This is why if you look at a guitar saddle (bridge) they are typically slanted so you have a longer speaking length on the larger diameter strings.

Since most of us judge our intonation with our ears and not by staring at a line drawn across the fingerboard we've probably trained ourselves to make this adjustment without realizing it.

Greg Clinkingbeard · #4 02-19-2009, 06:47 PM

Is the bridge straight and positioned between the notches on the ff holes?

bigweirdbeard · #5 02-19-2009, 07:32 PM

Yeah the bridge is straight with the F holes.. From all the pics I found thats how they were set up..
I don't have access to a normal bass that I could compare this one to. It would have helped a lot in the building.
I could get used to playing it like this.. I mean I am learning it from scratch anyway pretty much.. But I feel like if this is not how the bass should be I don't want to learn this bad habit. I am sure I could fix it if I just knew what was wrong..

Thanks for the reply's guys.

bigweirdbeard · #6 02-19-2009, 07:39 PM

Quote:

Originally Posted by shadygrove

Since most of us judge our intonation with our ears and not by staring at a line drawn across the fingerboard we've probably trained ourselves to make this adjustment without realizing it.

Yeah this would be like almost a 45 degree line for correct intonation.. Compared to what I am used to.90 degrees..

It may be normal... But since we made so much of the bass I just don't know for sure..

reedo35 · #7 02-19-2009, 08:23 PM

I Have to see a picture of this!!!

bigweirdbeard · #8 02-19-2009, 08:26 PM

I will put I pic up.. I want to take some anyway.. It is pretty cool looking IMO.

Andrew McGregor · #9 02-19-2009, 08:27 PM

I can't see how that is physically possible... post pictures, including showing what you think is going on with the intonation.

Or... hmm... what are your string heights? How much scoop is there in the fingerboard?

bigweirdbeard · #10 02-19-2009, 08:37 PM

Quote:

Originally Posted by Andrew McGregor

I can't see how that is physically possible... post pictures, including showing what you think is going on with the intonation.

Or... hmm... what are your string heights? How much scoop is there in the fingerboard?

I don't see how it is possible either,, The length between the the nut and bridge would need to be different on each string to make this happen..Yes?
Well I will try and get some pics up anyway..
Nice site here.. I can't believe How many reply's in such a short time.. Cool.

shadygrove · #11 02-19-2009, 08:47 PM

Quote:

Originally Posted by bigweirdbeard

Yeah this would be like almost a 45 degree line for correct intonation.. Compared to what I am used to.90 degrees..

It may be normal... But since we made so much of the bass I just don't know for sure..

That's a whole lot more off than the very slight adjustment for string diameter I had in mind. Maybe with pictures the luthiers here can help you out as it sure does sound like something's out of whack.

Hope it's nothing too major.

bigweirdbeard · #12 02-19-2009, 09:38 PM

This is the bass.. My friend is playing it.. It is a 4/4 I believe.

Jake deVilliers · #13 02-19-2009, 10:29 PM

Hey cool! Nice tailpiece. The bridge looks okay from that angle - can you take a couple more from the side or at an angle? It would be good to see the string heights too.

I'm wondering if all the strings are coming off the front of the nut. If a string is longer on that end it will make it impossible to note correctly. Maybe loosen off a string a little so you can pull it sideways at the nut - then you'll see where it wiggles.

Andrew McGregor · #14 02-19-2009, 11:54 PM

That's a nice bit of work.

I think Jake has it... the shape of the nut slots could do this, if the effective length of the open string is not precisely the same across all four.

Remotely the fingerboard profile could. Since stopping the string changes the tension, if those strings are super-low tension you might effectively be pulling the notes by stopping them.

Fred19137 · #15 02-19-2009, 11:58 PM

I know i know. If i hear you right the note dont follow a grid like frets. they kind of pull away? If that is the case It has to do with the bridge. If you tilt the e side of the bridge down and the G side up everything should be fixed. But be carefull loosen the strings before each move. If you try to short cut u could bust the bridge!!!!!!!!!

Fred19137 · #16 02-20-2009, 12:01 AM

It is all the bridge look at electric guitars and basses their bridge tilts doubles are no exception I had to do thie just the other week to my friend's bass and it is fine now.

Andrew McGregor · #17 02-20-2009, 02:23 AM

Er, no. The bridge should be square. End correction does exist, but that's not the problem here.

**Matthew Tucker** · #18 02-20-2009, 02:58 AM

If all your strings are the same length, it's physically impossible for the same stop length "fret" on each string to be out of tune, UNLESS the strings are so high, that as you pull them down they are stretching and the change in tension is making them sharp. The only other thing that could change things is if the neck is not completely stiff, so that when you pull the strings down, the tension is pulling the neck forwards.

What is the string height? what kind of strings? and ... er ... you did put a sound post in there, didn't you??

**Matthew Tucker** · #19 02-20-2009, 03:06 AM

Quote:

Originally Posted by shadygrove

This is why if you look at a guitar saddle (bridge) they are typically slanted so you have a longer speaking length on the larger diameter strings.

IMO the slanted bridge on a guitar or bass guitar has nothing to do with optimising the speaking length of the string. The difference in tone would be infinitesimal.

When fretting the thinner strings, they are affected more by the slight increase in tension as the string bends towards the fret, and even as the finger presses the string between the two adjacent frets, and the slightly altered string length compensates for this. On a fretted instrument your intonation position (fret) is fixed, and you can't adjust for small differences in tension as you can on a fretless instrument, so you have to compromise with a "compensated" bridge saddle.

I'd be interested if a fretless bass also needs a "compensated" saddle. Somehow I doubt it. An Oud doesn't

uprightben · #20 02-20-2009, 06:44 AM

What is your neck and fingerboard made of? If the problem is really as you describe it and not just a beginner perception issue, it's got to be your nut or maybe a floppy neck. Your bridge looks to be on correctly. Sorry fred, but you should never angle your bridge on a DB- the bridge feet should be fitted perfectly to the top and moving things will ruin that fit, rob you of sound and might even damage your bass. Make sure that the bottom of your nut is parallel to the bridge and that the strings are firmly in contact with that bottom edge of the nut.