Odd Intonation? Problem

[TeeSee]

Hi all, I'm looking for advice on my Bronco bass. I've a really strange problem I've never encountered before.
I changed the bridge on it for a Sung Il bb404 - I have one already on another guitar and very pleased with it. There is a strange problem though, while perfectly tuned, on the E,A & D string that I play on the fifth fret, when I play the open string above it, the open string is a semitone flatter.
I (think) I understand that intonation imbalance is usually encountered a lot further up the neck and I'm at a loss to figure out what is the problem.
When I fitted the bridge the distance from fret end of the nut to measures 14 and 7/8", double that and by my calculations it's 29 and 3/4" to bridge. I've set the intonation on the g string to it's furthest point forward and set the bridge to that point before drilling the holes. Just in case I've miscalculated I keep measuring the distance but it is still smack on 29&3/4" to the fitted bridge to fully extended saddle on G.
I'm at a loss to figure out whats going wrong and no amount of adjusting intonation alleviates it.
I've got a suspicion tho about something, I've replaced the disc type D & G string tree to one of those string trees that spans A,D & G, I don't know whether that has something to do with it?
All advice gratefully received.

 

[Zooberwerx]

How are you eval'ing / setting intonation?

Riis

 

[john m]

Is your action high? That would bend fretted notes sharp.
Was the intonation good with the old bridge?

 

[TeeSee]

guess work atm, haven't really tried to set intonation on yet, due to this problem. But if I were going to I'd put the tuner on and set on 12th fret, I've done that before and always sounded right to me, is there a different and better way?

 

[jmattbassplaya]

Is your action high? That would bend fretted notes sharp.
Was the intonation good with the old bridge?

I had this issue with a Les Paul that’s nut was cut too high.

 

[TeeSee]

Is your action high? That would bend fretted notes sharp.
Was the intonation good with the old bridge?

Yeah I forgot to mention that the old bridge I never noticed anything like this.

 

[TeeSee]

Is your action high? That would bend fretted notes sharp.
Was the intonation good with the old bridge?

Hmm you know what, I hadn't set the action yet other than to higher it to come off the fret board a just a little. Maybe I should do all that first with feelers before , but I don't think the action is very high TBF

 

[Zooberwerx]

guess work atm, haven't really tried to set intonation on yet, due to this problem. But if I were going to I'd put the tuner on and set on 12th fret, I've done that before and always sounded right to me, is there a different and better way?

Simplest route: match-up the 12th fret harmonic and 12th fretted...that's a starter. Leave the open string out of the equation for now.

Side note: this is all predicated on a proper string install (wraps, break angles, witness points). You're all over-the-map given your description. There's a prescribed route which should optimize your outcomes.

Riis

 

[TeeSee]

Simplest route: match-up the 12th fret harmonic and 12th fretted...that's a starter. Leave the open string out of the equation for now.

Side note: this is all predicated on a proper string install (wraps, break angles, witness points). You're all over-the-map given your description. There's a prescribed route which should optimize your outcomes.

Riis

I'll admit I'm not the most clued up in guitar set ups, but I usually follow the Jon Carruthers series of shorts on YT, always found him to be pretty good.
Is there different proscribed route that you'd recommend?
The break angles are pretty fierce, as I wind right down to the bottom of the peg so there's little buzzing. I'm also intrigued with @jmattbassplaya description of his problem as the old bridge was a piece of flat plate like the standard fender bent plate and this bridge has more substance to it.

 

[Zooberwerx]

I'll admit I'm not the most clued up in guitar set ups, but I usually follow the Jon Carruthers series of shorts on YT, always found him to be pretty good.
Is there different proscribed route that you'd recommend?
The break angles are pretty fierce, as I wind right down to the bottom of the peg so there's little buzzing. I'm also intrigued with @jmattbassplaya description of his problem as the old bridge was a piece of flat plate like the standard fender bent plate and this bridge has more substance to it.

Don't forget to set your witness points (well-defined break points over the nut and bridge saddle). A few more starting points:

*Tune the strings to pitch using the 12th fret harmonic on each...more on that later. I trust you have a passable tuner. We want to see how the bass responds under duress (~140 lbs?).

*Check and re-adjust the relief as necessary. A perfectly straight neck / fingerboard is a no-no.

*Set your string height for buzz-free performance. This will vary instrument-to-instrument and user's technique. Doesn't have to be perfect as we're just roughing-in the set-up. We'll ice the cupcake later.

*Check your intonation by comparing (via tuner) the 12th harmonic (gold standard) vs the 12th fretted. If the fretted is flat, move the saddle forward...if sharp, backwards / retreat. This is time-consuming as you'll be constantly re-tuning but eventually you'll get each string dialed-in.

This is really basic and, in essence, ignores other components & details which we can address later. We're just trying to get the bass in-tune with itself for the time being....which is why you posted in the first place!

Riis

 

[TeeSee]

Hi Riis thanks for this info, really appreciate it, got descended on by the wife's family now so there goes my Saturday afternoon (can't find an emoticon for grumpy)! I'll start looking at this in earnest tomorrow morning while it's quiet, and report back to you, thank you once again.
Tony

 

[jmattbassplaya]

I'll admit I'm not the most clued up in guitar set ups, but I usually follow the Jon Carruthers series of shorts on YT, always found him to be pretty good.
Is there different proscribed route that you'd recommend?
The break angles are pretty fierce, as I wind right down to the bottom of the peg so there's little buzzing. I'm also intrigued with @jmattbassplaya description of his problem as the old bridge was a piece of flat plate like the standard fender bent plate and this bridge has more substance to it.

So the bridge was fine on the Les Paul and was the standard tune-o-matic, but the nut was cut too high so that all your “cowboy” chords would be played sharp. The fix was to recut the nut and redo the setup.

 

[Zooberwerx]

Hi Riis thanks for this info, really appreciate it, got descended on by the wife's family now so there goes my Saturday afternoon (can't find an emoticon for grumpy)! I'll start looking at this in earnest tomorrow morning while it's quiet, and report back to you, thank you once again.
Tony

....and you haven't retreated to your "safe room"?!? You lose your man-card for 3 days. Don't feel bad...I have to take Susan to the market later. Wouldn't be so bad if moving aisle-to-aisle but she bounces around the joint like a Roomba.

Let us know how things progress.

Riis

 

[Turnaround]

Hi all, I'm looking for advice on my Bronco bass. I've a really strange problem I've never encountered before.
I changed the bridge on it for a Sung Il bb404 - I have one already on another guitar and very pleased with it. There is a strange problem though, while perfectly tuned, on the E,A & D string that I play on the fifth fret, when I play the open string above it, the open string is a semitone flatter.
I (think) I understand that intonation imbalance is usually encountered a lot further up the neck and I'm at a loss to figure out what is the problem.
When I fitted the bridge the distance from fret end of the nut to measures 14 and 7/8", double that and by my calculations it's 29 and 3/4" to bridge. I've set the intonation on the g string to it's furthest point forward and set the bridge to that point before drilling the holes. Just in case I've miscalculated I keep measuring the distance but it is still smack on 29&3/4" to the fitted bridge to fully extended saddle on G.
I'm at a loss to figure out whats going wrong and no amount of adjusting intonation alleviates it.
I've got a suspicion tho about something, I've replaced the disc type D & G string tree to one of those string trees that spans A,D & G, I don't know whether that has something to do with it?
All advice gratefully received.

It's my understanding that the Bronco bass is a 30" scale. Why did you set the bridge at 29-3/4"?

 

[Five or Six]

Simply put, do a full setup. Then check everything. Are these the strings that came on the bass? If so, throw them in the garbage, then do a full setup!

 

[Engle]

It's my understanding that the Bronco bass is a 30" scale. Why did you set the bridge at 29-3/4"?

^This. Did you measure from the nut to the center of the fret? That should be 15 inches.
Your bridge should be placed so that when the G string saddle is adjusted to its furthest point forward (toward the nut), the point where the string leaves the saddle is 30 inches from the nut. I usually add about 1/16 to that if the bridge doesn't have a lot of travel.

 

[TeeSee]

It's my understanding that the Bronco bass is a 30" scale. Why did you set the bridge at 29-3/4"?

They do say it's a 30" I just measured from the edge of the nut to 12th fret and the measurement was 14.875" to the crown of the fret, then doubled it = 29.75". Did I do something wrong? I'm still a newb at this sort of thing

 

[TeeSee]

Simply put, do a full setup. Then check everything. Are these the strings that came on the bass? If so, throw them in the garbage, then do a full setup!

Nope, these were a new set of Roto flats I put on a couple of months ago when the old bridge was on. The 20 years old rounds went in the bin finally , but I'm getting the distinct feeling form comments I've perhaps jumped the gun, I'm going to research witness point tomorrow and give it a good set up. Thank you to all for your comments so far, I'll be back tomorrow.
Cheers all.

 

[Lionel Albert]

Hi all, I'm looking for advice on my Bronco bass. I've a really strange problem I've never encountered before.
I changed the bridge on it for a Sung Il bb404 - I have one already on another guitar and very pleased with it. There is a strange problem though, while perfectly tuned, on the E,A & D string that I play on the fifth fret, when I play the open string above it, the open string is a semitone flatter.
I (think) I understand that intonation imbalance is usually encountered a lot further up the neck and I'm at a loss to figure out what is the problem.
When I fitted the bridge the distance from fret end of the nut to measures 14 and 7/8", double that and by my calculations it's 29 and 3/4" to bridge. I've set the intonation on the g string to it's furthest point forward and set the bridge to that point before drilling the holes. Just in case I've miscalculated I keep measuring the distance but it is still smack on 29&3/4" to the fitted bridge to fully extended saddle on G.
I'm at a loss to figure out whats going wrong and no amount of adjusting intonation alleviates it.
I've got a suspicion tho about something, I've replaced the disc type D & G string tree to one of those string trees that spans A,D & G, I don't know whether that has something to do with it?
All advice gratefully received.

Check your first frets if it's too sharp, your nut is not well filed.
A lot of people don't pay attention to the nut but it's a very crucial part.
Maybe you need nut files.

 

[Engle]

Nope, these were a new set of Roto flats I put on a couple of months ago when the old bridge was on. The 20 years old rounds went in the bin finally , but I'm getting the distinct feeling form comments I've perhaps jumped the gun, I'm going to research witness point tomorrow and give it a good set up. Thank you to all for your comments so far, I'll be back tomorrow.
Cheers all.

Was the intonation good before you changed the bridge? If so, put the old bridge back on, put a piece of masking tape beside it and mark (or measure) where the string leaves the G string saddle. Then install the new bridge so with the saddle almost all the way forward, the string leaves the saddle in the same place.
All this other stuff people are telling you is fine tuning. It's not going to fix the problem if the bridge is placed where the bass is a semitone out at the 5th fret