Should I recess my Kahler bridge?

[bassocontinuum]

I have just put together a Warmoth bass build (Deluxe 5 P bass body / Deluxe 5 (4+1) neck).

I have fitted a Kahler 7450 bridge without a bridge route.

After stringing up I have a small problem in that even with the bridge saddles set to the lowest point the action is still generally too high.

As far as I can see I have two choices to fix this:

1) Recess the bridge into the body by a suitable amount (probably 2-3mm).
2) Shim the neck (i.e. shim the neck side of the neck pocket to create an 'action-lowering' neck angle).

I am quite happy to do #1 - if it is the correct solution - even though it means getting the router out & making a jig -  but wondered if anyone could advise what the pros & cons of each method are?

I also assume that removing material from the neck pocket (or neck) would have a similar effect to recessing the bridge, but this doesn't seem like the most appropriate way to go.

By the way I didn't get Warmoth to route the bridge at the time of ordering as at that stage I hadn't decided on which type of bridge I was going to use.

Any help would be greatly appreciated...

 

[line6man]

DON'T RECESS THE BRIDGE.

That would be a permanent modification to the body, and very easy to screw up as well.

I've seen threads about this kind of thing on TalkBass, and the general consensus seems to be that shimming the neck is the best method to lower the action.

 

[Wyliee]

On the contrary, Line6man.  The old Kahler 7450 bridge was recessed on the body.  The bridge plate is pretty massive.  Take a look at the bridge routing options on the Warmoth site.

http://www.warmoth.com/Bass/Options/BassBridgeRouting.aspx

 

[line6man]

On the contrary, Line6man.  The old Kahler 7450 bridge was recessed on the body.  The bridge plate is pretty massive.  Take a look at the bridge routing options on the Warmoth site.

http://www.warmoth.com/Bass/Options/BassBridgeRouting.aspx

You guys have a CNC program setup for that routing, and it's done before the body is finished as well.

 

[Wyliee]

On the contrary, Line6man.  The old Kahler 7450 bridge was recessed on the body.  The bridge plate is pretty massive.  Take a look at the bridge routing options on the Warmoth site.

http://www.warmoth.com/Bass/Options/BassBridgeRouting.aspx

You guys have a CNC program setup for that routing, and it's done before the body is finished as well.

It's not a terribly complex shape.  If the OP has the skills to do the rout and is comfortable making the mod, I would stand by my original recommendation.

 

[tubby.twins]

I am quite happy to do #1 - if it is the correct solution - even though it means getting the router out & making a jig -  but wondered if anyone could advise what the pros & cons of each method are?

The benefit for #1 (recessing the Kahler bridge) is that you get the ability to use a wonderful, highly adjustable and rock-solid stable bass bridge at the correct height for its intended use.  I have 4 Gecko basses with Kahler bridges, and they take time to adjust properly, but once you get everything set up, it's perfect.

I also assume that removing material from the neck pocket (or neck) would have a similar effect to recessing the bridge, but this doesn't seem like the most appropriate way to go.

Actually, that would have the opposite effect.  It would make the neck "lower" against the face of the body, and if your bridge is already too high, it makes the problem worse.

I second Wyliee's recommendation to recess the bridge plate.  I would be wary of shims unless they were securely glued in place (on the body) and you had the angle set just right.  If you do decide to go with the shim, consider using a dense wood like Wenge.

Here's another thing to try.  Remove one of the saddles from the Kahler bridge by turning it counter-clockwise until it comes out completely.  If your saddle is the standard "short" saddle (11mm tall) then you can use some sandpaper or a grinding wheel to shave off about 1mm from the UNDERSIDE of the saddle.  This will allow you to get the outer strings (especially the G string) a bit closer.  I did this on my Gecko basses, which were fretless and had the recessed bridge plates, and it made a world of difference for getting that low action that I enjoy.

However, if your bridge saddles are 15mm tall, then you should order the short saddles from http://www.kahlerparts.com and use those instead.  I can't imagine a scenario where you'd want to use the taller saddles, unless the neck was really tall, or you like your bass to have high action resembling a suspension bridge.  

 

[bassocontinuum]

Thanks for all the replies.

In the end I decided to recess the bridge. This kind of thing is never a five minute job - but I made the router jig, did a test run, and then for real on the bass. Several hours work, but it all worked out fine. I ended up with a nice flat bottomed recess 3mm deep in the correct place & the correct size! The action is now where it needs to be without any of the bridge saddles being at any extremes of position.

Thanks to tubby.twins for the info on the longer saddles - useful to know.

It really is a very nice bridge - very adjustable. Probably looks better recessed into the body too.

 

[tubby.twins]

Any pictures to post? 

 

[bassocontinuum]

Here you go...

Strangely, due to some kind of optical illusion it makes it look like the lower left corner of the bridge isn't recessed - but I assure you it is!

The body hasn't been finished yet - hence the pencil marks!

 

[Mor Paul]

Looks clean!
What kind of pickups are those? I don't see many single coil blade bass pickups.

 

[tubby.twins]

Very nice work.  I'm curious about the pickups as well.  You're using D'Addario strings, right?

When you get around to finishing the body, you may find that you need to scrape out a bit of the finish that flows over the edge of the route that you just made.  It's probably a good idea to mask off that area after the first or second coat, to save you the time and trouble of needing to scrape away the excess later.  I've had to do that on all my Gecko bodies with Kahler bridge routes.  Otherwise, the excess finish near the bottom edges causes the bridge plate to raise up and not sit flat within the route.

 

[line6man]

Those look like Yamahas to me:

 

[line6man]

Whoa! Holy freaking crap that image is big. Sorry about that guys.

 

[bassocontinuum]

Looks clean!
What kind of pickups are those? I don't see many single coil blade bass pickups.

The pickups are Yamaha - the same as fitted to the BB415/BB615. I already own a BB615 & like the sound but not the neck - so I decided to build a bass with the dimensions/neck shape etc. around these pickups. As the bass is scratchplate-based, it means I can experiment in the future with different pickups or electronics by making a new scratchplate & fitting the desired hardware.

I had read that a lot of people preferred the sound of the BB415 (which is passive) to the (active) BB615, so I wired this bass so I could switch between either & have the best of both worlds. The pickups are identical in both models.

Very nice work.  I'm curious about the pickups as well.  You're using D'Addario strings, right?

Yes, the strings are D'Addario XL's - I find they are a good neutral starting point.

When you get around to finishing the body, you may find that you need to scrape out a bit of the finish that flows over the edge of the route that you just made.  It's probably a good idea to mask off that area after the first or second coat, to save you the time and trouble of needing to scrape away the excess later.  I've had to do that on all my Gecko bodies with Kahler bridge routes.  Otherwise, the excess finish near the bottom edges causes the bridge plate to raise up and not sit flat within the route.

Thanks for the tip. I'm actually planning a woodstain + TruOil finish so I would imagine this won't be a problem in this case.

Here's a shot of the body showing more of the pickups & controls:

In case you're interested, the controls are (from left to right, top to bottom):

Pickup blend (active mode)
Bass cut (passive mode)
Treble cut (passive mode)
Volume (big knob)
Bass cut/boost (active mode)
Middle cut/boost (active mode)
Treble cut/boost (active mode)
Pickup select (passive mode)
Active/Passive switch
Mute pushbutton (mutes output - useful in theatre shows etc. to mute instrument without losing volume setting)

The number of controls required a large custom scratchplate - it was a bit of a squeeze getting them all in!

 

[baskruit]

Damn, that's an impressive collection of knobs and switches.

Brave job, that DIY routing. I like it.
I have a Squier J-bass here with a Gotoh-201 and without a shim (couple sheets of paper), the action just is too high. It's a squier so there's nothing much to lose.... So I may have a go at that some time. Should be a cool experience.

 

[bassocontinuum]

Damn, that's an impressive collection of knobs and switches.

Yes, I did get a bit carried away - but it's not really as complicated as it looks.

Brave job, that DIY routing. I like it.

Yes, getting the router out for this kind of thing where you only get one shot at it does quicken the pulse. I tend to take things very slowly & thoughfully & it's worked out OK so far. The battery box route on the back of the bass was actually trickier because it needed a dual route; one for the cavity itself & one to recess the flange flush with the surface: