Asymmetric 5-String Necks...

Discussion in 'Luthier's Corner' started by RobbieK, Jun 4, 2020.

  1. Hi all. I have made many instruments over the years and always shaped necks with a symmetrical profile. A while back I worked for a luthier who shapes his necks asymmetrically. If memory serves, the DG side was thinner than the BE. Does that sound right?

    1: When I play, my thumb doesn't really go near the lower side of the neck. In fact it lives mostly on halfway or just above. (I'm a pro player with decent technique.)

    2: I have set up many 10+ year-old basses in my time, and most have developed a slight twist towards the treble side. IOW, more relief on the G than on the low B.

    So why remove material from the treble side? Wouldn't it make more sense to have a thinner EB side?

    Beej likes this.
  2. ctmullins

    ctmullins Dominated Gold Supporting Member

    Apr 18, 2008
    MS Gulf Coast
    I'm highly opinionated and extremely self-assured
    I discovered this years ago when I bought my Tobias. I found it amazingly comfortable, and have mimicked this carve on everything I’ve built. (I’m an amateur player with questionable technique. :bag:)
    kesslari likes this.
  3. Beej


    Feb 10, 2007
    Vancouver Island
    I made my first asymmetrical neck years ago based on seeing one and wanting to try it on guitar. I followed what someone else had done and made it thicker on the low E string side, and thinner on the high E side, then moving to the opposite as one moved up the neck. I ended up feeling more comfortable higher on the neck and less so near the nut. I then made one with no "change" in the asymmetry, just thicker towards the high E side all the way up. I liked it more, and I've done it on several personal instruments including my Special Edition Build Off which is just about finished. It's not much change, pretty subtle, but I like it. :thumbsup:
  4. Arie X

    Arie X

    Oct 19, 2015
    because it helps players wrap around the treble side easier.
  5. Bruce Johnson

    Bruce Johnson Gold Supporting Member Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    Over the years, I've shaped a couple of customers' custom necks with an asymmetric profile, because they wanted it. My own main experience with asymmetric neck profiles is that I own a '91 Carvin Bunny Brunnel BB75F, fretless 5-string. An amazing bass all around. I consider it to be the best ergonomic-design bass that I've played. The best you can do ergonomically with a relatively standard form bass.

    The Bunny Brunnel series Carvins have an asymmetrical neck profile. Basically, the high (thickest) part of the profile, which is normally right down the center, is moved over about 1/4" to the bass side. So, the treble side of the neck ends up flatter (larger radius), and the bass side rounder (smaller radius). The explained reason for this is that your thumb should normally ride on that high spot. Moving it over to the bass side rotates your wrist toward you, making your fingers more outstretched and flatter, rather than curled up. If you are playing fast soloing, lots of notes and patterns, keeping your fingers flatter is generally considered better hand form. That's how Bunny and Carvin explained it in the sales literature.

    Me, I'm an old-school style bassist. I pluck hard, don't play many fast notes, and like to keep my fingers curled. So for me, the asymmetric neck profile wasn't comfortable or useful. I won't say that it was uncomfortable, but it's not my preferred neck shape. But I can appreciate why many players may like it, if you are into fast soloing and want to develop the flatter fingers hand form.
  6. JIO

    JIO Scott Lives Gold Supporting Member Commercial User

    Jun 30, 2010
    The Mission SF/CA
    musician/artist/owner - Gildaxe
    asymmetric neck profile, J spacing... (hard to illustrate with a pic)

  7. Thanks for all the replies.

    Mike was the luthier I was talking about. He made his necks by hand, shaping mostly with a drum sander believe it or not. Except for occasional checking with calipers, it was all by eye. And yes, they were certainly comfortable necks to play!

    Thanks for this mate. I think I see what is going on. It means the centre line is sort of tilted towards the treble side. And this follows the taper of your thumb more. It makes sense. I'll give it a go on a 5-string bass I'm modding...
    ctmullins likes this.
  8. Bruce Johnson

    Bruce Johnson Gold Supporting Member Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    No, on the BB75 Carvin, the center is tilted toward the bass side. Unless I'm misremembering.