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PJ electric and double bass hybrid Project

Discussion in 'Luthier's Corner' started by shushi_boi, Feb 3, 2014.

  1. shushi_boi


    Aug 6, 2012
    Yuma Az
    Hello everyone

    I'm a bass player who's intrested in making a project of my own. This question is more directed towards those experts, or anyone who knows a fair amount about both an electric bass and a double bass. I'm trying to build an electric bass/double bass hybrid. How I intend to accomplish this is by installing a neck adjuster which will allow me to switch from a electric bass bass neck (34” scale length) to a double bass neck (total scale length of 41.5") which will virtually turn my instrument into a versatile instrument. Because it can have an adjustable neck, its body will be hollow when I'm playing as a double bass and not hollow when I'm playing it as an electric bass.

    The cool thing about my adjustable neck is that when I play as an electric P/J bass, the body becomes solid (extra 7.5" of neck wood is inside the body) but when I expand the length of the neck when I want to play as a double bass, the extra wood of the neck that was inside the body makes the body hollow from the inside so that the extra wood increase the length of the neck, and the combination of having a longer neck and a hollow body will be the key for me to being able to produce as close to an authentic double bass sound as I possibly can :)

    My ability to change the scale length will depend on my tunning knobs, when I unlock a switch, the extra strings will uncoil as I increase the scale length (I'm not sure if I'm understandable to this point) Not only do I search to turn my instrument into an electric P/J and Double Bass hybrid, but I'm also looking for methods of getting as close to an authentic sound from a double bass and P/J electric bass as I possibly can.

    I was just mentioning about how adding an adjustable neck will allow me to create a double bass and PJ electric hybrid. (which really is the whole key behind my project :) )

    Because it will be similar in size when expanded to a double bass, I hope it'll perform better than a Eminence portable electric upright Bass and almost or close to the volante bass (Because it will be the same length, except the size of my body is bigger than the Eminence, which is tonally closer to an actual double bass). So not only am I engineering my bass to sound like a double and an electric bass by having the ability to adjust the size of it's neck, but I'm also looking for the type of woods (specifically for body and back neck) that would be perfect for both instrument tones.

    So I'm looking for a tone wood body (or a combination of more than one woods) that will be perfect in terms of performing well for both the applications of being an electric solid body bass and at the same time a hollow double bass body. (I'm looking for a body that could perform very well as the solid-body for an electric bass and the hollow-body of a double bass)

    I've already solved 1/3 of the puzzle because I know the fretless board will be Macassar ebony (a high tonewood) which is perfect for both electric bass and double bass. Now I'm searching which tonewoods should I use for the body and back neck that would be perfect for my project. Not only that, I have to incorporate as much elements from a double bass and an electric bass (the best from both worlds) as I possibly can, which I think I solved the most crucial ones.

    In regards to searching for a body, I've been reading and I heard excellent responses and feedback from the quality of the italian alpine spruce as a top body, which I heard made white/swamp ash, brazilian rosewood sound like a joke. Because of the construction of the double bass' body, its top is made from spruce (unspecified) with maple on the sides and back. I wanted to know how italian alpine spruce would rank in tonality and quality as well from this tone-o-meter.

    What are the characteristics of the italian alpine spruce as a tonewood? How would the italian alpine spruce rank up in terms of tone, resonance, sustain, etc. in comparision to all the other tones wood that are classified in the warmoth website's tonometer for body? I listed the source of where I obtained my information concerning my interest in italian alpine spruce wood;

    The reason why I asked for this is so that I can easily compare all the other wood bodies from the warmoth website (in terms of body tonewood) with the italian alpine spruce, to be able to determine which wood body or combinations of wood bodies that I would need to be perfect for creating both a really close authentic double bass sound when the body is hollow and a really close authentic sound to an electric precision/jazz bass when the body becomes solid.

    Is there a better tone wood body than the italian alpine spruce that warmoth has available for my project or should I stick with the italian alpine spruce for my body? And depending on which body you recommend, is there a back neck you would recommend as well that complements both the body and the fretless Macassar ebony board? (I've been having my eyes set on purple heart for a while now in terms of tone, but I don't know which back neck would go perfect with my body to get really close to obtaining both authentic sounds from an electric PJ and double bass) Thank you for your time :)
  2. Beej


    Feb 10, 2007
    Victoria, BC
    Do you have a drawing yet? I think it's probably worth really figuring out what it will look like and how it will function before getting too mired in tonewoods. Your instrument will be a little bit unique to get bogged down in traditional construction I think...
  3. shushi_boi


    Aug 6, 2012
    Yuma Az
    I think the description is well about detailing the functions, but in regards to you thinking if it's possible, it is as long as you have the right materials which I'm at that particular stage and trying to find out. By nature I'm an engineer and by desire I'm an artist sort of say, well I like to be one ;)

    Well for the most part, much of the components that i'll need will be custom made and so fourth, and yes I'm still in my planing stage where I'm looking for an approach to this method. It will be unique to the extent that it's body will be subject to being hollow and solid and that it has a adjustable neck. Not only that, I also designed movable platforms in the body which allows me to raise the level of the pickups up and down, either close to the strings (when I'm playing electric bass) and down when I'm playing double bass (to avoid getting that electric sound). But I wont scratch much into that or even more as I'll lose my audience and the purpose of this question if that's what your getting at ;)

    There is much detail and I'll try to upload a picture on the progress of my design and so fourth... This question is mostly towards those who are arborists, and electric solid body and hollow body double bass experts as well. I'll get into more detail about the functions of many of my devices, such as my tuning knobs which will act as coiling devices for the strings when the neck decreases in size :p This touches many grounds and its understandable if you get a little lost...
  4. Eric Hochberg

    Eric Hochberg

    Jul 7, 2004
    Do you think there is a need for an instrument like this, or are you doing it strictly for the challenge?
  5. All I can say is: Edsel.
  6. shushi_boi


    Aug 6, 2012
    Yuma Az
    Well its both. :smug:

    With the versatility of producing so many tones, all I'll ever need is one instrument. (which wont sound like the best double bass when its double bass and wont sound like the best electric when its playing as an electric)

    I mean everyone who adds piezos to their electric basses or DP120 Model One humbuckers are looking for a sound similar to the double bass and what my project does is that it designs an instrument with the ability of performing as these two instruments with a wide variety of tones in between. (that wont just sound as fake imitator of a double bass).

    I mean this is not just an abomination I'm trying to create, it's an attempt to get electric guitar players closer to these boundaries that separated electric players from double bass players (especially those who love both instruments). It's not design necessarily for the everyday bass player, but those who truly appreciate a good quality double bass tone. :cool:

    What I'm trying to do is create an electric bass that has similar characteristics of a electric upright, without the restrictions that the common double bass and electric instrument presents to us. ;)
  7. TroyK

    TroyK Moderator Staff Member

    Mar 14, 2003
    Seattle, WA
    So, I'm not a designer and I don't want to quash entreprenural creativity, but I can't imagine carrying two necks, bridges, strings, etc. and a body that can be solid and Spector sized or hollow and 3/4 double bass sized and have it be any more portable than simply taking a double bass and a fender on a gig, which lots of people do.

    I agree with above: What's the application and do have a drawing? It's possible that I'm just not smart enough to follow this conversation, but as someone with a reasonable amount of experience gigging with both instruments...I don't get it.
  8. P Town

    P Town

    Dec 7, 2011
    Add a built-in amp, and speaker cabinet, and you are all set.
  9. TroyK

    TroyK Moderator Staff Member

    Mar 14, 2003
    Seattle, WA
    So, question: Do you play doublebass?

    Or is this just about an aspiration for some tonal versatility?

    What type of music are we talking about play with this new creation? What type of gigs are you on that call for this sort of thing?

    And, again, what's wrong with taking both a doublebass and a bass guitar to a gig to get that tonal range? Lots of people do it.
  10. shushi_boi


    Aug 6, 2012
    Yuma Az
    Sorry, I don't think you understand my concept here, I created a diagram with a 6 foot man as a point of reference along with a basic concept and functions of my bass

    (-‸ლ) YOu don't carry a pair of necks... :scowl: if you read carefully you would have read that I said it's the same neck, it only retracts INSIDE the body when I'm using a lower scale length, making the body also hollow in effect -.- But the size of the body isn't spector size, it's nearly double or triple the size, I'm still trying to figure out how much width I should add to the body though





    I'm sorry if I sound a little irritated, just that I came back from a night class and I went through so much trouble being thorough with my explanation that these pics summarize this well :p ... but I still have the problem on deciding which wood body I should use, which would allow me to progress with this project and would allow me to inform all of you guys about my results
  11. TroyK

    TroyK Moderator Staff Member

    Mar 14, 2003
    Seattle, WA
    I don't see pics, sorry.

    I guess I can kind of imagine what you're saying now. I think a couple of challenges:

    1) It's going to be tough to find strings that work at both scales.
    2) I think the idea of sliding the neck in is kind of cool actually. I kind of wonder if the folding DB people have tried that. But, the long scale also puts a lot of pressure on a neck and I imagine the mobile joint to problematic.
    3) If the "hollow body" is the space that the neck vacates when it's slid out to DB mensure, that's not really the type of hollow body that produces DB sound. Do some reading on how bass bars and sound posts work.

    Have you played some acoustic bass guitars? They don't sound much like doublebasses.
  12. shushi_boi


    Aug 6, 2012
    Yuma Az
    Well the thing with my bass is that it relies on the same functions of an electric upright, take for example my quote from before

    "Because it will be similar in size when expanded to a double bass, I hope it'll perform better than a Eminence portable electric upright Bass and almost or close to the volante bass (Because it will be the same length, except the size of my body is bigger than the Eminence, which is tonally closer to an actual double bass)"

    The Eminence isn't hollow at all, but the pickups and the scale length is what allows it to get up to 90% of the sound from a double bass. The volante bass in the other hand is pretty hollow, not to the extent of the double bass, but it's tone and combination of amount of hollowness, pickup amplifications allows it to almost sound identical to the double bass, that's amplified. (which the construct of my bass is similar)

    As for the neck problem, it'll be spring loaded, which I've already done on early projects in the past, and the tuning knobs will be custom made to retract and coil up the strings as the fretless board increases in scale length. The string problem is by theory I think already solved. The strings like the tuning knobs will be custom made as well, they will be very thick towards the top end and get thinner as they reach towards the bridge so that when it's electric bass, the strings will be around the correct proportion and the proportion of the strings when I'm playing as a double bass when I increase the scale length will be equal to the total gauge length of double bass strings {theoretically speaking that is}

    By nature, even if my bass neck is inside the body, it isn't completely hollow, it's semi-hollow which many bass guitars are that sound great (here we only have a minute issue on the side of the electric bass) And, the space the neck occupies isn't the main hollow area, its just the center, actually, it becomes more hollow as there is a smaller body that really not that hollow that's part of the neck which, when it expands, it really makes the main body hollow, if you have trouble grasping this part, I can go more in detail

    and follow this link to find a visual representation. NOTE that this representation will be subjected to constant changes (example, the width of the body of my guitar project, etc.) as I am very precocious and plan-ful about my projects, they take a while because I want to do everything as right and best as I can.

  13. frankenbass2014


    Jan 26, 2014
    a sliding retractable neck would be possible with a good solid maple neck or even an aluminum insert that is slotted for it to slide on. i think it would be a pretty cool and different project, if you can pull it off. i dont know much about double bass, but i do know that the angle of the fretboard and neck in relation to the bridge is way different from an electric bass, so you would have to take that into account when wanting to play it like a guitar. also you would have to take into account the taper of the neck in relation to the bridge because it would change as you changed the length of your neck. as far as being a hollow body instrument when the neck is extracted, i think you need to rethink that idea. maybe the best you can look forward to is semi hollow body. anyway, i think its a great idea, and if you can pull it off then youll have something unique :) good luck on your build :)

    edit: just say your pics. i guess we were posting at close to the same time, so i missed it. i noticed that it isnt just the neck you want to be extendable, but possibly an entire body shaped insert? plan out your bracing very very well. remember, even hollow body and acoustic guitars have very significant bracing inside to keep string tensions from pulling the deck wood away from the sides, or buckling the instrument entirely. as i said before, if you can pull it off, it will be very unique, and youll have massive bragging rights lol :)
  14. shushi_boi


    Aug 6, 2012
    Yuma Az
    Haha thanks frank! But the sweet thing about my project is that the neck is already attached to a smaller body (a second one) which makes up for most of the space within the main bass body so it not only keeps the proportions accurate, but also makes the body more acoustically, which is suitable for a double bass... I'll let you know what results yield from this project, you'll be one of the first to notify :p if you'd like
  15. frankenbass2014


    Jan 26, 2014
    absolutely lol im a big fan of anything different and unique :)
  16. You need to figure out how to work a trombone into it too.
  17. shushi_boi


    Aug 6, 2012
    Yuma Az
    These are some real issues/questions that I'm facing right now;

    >Should I use italian alpine spruce top? If so, what should the rest of the body be made of? & back neck?

    >What material should I go for the bridge, wood or metal?

    >What wood should I go for my adjustable platforms (which adjust my p pickup, j pickup, and humbucker pickup) ? They're the electric bass guitar portion of my bass.

    >How hollow should I make the body and how wide?

    >Should I have my body be carved by an expert?

    etc. etc. etc.
  18. TroyK

    TroyK Moderator Staff Member

    Mar 14, 2003
    Seattle, WA
    Okay, so I applaud your creativity and innovation and would be interested in seeing outcome and hearing you play it.

    We have different perspectives on the percentage to which an Eminace sounds like a double bass, but that helps me better understand your goals.

    Good luck with your project
  19. xshawk


    May 5, 2013
    I'm intrigued by your initial idea, but what I pictured wasn't really what you were drawing, so had some questions for you...

    first, what is your expected thickness of the body?
    (from front-to-back)

    Next, my concern is related to the strings..
    I would be interested to hear from a qualified luthier as to how well you can play a 34" scale bass on just part of the longer DB strings...
    If that is doable, then the next question is how to reel them up in such a way when in short scale that they:
    #1 stay in tune, and
    #2 don't get kinked or otherwise damaged so that they won't play properly when re-extended.

    not sure the metal in the strings would handle spooling onto a small diameter post then un-spooling again more than once or twice. particularly the thicker strings.

    It will be quite interesting if you can design around the physics challenges presented by such a puzzle, I think a previous poster was right... wood types are a much lower priority until you have the mechanics engineered...
  20. shushi_boi


    Aug 6, 2012
    Yuma Az
    Sorry :D I was referencing to a modified Eminace that has some accessories to the merchant or the messenger bass :p Someone showed it to me in the forums

    Just out of curiosity for future reference, about what percentage would you give an Eminace, and perhaps the volante as well?

    Volante sample:

    btw I know I'm never going to get an authentic double bass sound, I merely want to get the sound of an amplified one, as close as possible, so I set my standard to the real thing, not the electric uprights (which I know it's impossible to some degree)

    but who knows, maybe the key is how the sound post works in a double bass = it transmits vibration to the back, which it then vibrates differently from the front, which produces certain peaks and valleys of resonance in response to the bass, perhaps the closet possible that I can imitate the designs of the double bass that produces these certain valleys, then my guess would be amplifying them (instead of the other noises going on) and depending how I position my pickups, and a number of things will be the determining factor to all this thing I guess.

    And the physical form of the body as well, which I'm going to have to get in contact with a Double Bass luthier that's an expert in the area of knowing bodies, and determining the function of many shapes, etc. etc.

    But right now, I'm looking for which type of tone wood to begin with, which I heard the italain alpine spruce top was my best guess. And don't worry, I wont make a slightest scrape to any type of wood before I'm sure that I know how everything going to work out, that's how I work (unless I make a lab rat lol)