Hypothetical (for now) tonewood study

Discussion in 'Luthier's Corner' started by HaMMerHeD, Jan 13, 2013.

  1. HaMMerHeD


    May 20, 2005
    Norman, OK, USA
    This is something I've been thinking about quite a bit. I have a few connections and some heavy hitter scientific type friends who could help me pull it off.

    The idea is to design and execute a double-blind tonewood study. I'd like to get some ideas from the others around here.

    Here is what I have come up with already.

    Because of the sheer number of species used in bass production, the study would necessarily be limited to hardwoods commonly used in the manufacture of solid-body electric bass guitars.

    Here's the general idea:

    Using automated tools wherever possible, build 20 sample bass bodies out of billets of each designated test species.

    Test species would include: alder (Alnus rubra), ash (Fraxinus pennsylvanica), swamp ash (also Fraxinus pennsylvanica), basswood (Tilia americana), genuine mahogany (Swietenia macrophylla), african mahogany (Khaya ivorensis), and soft maple (Acer rubrum).

    So that's 140 bass bodies. The lumber should be selected either randomly or based on a strict set of quality control parameters. If we further specified only domestic American hardwoods, it'd be 100 bodies.

    Each body would then be sealed, painted, and given a clear coat. To ensure as far as possible identical finishing jobs, the bodies should be weighed between each step, and the same amount of sealer, paint, and clear coat should be applied to each body. They'd have to be painted to maintain a blind recording. If the musician can recognize the species of wood when recording on sight, the whole thing is sunk.

    A serial number inside the electronics cavity should be the only identifying mark, and the serial number should be a bar code encoding of a random string of numbers and letters, so that there's no chance of the musician figuring out what it is.

    After the finishes have been allowed to fully cure, recording would begin.

    The same neck and hardware should be used on all bass bodies. I think there should be no controls...just a pickup and an output jack.

    Each recording should begin with a new set of strings.

    I'd need a few musicians willing and able to record the same test bass line about a zillion times. I'd want at least 10 recordings of the same test bass line on each bass, so that's 1400 recordings per musician. An extensive questionnaire should immediately follow each performance, including a question about which species the musician thinks the bass was. At no point should the musician ever be told that he/she is right or wrong about anything.

    The test bass line should fully exploit the frequency range of the instrument. A part of each track should be mixed with a pre-recorded band, so that the test also includes the sound of the instrument when mixed with other instruments.

    After all the recording is done, a small army of listeners (both musically educated and musically "ignorant") should be recruited to listen to each track.

    I'm not really certain what they should be looking for, other than exaggerated or attenuated frequency bands. I'm not a tonewood believer. Any questions regarding "full" or "open" or "bright", or "dark", or whatever other adjective you want should be reformulated to describe what those terms actually mean, in language that any listener can understand. If you can't explain the question, it's not a valid question.

    Thoughts? Opinions (other than how stupid I am, because I already know that)? Ideas? Suggestions?

  2. HaMMerHeD


    May 20, 2005
    Norman, OK, USA
    Also, during recording, the basses should be mounted on a playing stand by a studio technician, so that the musician never lifts it himself/herself.
  3. This sounds like an interesting school project, except that it would cost a lot.


    Have a robot do the plucking so you eliminate the human factor

    Have a wave analyser type of thing setup to visualize the differences picked up. That in combination with the human listeners, will help you define those subjective words like "bright" and "deep" ... maybe you can even find "growly"

    Use a flat-response pickup

    You don't actually need to build guitars. You need wood. You need a simulation of a neck. That's it. The wood needs to be the same size and shape.

    You'd probably help yourself by defining different qualities of wood and use those to create a simulator. Qualities such as weight, density, etc. At some point you should be able to link up these qualities to the different tonal qualities coming from the electronics.
  4. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    Set ups should be done to exact measurements. Including tuning.

    Would you be assembling all the instruments at once? If not -- if, say, you had 20 neck, string and hardware sets, to set up 20 instruments at a time -- you'd want to prearrange it so that each species gets each neck-pickup-bridge set once.
  5. HaMMerHeD


    May 20, 2005
    Norman, OK, USA
    I was going to assemble the instruments as they are used in recording, meaning:

    Bass A203497124 gets assembled, set up, and recorded.

    Neck and hardware are removed from bass A203497124.

    Bass Y23A345892 then gets assembled using the same neck and hardware, set up, and recorded.

    Rinse and repeat for the remaining 138 bodies.

    Tedious, yes. But it's the only way I can think of to remove the neck, hardware, and electronics as variables.
  6. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    Just for kicks, to test the psychology instead of the the wood -- I'd love to see another test where the headstocks and neck plates were randomly identified as "Fender" USA, "Fender" China, "Ibanez," and something that sounded super cheap. In that test you could even neglect mentioning the different woods, or claim they were all identical bodies.
  7. Hopkins

    Hopkins Supporting Member Commercial User

    Nov 17, 2010
    Houston Tx
    Owner/Builder @Hopkins Guitars
    Every instrument should use the same pickup in the same location. Instead of being mounted on foam, there should be a solid wood spacer. This will insure pickup height is the same from bass to bass. It may be easier to build a jig to mount the pickup above the strings to make it quicker to install from body to body.

    Extra care should be taken to make sure the action is at the same height between each instrument. The same bridge should also be used on each instrument.

    Also every body should also be recorded with a common neck, to test if body wood has any impact.
  8. HaMMerHeD


    May 20, 2005
    Norman, OK, USA
    That's a good idea Pete. I think it could be done with a handful of recordings of the same bass.

    So the announcer person says "This was recorded with an American made Fender bass."

    And on the next clip "This was recorded with a Chinese made Fender bass."

    And then Ibanez, Gibson, Korea, Mexico, blah blah, blah.
  9. HaMMerHeD


    May 20, 2005
    Norman, OK, USA
    As outlined in the first post, they'd all use the same neck and hardware, and the bodies (including pickup routes) would all be made via CNC, so they'd be as close to the same as possible.
  10. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    Well, using the same neck and hardware definitely eliminates some variables, very good. It introduces a variable in the form of break-in. So, solid thread inserts would be necessary. It could be necessary to re-run the tests of some porttion of the first units, to see whether the neck had changed any.

    Since this would take place over many days, there would have to be good temperature and humidity control. Too bad it's probably impossible to also control barometric pressure. You'd want to do your best to eliminate impressions being skewed by the weather, by having no windows, and by having testers acclimatize to the controlled conditions for some amount of time beforehand. And there's also bias by time of day and by time from last meal. A small, sugar-included snack before each test helps to eliminate that last one.
  11. HaMMerHeD


    May 20, 2005
    Norman, OK, USA
    Good points, PJ. Now that you mention it, Oklahoma has quite unpredictable weather so there could be a lot of really messy variables there.

    It may be necessary to execute the recording phase in a more temperate climate.

    Or maybe a mechanical player would be best, as ibateur suggested. Care would have to be taken to make sure nobody in the studio was aware of what kind of wood was being tested...sand, fill, and paint ALL surfaces, the neck pocket, pickup cavity and electronics cavity.

    I've been using these threaded inserts: http://www.amazon.com/Stainless-Threaded-Threads-Hardness-Strength/dp/B002WC8TSE/

    I think they'd do the trick.
  12. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    I disagree - I think the pickup should be mounted conventionally, so that the test can't be seen as testing the wrong thing. You wouldn't want people to be able to disqualify your findings by being able to say, "Sure, you found (some difference / no difference) with the pickup (hard-mounted / floating above) the body, but that's unrealistic. You've changed the normal coupling to the body, so you got the wrong impression of the body wood."

    I'd regulate the distance between pickup and strings closely as part of the setup, that's all.

    Towards similar end,I'd use a stock Fender pickup rather than an unusual "wide-range" pickup. If we are trying to separate the wood from the psychology, I think this would be best, so that they don't "all sound weird."
  13. HaMMerHeD


    May 20, 2005
    Norman, OK, USA
    See, a J pickup sounds weird to me. I'm used to the hifi active humbucker sound, so when I hear a P or a J, they sound...crude, and weird.

    A Precision pickup may be the best choice, if only because it's the most common.
  14. Musiclogic

    Musiclogic Commercial User

    Aug 6, 2005
    Southwest Michigan
    Owner/Builder: HJC Customs USA, The Cool Lute, C G O
    Very cool idea Mark, and really expensive inserts....LOL
  15. rdrr


    Mar 29, 2005
    Newburyport MA
    You should use the threaded inserts as suggested and also ensure that all bolts are torqued the same amount on each bass. In addition I wouldn't worry so much about having 10 different players test each bass. You should record each one and then create a survey out of the recordings where N number of people could review all of the recordings and have a larger sample size.

    Are the bodies going to be one or multiple pieces? If they are multiple I think you would want to make sure that they are assembled as similarly as possible.

    If possible I would record each bass before any finish was applied as well to test the effect finish has, if any, on the sound.

    I would also add a series of basses made out of plywood to the mix.
  16. HaMMerHeD


    May 20, 2005
    Norman, OK, USA
    Thanks, JC. I tried the brass ones first, and they kept breaking. The stainless ones are pretty rugged.

    For the sake of commonality, I think 2-piece bodies are the way to go, with the glue joint directly down the center line on all of them.

    Good idea about recording before and after painting.

    Plywood seems like a good idea.
  17. ps10black


    Jul 21, 2012
    I just did a similar thing although knowhere near as scientific using MDF Sapelle and Kalantas using a removable neck and bridge pickup assembly, there is very little tonal difference between them leading me to believe two possible scenarios, One the neck is the major contributor to the sound or the timbers have very little impact on the tone of a guitar, I am possibly going to construct an MDF neck and se what happens??

    I posted the clips and let the forum decide which was which, but long story short the MDF polled in as a fave??????? with most saying that there was such a little diference tht it didnt really matter

    The results of the tests are over on MLP, Like I said not exactly as scientific as what you are proposing, but still very interesting how close they all sounded

  18. Dean N

    Dean N Supporting Member

    Jul 4, 2006
    Pittsburgh, PA
    I'm wondering if paint would be needed at all. If it were double blind, wouldn't the musician (or preferably, robot :smug:) not even get a vote on sound? I suppose if he could see the wood, there's a variable right there.. it could affect his playing (oooo, wenge! sweet! Ewww, basswood. Ghetto bass). But I'd guess that a darkened studio (and/or blindfolded musician) would introduce far fewer variables than paint. How about one of those guitar body sleeves, like a beer koosie?

    Also, you'd have to add in an exotic wood or two like bubinga or wenge. Maybe even two or more swapped necks (I dig the threaded insert idea, complete with mini torque wrench) to test "the sound of wood".

    (Edit: I see someone beat me to the measured torque idea!)
  19. Scott in Dallas

    Scott in Dallas Commercial User

    Aug 16, 2005
    Dallas, north Texas
    Builder and Owner: DJ Ash Guitars
    Since you can't put the same set of strings on each instrument, the sound will vary.
  20. Dean N

    Dean N Supporting Member

    Jul 4, 2006
    Pittsburgh, PA
    Scott, I think the idea is moving neck (threaded inserts), strings (quick-release bridge) and all onto different bodies.

    Heck, If you didn't have controls (pots) and went direct from pickup to jack, you could probably even use a quick-connect EMG-style system and transplant electronics too.