Since I've been building guitars and basses since 1973, and after reading so many comments/debates on the many public forums for years about whether or not the wood used in building an instrument has any effect on its resulting tone, I thought that I'd share my thoughts and experience in an attempt to dispel some of the rumors, or at least state my opinion about it, specifically concerning solid body electric basses.
For starters, in my opinion, those that can't tell if the type of wood used has an impact on a bass's tone, I consider lucky. However, I have to also think that they have little or no experience with the tonal differences of playing lots of examples of the same instrument, with the only variable being the wood (i.e. many identical P or Jazz basses with different woods used on the neck and bodies), or they just want to believe that 'everything else' is responsible for it's tonal properties. Maybe they're just completely happy owning and playing budget instruments, and try to justify/convince themselves that their Squier is the same as an american vintage reissue, or maybe they just aren't capable of hearing it, since some have better ears and are more sensitive to tonal nuances than others. I might add that by using a Squier as an example, I am in no way saying that their tone is necessarily inferior, since I've owned, serviced and played many of them, but what I am saying is that their tone is different. Even when replacing the pickups with american ones, their basswood or agathis bodies still do not sound exactly like their swamp ash, hard ash or alder US counterparts.
I do not believe the premise it is a 'hype' by luthiers in an attempt to charge more money for their instruments, since quality, thoroughly dried, aged and seasoned wood is more expensive than cheap lumber. To some, the highly figured woods, like flamed/fiddleback, quilted and birdseye are more visually appealing, thus is quite a bit more expensive, but I personally find them to actually have a less predictable and even tone, due to their non-uniform density. Highly figured wood has many varying soft and hard spots in it, and is generally less stable than the less expensive straight grained 'clear' or 'plain' wood of the same species, especially when it come to maple when used in building a neck, since different areas in a single piece can expand, contract and resonate at different rates and frequencies.
The Human 'Perception' Variable:
Many, 'non-believers' often use the argument that 'people hear what they want to hear'. To me, that 's a bunch of BS. Believe me, I really do wish I could 'convince' myself that balsa wood sounded like swamp ash or mahogany, but it most certainly does not. Nor does basswood sound like alder. Trying to place an exact percentage of how much it effects the tone is an excercise in futility, but I will say that, to me, it has a large effect, and determines the overall 'voice' of the individual instrument. I have often referred to it as a bass's sonic 'fingerprint', where while they can be very similar, no two are exactly alike. I am not talking about the power of suggestion, or others telling you what to 'listen for'. I'm talking about the personal 'connection' that you make with an instrument when you play it, without being influenced by someone else's opinion.
Rather than just believing what you're told (or read/heard on the internet & magazines), the proof for me is putting any instrument in my hands and actually playing it. Even unplugged, I can readily hear a difference. In my opinion, listening to sound comparison mp3 clips over the internet can't really tell you much, since many of the examples are skewed/jaded in one way or another, so I personally find them to be little more than entertaining, and certainly not proof of anything one way or the other. I will say that, to me, generally, heavy hard ash or maple bodies will have less volume acoustically, but will have more sustain, as well as a brighter tone. The ligther weight alder or swamp ash bodies will be louder, fuller, have more thump and punch at the expense of a bit less sustain. And as far as necks go, one piece maple necks have always had the tendency to be brighter and clearer than maple necks with rosewood boards. Maple necks also usually have a clear lacquered or poly finished fingerboard to protect the wood, which also contributes to yet a slightly brighter tone. Personally, I am not a fan of ebony boards on Fender type basses, since every one that I've played that had one sounded bright and on most of them, actually sounded harsh. Some have argued that believing that wood makes a difference is like believing in God because a priest, minister or rabbi told you that he does, but again, that's simply nonsense. We're talking about a tangible item here that you can touch and feel. While others say they need proof in a double blind test. All I can say to them is that if you need a double blind test to 'prove' it to you, you should probably go get your ears checked first.
Others claim it's the 'quality of construction', but that theory goes out the window when comparing instruments built to the same standards and specs by the same manufacturer. I've often compared three or four 2010 fender AV RI P basses that were on my bench at the same time, which I found to have an excellent quality of build. I mean, they weren't set up and dialed in perfectly, but their neck pockets were a good fit and all of the hardware (bridge, pickups, tuning keys etc) were installed properly, in the correct locations, and to spec.
Pickups, Pickup Location, and Electronics:
Again, if the same pickups and pots are used, with the only variable being the wood, then the pickups don't enter into the equation. Some say that no two of the same pickups sound exactly alike, and while that can be true, I've found that as long as they are of the same age, model and spec from the same manufacturer, the magnetic flux and type, number of winds, the bobbin material and thickness, manner in which they were wound, copper content of the coil wire, DCR, and inductance, are extremely consistent from pickup to pickup. I've installed 100's of Seymour Duncan SJB-1's and SPB-1's in P and J basses, and have yet to hear any difference from pickup to pickup, even when testing multiple duncan spb-1 p bass pickups in the same bass. And back to my 'fingerprint' analogy, the fingerprint is the acoustical voice of the instrument which everything else follows. Much like a singer's voice being mic'ed using different mic's, in different rooms, or at different distances/locations, even on different days. It becomes clear that no matter what mic you use, for example, to record Paul McCartney's voice, it's still going to sound like Paul McCartney, whether you use a Shure SM58 or a Neumann U87, up close or far away. Yes, pickups and their placement each have their own tonal balance, like having alot of midrange or boom and sizzle, but the wood determines the manner which the strings vibrate, respond, sustain and resonate. The pickups, just take their 'magnetic picture' of it. Again, everything esle is 'downstream'. And even though we're talking about an electric amplified instrument, it's not all about magnetism, or electronics. Years ago,on more than one occasion I had a couple of customers that played Rickenbacker 4001's exclusively, ask me to install a Jazz Bass pickup in the bridge position in an attempt to get more of a 'jazz bass tone' out of them. Well, guess what? The basses still sounded like a 4001 and nothing like a jazz bass. By the way, on all of them, their original pickups were later re-installed back in them. In my opinion, everything stems from the source - the wood. If it were ALL about the pickups and electronics, as many contend, as a drastic example, using the same pickups and pickup location, try comparing a bass with a body made out of rubber to one made out of marble, or try comparing one with a composite graphite neck, to one made out of wood. Needless to say, I think that the results would be obvious, even to the layman.
Bridges, Pickguards, Strings, Tuning Keys, Body Shape, Neck Design:
Every component used on a bass contributes to it's final voice, and different bridges and tuning keys can, and do make a difference, but I haven't found them to be as large of a contributor to a bass's overall tone as the body and neck wood that it's made of. A neck with additional steel support rods for extra strength, as used in an aftermarket Warmoth standard bass neck, is about as far away sounding from a vintage Fender bass neck as can be. I've found that the extra steel rods and their added weight/material skews the results in those particular necks. They sound dead and non-resonant to me, but some bassists seem to like them. The body's shape also contributes to a bass's tone. A good example of this is the '69 & '70 Gibson EB-1 compared to the thinner 'SG shaped' EBO. They both have the same scale length, fret size, mahogany bodies, necks, pickup and electronics, but they have a different 'voice' if you can get past the tone of the mudbucker ;-). Even a large pickguard can change the tone slightly. I would compare its effect to resting the entire palm of you hand on the body. And of course, strings, being roundwounds, flatwounds or anything in between make a big difference in tone and attack, but I'm not talking about flatwounds on one bass compared to rounds on another, so that's a whole other topic and has nothing to do with the wood.
Amplifiers and EQ:
While you can add a little treble to try and compensate for a darker sounding bass, or turn the treble down to darken a bright one, I've never been able to duplicate one bass for another using equalization, ( or compression), and I'm very capable of manipulating/adjusting high end parametric eq's. Some argue that no one in the audience or your band will be able to tell the difference live or on a recording, especially when you add all of the other instruments and that is often true, but I what I really care about is how a particular bass inspires ME to play it in its tone and response, so again, I find that just a poor excuse to say that the differences don't exist., or that they don't matter. Others have said that once you add distortion, you can't tel the difference either, but just ask any guitarist about that one. The instrument's inherent voice dictates the distortion that follows, and I've found that distortion or overdrive can even magnify the different voice of the instrument, as opposed to mask it.
To me, there is no magic to it, and whether someone loves or hates a particular bass's tone is an opinion/preference that's entirely up to the individual player. In that way, and ONLY that way, it doesn't matter at all what wood that it's made out of if you love it. Personally, I prefer the tone of vintage Fender basses, Gibsons and Rickenbackers, so the guidelines and recipes for wood choice, weight, design and construction that I use to build my basses are very clear, and the results have always been quite predictable. One excellent example of the wood making a difference is the three custom scratchbuilt Rickenbacker style semi hollow basses that I built for myself (you can view them on this website). While they all have a tonal range in the same neighborhood, they all sound slightly different from each other, and two of them we built from using the same planks of wood!
..........It doesn't matter to me whether you 'believe' me or not. I'm not trying to convince anyone to think one way or the other, and certainly don't care to get into a debate about it. I've found that most people believe what they want to believe, and others just like to get into circular debates regardless of the subject matter (often 'engineers'). Most experienced luthiers that have been building instruments from scratch, that select their own wood, know exactly what I'm saying, and you don't have to 'believe' them either, but I do think that anyone that actually builds guitars and/or basses and thinks that the wood's impact on the tone is 'subtle' or 'unimportant' has very little experience in building and should probably put their efforts elsewhere. Anyway, I just thought that I'd share my thoughts on the subject...............so, just get out and play! ;-)
For more info as to how wood and construction effect tone, you might be interested in reading the first post in this thread from my old friend Neal Moser on his "shredder' website: "Wood: Everything that you ever wanted to know". I found that the statements parallel my findings pretty closely.