+ - semi hollow body

stringplayer · #1 03-11-2008, 09:09 AM

i'm building my first bass and i'm a bit scared that the bass is going to be very heavy.

i have a body of walnut and a top of mahogany and i have been thinking of making the body semi hollow.

what are the advantages and disadvantages of a semi hollow body?

greatings,
cedric

JLBW · #2 03-11-2008, 09:26 AM

I wouldn't worry too much about the weight. Of course more than one factor play a role in the weight equation but unless you're making the body super thick it's not gonna be too much of a problem. Personally I like solid bodies better but that's just me. I have a semi hollow and in my opinion the mids on that one are more "airy". Good luck with the build!

All the best

eleonn · #3 03-11-2008, 10:16 AM

Walnut is not a very heavy wood. I made mine out of peruvian walnut and tried to do it as slim as I could and it turns out Ok. Havent weight it but would say is around 4 kilos.

stringplayer · #4 03-11-2008, 10:21 AM

and how thick is your body?

eleonn · #5 03-11-2008, 10:43 AM

SDB Guitars · #6 03-11-2008, 12:01 PM

If you just want light, use a body wood like Spanish Cedar... it's a mahogany variant, but it's *very* light. You'd probably want a hard finish, though, as it's also fairly soft.

Chambering is fairly common to reduce weight, and of course, semi-hollow really isn't that hard to do. This one is hollow on both halves, with a solid "core" through the middle. I left about an inch or so width at each edge:

stringplayer · #7 03-11-2008, 12:12 PM

yes i know it isn't that hard to do, but now my question is doens't it effect the tone to much?

and you say use another wood but thats already to late, i'm already bussy with the woods...

eleonn · #8 03-11-2008, 12:33 PM

I wouldnt be worried about the weight of a walnut body. You can weight the body already shaped before any chambering and see if it weights to much for you having in mind that it will be even lighter after edge rounding, neck pocket routing (if you go for a bolton or setneck), pickups routing and control cavity routing.

stringplayer · #9 03-11-2008, 12:55 PM

ist a necktrough...

maybe i'll first look if it isn't to heavy and if it is i'll maybe hollow the body

DSB1 · #10 03-11-2008, 01:58 PM

Walnut is not a very heavy wood. Be careful chambering, this can easily be overdone and leave you with a neck heavy instrument.

There is no formula for figuring out how to balance a bass properly...it's something you get a feel for over time. There are also many things that contribute to it like headstock size/tuners, neck material, body material/thickness/if its chambered or not etc etc.

Since this is your first build try to emulate something that you know works. If the woods aren't exactly the same then find out how different they are and make adjustments.

bassmodder · #11 03-11-2008, 02:04 PM

I built one out of pine. Yes pine. With an aluminum "sandwich" between the front and back. Now THAT was a neck heavy instrument. Played fine if you could juggle the neck.

envika · #12 03-12-2008, 04:29 PM

the other negative is that it's likely to feed back at high volumes if it has f- or similar sound holes

but the sound cannot be denied

SDB Guitars · #13 03-12-2008, 04:58 PM

Quote:

Originally Posted by envika

the other negative is that it's likely to feed back at high volumes if it has f- or similar sound holes

but the sound cannot be denied

This is more the case with a graduated arched top, something that has been thinned quite a bit, and has a large hollow vibrational chamber.

Most "semi-hollow" instruments have a solid center, so your hollow chamber is limited to either side of the neck line... add to that the fact that the top won't act like much of a "soundboard" because it's too small to provide much vibrational feedback, and generally at least .25" thick.

I spent some time at Darrin Huff's shop a couple of weeks ago, and he showed me a bunch of archtop top/back sets he had made... even the ones of heavy woods like zebra wood were incredibly light and resonant. I'd guess they were carved to around 1/8" thick or so, 3/16" at the most, and they were all ~16" wide in the lower bout, and would not have a solid center area to impede the top's vibration.

I've played Thinline Tele's (semi-hollow) for a while now, and I have not once noticed that it fed back more than my Strat or Les Paul, neither of which are hollow. You're not likely to get any more feedback from most small bodied semi-hollow basses than from a well put together solid body, IMO.

stringplayer · #14 03-13-2008, 10:24 AM

but, what is now the real diference in sound?

zazz · #15 03-13-2008, 11:05 AM

Quote:

Originally Posted by stringplayer

what are the advantages and disadvantages of a semi hollow body?

greatings,
cedric

well the upside is tone and the downside is feedback..

i would however take a look at the epi casady.....its acctually has got a solid through neck but it thins out along the body unlike many other makes ...it doesnt make contact with the front wood facia..including the pickup ...so the whole assembly is floating ...giving you the tone.....but because it still has that through spine it keeps under control that feedback.

if you play say one of those artcores ..its solid all the way thro...its like a solid body with chambers each side ,,,so in essence you are playing a solid with chambers ...and to be blunt it looks like a semi but sounds like a solid.

so there you have it.

of course if you want to go the whole hog then slam some darkstar pickups in it......fortuantely the casady has some pickups that sound imo better.

you should really look at what casady has designed ...he has been playing gibson semis since the 60s and decided to use epiphone to produce the ultimate tone monster ..non feedback semi...

and i think he might have just got it right .

SDB Guitars · #16 03-13-2008, 05:29 PM

Quote:

Originally Posted by stringplayer

but, what is now the real diference in sound?

On a small-bodied bass sized equivalently to your average electric bass? Not a whole lot of sound difference. That's the point. There will be *some* difference, of course, but it will be minimal at best, and definitely secondary to your selection of strings, pickups, preamp, etc, all of which affect the tone more, because it is an *electric* instrument, not an acoustic one. Most likely you would see a slight "softening" or "rounding" of the tone. Of course, those terms are completely subjective, and you might just as easily see them with a change in pickup selection, addition (or removal) of a preamp, or even string gauge/brand/material (stainless steel vs. nickel vs. flats vs. tape wound).

A semi-hollow body does not have the internal air volume to resonate well at bass frequencies, given the size of the waves required to mechanically vibrate that size and thickness of a top (1/4" average). In my opinion, you would need a body at least as large as an ABG, and a top no thicker than 1/8" before you started to see significant feedback resonance, and much more than minimal coloring of the tone.