Double Bass Sealed DB

[pbasswil]

Curious thought just came up:

What would a bass that was hermetically sealed (no ƒ holes) sound like?

I know that speaker cabinets can be sealed or ported, and each design has its strengths.

Curious!

 

[Cannabass]

well technically speaking.. i dunno.

 

[iiipopes]

Have you ever tried to talk with your hand over your mouth?

 

[Eric Swanson]

Throw a little quick-release painter's tape over your f holes, if you really want to know, then tell us!

 

[pbasswil]

Have you ever tried to talk with your hand over your mouth?

There's a thought.
I can make vocal music with my mouth shut -- it's called humming. Now what's the DB equivalent of humming? :^D

Funny though, I never thought of a DB's sound coming mostly out of its ƒ holes -- not in the same way speech mostly comes out the gap between your lips. But maybe it does; I dunno.
There's material for someone's thesis here!

 

[pbasswil]

Throw a little quick-release painter's tape over your f holes, if you really want to know, then tell us!

At the moment I only have an Eminence. Someone else will have to do this important research!

 

[RCWilliams]

Actually, I'm getting ready to build one. we are starting to make What I have called the Guber Fiddle, looks a little like a peanut, the first one was surprisingly loud. a little short on the bottom end but not so susceptible to feed back. revision #2 is under way.

So naturally I want to make a ... you guessed it, Guber Bass. it will be cornerless have a built in pickup system , and be completely strange looking.

again the idea is to give an excellent acoustic sound from a bass with less susceptibility to feed back, we'll find out any way. if nothing else it will cause a few arguements. I hope to have done by ISB.

 

[drurb]

There's material for someone's thesis here!

This has been the material of many thesis and formal publications.

Doing this, leads you to Invalid Link Removed and others. The there's all the research done by Carleen Hutchins and members of the Catgut Acoustical Society (CAS) and the collected works right here. Also check out Invalid Link Removed (the 2007 paper seems quite relevant) in the Acoustical Society of America (ASA).

So, after all this I sure can't tell you what a bass without f-holes would sound like but the lack of f-holes would seem sure to destroy the usual Helmholtz resonance and plate tuning. Covering the f-holes would not be the same as closing them with solid material as if they'd never been cut in the first place.

 

[pbasswil]

Very cool, RC. Please keep us posted! And take pictures, will you?

Actually, I'm getting ready to build one. we are starting to make What I have called the Guber Fiddle, looks a little like a peanut, the first one was surprisingly loud. a little short on the bottom end but not so susceptible to feed back. revision #2 is under way.

So naturally I want to make a ... you guessed it, Guber Bass. it will be cornerless have a built in pickup system , and be completely strange looking.

again the idea is to give an excellent acoustic sound from a bass with less susceptibility to feed back, we'll find out any way. if nothing else it will cause a few arguements. I hope to have done by ISB.

 

[robobass]

Have you ever tried to talk with your hand over your mouth?

Seriously though, I imagine you'ld mainly loose bottom and volume, but clarity not so much.

 

[RCWilliams]

as I looked at my post, I realized that what I had intended to say did not come across as intended. what we are doing has more to do with an amplified instrument, and the intent is to develop an amplified sound that has more of an acoustic tonal quality. It is not indended to be played unamplified.

 

[pbasswil]

as I looked at my post, I realized that what I had intended to say did not come across as intended. what we are doing has more to do with an amplified instrument, and the intent is to develop an amplified sound that has more of an acoustic tonal quality. It is not indended to be played unamplified.

Gotcha. But in order to capture that acoustic quality, will you be putting some sort of mic inside?

 

[iiipopes]

There have been "acoustic" guitars with saddle pickups doing exactly this for years, of course. It all started when Les Paul had Epiphone make him a guitar with a 1/4 inch thick top. They resisted, claiming it wouldn't resonate. He said something to the effect of, "Exactly!"

Try making a thin-line instrument with shallow ribs, and a thick top and back, with a good pickup, like a Full Circle, Revolution, etc., in the usual place. That should get acoustic-style tone in an amplified setting.

 

[robobass]

There have been "acoustic" guitars with saddle pickups doing exactly this for years, of course. It all started when Les Paul had Epiphone make him a guitar with a 1/4 inch thick top. They resisted, claiming it wouldn't resonate. He said something to the effect of, "Exactly!"

Try making a thin-line instrument with shallow ribs, and a thick top and back, with a good pickup, like a Full Circle, Revolution, etc., in the usual place. That should get acoustic-style tone in an amplified setting.

I remember a Gretsch guitar which looked like a standard hollow body, but on closer inspection the F-holes were only black decals. Was that the intent (less feedback)?

 

[iiipopes]

I remember a Gretsch guitar which looked like a standard hollow body, but on closer inspection the F-holes were only black decals. Was that the intent (less feedback)?

Yes. The feature was and still is on several Gretch models, all the way from the lower end 6119 "Tennessean" to the 6122 Chet Atkins Country Gentlemen model.

 

[bassist14]

i remember a thread some years ago where a pic of a bass without f-holes was posted

edit: found the thread, but the pics are gone (there was a link to an ebay-auction)

edit 2:[Invalid or Expired Link Removed]

edit 3: here too

 

[james condino]

.....
What would a bass that was hermetically sealed (no ƒ holes) sound like?
...

I've only built one double bass, blogged here, but I've also built several hundred other instruments- mainly mandolin and guitar family; about 1/3 of them carved top and back. These days I almost always carve out the soundholes after the majority of the instrument is built and it is strung up and fully functional (except for "flat top" steel string and classical guitars, mainly due to the intricacies of the rosette). I do it for a very distinct reason- so I can, for the lack of a better term, "tune" the voice of the instrument in real time while I play it. I often do it in small bits over several weeks.

You can find a LOT of data on acoustic research that gets into the very techy nerdiness of what is actually happening. In simple terms, there is an ideal aperture size for a given box. Generally the response that you hear is inverse to the size of the soundhole: i.e.- smaller soundhole gives more low end and increase it too much and the bottom starts to drop out. A lot of people are very opinionated on the how and what specifics, but mine is based upon experience. There are a lot of variables that come into place for the sound of your bass, so the above is a simple overview. I've found that when I start out with the first drill hole sized aperture- on say a mandolin- the instrument has a HUGE perceived bass response, but the mids and highs are lacking. As the soundholes get larger, you gain some and lose some until you get a nice balance that is sort of the optimum for that given box. The same is true for your double bass, but your ability to perceive the acute highs is less due to the nature of the instrument..

Remember when I first blogged the soundport on my bass build? It was a little small and I was completely disappointed with it. On a whim, months later I opened up everything by about 40% more and everything came into focus and I love it now. I find a similar experience when carving out the other soundholes. I've gone too far in my zeal (and soundhole size)and had the bottom drop out. On a few of those occasions where I thought I completely blew it, I kept going and know that you can keep expanding and push it an octave further- not necessarily explained as well as some would like, but you can correct it some. Binding the soundholes will bring things back down a little if you overshoot it. These days I generally use a peterson tuner on the workbench to monitor things while I'm opening up the holes so I can be very precise in evaluating where it goes.

Right now I've got a new mandolin on one of my workbenches. It has been strung up for two months and I've been playing it every day - with no soundholes cut yet. The voice is surprising and I've been able to hear it mature and open up- it has a surprising amount of response and resonance, but no volume or punch externally; yet I can tell that within those confines, it is just waiting to jump out and knock me over with power when it is let loose. Bass nerds may have a little bit of trouble making the leap from such a small instrument up to theirs. I play and build both and I can comfortably say that there are commonalities across many instruments than have no boundaries and as a whole, a very well made mandolin absolutely blows me out of the water compared to any other instrument, regardless of size, for how much power and volume comes out of that tiny little box. At the highest levels of the instrument's craft, it almost does not make sense how responsive they are- but try getting a gig with a piano player and nice horn section as a mandolin player....I digress... When you cut open the soundholes, what is going on is a lot like what happens when you blow across the top of an open bottle- you're not just affecting the air in the box, there are changes in pressure on both the inside and outside. I believe it is called "the reed effect"; I'm sure the very educated acoustic nerds here can express it in much better physical and mathematical terms than I can and quote sources for additional references. I only wasted 7 years in college....

So- what would a very nice bass sound like with no soundholes? You will definitely have a voice, tone, and response coming off the plates and body, but it will lack volume and the ability to really let loose and resonate all over the place and rattle down into your bones like a nice traditional configured bass with soundholes. This has some very good advantages if you play in large venues at high volumes- like when I gig at some of the larger rock clubs with my carved bass plugged in and wind up stuffing all of my t shirts/ jackets / towels inside all of the soundhole openings and under the bridge and afterlength to keep some of the feedback down.

Covering up any existing soundholes with tape or Doug's Plugz or such WILL have an effect on the voice and response of your bass. Take it an even larger step and open the trap door on your bass and play it for a while to see how the tone and voice are changed (Whatddya mean yo don't have one?????).On many of my ported instruments I offer soundhole plugs for both the ports and main soundholes so that you have several options of voice and projection for playing and recording options. It makes for a very cool instrument to be able to have 3 or 4 different voices in one package. Come to the Guild of American Luthier's convention in Tacoma this July- I'll show you in person in both one on one examples and in workshops I'll be giving. Your mileage may very and you'll get very different reponses among individual instruments.

Ciao,
j.

 

[Jazzdogg]

I always enjoy your writing style and learn a lot from your posts, J.C. Thank you!

 

[RCWilliams]

Sound post?

 

[iiipopes]

Yes, his posts to this forum are always sound posts.