The Maccaferri Resonator: pro and con

mmaslan

Some questions for people who have played guitars that have them:

How would you describe the effects of the resonator on the sound of the grande bouche?

If you were having a grande bouche model built and cost were not a factor, would you have a resonator put in it?

To get things going, I direct you to two statements on the resonator:

David Hodson: http://www.hodsonjazzguitars.com/
Paul Hostetter: http://www.lutherie.net/resonate.html

Bob Holo

Wow - you're not getting much response on this thread... OK, I'll throw the first pitch... Let me preface this by saying that I've never played a resonator model though as a person who has done speaker design; I find the concept interesting and have spent some time thinking about these types of acoustic design issues.

Here's what I can tell you. It is likely a fallacy that this can increase the acoustic output of the guitar. A guitar's chamber is primarily a helmholz resonator constituted by a soundboard which acts as a transducer and a hole which acts as a vent. So, it puts out sound primarily from the soundboard, and secondarily - resonance peaks via the sound hole which is effectively a vent - much like the vent found in loudspeakers. The acoustic power is dominated by the design of the soundboard and the nature of the chamber (IE< that it is ported and tuned to a frequency dominated by the huge narrow port that the soundhole constitutes on a D-Hole) When people say "It makes the guitar louder" what they may be experiencing is:

1.) "it's louder at different frequencies" which might occur if the resonator effectively decouples the top and bottom bouts; creating two tuned chambers fed by the same port and resulting in two primary resonances instead of one... which may make the mids more punchy at the expense of bass response

or...

2.) "It's louder when you stand in front of it" While I seriously doubt that anything as simple as the resonator could constitute a true wave guide to increase efficiency, it may focus or redirect selected harmonics. Ironically in speaker design - you try as hard as you can to keep this sort of thing from happening to reduce tonal coloration - but if your goal was to equalize the sound toward mids and cruncy resonance peaks - hey - it's one way to get the job done! If it's doing this it would likely increase directivity of the output on axis and depending on what's actually happening (would need to measure apples to apples in a sufficiently accurate lab setup to say for sure) it may or may not reduce output off axis and again - tilt response toward higher registers. I have no way of knowing how much - if at all - the resonator may affect the overall output of the guitar over its effective frequency range. If it's capturing backwave off the interior of the soundboard and putting it out antiphase to the primary output of the soundboard, it may actually reduce or comb-filter some of the very upper mids and give the guitar a hollow or megaphone-like tonal quality.

So, in theory - if it does anything, it will likely increase the directivity of sound and equalize the tone of the guitar toward the upper mids; possibly producing a throaty megaphone-like character but not significantly increasing the overall acoutstic power.

Josh Hegg

Great post Bob.

I have played a guitar with a resonator. And.. I would never buy one. To my ear it chokes the tone of the guitar especially in the low end. I know a good sounding gypsy guitar does not have (what most modern guitar players would call a good low end) a booming low end but the low end tone that the guitar makes is important to the over all sound of the guitar. The guitars I have played that have the internal resonator seem to have an increased mid range. This is great for some instances and back when they made them (in the 40s I think) they were great for recording with the technology they had at that time. Bob is right when he says that the sound is more pointed or directional to paraphrase. I have read that many players ended up taking them out because they just buzzed to no end and didn't make enough difference to in sound to keep. On that note most gypsy guitars are as loud if not louder these days then those with the internal resonator. If you have the means to buy a Selmer with one to have just for the sake of having a cool, past guitar experiment then go for it. But I would say don't go looking for one because you want a louder guitar. I think the Saga DG-500 is louder by far. I know that Dunn makes some guitars with the internal resonator and I have played on of his for a while that does not have it and it is by far the loudest guitar I have ever played. If you can try out a guitar with the resonator and make your own hypothesis that would be the best.

"If you were having a grand bouche model built and cost was not a factor, would you have a resonator put in?" My answer is - No

Cheers

andy

Mark,

Does this mean you're having one made?

Andy

mmaslan

No, Andy, I'm not having one made unfortunately, but that doesn't meant that you shouldn't! I have a Collins petit bouche that's only a few months old and it's a great guitar. But I've noticed that Michael offers the resonator as an option on the grande bouche and was surprised when he told me that nobody had yet ordered a guitar with it. Of course I fantasize about getting a grande bouche to keep my guitar company. . . .

Anyway, I thought it would be worth hearing what some people with expertise have to say. It's an intriguing feature, and I'm sure a lot of members are curious about it. Bob's amazing post confirms what Paul Hostetter says on his web site: it doesn't make the guitar louder (though that was the intent), but it does affect the tone. Presumably Django's grand bouche had one, and to me that's reason enough to be curious.

Thanks for the posts. Does anybody want to come to the resonator's defense?

a

didn't djang dump his d hole for a little bouche?

Russell Letson

Michael Dunn's own guitar (at least as of last year) is a Mystery Pacific, which does have the resonator--there are photos of it ("The Queen") on the first gallery page at his site, michaeldunnguitars.com. I played it a few years back when trying out a group of his instruments and would have bought it on the spot had it been for sale. It seemed to me to be responsive, focused, and balanced. On listening to the recordings I made at the time, I'd also say that its bass was not as round as that of a Rhythm Futur I liked. (I eventually bought a cedar Daphne of which I am very fond.) But Michael's target sound is not exactly Selmer-clone--his guitars are darker and sweeter, with none of the nasal gnashiness of, say, every Jorgenson model Gitane I've tried.

I'd guess that by itself the presence of a resonator means less than the skill of the builder--which is generally the case when you wonder about a single factor of design or materials.

kimmo

mmaslan wrote:

Presumably Django's grand bouche had one, and to me that's reason enough to be curious.

No, Django's grande bouche did not have the resonator, at least I have yet to see a picture with Django holding a guitar that could visibly be verified to contain one. But I have seen lots of pics where you can clearly see that there are no extra constructions in the soundhole. In the mid thirties (D-hole days) he had a deal with the guitar shop, that he could come and choose Selmers for him and probably for the band also. He either must have chosen ones without internal sondboxes or he tore them out himself.

I know, a LOT of the existing articles explain how Django's loud sound has the internal resonator to thank for (a false assumption that keeps repeating itself). It seems that although he didn't in general seem too picky about his guitars, this was one feature he really didn't like.

kimmo

joef

I don't think you should be buying a resonator to improve volume, but rather for tonal reasons.
My Mystery Pacific has a resonator and the only drawback is that it's harder to retrieve a pick from the inner sound chamber. But a pencil with some sticky tape on the end always does the trick.:-)

I also have the Ibanez Mac 10 D-hole designed and signed by Maccaferri. This does not have a resonator. It sounds very loud, but this is partly because it does not have an even response. There is a very loud primary resonance around low B, for example.

The Michael Dunn guitar, on the other hand has a much more balanced response , with no lumpy resonance, and is still plenty loud enough. In fact it projects better - ie although it may not sound extremely loud to the player, the sound carries extremely well across the room. You cannot always judge the true sound of a guitar from the player's position.

Do not make the mistake of getting a guitar that is loud because of peaks in its response, because these cause feedback and will have to be equalised out when playing live anyway. In fact, because the resonator evens out the balance of the guitar sound, it reduces the potential for feedback and the need for severe EQ.

regards
Joe

gadjojazz

I am lucky enough to own an original Selmer from 1932 with the box intact. It certianly evens the sound out but doesn't make the guitar any louder from similar models I've tried without the box. Mine needed some cleats as a split had developed and a rattle ensued. All is well now but my repair guy said it was a hard job to get in there.
Another point is that a lot of the Selmer D holes out there are re-necked four strings. Now none of these had boxes and had the paper label glued directly on the guitar's back. These guitars were constructed with thinner tops than the six string models so when converted can either sound stunning or fall to bits. I assume that by now only the former exist giving the impression that all D holes sound the business.

scot

A few years ago I played a Selmer with a resonator, #163 recently sold by JM, and recently a Dupont 12-fret with a resonator. The Selmer was unbelievable light in weight and had a similar sound to other d-hole Selmers I'd played. The Dupont with a resonator sounded a lot like other d-holes, too. The big difference to my ears was that the resonator guitars were less "boomy" and generally had a drier sound than the guitars that don't have the resonator. The "character" of the sound was in my opinion about the same.

Joe F's comments sound right on the money to me. And Kimmo is right about Django's guitar. I've never seen a photo where you could spot a resonator.

I've always wanteed to try a "Jorgenson" model Dupont because it's a long scale d-hole with a resonator. I have always found that the shape of the sound hole does not have nearly as much effect on the sound as the length of the scale does. I've played short scale oval hole guitars and these usually sound closer to the sound we associate with the d-hole. I've played long scale d-holes and it's the same - closer to an oval hole sound.

A Selmer type guitar doesn't have a dreadnought's bass, but a good one
has a sort of growl in the bass that no other type of guitar has. This is especially true of a good Favino.

Best
Scot