[Jolle]

I've noticed while trying out mouthpieces, that there is a big difference between my old Selmer Signet and my new Chicago Jazz Series in responsiveness with the same mouthpiece.

My own BergLarsen Steel 115/2/SMS responds great on the Selmer, but is more difficult to play, especially in the low register, on my CJS. The sound is great, but it requires a lot more control.

On the other hand, trying a Lebayle jazz (great mouthpiece by the way!) I noticed it played beautifully on my CJS, but had a boring sound on my Selmer. I didn't buy it (yet), I want to try out some other ones before getting me a new mouthpiece. But it's defenitely a candidate, more than the dukoff I tried (honkin' only), or the Meyer (far too classical for me)

I believed I read something here about an influence of the bore on the size of the chamber optimal for that saxophone. Is there any mouthpiece specialist willing to shine a light on this? It would help me in my search for a new mpc, as it can narrow the search.

Thank you in advance.

 

[Saxland]

Is the Chicago Jazz alot more freeblowing than the Selmer Signet?

 

[Jolle]

Is the Chicago Jazz alot more freeblowing than the Selmer Signet?

Quite the other way around I would say. Even with a bent neck (and thus some intonation problems), the Signet is more freeblowing. As far as I know, it's a Buescher stencil.

 

[bfoster64]

I'd love to see an informed answer to this question as it has occurred to me many times when comparing mouthpieces on my B&S and Buffet SDA tenors, only to find that some pieces play great one one horn but not the other.

Correct me if I'm wrong, but the SDA generally has a bigger bore that the B&S. The B&S seems to have a fairly small or modern bore until you get down to low C#, C, B, and Bb, where it sounds more like a Keilwerth or a large-bore horn.

 

[LampLight]

I'm not a mouthpiece expert, but I've heard the big bore/big chamber, small bore/small chamber advice from a few sources, including Patrick Springer at http://www.springermpc.com/mpcprof.html. See Patrick's comments about the Hard Rubber Tenor versus the Rollover Tenor.

 

[Wind_Mill]

I could be wrong here, but if you start measuring the IDs and lengths of body tubing, compare bow dimensions, etc. I venture the CJS and the Signet are going to be too close physically to infer any expected differences in mpc compatibility. Could it be their necks?

This "bore" discussion should keep in mind that for horns to be tenors, they have to share the same volumetric displacement inside. Having a "big" bore at one cross-section dictates having smaller dimensions elsewhere.

 

[Wind_Mill]

Correct me if I'm wrong, but the SDA generally has a bigger bore that the B&S....

I don't have a modern B&S to compare, but as best I can tell, the ID of the SDA tenor body tube alone is about 1/2 mm wider than many other horns, top to bottom. However, it seems to be the bow size & curvature where the differences really start to crop up. The SDA bow isn't that substantial; perhaps you could label it a small-bore horn if that were the criterion. The bows on Zephyrs and many (not all) JK horns are huge by comparison. The Zeph moreover has a runty body tube, almost a cm shorter than most others [=those I've measured] in length from high-F center to low-D center.

 

[bfoster64]

And there's the rub. Once you start comparing bores, you realize each part of the sax, from neck, to body, to bow, to bell, needs to be looked at.

Regarding the bow on an SDA, it doesn't stick forward as much as say, a Keilwerth's, but doesn't it extend down a bit further?

I've often wished someone would make a catalog of 3-d graphic models of the bores of each horn, if only to satisfy my intense intellectual curiosity about how the shape of each horn matches up with the differences in sound that I hear when I play them! You could superimpose the graphics on each other and get a visual on even the most subtle differences.

 

[jbtsax]

Several of the books on woodwind acoustics state that the volume inside the mouthpiece (in the area past the end of the neck) should closely match the volume of the "missing cone" if the sax neck were continued to an imaginary apex in order to work properly. In his book "The Saxophone is my Voice" Ernest Ferron describes this in detail and gives a method to measure and compute the area of the "missing cone".

It would follow that a larger bore saxophone would have a larger missing cone area that would be satisfied by a mouthpiece with a larger chamber. It should be noted that the "effective" mouthpiece volume is a bit difficult to measure because it involves the area where the reed vibrates as well as the space actually inside the mouthpiece itself.

John

 

[Wind_Mill]

It would follow that a larger bore saxophone would have a larger missing cone area ....

I vaguely recall the Ferron text but you've lost me here. Considering that tenors in general need to have pretty much the same displacement to be tenors, I don't understand how a larger bore at some cross-section within the horn proper dictates using a *larger* mouthpiece chamber. More importantly, mouthpiece chambers vary perhaps only a couple cm3, something that can be compensated for by adjusting the distance the mouthpiece is placed onto the cork. Are you certain Ferron wasn't merely discussing theoretical requirements for proper tuning? (I'd better go hunt that book down ..... I have it but haven't seen it lately.)

 

[J.Max]

I could be wrong here, but if you start measuring the IDs and lengths of body tubing, compare bow dimensions, etc. I venture the CJS and the Signet are going to be too close physically to infer any expected differences in mpc compatibility. Could it be their necks?

This "bore" discussion should keep in mind that for horns to be tenors, they have to share the same volumetric displacement inside. Having a "big" bore at one cross-section dictates having smaller dimensions elsewhere.

Yes, the "bore" is really referring to the way that it "flares" out in the cone. This is what the Rascher people talk about when they refer to the parabolic bore. It isn't a different volume, just different proportions in different sections.

 

[Jolle]

I could be wrong here, but if you start measuring the IDs and lengths of body tubing, compare bow dimensions, etc. I venture the CJS and the Signet are going to be too close physically to infer any expected differences in mpc compatibility. Could it be their necks?

Well, if I try to put the neck of my CJS on the Selmer, I have a few mm(!!!) space left. The diameter of the tenon of the Selmer Signet is a few mm bigger than that of the CJS. So I doubt there is not that much difference between both. In fact, one can see the difference in dimensions with the eye.

The Selmer Signet is supposed to be a Buescher stencil
The CJS is, according to my sax teacher, more built like a Selmer SA.

Thank you all for the nice explenation of the concept "bore". This is interesting, I learn a lot about that "copper music tube"

I hope a mouthpiece expert can tell something more about the interaction between the bore of the sax and the chamber. Thanks for the link, Lamplight.

 

[MojoBari]

I just added a FAQ answer on my site about mouthpiece chamber volume size vs its effect on intonation.

I do not think you can tell a lot from the sax bore and taper. It depends on what is missing on the end of the sax. The sax maker could make the neck a little longer/shorter so that standard mouthpieces can be used. Some sax makes seem to have short necks like some Martin bari and tenors. Some owners have had their necks extended to allow them to use more of mouthpieces that are available.

The player's physical makeup and embouchure is a big factor too. Most theoretical texts may only mention this. Benade had done a few studies of this and showed that it is quite significant. So I think you need to just start with whatever set-up you have to get a data point on how you get along with it. Then if there is a problem, you can just do trial-and-error or you can try a larger/smaller chamber based on which way your intonation if off.

 

[Jolle]

Mojo, your site rules, really. Those FAQ have opened my eyes on more than one issue. Thank you.

 

[bfoster64]

I read the FAQs on Mojo's site, and I particularly like the way he explains how changes in chamber effect changes in intonation in different registers of the horn. I've read the Yamaha article by Stephen Duke on "Pitch Center" a number of times, which focuses on how embouchre effects intonation in different registers, and I've seen other explanations and discussions of the relationship between chamber volume and intonation, but Mojo's explanation was so concise and made it crystal clear.

To quote:

The effect of too large/small a chamber volume on intonation is not all that difficult. If your chamber volume is too small, you will (hopefully) find yourself pulling it out on the neck cork in order to increase the chamber volume so you can tune the mid-range of your sax. This lengthens the distance from the mouthpiece to the tone holes of the sax. The % increase in length is greater for the high notes than the low notes. Thus your high notes will be flattened more than your low notes. The high notes will be flat and/or the low note sharp when you tune the mid-range. If the chamber is too large, the opposite happens. This could fix an intonation problem or create one.