Horn shapes

[emgcr]

Here is the link to "Modern Gramophones and Electrical Reproducers". (1929). : https://archive.org/details/ModernGramo ... 1/mode/2up

[anchorman]

Thanks Graham!

[Orchorsol]

Here are the Wilson articles from 1926 (presumably an earlier iteration of his curves than in the Wilson & Webb book).

[Inigo]

Thanks for those interesting articles!
The final note of P Wilson about fibre needles and Parlophone records leans on one of our favourite topics; which records are most of least suitable for fibres. Personally, I've found that all those laminated records are not keen to triangular bamboo needles, producing the infamous effect of burning the shellac. I've always felt that this outer layer of these records which has more shellac percentage is the cause of this burning effect. I've always felt that for triangular bamboos, a bit more abrasive surface works much better, as is the case of non laminated records, as HMV or Victor. In Spain, before 1933, records such as Parlophone, Odeon, Regal (our Columbia branch brand name) were all laminated, and produce such burning effect. After that date, all were absorbed by Gramófono (our EMI branch) and no more laminated records were made.
Only apart from our EMI branch was left our independent Columbia brand, which continued making records also with conventional shellac, but used a much finer material which also produces burning and problems with bamboo needles. In the other hand, they are delicious for playing with modern electrical pickups, and are of overall better sound quality than the EMI products. These were associated with UK Decca from 1943 on, and benefited from that company's recording techniques and equipment. In those, ffrr recording was introduced secretly, but its presence is obvious to the educated ears... They sound incredibly beautiful.
Of course, there are the BCN cactus needles, different from bamboos, and now made and sold by our colleague Orchorsol, which are famous for overcoming all these problems...

[anchorman]

Interesting to see Wilson talking about the Columbia Plano-reflex horns as though they’re based on sound (pardon the inadvertent pun) principles. Lots of good info in that book!

[Orchorsol]

Thanks for those interesting articles!
The final note of P Wilson about fibre needles and Parlophone records leans on one of our favourite topics; which records are most of least suitable for fibres. Personally, I've found that all those laminated records are not keen to triangular bamboo needles, producing the infamous effect of burning the shellac. I've always felt that this outer layer of these records which has more shellac percentage is the cause of this burning effect. I've always felt that for triangular bamboos, a bit more abrasive surface works much better, as is the case of non laminated records, as HMV or Victor. In Spain, before 1933, records such as Parlophone, Odeon, Regal (our Columbia branch brand name) were all laminated, and produce such burning effect. After that date, all were absorbed by Gramófono (our EMI branch) and no more laminated records were made.
Only apart from our EMI branch was left our independent Columbia brand, which continued making records also with conventional shellac, but used a much finer material which also produces burning and problems with bamboo needles. In the other hand, they are delicious for playing with modern electrical pickups, and are of overall better sound quality than the EMI products. These were associated with UK Decca from 1943 on, and benefited from that company's recording techniques and equipment. In those, ffrr recording was introduced secretly, but its presence is obvious to the educated ears... They sound incredibly beautiful.
Of course, there are the BCN cactus needles, different from bamboos, and now made and sold by our colleague Orchorsol, which are famous for overcoming all these problems...

Thank you for the kind words! BCNs can "burn" some records, mostly just some of the US dime store labels and a few mainland European ones, but I did for example once have a problem with a UK Decca test pressing. Ibota wax helps with this problem.

It's curious that Percy Wilson mentions a problem with laminated Parlophones - I've never noticed a problem, nor heard that anywhere else. But maybe bamboo fibre needles cause this problem on a more widespread basis than thorn needles.

(Apologies for thread drift away from horns!)

[anchorman]

from Mr. Wilson:

"As I have remarked before, there is probably some functional relationship between the length of the horn and the width of the open end which will give the most satisfactory results. We await some bright genius who will show us what that is. In the meantime we can only go on trying and trying and trying.As I have remarked before, there is probably some functional relationship between the length of the horn and the width of the open end which will give the most satisfactory results. We await some bright genius who will show us what that is. In the meantime we can only go on trying and trying and trying."

Have we had a bright genius who has determined what gives the most satisfactory results yet?

[Marco Gilardetti]

Are you joking? Of course yes! The horn loading theory is well known and assessed since many decades.

[anchorman]

Only slightly

I’ve progressed in my reading a little bit more, and the book I’m currently studying gets into this a little deeper.

[emgcr]

The definitive book on the subject is : "High-quality horn loudspeaker systems" by Bjørn Kolbrek and Thomas Dunker published in 2019. ISBN : 978-1-5272-4542-6. It is an expensive, but very good value, publication running to over one thousand pages and currently seems to be hard to find on the open market. It could still be available from Parts Express or local libraries.

https://www.parts-express.com/High-Qual ... ms-500-032

Apologies that two of the images are sideways but click on them to make vertical ! Click on any image to enlarge.