Best sounding horn size?

[wtt11]

I know some people are not satisfied by the sound coming out from variety of existing horns and are trying to make their own hi-fi horns. I have got bored on those reproductions too and am asking for some advices including dimension and material used from who have done that before. Matched machine is a Edison triumph. Thanks in advance

[De Soto Frank]

I think Greg Bogantz might have some insight, especially if you're thinking beyond the standard external horn "funnel".


Within the realm of straight-horns, it is my personal observation that a 30" horn ( or longer ) sounds "better" than the shorter ones, and ones from heavier metal such as brass or steel with a silk ( or other fabric ) jacket sound better than segmented steel "morning-glories" (less sympathetic resonance of the horn itself: "tinny ringing" at certain pitches ).

[52089]

The best cylinder horn I've ever heard is still this one:

[youtube]http://www.youtube.com/watch?v=jhLjcfswHb0[/youtube]

Keep in mind that it sounds that good even after camera processing and Youtube processing. I can only imagine what it sounds like in person!

[wtt11]

Thanks The longer, the better??? Does it always hold true or there must be a threshold length? I heard that Edison made an extremely long horn for recording purpose and the quality turned out to be not worthy compared to the amount of work and money devoted. Is is true in reverse playing back? Ok, I''ll try to make inner surface as smooth as possible. Cygnet horn is looked weird on early machine and attempt to make challenging curved horn is not considered so far. Any other thought?

[De Soto Frank]

The video that 52089 posted is the one I was trying to recall. I believe forum member gregbogantz knows the gentleman that made this horn.


The engineers at Western Electric who developed what became the Victor Orthophonic machines designed their exponential "ideal horn" based on scientific principles of matched impedances, albeit on an acoustic, mechanical level, but their work was thorough and well-grounded.

I believe the horn in a Victor Credenza measures around 6 feet from reproducer to grille-cloth. The section-profile of the horn is also important.

The business of "folding" the horn was primarily to minimize the space taken-up by said machine.

I think horns for the smaller Orthophonics were scaled-back in size, but kept the basic proportion of the "ideal" Credenza horn. The general consensus is that the smaller Orthos lack the "depth" or bass-response of the larger machines, but perform favorably in the mid and high ranges.

[Edisone]

If you have the space for it, try to make the small end very long and gradually tapered. Even a conical horn can sound fine if it's long enough - the error in short horns is that they usually flare out too rapidly. Example: the 8-panel horns on cheaper Columbia & Standard machines - they would have a more solid tone if they were the same outer diameter but maybe 12" longer. That might tip over the machine I use for an example, however!

columbia_bq.jpg (111.54 KiB) Viewed 3111 times

For its length, the Edison Gem/Fireside horn has an excellent shape; I don't think that a wider flare would make it sound any better.

GemHorn.jpg (19.52 KiB) Viewed 3111 times

The Edisonic machines were based on Edison's recommendation that they try longer horns for more bass, but with the DD's system of swinging the horn to track records, they had very limited space, so grafted-on only a few inches of small diameter. You can see the grafted section in this pic.

EdisonicGraft.jpg (96.73 KiB) Viewed 3111 times

[wtt11]

Thanks for your illustration!

[gregbogantz]

Generally speaking, when it comes to full frequency range horns, bigger is better. The length of the acoustic path taken from the reproducer to the mouth of the horn is largely responsible for the extension of the frequency response into the bass range. To fully support the long wavelengths of sound waves in air that represent bass frequencies, the mouth of the horn also needs to be commensurately large. Yes, the Victor Credenza horn is about 6 feet long, and that length in combination with its also large mouth area allows the horn to support bass frequencies down to around 100 Hz before the response falls off precipitously. But bigger would be better yet. To extend the response down to 50Hz, the horn would have to be twice as long and have about twice the mouth area of the Credenza horn. Which gets a little ungainly when trying to fit it into a house of reasonable size.

But just as important to the quality of the sound is the geometry of the taper of the horn as it progresses from the small throat that connects to the reproducer to the large flare at the end of the bell of the horn. It can be shown mathematically that just a few deliberate types of taper are significantly superior to any kind of random shape. The exponential taper is by far the most popular of these deliberate shapes (the Brits also seem to favor the tractrix shaped horn). The horns used in the Victor orthophonic machines are of the exponential taper shape, including that used in the Credenza. Use of a proper taper will result in much smoother frequency response over a broader range than a less desirable shape such as a simple conical or a random flare such as was used in the early Victor, Columbia, and Edison horns. A smoother frequency response is one of the fundamental requirements needed to provide a natural sound quality from a reproducing system.

The "Ediphonic" horn that you see and hear in the above videos was deliberably designed by Tom Kimble who is a mechanical engineer friend of mine to be of the exponential shape while being about the same length and overall size of a typical cygnet horn of the Edison cylinder machine era. This horn was a deliberate project meant to illustrate that a proper exponential horn could have been made by Edison in the 1920s which would have sounded better than any other Edison horn of the day while still being about the same overall size. I think the video proves that this is correct. I have heard this machine in person, and there is not a better sounding cylinder machine in my experience.

[VintageTechnologies]

My favorite horn is the Edison metal cygnet. It has a long slender taper to start. I think its projected sound is a bit more directional than the wood cygnet horns with their wider flare.

Any cygnet sounds good and takes up a lot less floor space than a regular horn. I also like their aesthetic shape more than I do a straight horn.