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leliep

Tractrix horn for tweeter

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Posted · Tractrix horn for tweeter

This is a Tractrix horn that I constructed with Fusion 360 (imported calculated data) and printed with Cura on my UM3.

 

At the back side of the horn a tweeter is going to be mounted and the whole stuff will become part of a stereo audio system (I made two of them for a friend of mine who is an audio fanatic).

 

Material: Ice PLA, colour "Glamorous Gold", printed with 0.8 nozzle and some PVA support.

 

 

 

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Posted (edited) · Tractrix horn for tweeter

No idea yet how it sounds, because the guy who received the horns from me hasn't yet finished the speaker construction. I constructed and built it (the two horns) on demand.

Edited by leliep

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Posted · Tractrix horn for tweeter

Beautiful job. I am looking to print a tweeter (5khz) and midrange (300Hz) horn too. I just need some more experience working with plastics. My day job is teaching people how to use CADCAM software for thermal cutting machines.

 

Are you willing to share the STL file?

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Posted · Tractrix horn for tweeter

Is he going to polish and paint it, or does it stay as-is? If used as-is, I also wonder what the effect of layer lines would be on the sound? Would that divert or filter some tones?

 

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Posted · Tractrix horn for tweeter
4 hours ago, geert_2 said:

Is he going to polish and paint it, or does it stay as-is? If used as-is, I also wonder what the effect of layer lines would be on the sound? Would that divert or filter some tones?

 

He left it as-is (and likes it).

Regarding the layer lines effect of the horns, I just discussed this with a friend of mine who is a real analog audio guy and who designed and built the crossover network for the speakers (which turned out to be a real pain in the neck to optimize it) and did also a lot of measurements of the speaker system. In his opinion the acoustical effect of the layer lines is insignificant. My own tinnitus doesn't allow me to be an audio reference listener :-/ so I don't have an opinion on that.

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Posted · Tractrix horn for tweeter

The textured surface will not be any problem. Sound does not move like water from a garden hose. The air particles bump into adjacent ones to transmit sound. Other than that, they are pretty much stationary. Important is a rounded edge at the mouth and a perfect fitting throat to the driver to prevent diffraction.

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Posted (edited) · Tractrix horn for tweeter

Seems to  me that the texture (which would not just sit on the surface) would have some affect on the sound much the same way different woods with different grain patterns/densities shape an instument's sound.

 

I can see where different infill patterns, densities, varying densities, etc. can also affect the sound.

 

This would also go for different cavities and such

Edited by kmanstudios

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Posted · Tractrix horn for tweeter
Just now, kmanstudios said:

Seems to  me that the texture (which would not just sit on the surface) would have some affect on the sound much the same way different woods with different grain patterns/densities shape an instument's sound.

 

I can see where different infill patterns, densities, varying densities, etc. can also affect the sound.

Not sure about that, because in this certain setup the horns are being used as tweeters, with low power input (the FRS 5 X drivers are suited for 5W). I think what you mean here is happening mostly for the lower frequencies with the airwaves transporting a lot of more energy, where material resonances can (and do) influence the sound. But a definitive answer would require some more measurements to check for resonance effects in the horn material.

The horns definitely bundle the sound waves, which gives the speakers a very special directional characteristics (which I do not like).

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Posted · Tractrix horn for tweeter

Generally a horn high frequency element is acoustically inert regardless if it is metal, wood, MDF or plastic. Material resonances are not significant if properly designed.

 

Musical instruments are built to resonate. Resonant cavities and thin, lightweight construction make this possible, The only danger for a horn is reproducing frequencies too low for the flare rate. Then they honk. This project is very cleverly designed. I would guess it is good for frequencies>1000Hz.

 

Audiophools attach myths to just about everything.

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Posted · Tractrix horn for tweeter
3 hours ago, Rowuk said:

Audiophools attach myths to just about everything.

?????

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Posted (edited) · Tractrix horn for tweeter
On 1/5/2019 at 12:14 AM, Rowuk said:

Generally a horn high frequency element is acoustically inert regardless if it is metal, wood, MDF or plastic. Material resonances are not significant if properly designed.

 

Musical instruments are built to resonate. Resonant cavities and thin, lightweight construction make this possible, The only danger for a horn is reproducing frequencies too low for the flare rate. Then they honk. This project is very cleverly designed. I would guess it is good for frequencies>1000Hz.

 

Audiophools attach myths to just about everything.


 

Edited by Ro808

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Posted (edited) · Tractrix horn for tweeter
13 hours ago, Ro808 said:

This is nonsense.
Horns, specifically large format diffraction horns, will honk long before their cut-off frequency has been reached.

Moreover, metal horns are prone to ringing, due to vibrations of the walls.
 

You obviously have no experience with horns, so we will just leave your "honk" claim where it lays. As far as ringing metal horns goes, it depends if there is something with enough "power" to excite the resonance, the frequency of the resonance, as well as if there is adequate damping or not. What you claim are the typical "horn" criticisms from those without experience. Sadly, there is a lot to be learned that gets blocked with these "attitudes".

 

I have tried this horn (modified it for a 1.4" compression driver), as predicted, it sounds just fine above 1K, low order crossover possible at 1.5Khz. No honk, predictable radiation pattern, 6dB of gain between 1.5 and 4 Khz. After that a smooth rolloff. Easy crossover with one cap. Nice project.

Edited by Rowuk
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Posted (edited) · Tractrix horn for tweeter

Removed

Edited by Ro808

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Posted · Tractrix horn for tweeter

What is your point? Actually don't bother, you have been off subject from the beginning. You should take your type of debate to Audiogon or DIY Audio. There are many more there equally willing to profess the useless. Please stop hijacking this thread.

 

This project (the one that was offered and that I also printed) is good, sounds good and is free from any nasty artifacts as long as you play by the rules. Honk is caused by not playing by the rules - mostly pushing the horn too low. This project works fine starting at about 1500 Hz. I can recommend it to any wanting to experiment with 3d printing of horns.

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Posted · Tractrix horn for tweeter
3 minutes ago, Rowuk said:

You should take your type of debate to Audiogon or DIY Audio.

And, th4ey would tell you to take it to a 3D printed forum, or just tell you to buy one.

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