I am new to audio Community, facinated about acoustic impedance maching devices AKA(horns) 🙂.
I am currently planning to build a FLH with vented chamber
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From some knowledge on reading tons of treads on horns, I know that the straight round horn is the best case scenario 😀. But horn gets very long therefore, folding.
So in folding horns, 90 degree bend better than 180 dergree ?.
Does 180 degree bends mess up air flow ?.
Does it creates higher order modes ?.
Causes unwanted turbulence ?.
I have never seen a FLH with 180 degree bend. But a 'TON' of tapped horn with 180 degree bends....
This is my first thread, And english is not my mother tongue. Please forgive me if there is any mistake 🙂. And feel free to correct me
.
kind regard🙂.
I am currently planning to build a FLH with vented chamber
.From some knowledge on reading tons of treads on horns, I know that the straight round horn is the best case scenario 😀. But horn gets very long therefore, folding.
So in folding horns, 90 degree bend better than 180 dergree ?.
Does 180 degree bends mess up air flow ?.
Does it creates higher order modes ?.
Causes unwanted turbulence ?.
I have never seen a FLH with 180 degree bend. But a 'TON' of tapped horn with 180 degree bends....
This is my first thread, And english is not my mother tongue. Please forgive me if there is any mistake 🙂. And feel free to correct me
.kind regard🙂.
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How many folds, as 180 or not matters. That can represent a sine wave and anything else is a just a weird mess. Anti nodes and nodes at folds or driver positions as well as the ends or start of the ‘enclosure. Thats plain and if works out as real or not. Youre forced into being really accurate.
I dunno why anyone would do otherwise and if you look at what might happen if you use all lengths and folds of the same interval(or essentially two intervals) you create a reality that is realistically portrayed and exists instead of the awkward randomness that a bad bad guess at infinity?
The results in those are unique and always show why it matters. However people must compromise to fit things and thats unfortunate because its not as bad as it might seem. Their are drivers that suit box shapes and lengths that make good disquises and even skinny long ones that are further disquises and hidden?
I dunno why anyone would do otherwise and if you look at what might happen if you use all lengths and folds of the same interval(or essentially two intervals) you create a reality that is realistically portrayed and exists instead of the awkward randomness that a bad bad guess at infinity?
The results in those are unique and always show why it matters. However people must compromise to fit things and thats unfortunate because its not as bad as it might seem. Their are drivers that suit box shapes and lengths that make good disquises and even skinny long ones that are further disquises and hidden?
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My bass horn consists of only one 180 degree fold 🙂. Based of the reply I think its fine to fold 180.😀.
Short OT...
@ Turk
which kind of Horn/Adapter is the second of your pictures? Is this a Martin Audio Horn?
Greets Swany
@ Turk
which kind of Horn/Adapter is the second of your pictures? Is this a Martin Audio Horn?
Greets Swany
yes Swann it is.
Vishnu phase matters which way is your driver facing? would you mind sharing your plan?
Vishnu phase matters which way is your driver facing? would you mind sharing your plan?
Auto Phase in Hornresp may pick the wrong delay settings. The delay time should be roughly a negative second for every foot (30.48 centimeters) of the horn path as sound travels 1130 feet per second.
Group delay and phase won't be representative until subtracting delay equivalent to the path length, see posts #12-16:
Simple Tapped Horn Tutorial using Hornresp | AVS Forum
Brian Steele makes spreadsheets supporting different layouts, The Subwoofer DIY Page - Horn Folding.
Here is the thread: Spreadsheet for Folded Horn Layouts...
This i my design: JBL 2226H 30 hz "horn" i built, images at the end. Brian calls it BOXPLAN-PARAH.
When you do a 90 degrees fold, the distance beteween the outer perimeter and the inner determines the frequency where you get cancellation. When the outer perimeter is half a wavelength you get cancellation. As an example, the largest bend in your design is 340 mm from side to corner. Total length is 680 mm. A full wave is 1360 mm, 1.36 m. Speed of sound is 340 m/s. Divided by 1.36 m you get 250 Hz.
180 degrees bend you will have to double the distance, or half you frequency. The same example will give cancellation at 125 Hz. So avoid 180 degree bends.
Here is the thread: Spreadsheet for Folded Horn Layouts...
This i my design: JBL 2226H 30 hz "horn" i built, images at the end. Brian calls it BOXPLAN-PARAH.
When you do a 90 degrees fold, the distance beteween the outer perimeter and the inner determines the frequency where you get cancellation. When the outer perimeter is half a wavelength you get cancellation. As an example, the largest bend in your design is 340 mm from side to corner. Total length is 680 mm. A full wave is 1360 mm, 1.36 m. Speed of sound is 340 m/s. Divided by 1.36 m you get 250 Hz.
180 degrees bend you will have to double the distance, or half you frequency. The same example will give cancellation at 125 Hz. So avoid 180 degree bends.
Thank you for sharing sir
.I dont know if it will work, does adding wood pieces like this for dividing the airflow decrease the internal turbulence and change the cancellation frequency to a higher one ?. Or is it a dumb design fail 😱. I need this horn to go about 150hz high. Please correct me 😕.
here's what the late Dr. Bruce Edgar said in an article for a horn he made for me
key words = "somewhat" and "diagonal reflectors" (I don't know how far that goes)
key words = "somewhat" and "diagonal reflectors" (I don't know how far that goes)
I dont know if it will work, does adding wood pieces like this for dividing the airflow decrease the internal turbulence and change the cancellation frequency to a higher one ?. Or is it a dumb design fail 😱. I need this horn to go about 150hz high. Please correct me 😕.
I thought that it could act like some sort of a phase plug, and hopefully reducing high frequency interference 😕.
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Vishnu Vinod,
Adding a second set of internal corners to your folded/bent horn path would not be useful, though longitudinal bracing is helpful to stiffen up the horn path.
The EAW BH760, KF940 and countless other horns have similar bends of near 180 degrees as in your design, yet show no cancellations due to the bends until above 1000Hz, well past your crossover range of 150Hz.
Art
Adding a second set of internal corners to your folded/bent horn path would not be useful, though longitudinal bracing is helpful to stiffen up the horn path.
The EAW BH760, KF940 and countless other horns have similar bends of near 180 degrees as in your design, yet show no cancellations due to the bends until above 1000Hz, well past your crossover range of 150Hz.
Art
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