I was suggested to a use a fairly long port inside my planned enclosure size.
I want to know if is is possible to utilize a bent port to save space. My questions -
1. While bending, should the bend be equal size, a perfect U?
2. Suggested placement of port?
3. What disadvantages are there with a bent port?
My setup - Two ND91-8 in a soundbar configuration.
PartsExpress suggested to have 0.142 cubic feet volume with a single round port 1.5" wide and 8.9" long. That will result in an F3 for the system at 66 Hz. No separation.
My dimensions = 16" wide x 4.5" height x 3.5" thick
If I put a 9" long port inside a 16" wide box, there wont be much space. PE suggested other sizes for port but they were roughly same.
What to do?
I want to know if is is possible to utilize a bent port to save space. My questions -
1. While bending, should the bend be equal size, a perfect U?
2. Suggested placement of port?
3. What disadvantages are there with a bent port?
My setup - Two ND91-8 in a soundbar configuration.
PartsExpress suggested to have 0.142 cubic feet volume with a single round port 1.5" wide and 8.9" long. That will result in an F3 for the system at 66 Hz. No separation.
My dimensions = 16" wide x 4.5" height x 3.5" thick
If I put a 9" long port inside a 16" wide box, there wont be much space. PE suggested other sizes for port but they were roughly same.
What to do?
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The effective length of a bent port is the distance through the centre.
The area of cross section should be maintained throughout the bend (90 degree plumbing pipe elbows are handy for this).
You place it wherever you can squeeze it into that long, narrow shape!
There are no disadvantages with a bent port. (Make sure the entry is at least 3" from the internal enclosure wall.)
The area of cross section should be maintained throughout the bend (90 degree plumbing pipe elbows are handy for this).
You place it wherever you can squeeze it into that long, narrow shape!
There are no disadvantages with a bent port. (Make sure the entry is at least 3" from the internal enclosure wall.)
I didn't quite understand this. So if the straight port is to be 9" long, with a bent port the "U" should also measure 9" as well, ie, 4.5" for each leg?
Since one leg will be attached to the wall, the other leg should have its opening atleast 3" away its nearest obstruction, which it sees?
the height and depth are going to prevent a 1.5 inch port from being 3 inches away from an adjacent wall, could also interfere with driver mounting.
is this soundbar intended for wideband use? sealed and slightly larger may provide the same end result.
is this soundbar intended for wideband use? sealed and slightly larger may provide the same end result.
I have never worked with a port tube before. I was looking for extra punch with this setup.
If sealed, for some reason WinISD suggests that going beyond 0.2ft3 would result in Fs going no lower that ~85Hz, two drivers.
With sealed how big the enclosure would you recommend?
A. The distance around the outside of the U is greater than the distance around the inside of the U. The effective port length is the distance through the centre of the U.
B. The internal entry to the port should be at least 3" from the enclosure walls.
P.S. As I hinted, you may have difficulty fitting a U shaped duct into your enclosure shape, and that's the major design problem to be addressed.
not entirely sure what you mean by punch?
soundbar to me is a horizontal arrangement of drivers and depending on the distance between them you wind up with comb filtering.
not sure what result you are going for but if your soundbar is going to be a center channel in a multi channel surround system i'd be less concerned with low frequency capability as i would be with smooth mid response.
soundbar to me is a horizontal arrangement of drivers and depending on the distance between them you wind up with comb filtering.
not sure what result you are going for but if your soundbar is going to be a center channel in a multi channel surround system i'd be less concerned with low frequency capability as i would be with smooth mid response.
The two arms of the U can be different lengths, if that is what you mean. The U shape does not have to be symmetrical.
Have you considered whether an L shaped duct would fit in?
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U-shaped and L-shaped vents both work. Each time you change the direction of the airflow, however, you are adding in greater resistance. The mass of air in the port is an important element of the performance of the port. When the port is bent, it takes more effort to make that air mass move. In order of preference, a straight port is better than a bent one. A 90 degree bend is better than a 180 degree bend. A single bend is better than two bends. Having said that, you need to build what fits best in your box. There is probably some correction factor for calculating vent length that can be applied to vents that have bends, but I never found one and it's been a long number of years since I was looking.
Effective "length" of any bend is the average of the minimum distance (the "inside" or shortest distance of the elbow) and the maximum distance (the "outside" or longest distance of the elbow). For example, if you have a 90 degree radius and the "long" side measures 10 inches and the "short" side measures 6 inches, you have an 8" effective length through the radius.
Effective "length" of any bend is the average of the minimum distance (the "inside" or shortest distance of the elbow) and the maximum distance (the "outside" or longest distance of the elbow). For example, if you have a 90 degree radius and the "long" side measures 10 inches and the "short" side measures 6 inches, you have an 8" effective length through the radius.
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