Bass bin horn height questions

[Turbox]

Does anyone know what the effect the height of a bass horn has on the passband of the Horn?

 

for example, if you had a single height MWM bin, and you kept the same design, but increased the horn height, how would that effect the passband of the horn, and what about the sound? keeping all things equal, I'm thinking that it would not affect the passband but would flatten the horn response and increase its efficiency.

 

another example, the BFM THT keeps the same design but does essentially modify the horn height. which flattens the response, and makes the horn more efficient, less distortion etc?

 

am I way off base here? or will this work.

 

from my other thread, I have a custom centre channel, I'm thinking of trying building a single MWM, and 1.5x the height of a single MWM. but I need to know that the design will work. a double height MWM is to high for my application.

[Turbox]

help?

[mustang guy]

I have the same frame of reference from BFM and that it flattens the response curve

 

In those forums they talk about maximum widths and diminishing returns with going wider. The max width on a THT for example is 30". You could go bigger, but the extra materials, weight, difficulty getting through doors, etc., outweighs the slightly improved FR.

 

edit: I didn't read your question carefully. Sorry, you were asking about the passband.  I haven't a clue. Sounds like it would be a good experiment, though. If a guy had a couple different width THT's he could do that easily.

Edited November 21, 2014 by mustang guy

[mikebse2a3]

Does anyone know what the effect the height of a bass horn has on the passband of the Horn?

First I assume you are going to keep the horn's mouth area the same which then means the horn's width will also change and become smaller.

This will affect the polar response of the horn in both the vertical and horizontal polar responses and thus the on axis frequency response will be altered how this might affect the smoothness isn't clear because depending on other factors (for example the drivers natural response when mounted on the horn) so it could be smoother or rougher, I would assume the mid and upper portion of the horn's on axis response to be most affected.

What is the bandwidth your trying to cover with this horn?

If the bandwidth that you are covering has wavelengths significantly larger than the width and height of the horn's mouth then I don't see changing the aspect ratio of the horn's mouth (as you have described) having any significant effect on the frequency response of your required bandwidth. In other words if you are only using the bass horn to cover the bandwidth of say 30hz to 100hz then the wavelength at 100hz is approximately 11 feet and thus a change in vertical mouth height of even a foot will have very little effect at 100hz.

miketn

Edited November 21, 2014 by mikebse2a3

[jwc]

Yes.  If increase the mouth by XX ratio, then decrease the width by the same.  Doing this "maybe" might flatten the curve.....I wouldn't put money on it.  However, I bet it would be fine....and look very cool.

 

If you increase the height by 1.5x and keep the width of horn and the length of horn the same, you may have a less flattened curve.  Wouldn't recommend.   Big mouth with way more rapid expansion.  If you had the time, money....I would love to see it :}

Edited November 22, 2014 by jwc

[jwc]

I haven't looked at the THT in a bit.  When you increase the height, does it increase the path length too?

[twistedcrankcammer]

Does anyone know what the effect the height of a bass horn has on the passband of the Horn?

 

for example, if you had a single height MWM bin, and you kept the same design, but increased the horn height, how would that effect the passband of the horn, and what about the sound? keeping all things equal, I'm thinking that it would not affect the passband but would flatten the horn response and increase its efficiency.

 

another example, the BFM THT keeps the same design but does essentially modify the horn height. which flattens the response, and makes the horn more efficient, less distortion etc?

 

am I way off base here? or will this work.

 

from my other thread, I have a custom centre channel, I'm thinking of trying building a single MWM, and 1.5x the height of a single MWM. but I need to know that the design will work. a double height MWM is to high for my application.

 

 

Turbox,

 

I see no reason why an MWM Double bin would be too tall for your application if you put your squaker in the lower bin woofer hatch and your tweeter in the upper bass hatch, or am I missing something here??? Wouldn't be any taller than the Belle cener you built, just a lot wider!

 

Roger

[mustang guy]

I haven't looked at the THT in a bit.  When you increase the height, does it increase the path length too?

The plans don't have any way of increasing the height, only the width. 

[Rowan611]

THT is always the same height, 36". Width can be up to 36" also, essentially giving you a 36x36x36 box. However, I don't know of any normal door that would fit through. Also, as Mustang said earlier, it comes down to the laws of diminishing returns. I'm guessing there isn't a whole lot of difference between a 30" THT and a 36". But, I could very possibly be wrong. It's happened before .

Have no idea regarding passband.