what does a horn box sound like? how to plot response curve?

[RSDXzec]

I've seen videos/opinions that a few people prefer to build a horn box, because apparently they get louder. Looking up information on google isn't helping much, but i'd really like to get an idea of what a horn sounds like. Right now I have a ported box tuned to 25hz, which I modelled on winisd. I may be building another box soon, so I'd like to see what kind of an improvement I could get. Unfortunately winisd doesn't model horns it seems... or i just can't find how to.

So does anyone have any clues as to how to model one of these boxes? what they sound like? or any links online which explain a bit about them?

Cheers.

[TitoThePirate]

don't take this exactly but, i heard Horn Enclosures, take the idea of having a subwoofer in a Corner of the room, and the idea is to use that in an enclosure to raise effiency. i'm probly horribly wrong, but thats what i've heard, any additions or other thoughts please correct me.

[RSDXzec]

don't take this exactly but, i heard Horn Enclosures, take the idea of having a subwoofer in a Corner of the room, and the idea is to use that in an enclosure to raise effiency. i'm probly horribly wrong, but thats what i've heard, any additions or other thoughts please correct me.

fair enough, I'll see what others have to say. It's this high efficiency that I'm after because I don't have much power to work with.
I'd really like to know if it will still sound good though, and how to properly design one from one of the more experienced members here.

I've looked at bandpass, 4th order i believe, but i don't like the idea of not being able to acces my subwoofer without opening up the box.

[hispls]

I can almost guarantee you have not see a true horn in a car. More likely you have seen just a flared port, or possibly some attempt at a 1/4 wave or t-line.

This is what a proper horn for a subwoofer would look like:



Put that in the back of your Honda!


Though some people use things like this:



This "folded horn" style is somewhat more practical for the car, but still would take up a tremendous ammount of space to do right.

[RSDXzec]

I can almost guarantee you have not see a true horn in a car. More likely you have seen just a flared port, or possibly some attempt at a 1/4 wave or t-line.

This is what a proper horn for a subwoofer would look like:



Put that in the back of your Honda!


Though some people use things like this:



This "folded horn" style is somewhat more practical for the car, but still would take up a tremendous ammount of space to do right.

yeah that second design is what I'd like to adapt to my car. I have about 4.5 cubic feet to work with. But I'd like to be able to compare it to my ported box in winisd so I can see if the work is worth the improvements. Do you know if there's any way to do this?

And how would I go about designing a box like that? all I've designed is a ported box so a horn would be a fair step up. I'd also really like to have access to the woofer without having to take apart the box to get to it.

[Dirtrider4eva]

OP, lets say you want to do 2 8s in a flared/ 1/4 wave enclosure, youll still be louder with a single 15" in a traditional slot port / aero enclosure man..

[Buck]

Horns are very loud if done right, but don't necessarily fit every application. I don't design them as of now, but what woofer(s) do you have? What are you trying to achieve?

[hispls]

yeah that second design is what I'd like to adapt to my car. I have about 4.5 cubic feet to work with. But I'd like to be able to compare it to my ported box in winisd so I can see if the work is worth the improvements. Do you know if there's any way to do this?

And how would I go about designing a box like that? all I've designed is a ported box so a horn would be a fair step up. I'd also really like to have access to the woofer without having to take apart the box to get to it.

There are very few people that really do accoustics of horns. You can more likely find them on home theater forums. The whole point of a true horn is a woofer in a tiny sealed box firing into a very narrow throat (some fraction of cone area) tapering out at a calculated rate to some multiple of the cone area with a length according to the lowest frequency you need it to play. Hence the length of a true horn is absurd for real low frequency (notice the size of a horn on a 2" midrange...then scale that up exponentially). Easy access to the woofer is going to be difficult.

[hispls]

yeah that second design is what I'd like to adapt to my car. I have about 4.5 cubic feet to work with. But I'd like to be able to compare it to my ported box in winisd so I can see if the work is worth the improvements. Do you know if there's any way to do this?

And how would I go about designing a box like that? all I've designed is a ported box so a horn would be a fair step up. I'd also really like to have access to the woofer without having to take apart the box to get to it.

There are very few people that really do accoustics of horns. You can more likely find them on home theater forums. The whole point of a true horn is a woofer in a tiny sealed box firing into a very narrow throat (some fraction of cone area) tapering out at a calculated rate to some multiple of the cone area with a length according to the lowest frequency you need it to play. Hence the length of a true horn is absurd for real low frequency (notice the size of a horn on a 2" midrange...then scale that up exponentially). Easy access to the woofer is going to be difficult.

[RSDXzec]

OP, lets say you want to do 2 8s in a flared/ 1/4 wave enclosure, youll still be louder with a single 15" in a traditional slot port / aero enclosure man..

I'm trying to go the best that I can on low power, considering my vehicle has a small alternator so I want to see how far I can get.

Horns are very loud if done right, but don't necessarily fit every application. I don't design them as of now, but what woofer(s) do you have? What are you trying to achieve?

I have a soundstream PCW-12 350W rms 12" subwoofer.
I'm trying to fit within the dimensions of
25"length x34"width x11.25"height

There are very few people that really do accoustics of horns. You can more likely find them on home theater forums. The whole point of a true horn is a woofer in a tiny sealed box firing into a very narrow throat (some fraction of cone area) tapering out at a calculated rate to some multiple of the cone area with a length according to the lowest frequency you need it to play. Hence the length of a true horn is absurd for real low frequency (notice the size of a horn on a 2" midrange...then scale that up exponentially). Easy access to the woofer is going to be difficult.

Well I'd like to make something a bit like this

that way I'd have easy access to the woofer and be able to increase it's efficiency.
I know it may take a while to get the knowledge and calculations right, but I am willing to learn, as I did for the ported box I designed and built.
If possible I would like to get into the low 30's, but like you said depending on the port length I'd need I'll have to see what's possible.

[hispls]

Well I'd like to make something a bit like this

.

Good luck putting a 6 foot long box in your car....

[RSDXzec]

Good luck putting a 6 foot long box in your car....

well obviously it would be smaller than that, I just wanted to show you an idea of the type of thing I'd like to do.

Using this app
ISHTEK Speaker Applet
I typed in my subwoofer specs and got this result


Not quite sure what it means yet, but maybe someone who does can tell me what kind of box I'd need or if it's possible.

ok well looking at that graph I'd go for an sd/st of a little under 4, so maybe 3.8 or so, so I can get to 30hz. And as I understand it, it has to do with the size of the throat of the horn.

[hispls]

30hz horn is going to have to be around 16 feet long. No matter how many times you fold it, that's still a big arse box. You'd be squeezing to get a 30hz horn for a 6" woofer in a car.

[RSDXzec]

30hz horn is going to have to be around 16 feet long. No matter how many times you fold it, that's still a big arse box. You'd be squeezing to get a 30hz horn for a 6" woofer in a car.

hmm... ok well I'm trying that software to see how far I get.
Just to make sure here, the compliance volume is the volume of the box right? I converted 4.5cf to m^3.
And how large can the port mouth be without being too big. The response I'm getting is very peaky and it seems that with a larger port mouth that I get a smoother response. But I'm unsure if this is effectively reducing the port length or not.



Cheers.

edit:
originally my idea was to do something like this


but when I started looking up horns what came up was stuff like in that youtube video.
How does this horn/ported design vary compared to the folded horn design?
Would I see any improvements in efficiency making this kind of box?

[oldschool4me]

you may be able to run a half a$$ one but likely will need a smaller sub to do it correctly. maybe an 8. its more popular in ht or pro audio situations because of the open area they are in. common in movie theaters also. putting that enclosure in a small area might not be very affective like sticking your traditional slot ported car box in your yard. doesnt work so well for output compared to a folded horn would. not sure how well most car subs would react in a folded horn either. try it out and let us know how it goes.