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View Full Version : what does a horn box sound like? how to plot response curve?



RSDXzec
04-12-2012, 09:32 PM
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
04-12-2012, 09:36 PM
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
04-12-2012, 09:52 PM
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
04-12-2012, 10:25 PM
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:

http://community.klipsch.com/forums/storage/4/988520/Goto%20horn%2030Hz%202%20-%20119967914.jpg

Put that in the back of your Honda!


Though some people use things like this:

http://www.virtualdj.com/image/97224/48781/folded%20horn%20sub.gif

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
04-13-2012, 01:41 PM
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:

http://community.klipsch.com/forums/storage/4/988520/Goto%20horn%2030Hz%202%20-%20119967914.jpg

Put that in the back of your Honda!


Though some people use things like this:

http://www.virtualdj.com/image/97224/48781/folded%20horn%20sub.gif

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
04-13-2012, 02:05 PM
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
04-13-2012, 02:10 PM
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
04-13-2012, 11:12 PM
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
04-13-2012, 11:13 PM
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
04-14-2012, 12:40 AM
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

http://www.youtube.com/watch?v=DtQemT84DtM
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
04-14-2012, 12:52 AM
Well I'd like to make something a bit like this

http://www.youtube.com/watch?v=DtQemT84DtM
.

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

RSDXzec
04-14-2012, 01:11 AM
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 (http://www.ishtek.com/spkr_app.htm)
I typed in my subwoofer specs and got this result
http://i41.tinypic.com/5n1w6o.png

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
04-14-2012, 01:30 AM
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
04-14-2012, 03:56 AM
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.

http://i39.tinypic.com/vyr611.png

Cheers.

edit:
originally my idea was to do something like this
http://i1013.photobucket.com/albums/af258/trendsetterscaraudio/scoobybox1.jpg

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
04-14-2012, 04:24 AM
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.

Joe89
04-14-2012, 04:52 AM
I liked mine, it played very low. I've never designed one though so I can't help ya out there... http://img155.imageshack.us/img155/2796/img1027hw2.jpg
http://img505.imageshack.us/img505/7867/img1031wg5.jpg

wenn_du_weinst
04-14-2012, 12:27 PM
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.

http://i39.tinypic.com/vyr611.png

Cheers.

edit:
originally my idea was to do something like this
http://i1013.photobucket.com/albums/af258/trendsetterscaraudio/scoobybox1.jpg

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?
thats not a horn

I liked mine, it played very low. I've never designed one though so I can't help ya out there... http://img155.imageshack.us/img155/2796/img1027hw2.jpg
http://img505.imageshack.us/img505/7867/img1031wg5.jpg not a horn

not even 1/4 wave horns are true horns. I'll be doing some 4'' horns for my bedroom pretty soon, they are huge and don't even drop under 50hz.

hispls
04-14-2012, 04:06 PM
90% of people seem to think that a flared port = a horn

wenn_du_weinst
04-14-2012, 04:10 PM
Pete kulicki started that entire thing. I have been caught calling my box a ''horn'' as well, but that is just so people know what the hell it is. I feel as if I said I run an exponentially increasing bass reflex enclosure I'd just get called out for pretending to make it sound complicated.

Kangaroux
04-14-2012, 04:21 PM
PWK has 9 friends on his facebook...lmao

itsblown
04-14-2012, 08:17 PM
Creep ^

RSDXzec
04-14-2012, 11:55 PM
90% of people seem to think that a flared port = a horn

my fault, I'm still pretty new to this. People on forums seemed to be calling it a rear loaded horn so I thought that's what it was. Do you know if there is any advantage to that design?


Pete kulicki started that entire thing. I have been caught calling my box a ''horn'' as well, but that is just so people know what the hell it is. I feel as if I said I run an exponentially increasing bass reflex enclosure I'd just get called out for pretending to make it sound complicated.

why did you build your box like that? did you notice any difference as opposed to a regular ported box?

RSDXzec
04-16-2012, 03:24 AM
question here, how is the group delay on a horn design?
I was looking at a 6th order bandpass design and the group delay was terrible. Very good efficiency but I'm not sure how nice it would sound in there...

Moble Enclosurs
04-17-2012, 01:57 AM
Pete kulicki started that entire thing. I have been caught calling my box a ''horn'' as well, but that is just so people know what the hell it is. I feel as if I said I run an exponentially increasing bass reflex enclosure I'd just get called out for pretending to make it sound complicated.

Actually, horns existed as some of the first enclosures designed. Back in the 40s these were very popular due to a certain company that tried to patent the idea. Not sure who took the idea into the market first, but other old schoolers have been using these designs well before any of us came along.
I can design horns very very well, BUT I am agreeable very much on the fact that the efficiency and output may only be compared to a proper BR design when the limitations of size are a factor. The same applies to tlines of the sort.
The marketing idea that horns are more efficient do not take into account that these are not based on the same concept of standard ported designs. They can be more sensitive to loading effects, but not more efficient in a lot of cases involving car audio. BUT, if done properly, one can utilize this style to control the response much more than a standard ported design, which will changes the effects of the sound, giving it a "loaded" effect more than a typical "loudness" factor.

The fact that the end of the horn path couples more so wiht specific frequencies that a standard port does not conform to, makes it a very interesting design when it can be applied properly to car audio applications. Such as that of an SUV with about 60% of the cabin being utilized for a wall, in which a horn (if all factors fit) will be very well utilized.

The thing with horns that differ from any other design style, out of the 8+ design ideas that can be used, relies on that area of the mouth. While the throat area can cause a compression that is increased, the mouth has an opposite effect from the mentioned coupling factor, where the intensity greatly overrides the pressure from the throat and then allows the proper waveform to be presented to the environment based on the area. The larger the area, the more efficiency you can have from the lower frequency range, which is why they can be tough to increase efficiency in a car.

It is correct to say that the taper is not directly related to the horn effects, BUT without that taper, the horn will then be self limited and not perform like it is meant to, so the taper is in fact a "horn" style, but in a smaller than recommended area, which nearly most car audio designs are, the use of the word "horn" may not be applicable, where-as a "tapered Tline" may be more appropriate, due to the fact that the tline is based on different acoustics than a horn in some areas of design.

SO much can be said about any of these designs, and those that know me, knwo I can talk forever on the subject lol. But I will leave it here for now and say that:
1. Yes, the taper does not mean horn
2. Yes, the vehicle limits the horns efficiency and proper coupling to be utilized as a full horn, BUT other styles will work well and can still be called a horn in its physical form.
3. A horn and a tline are two different designs and are calculated different, jsut as much as a bass reflex is calculated different than each as well.
Those that use the same figures to calculate for each of these, may have inaccuracies in the design.
4. The full understanding of the horn is not anymore complex than the full understanding of any other design, AS LONG AS it is created the way it was meant to be designed, and with the right figures. The bass reflex design, I can break down into a full page if necessary just as much as the horn. It is not glorified, but when you have the room and the right parameters, by all means use it to increase output NOT BASED ON SPL, but on intensity, which is more important with musical output..and is the main reason why a 140 on intesity based designs may sound louder than a 150 on a pressure based design.

Much more can be said, but I have to get to sleep and get up early to catch up on my own designs in progress lol.

Hope that helps a bit. So much more can be said.

Moble Enclosurs
04-17-2012, 01:59 AM
question here, how is the group delay on a horn design?
I was looking at a 6th order bandpass design and the group delay was terrible. Very good efficiency but I'm not sure how nice it would sound in there...

The group delay can be controlled much better in a horn than a BP because they are again, designed for different purposes. BUT, if you have the right driver, a 6th order can have a decent transience when added to the environmental factors of loading and gain.

RSDXzec
04-18-2012, 11:30 PM
Actually, horns existed as some of the first enclosures designed. Back in the 40s these were very popular due to a certain company that tried to patent the idea. Not sure who took the idea into the market first, but other old schoolers have been using these designs well before any of us came along.
I can design horns very very well, BUT I am agreeable very much on the fact that the efficiency and output may only be compared to a proper BR design when the limitations of size are a factor. The same applies to tlines of the sort.
The marketing idea that horns are more efficient do not take into account that these are not based on the same concept of standard ported designs. They can be more sensitive to loading effects, but not more efficient in a lot of cases involving car audio. BUT, if done properly, one can utilize this style to control the response much more than a standard ported design, which will changes the effects of the sound, giving it a "loaded" effect more than a typical "loudness" factor.

The fact that the end of the horn path couples more so wiht specific frequencies that a standard port does not conform to, makes it a very interesting design when it can be applied properly to car audio applications. Such as that of an SUV with about 60% of the cabin being utilized for a wall, in which a horn (if all factors fit) will be very well utilized.

The thing with horns that differ from any other design style, out of the 8+ design ideas that can be used, relies on that area of the mouth. While the throat area can cause a compression that is increased, the mouth has an opposite effect from the mentioned coupling factor, where the intensity greatly overrides the pressure from the throat and then allows the proper waveform to be presented to the environment based on the area. The larger the area, the more efficiency you can have from the lower frequency range, which is why they can be tough to increase efficiency in a car.

It is correct to say that the taper is not directly related to the horn effects, BUT without that taper, the horn will then be self limited and not perform like it is meant to, so the taper is in fact a "horn" style, but in a smaller than recommended area, which nearly most car audio designs are, the use of the word "horn" may not be applicable, where-as a "tapered Tline" may be more appropriate, due to the fact that the tline is based on different acoustics than a horn in some areas of design.

SO much can be said about any of these designs, and those that know me, knwo I can talk forever on the subject lol. But I will leave it here for now and say that:
1. Yes, the taper does not mean horn
2. Yes, the vehicle limits the horns efficiency and proper coupling to be utilized as a full horn, BUT other styles will work well and can still be called a horn in its physical form.
3. A horn and a tline are two different designs and are calculated different, jsut as much as a bass reflex is calculated different than each as well.
Those that use the same figures to calculate for each of these, may have inaccuracies in the design.
4. The full understanding of the horn is not anymore complex than the full understanding of any other design, AS LONG AS it is created the way it was meant to be designed, and with the right figures. The bass reflex design, I can break down into a full page if necessary just as much as the horn. It is not glorified, but when you have the room and the right parameters, by all means use it to increase output NOT BASED ON SPL, but on intensity, which is more important with musical output..and is the main reason why a 140 on intesity based designs may sound louder than a 150 on a pressure based design.

Much more can be said, but I have to get to sleep and get up early to catch up on my own designs in progress lol.

Hope that helps a bit. So much more can be said.


The group delay can be controlled much better in a horn than a BP because they are again, designed for different purposes. BUT, if you have the right driver, a 6th order can have a decent transience when added to the environmental factors of loading and gain.

thanks a lot for the info man, anything else you need to say I'm all ears. Trying to learn as much as I can about this design.
I'll have to look into the Tline design as well after reading that.

Cheers.

Moble Enclosurs
04-19-2012, 12:20 AM
thanks a lot for the info man, anything else you need to say I'm all ears. Trying to learn as much as I can about this design.
I'll have to look into the Tline design as well after reading that.

Cheers.

Kewl man! Yea, keep up the learning!