Horn Loaded Subwoofer???

[kainbrake2]

I want to build a horn sub for the house. i havent decided on the drivers, but im still trying to find some how to stuff on it. im not looking to copy cat i really just want to know what im doing.i dont mind copy catting i just dont know how to adjust according to the driver. i dont know how to go about designing the horn eather. one box i like is the wicked one from decware but i would like it cut in half but i dont know if it would mess up the whole thing or not. any way ive had good luck with this site so i though io would give this a shot.

here is the link to the wicked one
http://www.decware.com

heres a link to another one i like.http://www.rockprojekt.de/Technik/Images/Folded%20Horn.gif

[This Guy]

You just have to remember that most horn sub's are HUGE and don't go that low. I use a horn sub, or bass bin I should say. I have it firing into a corner to extend the lower frequencies, but even then, It's down 3 dB at 35 hz. No big deal to me since I pretty much exclusively listen to music on my system. The advantage to them, however, is extreme efficiency and very low distortion for the frequencies it can play. Mine averages around 104 dB with one watt at one meter. 100 watts is extremely loud, and that's all the 12" driver can handle. Search online for "Bill Fitzmaurice", i think that's how you spell it. He's designed many successful horn subwoofers and plans are available online.

[kainbrake2]

let me tell what i have to work with. the sub i build only has to keep up with a set of mach 1s and a set of cv at12s. now i have 2 sub channels to work with so i though about using one for a horn and the other for a vented enclosure. i would even buil the 2 in one unit. now ive done a little research and since the horns are so loud i think i can get away with a 10 inch or 2 8 inch drivers. and for the vented maybe a 12. but the cvs and the machs may get low enough that i dont have to use the vented box. the problem i have is these old speakers were not made for digital sound they were made for anolog sound with phonographs so they had to have these mega midranges and tweeters so make up for the high frequency loss. so when i use them for digital sound the mids and highs just outrun the lows. any way i just want something that will keep up and maybe get ahead for movies and stuff.

[This Guy]

Take a look at these designs. There are a bunch of them. http://www.billfitzmaurice.com/index.html

If your gonna make two subs, choose one design. Two vented or two horn loaded. Some of those designs do go low enough for movies, but again they are Huge. And many horn designs get an extended low frequency response when you stack them. If you're up to the woodworking and have the space, I highly reccomend a horn sub (s), there's nothing like it.

You could also look up the "Lab 12" horn sub, which is an absolute monster.

[Deadeye]

If you are not committed to a horn and even if you are check out the Pass DIY site. They have a tube transmission line sub that with Eq goes down to 18Hz. I have built 2 using 12" woofers. After firing them up I had to go around my house and correct all the things that were vibrating! While not as efficient as a horn they are much more efficient than most others. In my case 100WPC is sufficient. They are so easy to build anyone could do it.
http://www.passdiy.com/

[kainbrake2]

ill check out the transmition line stuff. as far as the horn the size is an issue thats why i want to use small drivers but i guess it may not keep up.

[kainbrake2]

hey DEADEYE i went to the pass site but i got a little lost. i saw some interesting stuff but can you give me a link to the cabinet you are talking about. the only thing i saw that might be the one you are talking about was the j lo. if i can get a good responce out of maybe 2 transmition lines i may try those instead of a horn, size is an issue here im just trying to get all i can out of a 10 or 12 inch driver.

[Deadeye]

Here it is. Let me know what you think. If anyone else is interested it is quite easy to scale it for 8", 10", 12", 15" or 18" woofers. One last thing. You don't have to leave them vertical. Lay one down and hide it behind the sofa.
http://www.passdiy.com/pdf/el-pipe-o.pdf

[This Guy]

Yeah even a horn based around a 10" driver is going to be huge. Big horn subs are pretty much obsolete now a days, atleast in home audio. Big amplifiers don't cost as much as they used to, so efficiency isn't as important anymore. Don't get me wrong, I love my horn, but mine is ****in huge. It's like 15" W, 35" L, 24" H. So weigh your options and build something cool man.

If you don't mind putting a hole in the wall, you could think about an Infinite Baffle sub if you want to do something different.

[Deadeye]

Yeah even a horn based around a 10" driver is going to be huge. Big horn subs are pretty much obsolete now a days, atleast in home audio. Big amplifiers don't cost as much as they used to, so efficiency isn't as important anymore. Don't get me wrong, I love my horn, but mine is ****in huge. It's like 15" W, 35" L, 24" H. So weigh your options and build something cool man.

If you don't mind putting a hole in the wall, you could think about an Infinite Baffle sub if you want to do something different.

That infinite baffle sub is something I was considering when I came across the El-Pipe-O. I was going to cut a hole in the floor and vent it onto my basement.

[kainbrake2]

the tubes are awsome did you down size the design any or did you build the exact thing? ive spent the last few hours looking at trans lines does anyone know how to make calculations for tube demensions or port exit sizes. looks like you calculate for tube cubic feet and just lay it out however it fits. i can find plans and all kinds of pictures i just cant find any guidlines on demensions or cubic feet. looks like most of them have a tube size close to the cone size but what determines the tube length? i just cant understand why i cant find info on how to use woofer specs to design an enclosure other than vented or sealed and some bandpass. in other words what math do i use to build the tube trans for some 8 inch or 10 inch so on so forth.

[Auricauricle]

;) ;)

[Deadeye]

The Pass Labs plans show an 8" woofer. In essence once you have a tube that is the same diameter as your chosen woofer the length of the tube is the variable. for the ones that Pass used the 8" woofers had a 40Hz resonant Fq. One 12 ft sonotube cut in half and 2X8" woofers. See the last paragraph in the file.

In my case I bought a 12' sonotube. Had them cut it in half and used one 12" woofer with 40Hz resonant Fq for each one. The length of the transmission line is dependent on the resonant Fq of the speaker. The line can be the length of the the wavelength of that Fq or 1/2 or 1/4. the tech aspects are quite simple and covered fairly well in the article.

[kainbrake2]

ok its coming together now, the only thing i dont know is how to get the wave lenght from the fs i just dont know the formula. but from what i understand i take the wavelenght and play with 1/2-1/4-or 1/3 of that for the lenght. if you can help me there ill try this project. also can you take a look at the decware link on the first post i made on this subject. its called the wicked one and wonder if it will wreck the function if i cut it in half, i dont know if the horn will still work or not.

[Deadeye]

http://www.mcsquared.com/wavelength.htm

The link will give you the wavelength of a given frequency. Just use 1/2 or 1/4 for the length of your tube.
A transmission line is always tuned to 1/2 or 1/4 of the length of the wavelength of the resonant frequency of the speaker used.
If you want to use 1/2 the wavelength for the length put one tube inside the other so you have a folded transmission line. Of course you put a cap on the outer tube. The space between the inner and outer tube should be the same volume as the inner tube.
The wavelength of 40Hz is 28.25 Ft long. So 1/4 would be 7.0625 Ft.
You don't need anything else but some loose packing for the tube.
This will work with any woofer just adjust the tube length for the resonant frequency of the speaker.
You will need to build one of the 2 Eq networks. I built 2 of the active ones as I don't like crossovers.
Horns are not my forte. They are just to hard to build.

[kainbrake2]

ok you have been a ton of help i will try this before anything else. so you used the opamp circuit. and correct me if im wrong but it looks like this circuit goes on the line level and not speaker level.

hey i hate to be a pain but what do you think about cutting the decware box in half, i think maybe if i do this and keep the same shape of the final horn but just half the volume it will work. what do you think?

[Deadeye]

Yes that is a line level circuit. This gets you away from inductors coils and large caps. I already had external electronic crossovers so I built two of the active Eq's in a small P-Box with a halfway decent power supply.
I already had most of the parts for them laying around.
I really have no expertise in the area of horns. However I believe the length and flare of the horn is critical for optimum performance. This is why Klipshhorns only work in a corner.