Box designs?
Sabrewing5
10-24-2004, 04:21 PM
I have just started looking at different types of subwoofer box designs and I was wondering what the est type of box is? I have found many different opinions throughtout the different websites i found. So far the one that seems most interesting to me is the folded horn. Anyone have anything to say about any designs, help would be much appreciated.
Brandish
10-26-2004, 11:51 AM
I think the word "best" needs to be eliminated from the car audio dictionary... Oh, and "vs."
There are many types of box designs, all of which have their own advantages and downfalls. I'm not going to get into the details, because that would just take too damn long to type out... There are MANY websites out there that will explain each design and it's benefits/downfalls. It all really boils down to what your goals are, which I can be broken down into three basic categories: SQ, SPL and SQL.
I will, however, comment on folded horn boxes because I've actually just ventured into that realm myself. I found a design from www.billfitzmaurice.com for the Tuba24 since I couldn't wrap my brain around designing my own folded horn, and spent some time building it.
http://members.rogers.com/insleybw/images/tuba_09.jpg
The design claimed an 8-10dB increase of output over a traditional sealed box, so I was a bit skeptical... This particular design is more pro sound-oriented, so it's designed to be very efficient, but doesn't have huge low-end to it. The reccommended driver for the box is I think an Eminence Beta 10, but I used a Pioneer TS-W254C because that's what I had available to me. Anyhow, to put things into perspective, I have this thing running off a 17W amp in the bay at work right now, and the output is incredible... Connected to a 300-watt amp in the sound lab, it easily outperforms two sealed 12s. I was very impressed... There are a number of other designs on Bill's web page, including the Auto Tuba which is more car audio-oriented, and uses a single 8" driver (which can be scaled up to fit a 10" sub). Very interesting stuff... Again, his website is www.billfitzmaurice.com. You have to pay for the designs, but it's only like $10, and saves you the headache of trying to figure out folded horns. You can see the rest of the build process of my Tuba at http://members.rogers.com/insleybw/tuba24.htm.
There are many types of box designs, all of which have their own advantages and downfalls. I'm not going to get into the details, because that would just take too damn long to type out... There are MANY websites out there that will explain each design and it's benefits/downfalls. It all really boils down to what your goals are, which I can be broken down into three basic categories: SQ, SPL and SQL.
I will, however, comment on folded horn boxes because I've actually just ventured into that realm myself. I found a design from www.billfitzmaurice.com for the Tuba24 since I couldn't wrap my brain around designing my own folded horn, and spent some time building it.
http://members.rogers.com/insleybw/images/tuba_09.jpg
The design claimed an 8-10dB increase of output over a traditional sealed box, so I was a bit skeptical... This particular design is more pro sound-oriented, so it's designed to be very efficient, but doesn't have huge low-end to it. The reccommended driver for the box is I think an Eminence Beta 10, but I used a Pioneer TS-W254C because that's what I had available to me. Anyhow, to put things into perspective, I have this thing running off a 17W amp in the bay at work right now, and the output is incredible... Connected to a 300-watt amp in the sound lab, it easily outperforms two sealed 12s. I was very impressed... There are a number of other designs on Bill's web page, including the Auto Tuba which is more car audio-oriented, and uses a single 8" driver (which can be scaled up to fit a 10" sub). Very interesting stuff... Again, his website is www.billfitzmaurice.com. You have to pay for the designs, but it's only like $10, and saves you the headache of trying to figure out folded horns. You can see the rest of the build process of my Tuba at http://members.rogers.com/insleybw/tuba24.htm.
CBFryman
10-26-2004, 09:18 PM
The most efficent woofer enclosure is a properly loaded horn enclosure.
The size of a true Bass horn is so un imagineably large that no one in here has any idea. This (http://www.melhuish.org/audio/horndesign.html) might give you an idea. grab yourself a frequincy you'd like ot have in your car then you do the calulations for compression chamber and horn size. a 42Hz wave has a 24ft wave length. in theory, for maximum efficency the wave length should be one wave lenght long and one in circumfrence. so if you wantto play a 30Hz tone at maximum eficency you can see the imposibility of it begine used in car audio. However, bent hoens are very often used in theatre and concert settings. yak now, thoes 15ft by 15ft massive boxes sitting on stage or by the stage....ya thats the sobwoofer. working at over 100dB efficency and with over 5kw going to each...well if youve been to a decent rock concert ever you hear the results.
People always say "oh you cant hear below 20Hz or therebouts. well to tell you the truth ive heard a 3hz sine wave. Produced by a massive Transmission line enclosure with 7kw. the threash old for 20Hz is about 75dB...120dB for 3Hz...and trust me you dont want to hear 3Hz... you may feel it every time a door is slamed or a car crash happens at a good movie theatre, but hearing it is painful. the most practical efficent enclosure in car audio to my knowledge is a Ported enclosure. followed closely by a passive radiator, then isobaric compound, then your easy yet crappy sealed. jus tthought id add in the infinite baffle sub...though this is least efficent of them all...check this (http://diy.cowanaudio.com/index.html) ya....your firends come over for a great movie experence and you pump out massive bass but there is no enclosure in the room...hmmmmm :screwy:
anyway there is no real best...just the most efficent...and even that can be debated.
The size of a true Bass horn is so un imagineably large that no one in here has any idea. This (http://www.melhuish.org/audio/horndesign.html) might give you an idea. grab yourself a frequincy you'd like ot have in your car then you do the calulations for compression chamber and horn size. a 42Hz wave has a 24ft wave length. in theory, for maximum efficency the wave length should be one wave lenght long and one in circumfrence. so if you wantto play a 30Hz tone at maximum eficency you can see the imposibility of it begine used in car audio. However, bent hoens are very often used in theatre and concert settings. yak now, thoes 15ft by 15ft massive boxes sitting on stage or by the stage....ya thats the sobwoofer. working at over 100dB efficency and with over 5kw going to each...well if youve been to a decent rock concert ever you hear the results.
People always say "oh you cant hear below 20Hz or therebouts. well to tell you the truth ive heard a 3hz sine wave. Produced by a massive Transmission line enclosure with 7kw. the threash old for 20Hz is about 75dB...120dB for 3Hz...and trust me you dont want to hear 3Hz... you may feel it every time a door is slamed or a car crash happens at a good movie theatre, but hearing it is painful. the most practical efficent enclosure in car audio to my knowledge is a Ported enclosure. followed closely by a passive radiator, then isobaric compound, then your easy yet crappy sealed. jus tthought id add in the infinite baffle sub...though this is least efficent of them all...check this (http://diy.cowanaudio.com/index.html) ya....your firends come over for a great movie experence and you pump out massive bass but there is no enclosure in the room...hmmmmm :screwy:
anyway there is no real best...just the most efficent...and even that can be debated.
sr20de4evr
10-26-2004, 10:12 PM
no you can't hear 3hz, no matter how loud it is. You can feel it, but that's very different
and your efficiency order is a little off, in cars bandpass is the highest practical one, followed by ported and passive radiator (they're a tie), then I'm not sure about isobaric and infinite baffle, but they're both more efficient than sealed.
and your efficiency order is a little off, in cars bandpass is the highest practical one, followed by ported and passive radiator (they're a tie), then I'm not sure about isobaric and infinite baffle, but they're both more efficient than sealed.
Abell255
10-26-2004, 10:59 PM
sr20, how's the brahma? i see you finally got it
sr20de4evr
10-26-2004, 11:13 PM
Right now it's sitting on my floor playing a 10hz test tone breaking in. I still don't have the box, so for now this is all I can do....;) It can move about 1.25" p-p on 80rms at 10hz freeair though, which is pretty fun.
It's a f'ing beast though, here are some pics of it sitting next to the e12a:
http://www.b15sentra.net/forums/showthread.php?p=1339734#post1339734
It's a f'ing beast though, here are some pics of it sitting next to the e12a:
http://www.b15sentra.net/forums/showthread.php?p=1339734#post1339734
Haibane
10-26-2004, 11:27 PM
yeah man what is with the gamecube...
Bigger isn't always better...
Bigger isn't always better...
sr20de4evr
10-26-2004, 11:35 PM
hah, the gamecube is my roommate's, I have the ps2, tv, receiver, towers, amps, and sub, but no gamecube....
Haibane
10-26-2004, 11:39 PM
Lol
Sabrewing5
10-27-2004, 01:22 PM
Now with me being new and all I was just wondering in all the horn designs i have noticed that the opening going outwards is bigger. I would think that if where the air is pumped out is smaller than where the air orginated, it would be alot more efficient per se
Sabrewing5
10-27-2004, 01:31 PM
G:\My Documents\My Pictures
Sabrewing5
10-27-2004, 01:31 PM
dang it dont know how to upload a pic
Brandish
10-27-2004, 03:08 PM
Right now it's sitting on my floor playing a 10hz test tone breaking in. I still don't have the box, so for now this is all I can do....;) It can move about 1.25" p-p on 80rms at 10hz freeair though, which is pretty fun.
It's a f'ing beast though, here are some pics of it sitting next to the e12a:
http://www.b15sentra.net/forums/showthread.php?p=1339734#post1339734
Is that frost on the backplate of your E12A? :eek7:
Welcome to club Brahma. Here's your Membership card and free t-shirt. :)
It's a f'ing beast though, here are some pics of it sitting next to the e12a:
http://www.b15sentra.net/forums/showthread.php?p=1339734#post1339734
Is that frost on the backplate of your E12A? :eek7:
Welcome to club Brahma. Here's your Membership card and free t-shirt. :)
sr20de4evr
10-27-2004, 05:01 PM
it's not frost, I'm not really sure what it is
I think it's some kind of oxidation but I'm not sure
I think it's some kind of oxidation but I'm not sure
Abell255
10-27-2004, 06:14 PM
lol sr20, nice....break that baby in. sure is a beast, let us know how it performs once you get it installed
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