Hi Prof. Smith,
You've got a real challenge on your hands, and I hope you're up for the work involved in getting anything close to usable output that low in the frequency range.
I'd like to kick off by saying that I don't think anyone here has ever built a subwoofer powerful enough to cause actual structural damage to a house or building. What Dave said about exciting resonances is true, but loudspeakers are so poor at transferring energy into the air, that no significant amount of structural movement could be caused by any reasonable subwoofer (or unreasonable for that matter).
You might rattle walls, shake glasses in a cupboard or irritate your neighbors, but your house isn't going to fall over. I've seen windshields break in car audio SPL competitions, but that's an extremely small, well sealed enclosed chamber, and the SPL in question is much higher than what you could reasonably achieve in a larger room, inside a poorly sealed house.
On to your question... a subwoofer that can produce 15-35Hz. You're going to need a very long pipe (unreasonably long if it's not tapered). You're going to need at least a 15" driver, but 18" or 21" would be better. You'll need a lot of power, and you'll certainly need to run active crossovers and probably need full EQ to control your desired upper rolloff, and match everything in your room.
Here's a design example for fun:
- AE speakers IB15 woofer
- Pipe that starts at 17.5" diameter and tapers to 8"
- 147" long
This gets you a tuning of about 15Hz, and with enough power, should produce good usable output down to 10Hz. I would suggest using two pipes and two drivers to try and even out the room.
Here's another - This is my favorite:
- BMS 18N860
- Straight pipe, 16.5" inside diameter
- 130" long
This gets you a tuning of 20Hz, which will easily produce the 15Hz output you're looking for. That driver has a lot of surface area, and a lot of excursion which is exactly what you'll need.
If you're willing to ditch the tube idea and build a TL in a box, then you have a lot more flexibility. You could build a line with the BMS driver, and a 0.2 taper that would actually be a manageable size. (about 2' tall x 4'deep x 20" wide). Heck, why not build 2, one for each corner! I built this style for my home theater using a Mach 5 Audio MAW-15 woofer and a 0.2 taper line tuned to 25Hz.
You might also want to look into IB setups, and definitely take a look at tapped horns. They'll be just as big as these tubes, but you might get more output. An ELF style system is probably going to run out of steam that low, and ported is also going to have some serious problems if tuned that low. A TL is probably the most "natural" way to go, but certainly not the smallest. A properly designed TL might not need any EQ at all to be flat in the range you're looking for.
If you have some more specifics, let me know and I'll see if I can lend a hand. You'll need to decide on price, pick a driver, pick a size limit, pick a desired SPL level in the range you're looking at, and we can go from there. The size/layout of your room would also be good to know.
Cheers,
Owen
You've got a real challenge on your hands, and I hope you're up for the work involved in getting anything close to usable output that low in the frequency range.
I'd like to kick off by saying that I don't think anyone here has ever built a subwoofer powerful enough to cause actual structural damage to a house or building. What Dave said about exciting resonances is true, but loudspeakers are so poor at transferring energy into the air, that no significant amount of structural movement could be caused by any reasonable subwoofer (or unreasonable for that matter).
You might rattle walls, shake glasses in a cupboard or irritate your neighbors, but your house isn't going to fall over. I've seen windshields break in car audio SPL competitions, but that's an extremely small, well sealed enclosed chamber, and the SPL in question is much higher than what you could reasonably achieve in a larger room, inside a poorly sealed house.
On to your question... a subwoofer that can produce 15-35Hz. You're going to need a very long pipe (unreasonably long if it's not tapered). You're going to need at least a 15" driver, but 18" or 21" would be better. You'll need a lot of power, and you'll certainly need to run active crossovers and probably need full EQ to control your desired upper rolloff, and match everything in your room.
Here's a design example for fun:
- AE speakers IB15 woofer
- Pipe that starts at 17.5" diameter and tapers to 8"
- 147" long
This gets you a tuning of about 15Hz, and with enough power, should produce good usable output down to 10Hz. I would suggest using two pipes and two drivers to try and even out the room.
Here's another - This is my favorite:
- BMS 18N860
- Straight pipe, 16.5" inside diameter
- 130" long
This gets you a tuning of 20Hz, which will easily produce the 15Hz output you're looking for. That driver has a lot of surface area, and a lot of excursion which is exactly what you'll need.
If you're willing to ditch the tube idea and build a TL in a box, then you have a lot more flexibility. You could build a line with the BMS driver, and a 0.2 taper that would actually be a manageable size. (about 2' tall x 4'deep x 20" wide). Heck, why not build 2, one for each corner! I built this style for my home theater using a Mach 5 Audio MAW-15 woofer and a 0.2 taper line tuned to 25Hz.
You might also want to look into IB setups, and definitely take a look at tapped horns. They'll be just as big as these tubes, but you might get more output. An ELF style system is probably going to run out of steam that low, and ported is also going to have some serious problems if tuned that low. A TL is probably the most "natural" way to go, but certainly not the smallest. A properly designed TL might not need any EQ at all to be flat in the range you're looking for.
If you have some more specifics, let me know and I'll see if I can lend a hand. You'll need to decide on price, pick a driver, pick a size limit, pick a desired SPL level in the range you're looking at, and we can go from there. The size/layout of your room would also be good to know.
Cheers,
Owen
thanks opc.
I have a few questions.
What would happen at below 20hz though? Since we cant hear those frequencies would it just shake things in the room?
Do you know where else I can get cheap pipes? I was quoted 100 pounds for a tube. It seems abit much.
I want to do this on a budget of say 300 dollars. whats the cheapest price?
Can you tell me the formula for lowest frequency without attenuation as a function of the pipe length?
If the pipe was 130 inches wouldnt it be very diffficult to stuff it with foam to taper it?
I have a few questions.
What would happen at below 20hz though? Since we cant hear those frequencies would it just shake things in the room?
Do you know where else I can get cheap pipes? I was quoted 100 pounds for a tube. It seems abit much.
I want to do this on a budget of say 300 dollars. whats the cheapest price?
Can you tell me the formula for lowest frequency without attenuation as a function of the pipe length?
If the pipe was 130 inches wouldnt it be very diffficult to stuff it with foam to taper it?
Hi Prof. Smith,
Below 20Hz, we interpret bass in a more "tactile" rather than aural manner. That's not a hard and fast number, and like upper frequencies, it varies from one person to the next. I would say both sensations are equally important for good bass reproduction, which is why some people insist on having in room response down to 10 Hz.
Ideally, you don't want any frequency to shake anything in your room. Strong bass calls for very diligent room treatment. You'll have to use a function generator to sweep though the entire low frequency range, and run around your room fixing everything that rattles. I did this in my home theater, and at very high levels it quickly becomes an exercise in futility. I find any sort of rattling to be extremely distracting during listening, so I made a point of not having anything rattle at normal to higher listening levels in my room. You'll most definitely have to do the same. Download FG.exe from the Marchand Electronique website, and play around with it. You can put it on a laptop or PC, and run a signal to your stereo. It'll generate any frequency you type in, and it's priceless to have when matching levels and trying to setup your room. Be extremely careful at higher frequencies (over 10K) as your ears don't hear them very well, and it's easy to fry a tweeter.
What kind of pipe was it that was offered for 100 pounds? If it was thick walled PVC than it's a deal, but if it's cardboard, like a sonotube, then 100 pounds is a ripoff. I can buy sonotube at the local Home Depot for under $20 for a 10ft length of up to 16" diameter. It's very thin wall though, and would probably need reinforcement for your application. If you can get an actual plastic (PVC) pipe for a reasonable amount of money, then I'd go that way. They're easier to paint and finish, and the stiffer walls will allow you to use them without any changes. There's an example here:
http://www.teresaudio.com/haven/
If you want to try an pull this off for $300, then take a look at this driver here:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=292-2526
It's the only driver I can imagine that will allow you to get that low, with a pipe, and produce reasonable output for so little money.
I can only assume the manufacturer's specs are optimistic (There's no way it's 107dB 1W/1M) but hopefully the Fs isn't too far off. You'll need a larger diameter pipe to accommodate the 21" driver, so keep that in mind. I think Magnetar used these in one of his OB projects.
The formula for pipe length depends on the driver parameters and taper, and it would be best to go to www.quarter-wave.com and download the excel spreadsheet that calculates everything quickly:
http://www.quarter-wave.com/TLs/Alignment_Tables_Calculator_3_3_09.xls
Take a look into that stuff and let me know what you think.
One more thing before we travel too much further, is that you really should consider how important all of this is to you. Have you ever heard what 15Hz sounds like? Have you ever heard a large organ played in a huge space? It's really quite incredible, but not in a "wow that's got bass" kinda way. You're going to have trouble finding anything with content that low, with the exception of some synthesized music and organ recordings. 99.999% of the time, a subwoofer with 15-35Hz response will be completely silent if correctly implemented.
Seems like a lot of work for 0.001% of the music.
Cheers,
Owen
Below 20Hz, we interpret bass in a more "tactile" rather than aural manner. That's not a hard and fast number, and like upper frequencies, it varies from one person to the next. I would say both sensations are equally important for good bass reproduction, which is why some people insist on having in room response down to 10 Hz.
Ideally, you don't want any frequency to shake anything in your room. Strong bass calls for very diligent room treatment. You'll have to use a function generator to sweep though the entire low frequency range, and run around your room fixing everything that rattles. I did this in my home theater, and at very high levels it quickly becomes an exercise in futility. I find any sort of rattling to be extremely distracting during listening, so I made a point of not having anything rattle at normal to higher listening levels in my room. You'll most definitely have to do the same. Download FG.exe from the Marchand Electronique website, and play around with it. You can put it on a laptop or PC, and run a signal to your stereo. It'll generate any frequency you type in, and it's priceless to have when matching levels and trying to setup your room. Be extremely careful at higher frequencies (over 10K) as your ears don't hear them very well, and it's easy to fry a tweeter.
What kind of pipe was it that was offered for 100 pounds? If it was thick walled PVC than it's a deal, but if it's cardboard, like a sonotube, then 100 pounds is a ripoff. I can buy sonotube at the local Home Depot for under $20 for a 10ft length of up to 16" diameter. It's very thin wall though, and would probably need reinforcement for your application. If you can get an actual plastic (PVC) pipe for a reasonable amount of money, then I'd go that way. They're easier to paint and finish, and the stiffer walls will allow you to use them without any changes. There's an example here:
http://www.teresaudio.com/haven/
If you want to try an pull this off for $300, then take a look at this driver here:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=292-2526
It's the only driver I can imagine that will allow you to get that low, with a pipe, and produce reasonable output for so little money.
I can only assume the manufacturer's specs are optimistic (There's no way it's 107dB 1W/1M) but hopefully the Fs isn't too far off. You'll need a larger diameter pipe to accommodate the 21" driver, so keep that in mind. I think Magnetar used these in one of his OB projects.
The formula for pipe length depends on the driver parameters and taper, and it would be best to go to www.quarter-wave.com and download the excel spreadsheet that calculates everything quickly:
http://www.quarter-wave.com/TLs/Alignment_Tables_Calculator_3_3_09.xls
Take a look into that stuff and let me know what you think.
One more thing before we travel too much further, is that you really should consider how important all of this is to you. Have you ever heard what 15Hz sounds like? Have you ever heard a large organ played in a huge space? It's really quite incredible, but not in a "wow that's got bass" kinda way. You're going to have trouble finding anything with content that low, with the exception of some synthesized music and organ recordings. 99.999% of the time, a subwoofer with 15-35Hz response will be completely silent if correctly implemented.
Seems like a lot of work for 0.001% of the music.
Cheers,
Owen
It was indeed a cardboard or fibreboard tube offered for 100 pounds. I guess because its a one off they have to increase the cost but I dont think sonotube is sold in the UK.
Wouldnt pvc walls be too thin though?
Well maybe its not 15hz I'm after then, however most of my music DOES conatin down to 20hz which my small monitors cannot handle. They probably cut off about 40hz. So its only that range between 20 to 40 hz I'm looking to fill in but it definitely feels like its missing.
Are you sure there isnt a cheaper woofer I can use?
Now that its clear that I only want down to about 20hz there must be a cheaper way no?
Its all experimental it wont be perfect anyway. I want deep bass but it doesnt have to be perfect. I have seen many woofers between 100 to 200 dollars. Surely there must be a cheaper option?
Also ideally I'd want to source the drive unit in the UK since shipping costs will be high.
Thanks
Wouldnt pvc walls be too thin though?
Well maybe its not 15hz I'm after then, however most of my music DOES conatin down to 20hz which my small monitors cannot handle. They probably cut off about 40hz. So its only that range between 20 to 40 hz I'm looking to fill in but it definitely feels like its missing.
Are you sure there isnt a cheaper woofer I can use?
Now that its clear that I only want down to about 20hz there must be a cheaper way no?
Its all experimental it wont be perfect anyway. I want deep bass but it doesnt have to be perfect. I have seen many woofers between 100 to 200 dollars. Surely there must be a cheaper option?
Also ideally I'd want to source the drive unit in the UK since shipping costs will be high.
Thanks
That's seems like a high price for the tube. I recall that I bought
off-brand Sonotubes here for about $50 which would do the job.
I don't think you have to spend a lot on the woofer for this - the tube
does much of the work. It's helpful if it's free air resonance is about
the 1/4 wave length of the tube. 11' is about 25 Hz. And you will
want to experiment with the use of stuffing to damp the response.
off-brand Sonotubes here for about $50 which would do the job.
I don't think you have to spend a lot on the woofer for this - the tube
does much of the work. It's helpful if it's free air resonance is about
the 1/4 wave length of the tube. 11' is about 25 Hz. And you will
want to experiment with the use of stuffing to damp the response.
Hi Prof. Smith,
I'm with Nelson on this one... if they want 100 pounds for cardboard tube, then you're definitely not getting a fair price. You'll have to go to your local big-box hardware/building store, and see what there is. The stuff they sell here isn't called "Sonotube" but there are several other brands of the exact same thing. It's used for pouring concrete pillars and making deck foundations.
The green PVC sewage pipes can often be found at construction sites or road works. They're about 1/4" to 1/2" thick PVC plastic, and they're extremely strong and heavy. That would definitely be ideal if you could get your hands on one.
As for the driver, you're pretty much on your own finding a good UK source. I don't know anything at all about who sells what in the UK, and I think in general the prices are a little inflated compared to the NA market. The only thing I can suggest is that you might be able to find some of the really great European pro-audio drivers that would probably be priced a little lower there.
Names to watch for:
Ciare
FaitalPro
ATC
Fane
18Sound
B&C
Beyma
Volt
Most of those might be a little more expensive than you're looking for, but if you're going to stretch your budget, definitely spend it on the right driver. Any old amp with a decent amount of power will be fine, and the active crossovers could be bread-boarded for $1. If you think $100 is too much for a driver, then you're probably out of luck. Expect to spend at least $100 to $200.
You're going to want an Fs in the twenties, preferably the low 20's. Anything much over 30Hz Fs isn't going to work in a tube tuned to 20 or 25 Hz. If you go with a smaller driver (12" or less) then you're going to need something with a lot of excursion. If you go larger, like 15"-21" then you can get away with far less excursion and still get decent output.
Avoid high Fs pro-audio drivers and cheap, low sensitivity car audio drivers. Also remember that if you go for a low sensitivity 10-12" driver, then you're going to need way more power to drive it, which costs more money in the end.
My approach to subwoofers is that they're really not worth doing unless you do them right. A bad subwoofer can ruin a good system, and causes serious listener fatigue/annoyance. You might be thrilled with all the bass initially, but you'll find yourself turning them down more and more until they're off completely, then you'll wonder why you built them in the first place. It doesn't have to be perfect the first time around, but set yourself up for success with a decent driver, and the rest can be sorted out as you go.
Cheers,
Owen
I'm with Nelson on this one... if they want 100 pounds for cardboard tube, then you're definitely not getting a fair price. You'll have to go to your local big-box hardware/building store, and see what there is. The stuff they sell here isn't called "Sonotube" but there are several other brands of the exact same thing. It's used for pouring concrete pillars and making deck foundations.
The green PVC sewage pipes can often be found at construction sites or road works. They're about 1/4" to 1/2" thick PVC plastic, and they're extremely strong and heavy. That would definitely be ideal if you could get your hands on one.
As for the driver, you're pretty much on your own finding a good UK source. I don't know anything at all about who sells what in the UK, and I think in general the prices are a little inflated compared to the NA market. The only thing I can suggest is that you might be able to find some of the really great European pro-audio drivers that would probably be priced a little lower there.
Names to watch for:
Ciare
FaitalPro
ATC
Fane
18Sound
B&C
Beyma
Volt
Most of those might be a little more expensive than you're looking for, but if you're going to stretch your budget, definitely spend it on the right driver. Any old amp with a decent amount of power will be fine, and the active crossovers could be bread-boarded for $1. If you think $100 is too much for a driver, then you're probably out of luck. Expect to spend at least $100 to $200.
You're going to want an Fs in the twenties, preferably the low 20's. Anything much over 30Hz Fs isn't going to work in a tube tuned to 20 or 25 Hz. If you go with a smaller driver (12" or less) then you're going to need something with a lot of excursion. If you go larger, like 15"-21" then you can get away with far less excursion and still get decent output.
Avoid high Fs pro-audio drivers and cheap, low sensitivity car audio drivers. Also remember that if you go for a low sensitivity 10-12" driver, then you're going to need way more power to drive it, which costs more money in the end.
My approach to subwoofers is that they're really not worth doing unless you do them right. A bad subwoofer can ruin a good system, and causes serious listener fatigue/annoyance. You might be thrilled with all the bass initially, but you'll find yourself turning them down more and more until they're off completely, then you'll wonder why you built them in the first place. It doesn't have to be perfect the first time around, but set yourself up for success with a decent driver, and the rest can be sorted out as you go.
Cheers,
Owen
I forgot to mention that the IB15 I was talking about earlier is actually pretty reasonable at $125. I don't really think you'll be able to find anything much cheaper that actually works. A quick XE conversion puts it at 85 GBP, which is less than the cardboard tube you were looking at.
http://aespeakers.com/shop/catalog/product_info.php?cPath=30&products_id=55
Shipping won't be that cheap, but if you're willing to wait, then I'm sure parcel post would be reasonable.
It might be worth looking into.
Cheers,
Owen
http://aespeakers.com/shop/catalog/product_info.php?cPath=30&products_id=55
Shipping won't be that cheap, but if you're willing to wait, then I'm sure parcel post would be reasonable.
It might be worth looking into.
Cheers,
Owen
Professor smith said:
For Sonotube in the UK try
BBM Ltd.
Builders suppliers with branches around the UK 😉 lots of different sizes.
Essex tubes claim to have stock tube Essex tubes
No idea about eithor company but if your after sonotube or similar worth an email 🙂
So given that Nelson Pass himself has stated that the cost of the woofer is not that important, are you sure there isnt a cheaper solution?
So any cheap 15 inch drive unit with Fs 20hz and high sensitivity will do?
When you mentioned that you can obtain sonotube but that its thin how thin is it?
So any cheap 15 inch drive unit with Fs 20hz and high sensitivity will do?
When you mentioned that you can obtain sonotube but that its thin how thin is it?
Professor smith said:
Observe the popularity of the Eminence 15" Alpha at about $58.
I happen to prefer more expensive woofers, but for this application,
they won't be that much better.
😎
I forgot to mention that I have a pair of those Lambda TD15M drivers,
but with dual voice coils. Very nice, and worth the $.
but the spec on the eminence woofer states that it can only go down to 40 hz. So will I get 20hz in my room or not?
Hi Guys,
Well, I'm sticking with my prior conviction on this one, especially after looking at that Eminence driver. I'm sure it would make a great midbass driver in a high efficiency system, but with 3.8mm xmax and a Fs of 41Hz, you'd be lucky to go lower than the little monitors you have now. That's definitely not to ticket to the 20Hz show.
I think there are varying degrees of what constitutes a "cheap" driver. If you read the El-Pipo article, you'll see that Nelson used 4 drivers that cost $395 each. Relative to other 21" pro-audio drivers, $395 is actually a bargain. The B&C unit will set you back $700. I don't think you can achieve the same results as he did, using a $50 woofer.
If you can find a cheap 15" driver with decent efficiency, X-max and a lower than 30Hz Fs, then go for it. My point is that it's hard enough to meet that criteria with an unlimited budget, let alone a budget of $50. I certainly won't be the one to stop you though, so if you can find something, then buy it, and we'll give it go.
As for that off-brand Sonotube, it's thin... really thin. My calipers tell me it's 1/8". I'm using it with a 6.25" driver right now, and I have used it with a 10" driver, but I did notice with the 10" driver that if I didn't keep the crossover low enough, then I could hear and feel the tube resonate at higher frequencies (Maybe 200Hz). I wouldn't suggest using anything that weak with a 15" driver. The thicker 1/4" stuff I've seen looks to be much stronger, and probably better suited to this application.
Cheers,
Owen
Well, I'm sticking with my prior conviction on this one, especially after looking at that Eminence driver. I'm sure it would make a great midbass driver in a high efficiency system, but with 3.8mm xmax and a Fs of 41Hz, you'd be lucky to go lower than the little monitors you have now. That's definitely not to ticket to the 20Hz show.
I think there are varying degrees of what constitutes a "cheap" driver. If you read the El-Pipo article, you'll see that Nelson used 4 drivers that cost $395 each. Relative to other 21" pro-audio drivers, $395 is actually a bargain. The B&C unit will set you back $700. I don't think you can achieve the same results as he did, using a $50 woofer.
If you can find a cheap 15" driver with decent efficiency, X-max and a lower than 30Hz Fs, then go for it. My point is that it's hard enough to meet that criteria with an unlimited budget, let alone a budget of $50. I certainly won't be the one to stop you though, so if you can find something, then buy it, and we'll give it go.
As for that off-brand Sonotube, it's thin... really thin. My calipers tell me it's 1/8". I'm using it with a 6.25" driver right now, and I have used it with a 10" driver, but I did notice with the 10" driver that if I didn't keep the crossover low enough, then I could hear and feel the tube resonate at higher frequencies (Maybe 200Hz). I wouldn't suggest using anything that weak with a 15" driver. The thicker 1/4" stuff I've seen looks to be much stronger, and probably better suited to this application.
Cheers,
Owen
Hi all
I've been following this thread for a little while with interest as I really do like the idea of a single, long tube being the source of resonance and bass extension.
I was wondering if the Visaton W300S would be a suitable driver for this setup. It has a low Fs of 23 Hz and a high Xmax at 28mm. However, it is only a 12" driver but on the plus side is quite cheap AUD155.
Visaton W 300 S
Due to size contraints in my room I was wondering if it would be possible to cut the "tube" and realign it so that it is in a U shape. Perhaps even to "wrap" around the rear of my rack and have the driver and port facing the same direction as the main speakers. I was also toying with the idea of stacking two of these U-shapes on top of each other. One with the driver on the right and the other on the left.
Also, does anybody have any recommendations for software in which I can draw/model these thoughts, because I'm just awful with AutoCAD.
Thanks!
Steve.
I've been following this thread for a little while with interest as I really do like the idea of a single, long tube being the source of resonance and bass extension.
I was wondering if the Visaton W300S would be a suitable driver for this setup. It has a low Fs of 23 Hz and a high Xmax at 28mm. However, it is only a 12" driver but on the plus side is quite cheap AUD155.
Visaton W 300 S
Due to size contraints in my room I was wondering if it would be possible to cut the "tube" and realign it so that it is in a U shape. Perhaps even to "wrap" around the rear of my rack and have the driver and port facing the same direction as the main speakers. I was also toying with the idea of stacking two of these U-shapes on top of each other. One with the driver on the right and the other on the left.
Also, does anybody have any recommendations for software in which I can draw/model these thoughts, because I'm just awful with AutoCAD.
Thanks!
Steve.
mrevie said:
Certainly you can make U shaped tubes and they will work fine, but I'm not
so certain that you want to have the opening of one tube next to the driver
of the other tube.
😎
Hi Steve,
That driver would be excellent for an El-Pipo, and if you used two of them, you could expect pretty impressive output levels.
As Nelson already said, the U shape is certainly not a problem, and if anything, I would say it has the potential to sound better and integrate more appropriately into a room. It would be very neat to see some FEM simulations to investigate the effects of having the tube opening on the ceiling and the driver on the floor. I think that it would be advantageous to have both the driver and the open end of the pipe against the floor, and generally in the same location. The pipe's I've built have all performed better laying down, but that could just be my room/listening location.
As for the stacking thing, if you're going to build two of them, then you should probably consider placing them in a stereo configuration, or at least having them in separate locations. You'll probably get a more even distribution with two separate locations, instead of just one.
For the software, I know some people really like Google Sketch-Up, but I much prefer Solidworks. All it takes is a few hours of tutorials to become reasonably proficient with Solidworks. Google Sketch-up has an easier learning curve though.
I'll model that Visaton driver in a few pipes either tonight or tomorrow, just to see how it looks.
Cheers,
Owen
That driver would be excellent for an El-Pipo, and if you used two of them, you could expect pretty impressive output levels.
As Nelson already said, the U shape is certainly not a problem, and if anything, I would say it has the potential to sound better and integrate more appropriately into a room. It would be very neat to see some FEM simulations to investigate the effects of having the tube opening on the ceiling and the driver on the floor. I think that it would be advantageous to have both the driver and the open end of the pipe against the floor, and generally in the same location. The pipe's I've built have all performed better laying down, but that could just be my room/listening location.
As for the stacking thing, if you're going to build two of them, then you should probably consider placing them in a stereo configuration, or at least having them in separate locations. You'll probably get a more even distribution with two separate locations, instead of just one.
For the software, I know some people really like Google Sketch-Up, but I much prefer Solidworks. All it takes is a few hours of tutorials to become reasonably proficient with Solidworks. Google Sketch-up has an easier learning curve though.
I'll model that Visaton driver in a few pipes either tonight or tomorrow, just to see how it looks.
Cheers,
Owen
opc said:
Sketch-up is also free... even the full pro version is a fraction of the $1000s that SolidWorks costs. It also only runs properly on a limited range of XP or Vista workstations.
dave
That horrible B-brand four letter word company used to make the B*$# Wave Cannon that had a 12" woofer placed about 1/4 of the way down a tube, making a double tuned pipe!
That Visaton driver looks interested but look at that chart. nearly flat from 200-1.5K but everything below 200 falls off rapidly. that 92db 1m/1w rating must be at 1k!! not so efficient down low! that sort of surprises me that it rolls off like that.
That Visaton driver looks interested but look at that chart. nearly flat from 200-1.5K but everything below 200 falls off rapidly. that 92db 1m/1w rating must be at 1k!! not so efficient down low! that sort of surprises me that it rolls off like that.
Nelson Pass said:
Now that I think of it, I'm not certain that I would place the ends of the "U"
in proximity to each other either.
😎
The U I had in mind wasn't a tight turn around, but rather the ends of it would be a metre or more apart from each other.
Probably the farther the better. I have often thought that if you have a room
of the appropriate dimensions, you can run your pipe straight from the woofer
location to the nearest corner. That way, your pipe end can act as a diffusor
for that corner down around the room's fundamental mode.
Remember, you heard it here...
😎
of the appropriate dimensions, you can run your pipe straight from the woofer
location to the nearest corner. That way, your pipe end can act as a diffusor
for that corner down around the room's fundamental mode.
Remember, you heard it here...
😎
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