Thanks!
Bigger cones = higher acoustic impedance = lower distortion, lower extension, higher sensitivity. They can play louder, but we do it to play cleaner and better, softer. Usually a high performance sub driver's motor will beat our little Vifa's motor for bass control too.
I had similar conversation with my wife trying to convince her we should get the 8" woofer patio speakers instead of the 5" woofers. She was afraid they would "be too loud for the neighbors." Non-audiophiles thiink the only reason for big speakers is to play louder! Telling her that big speakers play better softer made her head spin, but she pretended to believe me and now the 8" sond great and can play low and soft without bothering anybody.
Acoustic impedance increases with cone velocity which is why bass comes alive on small speakers when you crank them up. Then the neighbors get annoyed!
Bigger cones = higher acoustic impedance = lower distortion, lower extension, higher sensitivity. They can play louder, but we do it to play cleaner and better, softer. Usually a high performance sub driver's motor will beat our little Vifa's motor for bass control too.
I had similar conversation with my wife trying to convince her we should get the 8" woofer patio speakers instead of the 5" woofers. She was afraid they would "be too loud for the neighbors." Non-audiophiles thiink the only reason for big speakers is to play louder! Telling her that big speakers play better softer made her head spin, but she pretended to believe me and now the 8" sond great and can play low and soft without bothering anybody.
Acoustic impedance increases with cone velocity which is why bass comes alive on small speakers when you crank them up. Then the neighbors get annoyed!
types of wool felt?
Ronald, what kind of wool felt did You use?
It seems the F11/13 or F15 are used for sound absorption. The F11/13 is 95% wool, and the F15 is 55% wool. I also have some old wool blankets here that "might" work, but not sure on the density. I might play with that later on a single driver test box. For the current "cheap and cheerful" build, I will go with something proven, as the drivers are not in separate chambers (You will see why when I post pictures).
Also, if I recall, You used 5 mm thick? I am looking into 1/2" (about 12 mm), would that be overkill?
Here are the links to what I am looking into:
F-11/13 Wool Felt, 1/2" Thick x 72" Wide - The Felt Company
F-15N Wool Felt, 1/2" Thick x 72" Wide - The Felt Company
Building a nice cabinet for arrays sure does take some time. And I would still consider this current build "a prototype". It is going to be interesting how much improvement there really is. I like my Avebury system, but I am sure missing my arrays, esp with movies and large scale music. I am having withdrawals in fact.
Ronald, what kind of wool felt did You use?
It seems the F11/13 or F15 are used for sound absorption. The F11/13 is 95% wool, and the F15 is 55% wool. I also have some old wool blankets here that "might" work, but not sure on the density. I might play with that later on a single driver test box. For the current "cheap and cheerful" build, I will go with something proven, as the drivers are not in separate chambers (You will see why when I post pictures).
Also, if I recall, You used 5 mm thick? I am looking into 1/2" (about 12 mm), would that be overkill?
Here are the links to what I am looking into:
F-11/13 Wool Felt, 1/2" Thick x 72" Wide - The Felt Company
F-15N Wool Felt, 1/2" Thick x 72" Wide - The Felt Company
Building a nice cabinet for arrays sure does take some time. And I would still consider this current build "a prototype". It is going to be interesting how much improvement there really is. I like my Avebury system, but I am sure missing my arrays, esp with movies and large scale music. I am having withdrawals in fact.
Yes mine is about 5 to 7 mm thickness. Its origin was from France and it was advertised for isolation purposes. It's pure wool, not factory stuff and was pretty smelly. I remember my friend who picked it up locally at the other side of our country had to endure that smell all the way to my home (a 2 hour drive). He felt he was driving with a bunch of sheep in the backseat .
.Speaker: group purchase
Be aware that Koldby is trying to put together a group buy of the TG9 driver.
Somewhere in the range of $6-7.ea ...plus shipping I assume.
Perhaps he'll chime in here about that.
M
Be aware that Koldby is trying to put together a group buy of the TG9 driver.
Somewhere in the range of $6-7.ea ...plus shipping I assume.
Perhaps he'll chime in here about that.
M
It is in this post:
http://www.diyaudio.com/forums/full...tc9-line-array-cnc-cabinet-5.html#post5001458
Regds
Gerald
Perceval, for what you are looking for the previously mentioned 3FE22 should be a valid candidate. X-max 1.83 mm, X-damage 7.3 mm.
crossover at 600 Hz and go!
http://www.faitalpro.com/en/products/LF_Loudspeakers/product_details/datasheet.php?id=401000100
You can't be serious about the TC10FG00-04 though, looks more like a train wreck to me.
http://www.tymphany.com/wp-content/themes/pathfinders/cache/pdfs/TC10FG00-04.pdf
I bet it would have a chance to be popular because it will let you hear all kinds of new detail in songs.
You could also get a different amp for highs and lows and get one of the Scan Speak 10F offerings, the 10F 8414G10 looks attractive:
Source: Troels measurements x-max 2.4 mm, x-mech 7.5 mm.
crossover at 600 Hz and go!
http://www.faitalpro.com/en/products/LF_Loudspeakers/product_details/datasheet.php?id=401000100
You can't be serious about the TC10FG00-04 though, looks more like a train wreck to me
.http://www.tymphany.com/wp-content/themes/pathfinders/cache/pdfs/TC10FG00-04.pdf
I bet it would have a chance to be popular because it will let you hear all kinds of new detail in songs
.You could also get a different amp for highs and lows and get one of the Scan Speak 10F offerings, the 10F 8414G10 looks attractive:
Source: Troels measurements x-max 2.4 mm, x-mech 7.5 mm.
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I got blinded by the 93dB from the TC10...
Yes, I am already talking with Faital Asia, they have a warehouse in China... I'll probably be able to get some drivers from there.
I will need to have a serious talk with them about 12 or 15" woofers. Their offering is so vast, it's kinda hard to navigate and pick the one.
Looking for a woofer that would do 40 to 500Hz, then the 3FE22 on 500Hz and above.
Yes, I am already talking with Faital Asia, they have a warehouse in China... I'll probably be able to get some drivers from there.
I will need to have a serious talk with them about 12 or 15" woofers. Their offering is so vast, it's kinda hard to navigate and pick the one.
Looking for a woofer that would do 40 to 500Hz, then the 3FE22 on 500Hz and above.
I realise this is a pretty busy thread where a lot of subjects come and go.
I just wanted to put in a post about a fellow forum member of us.
For those of you reading this that might have missed this news, Dave, known as Planet10 is currently recovering from serious health problems. A couple of his forum friends have organised support for him and his family.
I figured I could help out by linking to that thread for those among us who would like to show some support:
http://www.diyaudio.com/forums/planet-10-hifi/304811-lets-help-ruth-dave.html
I just wanted to put in a post about a fellow forum member of us.
For those of you reading this that might have missed this news, Dave, known as Planet10 is currently recovering from serious health problems. A couple of his forum friends have organised support for him and his family.
I figured I could help out by linking to that thread for those among us who would like to show some support:
http://www.diyaudio.com/forums/planet-10-hifi/304811-lets-help-ruth-dave.html
I'm still trying to work out how much added bracing makes sense in a sub.
These frequencies we expect from it are long and do not correspond to any wall size to worry about. Yet we want a stiff enclosure, block the inside noise and retain as much inner volume as possible in such a small enclosure.
I've tried some ideas with bracing but most only complicate construction. I still think an inner steel frame would be worth the trouble and save volume. It will stiffen up the construction.
I've looked at the bracing scheme from Troels, which is elaborate and the absence of it in Linkwitz's Thor subwoofer.
My ideas seem to fall in between both. I will use damping materials inside. I still plan on using MLV, decoupled from the outside enclosure walls by gluing it in the L and T bracket frames. Some neoprene underneath the MLV as a decouple layer.
Slightly asymmetric bracing not to have the inner construction sing it's own song. Overkill? Probably... but adding less than 4 mm MLV doubles the mass compared to the 19 mm Birch sides by themselves. As it needs spacing it will take up some volume though, but not nearly as much as using wood braces instead of my proposed materials.
To come back to the pressure vessel? Yes I do think that's a smart idea. Just not one I can sell here. I'll keep the outer shape more conventional. The sound throughput will be hard to battle in any construction. That's why I want to use these dissimilar materials to make up for each of their specific "eigenmodes" and have mass to block as much sound as possible.
These frequencies we expect from it are long and do not correspond to any wall size to worry about. Yet we want a stiff enclosure, block the inside noise and retain as much inner volume as possible in such a small enclosure.
I've tried some ideas with bracing but most only complicate construction. I still think an inner steel frame would be worth the trouble and save volume. It will stiffen up the construction.
I've looked at the bracing scheme from Troels, which is elaborate and the absence of it in Linkwitz's Thor subwoofer.
My ideas seem to fall in between both. I will use damping materials inside. I still plan on using MLV, decoupled from the outside enclosure walls by gluing it in the L and T bracket frames. Some neoprene underneath the MLV as a decouple layer.
Slightly asymmetric bracing not to have the inner construction sing it's own song. Overkill? Probably... but adding less than 4 mm MLV doubles the mass compared to the 19 mm Birch sides by themselves. As it needs spacing it will take up some volume though, but not nearly as much as using wood braces instead of my proposed materials.
To come back to the pressure vessel? Yes I do think that's a smart idea. Just not one I can sell here. I'll keep the outer shape more conventional. The sound throughput will be hard to battle in any construction. That's why I want to use these dissimilar materials to make up for each of their specific "eigenmodes" and have mass to block as much sound as possible.
Ronald,
an idea to consider on the bracing of the enclosure for the sub. I haven't ever seen this done on a smaller enclosure but in large pro audio bass enclosures a friend of mine has used tension and compression rods through the sides of the enclosure to control the wall loading without having to use excessive or massive bracing. You tension some areas of the walls and add compression in others, so in fact you are both pushing and pulling on the walls and tuning the response of the vibrating membrane. You can still add some internal stuffing but as far as I am concerned in a sealed sub enclosure the only thing you are trying to damp are the upper frequencies that you don't want to emminate from the subs and comb filter with the arrays. So stuffing will be of limited use in a sealed sub for any low end tuning.
an idea to consider on the bracing of the enclosure for the sub. I haven't ever seen this done on a smaller enclosure but in large pro audio bass enclosures a friend of mine has used tension and compression rods through the sides of the enclosure to control the wall loading without having to use excessive or massive bracing. You tension some areas of the walls and add compression in others, so in fact you are both pushing and pulling on the walls and tuning the response of the vibrating membrane. You can still add some internal stuffing but as far as I am concerned in a sealed sub enclosure the only thing you are trying to damp are the upper frequencies that you don't want to emminate from the subs and comb filter with the arrays. So stuffing will be of limited use in a sealed sub for any low end tuning.
I've used threaded rods and nuts for bracing opposite walls of sub enclosures in car audio. The walls need to be thick enough so you can countersink the washer and nut on the outside, fill it in, and finish over it. Put a washer and nut on the inside too. I used glue on the nuts so they never come loose. It works well and doesn't take up a lot of volume.
Stuffing will help to increase the apparent size of the enclosure, often by quite a large margin so it can be helpful in trying to keep the size of the box down but still seem like it is bigger to the driver.
I wonder if Ronald has developed an aversion to threaded rods from the Towers construction
fluid,
I'm not sure that the stuffing works well at all at the extreme lower frequencies to make any real difference in loading. What I am saying is down around the fs of the driver in an enclosure I don't think adding stuffing makes much difference, up higher yes but at the extremes which is what a sub is really all about does it really do much? I unlike others would never use a sub that was not bandpass limited, I don't want that cone making mid bass or anything else, just the lower bass please. integrating a sub that makes any perceivable higher frequencies with another enclosure is a sure headache and something to be avoided if at all possible.
I'm not sure that the stuffing works well at all at the extreme lower frequencies to make any real difference in loading. What I am saying is down around the fs of the driver in an enclosure I don't think adding stuffing makes much difference, up higher yes but at the extremes which is what a sub is really all about does it really do much? I unlike others would never use a sub that was not bandpass limited, I don't want that cone making mid bass or anything else, just the lower bass please. integrating a sub that makes any perceivable higher frequencies with another enclosure is a sure headache and something to be avoided if at all possible.
Very good options here with the threaded rods... I've considered doing that. You can almost tune the enclosure that way. My solution won't be the same but I guess I could still tune it up to a point. I like to add weight, to counter the moving mass. This proposal I have will do both.
I'd still use threaded rods if I ever build another set of arrays. Though I'd make it stacked again, I'd keep it in separate pieces like I ended up doing anyway. I'm glad I had the threaded rods in there. It was the only thing holding it all in shape after the enclosure cracked.
I will use stuffing and am convinced it does make a difference. I agree it won't make the same amount of difference as it does in a mid enclosure but any loss of back wave energy is good in my book. This is also the reason to go with MLV and decoupling that from the enclosure walls. These things are not mandatory, but all details help in the end. It worked very well to keep an eye on detail in the arrays, I expect even the smallest change for the positive to help at these frequencies as well.
Not the easiest way, that I will admit, neither were my arrays. It will be built to last and be serviceable. Just like the arrays.
I'd still use threaded rods if I ever build another set of arrays. Though I'd make it stacked again, I'd keep it in separate pieces like I ended up doing anyway. I'm glad I had the threaded rods in there. It was the only thing holding it all in shape after the enclosure cracked
.I will use stuffing and am convinced it does make a difference. I agree it won't make the same amount of difference as it does in a mid enclosure but any loss of back wave energy is good in my book. This is also the reason to go with MLV and decoupling that from the enclosure walls. These things are not mandatory, but all details help in the end. It worked very well to keep an eye on detail in the arrays, I expect even the smallest change for the positive to help at these frequencies as well.
Not the easiest way, that I will admit, neither were my arrays. It will be built to last and be serviceable. Just like the arrays.