vasubandu
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Posts posted by vasubandu
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1 hour ago, CECAA850 said:
I think that at this point, anyone who wishes to answer the OP's questions on subwoofers is welcome to do so. All other posts aren't really necessary.
I kind of have to agree with this. I am not trying to offend or annoy anyone. If no one here is interested or wants to help me, I can just take this elsewhere. Was never my intention to create a commotion.
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3 minutes ago, MetropolisLakeOutfitters said:
That's why I keep telling you to make big giant ports.
There's two things that kill a sub's sound the fastest, one is port noise, second is box coloration / ringing, both of which are due to undersizing. Most people's complaints revolve around port issues though.
Thanks again. I assume that when I actually have the actual measurements to work with, some software will indicate optimal port size, or is it more subjective than that? I also have been looking for anything about port location but have not come up with anything useful. Logic suggests that it would matter.
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1 hour ago, wstrickland1 said:
I'm on boating/fishing forums where every now and then an alias is created that behaves just like this.
Behaves like what? I have posted my idea and sought input and suggestions. I have not claimed to be some oracle who has the secrets for the perfect subwoofer, and I have been respectful and appreciative for the help that has been given. I have not tracked anyone down, dragged them to my post, and forced them to read it. I have been candid about my own limited knowledge; and I have made fun of myself while encouraging others to join in. I happen to be dead serious about this, and two people who make top tier subwoofers and are acknowledged experts have encouraged me to pursue it. So just what behavior do you mean?
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1 hour ago, jimjimbo said:
If you don't want to listen to those that have many, many years of experience, then don't bother to ask. If you or others think I'm being rude here, I'm sorry, but this is just downright crazy.
I don't think that you are being rude at all, and I understand what you are saying. I always listen to people who have meaningful experience, and I consider what they have to say. But I do not blindly follow anyone. Actually, if I were just trying to make a great subwoofer, I would blindly follow @CECAA850 in a heartbeat. But that is not what I am trying to do. I am trying to test something different. And when people tell me that trying something different is a waste of time, I have to ask just what experience they have doing what I propose to do. And the answeris almost always none. So when people tell me that I am wasting my and their time, they are not speaking from experience. They are speaking from assumptions. This assumptions may be well founded, but no one has said "I tried that and it did not work."
And yes, this is downright crazy. That in a sense is the point.
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1 hour ago, Dave A said:
Yes you are. You are not listening to the collective voices of reason that speak from experience so you don't have to learn the hard way. I think you just like the conversations and are not serious about arriving at a destination.
I am listening, but I am choosing to try something different, at least in terms of the general direction. I am dead serious about arriving at a destination, but I happen to have a different destination. There is a well trodden path, and I am heading into the woods, which is what I usually do. People tell me that I am not going to reach the town at the end of the path, but I am not heading there. I still will need certain skills that I lack, and I will need to acquire them one way or another. I will still need help navigating my way to wherever I go, and I will get it where I can find it. Some may be interested in what I find, and I will gladly share it with them. Others will consider this a fool's errand, and I will respect their views. But I am not harming anyone. If people want to provide the help that I need, I will welcome it. If not, I will look elsewhere.
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This just makes me wistful for that $400 pair of CF-4 I missed i South Dakota.
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Dang @mimalmo what an awesome score. Let us know how the CF-3 are. Envious, but in a good way.
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2 hours ago, wvu80 said:
Nice!
What's the story? At that price, obviously you knew what you were looking at. I don't know what version those are but you beat the average by at least four hundred bucks!
This is 30 miles away from me, but I can't justify the price unless I am missing something.
Hifiheaven.net has used Heresy III for $649 http://hifiheaven.net/shop/Klipsch-Heresy-III-pre-owned?language=en¤cy=USD&gclid=CjwKCAiAk4XUBRB5EiwAHBLUMUiX5vP6bC-5UHWsLwfdNz3uJRZp9q8V_4aTkNctgON1yPp1r9EgdRoCTZAQAvD_BwE
New Audiovideo has them for $735. http://www.newaudiovideo.com/index.php?main_page=product_info&products_id=9856
One CF-3 is like a little brother who wants to tag along all the time.
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I have to say that I am a bit surprised by the reaction to this. I am trying to think things through and make wise choices, not slap something together. Nick at SI and another subwoofer designer you would know that I asked for advice both seem excited about the idea and have encouraged me. It may not work, but am I doing something wrong?
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1 hour ago, PrestonTom said:
I guess I take this hobby more seriously than others. Secondly, I am a cheap son of a gun and I hate to see others throw money away. Perhaps these are personal flaws ......
I don't take anything seriously. Never have. And I have never accepted that there is a right way to do anything. Things are the way they because of random and arbitrary reasons. Nothing exists that could not be improved with radical change. As I look back on the history of humanity for things that people took seriously, none of them endured. If humanity still exists in 300 years, do you think that we will still be listening to speakers and still have subwoofers? I don't.
Please understand that I mean no disrespect when I say these things. I am the outlier and i know it. My existence depends on people who take things seriously, and I am grateful for them. And I am not trying to mock or disparage the way things are. I am just playing with a few parts of it. So please do not take offense. Your taking this hobby seriously is a wonderful quality, not a flaw. Without people like you, we would not have standards, and things would fall into chaos. I would argue that it helps to have a few people like me pushing at the edges, but not too many.
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1 hour ago, PrestonTom said:
You have been saying all the right things. Unfortunately they have been falling on deaf ears. I also believe that design comes before buying parts. The problem is that a considerable amount of money is being thrown at the project. In my book, 1) getting a good low end response does not need to be expensive, and 2) two (decent) subs are better that one and that three are even better. All of this is being ignored.
What is perplexing is that there a number of good simulation programs that can answer these "what if" questions without spending a dollar. Are they perfectly accurate? Nothing is perfect but that can narrow things down quite a bit.
Hi @PrestonTom thanks for your comment. I hope at least that @CECAA850 comments are not falling on deaf ears. I am not ignoring him. I actually am paying close attention and goig back over what he has said to make sure I got it. I have some quirks in what I am doing, but I am trying to actually put together something that will work. I am curious about your statement that design comes first. Isn't it fair to start by saying, "I want to make a cylinder subwoofer., and then to impose that design constraint on the process? And isn't it fair to choose the drivers you want and then the build to accommodate them? So if I say I want a cylinder with HS-24 drivers, and I prefer a ported subwoofer, the the first thing I am going to see is that I will need 32-40 cubic feet of space. If I am going to stick with the design constraint of a cylinder my primary consideration is going to be ceiling height. For many reasons, I am going to want it as narrow as possible. A 5-foot diameter circle in my room is not going to work. A 4 foot diameter is still obnoxious, and a 2 foot diameter won't fit. So a 3 foot diameter is Goldilocks. I haver never build one of these before but I have build complicated things, and this seems like a rational approach to me. I know that it will provide the volume, I know the drivers are smaller than the tube, and I know that it will fit. If I am going about this all wrong, let me know. I may be crazy but I try not to be stupid.
And by the way, I get that great sound could be achieved less expensively and more efficiently. And if great sound were my immediate goal, I would do that. But my immediate goal is to make something I can play with and test.
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1 hour ago, CECAA850 said:
Unless I forgot to carry the one it looks like that tube will be almost twice as large as it needs to be. Please check my math. Too large of an enclosure can damage the drivers as they don't have the proper air spring to keep the drivers from overexcursion. That size would probably work as a ported enclosure although I don't think I've ever seen a ported dual driver tube.
Your math is dead on except that I am going ported. I just have not even started or figuring the ports out yet. And ported, it wants 16-20. SoI will end up right in the middle. That was the whole idea - match the enclosure and the drivers on size. And then work out the rest. Now your comment about a ported dual driver has me worried. I have a ported dual driver sub. The SVS B4 Plus that I was in love with is ported with 4 drivers. I just assumed. A quick bit of reseach shows a number of dual ports subwoofers along with some comments that most dual driver subs are sealed because of space issues.
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1 hour ago, CECAA850 said:
A crappy sub, a sub being pushed beyond it's capability or more than likely a sub that has not been set up properly.
Possibly all three, but I have heard what were supposed to be very good subwoofers and had the same sensation. I have a lonely PB2 Plus that is almost as old as my 15 year old son. I lack much of a reference point to judge it, just know that it is light years ahead of the Paradigm SW2200 that it replaced. I also am somewhat confident that I will have one r two great subs after my experiment ends. Either I will find a way for them to cohabitate that works, or they will be separate subs. Ism sure that it is not set up properly because I have not done much to set it up and I exhausted my immediate abilities in that respect. I doubt that I am pushing it beyond its capabilities because I don't listen to anything loud. I just need to get out more and hear what is possible.
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Just now, dtel said:
You are funny, I really doubt you have hearing loss at 30 Hz, it's more like your TV can't reproduce it
No you don't get it. I was trying to get 30 Hz out of my laptop speaker. One I ran it through the system everything was fine. But then I played a 20 Hz sine wave and my subwoofer made the place shake but I could not hear it. It was just fun that have the subwoofer that low in isolation so it was the only thing going. And I am not smoking anything at the moment.
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No seriously, have you ever felt pure 16 Hz bass? At least give it a try. How would you recognize it if you did not try?
As as to what I am smoking, I happen to live in Washington State.
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Hey guys I have a quick question and since everyone is here I thought I would ask.
A few days ago I comments on YouTube videos that have a tone of a certain frequency that I used to check how much I had lost. And then Iater thought I would check the low end, and I could not hear anything. I was starting to get worried, when I sat up and smacked myself in the head. I was listening on my computer. Of course I could not hear 30 Hz. We have Amazon Smart TV, so I have YouTube on the TV, and I checked the tones with it. I lost hearing somewhere in the neighborhood of 30 Hz, but that was not the fun part. When I played, 20, 18, 16, 15 and 12, I could feel but hear it. The funny thing is that when I played 16 Hz for some reason, everything in the room rattled and shook.
Did not know if everyone has done this, but for me it was a blast. I went down to 12 Hz and was still getting vibrations but not sure if that was real. OK, back to what you were doing.
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43 minutes ago, CECAA850 said:
If the picture in your first post is what you're building, I'll assume it's a dual sealed enclosure? If so, calculate the cubic area of the cylinder then subtract the volume of the driver displacement. That will give you total enclosure volume. If you divide that by 2 and the driver specs say it will work with that volume then you're good to go.
No, it is ported. I did not include ports because to be honest I was not sure where to put them or how large to make them. I was sure that I can find that information, but it wil be a learning experience. If this was going to be sealed, it would be half the size.
The HS-24 is 8-12 cf sealed and 16-20 cf ported.
I hope you know that part of the goal here is to give you guys something laugh your asses off about. Won't bother me in the least.
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9 minutes ago, CECAA850 said:
This is like saying, I have a car. I know how fast I want it to accelerate, I know how many cubic inches the engine will be and I know how much I want it to weigh. If one of those parameters is way out of whack your project will be a colossal failure. Of course a nice paint job may be more important than the actual performance of the vehicle itself to you in which case you would ultimately be happy which is really what's important in the end. I see you putting the emphasis of this project on aesthetics and performance is secondary to you. If that's the case, I wish you luck. Please post pictures as I'm sure it will be a fun project to watch come together.
I understand why you would think that, but in the end this is all about performance. Or rather it is about the effect of volume on performance. If I am right that the industry is squeezing enclosure size to the detriment of performance, then providing optimal space should improve performance. If it doesn't then my premise is wrong. I personally could not care less how it looks, but if I want to get others to look at it, I might need some aesthetic or curiosity help.\
Let me ask you this. In your system, which is pushed harder, speakers or subwoofer? Which is run closer to its capacity, and which, if any, is every driven beyond capacity? Which is more likely to be damaged from use? I don't know the answer to these questions of course, and they are genuine questions.
You know what I hate about subwoofers? It is that subwoofer sound that they all make. Hard to describe, but I know it when I hear it. It does not sound like any natural sound that I have heard, but it is part of subwoofer language. Usually right at the beginning. It is noise, not sound. I wold love to get rid of that and have nothing but sound from my subwoofer.
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14 minutes ago, CECAA850 said:
To a point. Normally if you have a fixed or semi fixed enclosure size, you need to find a driver that will work properly with that size enclosure in mind.
OK now you have me concerned. I have an enclosure that is an empty tube 6 feet long and 36 inches wide. I have the space recommended for the driver. Is there some reason why the driver would still now work in that enclosure? I thought that as long as I had nothing but wide open spaces and met space requirements, I was OK.
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15 minutes ago, CECAA850 said:
That can all be simulated. If you reverse a driver and reverse the polarity on that driver there will be no difference.
I know it can be simulated, and maybe those simulations are all accurate, but it would still be fun to see it. And every now and then, the simulations turn out to be wrong.
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10 minutes ago, Ceptorman said:
I hope your experiment works out, pretty gutsy to even try it. Carl (Cecca) does know a lot about subs, I believe he has built quite a few.
The only thing I might add, you might take some measurements and make sure you can move it. Most doors are 36" wide at the most, and that depends on removing the door itself, and maybe even the hinges. It would be a bummer to make this thing in your garage, then have it too big or heavy to move it. Good luck, keep us informed.
Pics are always nice.
I can vouch for @CECAA850's knowledge. The thing is, he sometimes seems not to realize it himself as he casually throws out huge chunks of information. My project is much different because of his advice even if he still thinks I am out to lunch.
My basement room has a 36 inch wide door t the outside that will actually allow a 36 inch object to pass through it. And I will make it in the family room with the TV. It is my space.
I am planning to pick up the shell pieces tomorrow and will assemble them and post pics. You guys need your laughs.
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58 minutes ago, CECAA850 said:
That's not how subwoofer design works. You take the driver(s) load the TS parameters into a modeling program, figure out what tune you want, check port velocities and driver excursion THEN see what type enclosure is recommended by the program. At that point you'll have some sort of educated guess as to the enclosure size.
I get that, I really do. But the math guy in me says that the process you describe must work equally forwards or backwards. Once i have the enclosure design and driver parameters, I can run simulations with different port and other variables to see what would occur. I can change the variables until I get numbers I like, and then I can finish the enclosure t the design. I agree that I could not make port decisions before doing the calculations, but there is no reason I could not start with the overall enclosure shape and dimensions. I am aware that my enclosure may be too big. IN that case, I will use calibrated bags of sand to reduce the air volume.
The thing is I don't want t build a subwoofer or even a great subwoofer. I want to build a giant tube subwoofer. I laugh too when I read that.
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48 minutes ago, CECAA850 said:
It's not what's stronger, it's what's needed. Two drivers won't blow a sonotube apart. Anything more than that is extra money spent.
OK now that I get. Makes a lot of sense. In this case, my sense is the extra money would not necessarily be wasted, although it depends on how things go.
I am very focused on appearances because in my world, appearances are more real than reality. If I want to present this as something genuinely different, which in many respects it isn't, then any distinction I can create helps. I just think that the reaction to a huge tube of curved plywood will be different than the reaction to a giant sonotube.
It occurs to me that none of this will make much sense to most people here. If they were going to spend the money for 2 HS-24 drivers and an amplifier to driver them, their only concern would be to make the best subwoofer they could using established methods. And they would be right.
Unless I blow the drivers, I can always go that route after my experiment. But for now, I am having my own kind of fun testing a few ideas, and I am sure that more will come to me. I mean, what would happen if I had 200 one-inch ports all over the sides (equivalent to 8" round port)? What would happen if I pulled the drivers a foot or two into the tube? Or changed their direction? With any luck,I will have a setup so I can try those things and hear what it does, not just look at some chart. Of course the 200 holes would require a shall replacement. In the end, maybe I will find nothing, but I will have not finding it.
In the meantime, your comments are all appreciated. I take them seriously and give them serious thought. You have saved me a lot of time going down pointless paths.
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I apparently mis-named this thread when I referred to CF-4.
Vasubandu's Tower of Subwoofer Build
in Subwoofers
Posted
Thanks @CECAA850 I have the HS-24 set up in WinISD, but it says something is wrong - missing information I think. Using what I have witih a 1200 liter volume, which I will have, wit one 5 inch port, the rear port air velocity is off the charts below 42. A 10" is not much better, 2 10" has me over 14 from 25 down, 3 10" limits the over 14 to 15-20, and 4 10" peaks at 12.25 around 18. I am still figuring WinISD out. The rest of the criteria that I understand still look good with 4 10 inch ports.
I am not sure why I would want to limit the ports and am still learning that.
I appreciate your taking the time to comment. If you want to check in from time to time and offer an occasional comment, that would be appreciated, but I won't expect you to help me. Whatever works for you will work just fine for me.