Re: looks greek to me
The simpliest way to try to describe an irrational number is to say that if written as a fraction it never ends & it never repaets itself. Square roots (or any root) of a prime number, plus many other irrational numbers can be easily pulled off a calculator (even more if it is scientific). The golden ratio is based on a number that is approximately 1.618.
What is nice about these numbers is that if you use them you tend to get dimnsions that don't support resonances as well.
Let's say we have a 2x1x1 box. if we can establish a resonace across the 1 width then we will have another the same across the 1 depth and the 2 reinforce them. In this box the length is an integer (Whole numbers) multiple of the 1 dimensions (ie 2x1) so it also supports that same resonace.
So of the 3 big standing waves we have 2 at the same frequency that is reinforced by the 3rd. so we have 1 monster resonance peak. By shanging the lengths of the box so that none are integer mulriples of one another we can spread the 3 resonances out and decrease their peaks.
An irrational number is just one that most of the time helps spread the resonances out in a nice non-uniform way (well most of the time -- a box with ratio (1/sqrt(2):1:sqrt(2)) ends up being 1:1.414159:2).
roystr said:
The simpliest way to try to describe an irrational number is to say that if written as a fraction it never ends & it never repaets itself. Square roots (or any root) of a prime number, plus many other irrational numbers can be easily pulled off a calculator (even more if it is scientific). The golden ratio is based on a number that is approximately 1.618.
What is nice about these numbers is that if you use them you tend to get dimnsions that don't support resonances as well.
Let's say we have a 2x1x1 box. if we can establish a resonace across the 1 width then we will have another the same across the 1 depth and the 2 reinforce them. In this box the length is an integer (Whole numbers) multiple of the 1 dimensions (ie 2x1) so it also supports that same resonace.
So of the 3 big standing waves we have 2 at the same frequency that is reinforced by the 3rd. so we have 1 monster resonance peak. By shanging the lengths of the box so that none are integer mulriples of one another we can spread the 3 resonances out and decrease their peaks.
An irrational number is just one that most of the time helps spread the resonances out in a nice non-uniform way (well most of the time -- a box with ratio (1/sqrt(2):1:sqrt(2)) ends up being 1:1.414159:2).
Re: looks greek to me
While the DIY-loudspeaker dialect of 'Audiospeak' might sound obscure and like Greek to you, there is one thing you can be sure of: As with Greek itself, it's just the language, not the concepts. If a couple of Greeks talk about a basketball banking off the backboard, taking a turn around the rim, and going through the hoop, that will definitely sound like Greek—but it's just basketball.
I agree with you that there certainly could be more concept-clarifying and term-defining literature available to hobbiests—and maybe there is, and somebody will turn us both onto it, or maybe its day is coming. In any case, I thought you might find this Audio Glossary at DIY Audio Corner helpful in the meantime. I did.
Best of success to you,
Don
roystr said:
While the DIY-loudspeaker dialect of 'Audiospeak' might sound obscure and like Greek to you, there is one thing you can be sure of: As with Greek itself, it's just the language, not the concepts. If a couple of Greeks talk about a basketball banking off the backboard, taking a turn around the rim, and going through the hoop, that will definitely sound like Greek—but it's just basketball.
I agree with you that there certainly could be more concept-clarifying and term-defining literature available to hobbiests—and maybe there is, and somebody will turn us both onto it, or maybe its day is coming. In any case, I thought you might find this Audio Glossary at DIY Audio Corner helpful in the meantime. I did.
Best of success to you,
Don
The 126 seems to be imbalanced when you look at the frequency response, but it definitely works in the suggested horn/BR enclosure, and it has a higher sensitivity than the 127.
thanks guys.
and the link to the glossery was a good read as well.
the thing is,to me its not the words so much as all the math. math,ratios,...then you got "fs" and "qes" and the rest. i have read the deffinitions of a few of them,,, but in my mind i have no idea what they mean in relation to each other.
thanx anyways,,,eventualy ill get the hang of it.
peace,
roy
and the link to the glossery was a good read as well.
the thing is,to me its not the words so much as all the math. math,ratios,...then you got "fs" and "qes" and the rest. i have read the deffinitions of a few of them,,, but in my mind i have no idea what they mean in relation to each other.
thanx anyways,,,eventualy ill get the hang of it.
peace,
roy
Quick question.
Has anyone built the folded monopole cabinet design on post #70 or #131? I'll be using a sub for lower enhancement and I was wondering which one would be better with a sub.
http://www.diyaudio.com/forums/attachment.php?s=&postid=526880&stamp=1102221644
http://www.diyaudio.com/forums/attachment.php?s=&postid=528487&stamp=1102449671
Has anyone built the folded monopole cabinet design on post #70 or #131? I'll be using a sub for lower enhancement and I was wondering which one would be better with a sub.
http://www.diyaudio.com/forums/attachment.php?s=&postid=526880&stamp=1102221644
http://www.diyaudio.com/forums/attachment.php?s=&postid=528487&stamp=1102449671
http://www.billfitzmaurice.com/plan...id/11?osCsid=cacb11493dfe060d42745363fc9b3e17
This is economical and extends pretty well. But will a horn sub have a delay due to the path it travels to get to the mouth of the enclosure? Is this even something I should be concerned with?
Thanks for everyones input on this thread. Not just my personal question but the entire project.
This is economical and extends pretty well. But will a horn sub have a delay due to the path it travels to get to the mouth of the enclosure? Is this even something I should be concerned with?
Thanks for everyones input on this thread. Not just my personal question but the entire project.
I think I'd more likely go with a sealed box, perhaps even a bipole sealed box. A dipole would be nice although it would probably have to be fairly large.
Dave,
Perfect timing, thanks. I was just looking around to figure out what box to try my 127's in just to have a reference as a double check to make sure I'm not off course in my OB pursuits.
Perfect timing, thanks. I was just looking around to figure out what box to try my 127's in just to have a reference as a double check to make sure I'm not off course in my OB pursuits.
johninCR said:
🙂
It came about because Chris & i were trying to figure what to do with the single pair of FE127s we have after killing 6 of them....
dave
May I ask what was the cause of death? I only have 1 pair and would like to keep them out of the graveyard. Did you come up with any easy cone or dustcap mods that were effective? Puzzlecoat, etc.?
johninCR said:
4 died while cleaning up after dustcap removal... we will not be producing a phase plug for FE126/127e (and the same problem likely exists for FE103E) see http://www.planet10-hifi.com/fe127.html.
The other 2 died from the failure of 1 channel of a miniA (bipoles). Voice coils glowing orange in the dark. They didn't like the full rail across them.
dave
glow in the dark
Jason - if you're watching, the ball's in your court. Even after repairing the previous damage, there's till something not quite right with the mini. It's currently at the mounain retreat - talk to Dave.
Jason - if you're watching, the ball's in your court. Even after repairing the previous damage, there's till something not quite right with the mini. It's currently at the mounain retreat - talk to Dave.
Dead Mini A
Hello Chris Dave and others:
Fe127
Thanks for the nice comments on my Fe127 folded mono. I have not heard them for a while. The last time I heard them I was very impressed with quality of the mid range. The vocals were excellent and the high range was very smooth. Yah they are a little thin on the bass, no big deal though. I have a sub that we integrated into them to bring up the bottom end. For 2 channel audio I like them.
I am watching this Mini A concern closely.
I am just in the final stages of completing my own mini A. I spent the weekend finishing off the cabinetry for the casing. I thought I had done a pretty good job. I took it upstairs to show my wife. I asked her what she thought and she looked at the floor, shuffled around a bit, avoided eye contact, and said " It looks nice.... Well actually it looks like a microwave oven." Crushed, I returned to my lonely work shop to try another approach. Maybe this time it will look like a toaster or some other kitchen appliance!
I think I will wait a little while before firing this one up. I hope you get the problem figured out. Please keep me in the loop.
Good luck
Hello Chris Dave and others:
Fe127
Thanks for the nice comments on my Fe127 folded mono. I have not heard them for a while. The last time I heard them I was very impressed with quality of the mid range. The vocals were excellent and the high range was very smooth. Yah they are a little thin on the bass, no big deal though. I have a sub that we integrated into them to bring up the bottom end. For 2 channel audio I like them.
I am watching this Mini A concern closely.
I am just in the final stages of completing my own mini A. I spent the weekend finishing off the cabinetry for the casing. I thought I had done a pretty good job. I took it upstairs to show my wife. I asked her what she thought and she looked at the floor, shuffled around a bit, avoided eye contact, and said " It looks nice.... Well actually it looks like a microwave oven." Crushed, I returned to my lonely work shop to try another approach. Maybe this time it will look like a toaster or some other kitchen appliance!
I think I will wait a little while before firing this one up. I hope you get the problem figured out. Please keep me in the loop.
Good luck
You must show her pictures of other amplifiers until she warms up to a few of them, and then integrate the design features or at least imitate them somewhat, or else you may have a series of those incidents!
After seeing Zaph's latest TMM with waveguide design over in the loudspeaker forum, I'm wondering if some type of waveguide would be beneficial with the 127 to clean up the top end. I was already planning to add a piece of hardwood in front of the driver, but can the shape of the front edge taper of the drive cutout make a beneficial difference? If so, how can I figure out the best shape?