The corrections above 200 are to be applied to the port output. Thus reducing the abnormalities displayed in the simmed system response.
The first tlp file posted was for the OEM spec's, the second one is for Zaph's measurements.
Wasn't commenting about you or anyone else whom knows how to properly design a wide band TL. xrk971 and many others I see applying TL design incorrectly, especially for sub design that I was speaking to.
What I find saddening is that while I'll model anything and everything some think that they are above this, demanding proof first. Perhaps something was missed. When I see a strong 2nd harmonic in a response curve, something IS wrong with the design that I was commenting on. How this applies to the port Q / position of the driver is relevant. I won't be placing any driver at 20% length because unless you use a very long high Q port that position is simply wrong. If I wanted to design a long BR speaker I'd have a long port. The end result would be a steeper cutoff below port frequency. Have to ask what would the benefit of that be. Not as clean due to the ringing that's for sure eg why we like TL's over BR designs.
The first tlp file posted was for the OEM spec's, the second one is for Zaph's measurements.
Wasn't commenting about you or anyone else whom knows how to properly design a wide band TL. xrk971 and many others I see applying TL design incorrectly, especially for sub design that I was speaking to.
What I find saddening is that while I'll model anything and everything some think that they are above this, demanding proof first. Perhaps something was missed. When I see a strong 2nd harmonic in a response curve, something IS wrong with the design that I was commenting on. How this applies to the port Q / position of the driver is relevant. I won't be placing any driver at 20% length because unless you use a very long high Q port that position is simply wrong. If I wanted to design a long BR speaker I'd have a long port. The end result would be a steeper cutoff below port frequency. Have to ask what would the benefit of that be. Not as clean due to the ringing that's for sure eg why we like TL's over BR designs.
X, I want to run AKABAK. It would not be wrong for you to ask me to, tho at this time I cannot
Simply want to see you do the best you can. You've got a good head on your shoulders and an eagrerness to learn, it's just alot of territory to cover getting all this wrapped around our heads
It's not my intent to bash you or anyone else, we have good communications elsewhere, like the gel speaker. Need to respond more to that one, not here
I did load the software but I couldn't do anything with it.
Paul
Edit: Nope, I've never designed an antenna or anything particularly of an RF bent, but I have designed key parts of a very special ventilator for saving the lives of premature babies, which later was improved and expanded to be able to also treat children and adults, and I've designed many parts of medical equipment used to analyze and recommend treatment for pulmonary diseases and sleep disorders. Besides having a BSEE, I sought and achieved approvals from the FDA and similar regulatory agencies around the world for numerous medical devices. Talk about having to be very complete in describing what a device does and how it does it while providing easily understood and complete proof of its performance and efficacy! Just like you. speaker design and building is just a hobby, but I've only been doing it for about 20 years, so I guess I still have much to learn.
Paul
Paul
Edit: Nope, I've never designed an antenna or anything particularly of an RF bent, but I have designed key parts of a very special ventilator for saving the lives of premature babies, which later was improved and expanded to be able to also treat children and adults, and I've designed many parts of medical equipment used to analyze and recommend treatment for pulmonary diseases and sleep disorders. Besides having a BSEE, I sought and achieved approvals from the FDA and similar regulatory agencies around the world for numerous medical devices. Talk about having to be very complete in describing what a device does and how it does it while providing easily understood and complete proof of its performance and efficacy! Just like you. speaker design and building is just a hobby, but I've only been doing it for about 20 years, so I guess I still have much to learn.
Paul
And I supplied the TLP file to hand you EVERYTHING! Yawn
Now while I'm still working out why I can't run what you are, don't see any reason under the sun why you cannot oblige me with installing the software yourself and opening the TLP file and read the thread. But I digress, this wasn't something you would do if your life depended on it.
So I was in fact correct to think that this wasn't about having an intelligent conversation. Instead you did take what was said in "general" personally. With that "I'll take this guy down" and nit pick everything to death just to show how much a twit he is. LOL
LOAD the software, open the file, apply the corrections and comment on the merits or the lack of. 25-35 years ago demanding such caca would have gotten you laughed out of the park. Sure I'll whip out my trusty ol Ti59 and the program cards load up the software I wrote back then and post a hand made connect the dots graph. Would that be better?! Suppose you would come off with some lame comment that the calculator wasn't as good as a HP41c or some such
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It would have been nice if you had made it clear about where the corrections were to be applied when you posted them. How is one to otherwise know if they're using an unfamiliar and unfinished software and containing bugs?
Exactly where in my posted response graphs did you see strong 2nd-harmonic effects and how did they hamper the performance? You still have not made your case about ports' aspect ratios and Q satisfactorily, yet you keep yammering about it.
As far as subs are concerned I have absolutely no need or desire for a subwoofer, and I'd consider it a waste of time to design a TL for one. There's virtually no content in music below 30 Hz, special effects and other noise excluded, and there's not a whole lot between 30 and 40 Hz, either.
The truly sad thing is claims being made without any explanation or description at the same time on how or why, and then not following up with easy to view and understand graphical documentation.
Exactly where in my posted response graphs did you see strong 2nd-harmonic effects and how did they hamper the performance? You still have not made your case about ports' aspect ratios and Q satisfactorily, yet you keep yammering about it.
As far as subs are concerned I have absolutely no need or desire for a subwoofer, and I'd consider it a waste of time to design a TL for one. There's virtually no content in music below 30 Hz, special effects and other noise excluded, and there's not a whole lot between 30 and 40 Hz, either.
The truly sad thing is claims being made without any explanation or description at the same time on how or why, and then not following up with easy to view and understand graphical documentation.
If you read up on (or you may already be familiar with) theory on acoustic pipe/resonator systems (like for HVAC, or auto exhaust, etc.) the chamber behind the driver has a low pass function and can be tuned in terms of its size and dimensions to adjust the frequency of the filtering. You should be able to model this using Augspurger's model or something similar that is more contemporary. This should be better than bends alone. In TL systems the chamber behind the driver must be larger in cross section than driver Sd, then a smaller line at about Sd leads to the line, which can be tapered. A straight pipe is another matter, and I believe that this has some significant disadvantages... all of this is a little murky in my memory at this point, but I thought I would throw it out there as a point of discussion.
-Charlie
-Charlie
I dug up some references that I saved at one time when I was looking into TLs and such. Might be helpful to you or others reading this thread:
Links related to TL that are helpful...
From: Transmission Line Theory
http://www.quarter-wave.com/TLs/TL_Anatomy.pdf
http://www.quarter-wave.com/TLs/Advanced_Models.pdf
http://www.quarter-wave.com/TLs/Calculation_Algorithm.pdf
Augspurger's Work:
http://documents.jordan-usa.com/Famous-Articles/Augspurger-Loudspeakers-on-Damped-Pipes.pdf
Brine Acoustics TL Hints (driver at L=0.5):
Quarter_Wave_Resonators
Linkwitz:
H-U frame woofers
Music and Design:
NaO U-frame
DIY-dipole-1
http://www.musicanddesign.com/images/olson.gif
A Thesis on the modeling of damping in TLs:
AN ELECTROACOUSTIC ANALYSIS OF TRANSMISSION LINE LOUDSPEAKERS
A Dissertation Presented to The Academic Faculty by
Robert Allen Robinson, Jr.
In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in Electrical Engineering
School of Electrical and Computer Engineering
Georgia Institute of Technology
May 2007
Links related to TL that are helpful...
From: Transmission Line Theory
http://www.quarter-wave.com/TLs/TL_Anatomy.pdf
http://www.quarter-wave.com/TLs/Advanced_Models.pdf
http://www.quarter-wave.com/TLs/Calculation_Algorithm.pdf
Augspurger's Work:
http://documents.jordan-usa.com/Famous-Articles/Augspurger-Loudspeakers-on-Damped-Pipes.pdf
Brine Acoustics TL Hints (driver at L=0.5):
Quarter_Wave_Resonators
Linkwitz:
H-U frame woofers
Music and Design:
NaO U-frame
DIY-dipole-1
http://www.musicanddesign.com/images/olson.gif
A Thesis on the modeling of damping in TLs:
AN ELECTROACOUSTIC ANALYSIS OF TRANSMISSION LINE LOUDSPEAKERS
A Dissertation Presented to The Academic Faculty by
Robert Allen Robinson, Jr.
In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in Electrical Engineering
School of Electrical and Computer Engineering
Georgia Institute of Technology
May 2007
I think Martin King's work is tatamount to a Phd thesis. Very comprehensive and thorough.
The OP is basically going down the road travelled by Augspurger. His AES paper pretty much sums up ways to flatten the response and identifies stuffing materials and densities to accomplish this.
However, I admire DrBoar's efforts here to experiment and find out things for himself. As a Sigma-Xi member, I fully understand the impetus to explore. I've done my share and intend to do more.
Paul, think we only got off on the wrong foot. If you don't want or need sub tl then that's fine. Don't blow it off because you personally see no reason for one. I assumed incorrectly that you had experience with LATL to make an informed opinion. If not simply reading the thread should have someone with your experience level up to speed in no time.
The current design I'm working on requires a upper extension upto ~200. This is then handed off to identical drivers in an MTM. By removing the low frequency energy from the mid drivers I'll eliminate doppler / FM distortion, at the same time will reduce the difference in acoustic character and the timbre remains the same. So I figured might as well discover what all could be done, what are the variables, how do they affect each other. This was after reading most of the links Charlie posted (thx C and many many many more. Compared the results of what known good designs behave like and modeled them. If what they did matches, how much error is there really?
Now I have stated the software has issues, it is beta after all. Never seen a beta software without issues. It has limitations we'd like to see included etc. When schmeet comes back to planet earth hope he'll have the time to resolve. Until then we wait, he's done a great job so far IMO and many others agree.
The current design I'm working on requires a upper extension upto ~200. This is then handed off to identical drivers in an MTM. By removing the low frequency energy from the mid drivers I'll eliminate doppler / FM distortion, at the same time will reduce the difference in acoustic character and the timbre remains the same. So I figured might as well discover what all could be done, what are the variables, how do they affect each other. This was after reading most of the links Charlie posted (thx C
and many many many more. Compared the results of what known good designs behave like and modeled them. If what they did matches, how much error is there really? Now I have stated the software has issues, it is beta after all. Never seen a beta software without issues. It has limitations we'd like to see included etc. When schmeet comes back to planet earth hope he'll have the time to resolve. Until then we wait, he's done a great job so far IMO and many others agree.
Although I used Augspurger's alignment tables early in my TL experimentation and learning (and found a mistake in them BTW that George acknowledged) but not his software, the only modeling software I use is Martin's. It's become second nature to me with all the modeling and building I've done and I can't surmise needing anything more. So, I guess I'm prejudiced as well as spoiled.
Paul
Paul
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You're essentially talking about a TL, which can be straight or tapered, appended to a coupling chamber housing the driver. Augspurger recommended the coupling chamber to comprise ~1/3 of the total volume. I've modeled as well as built one or two variations on these and they can work quite well.
Paul
Paul
We sure did! What you described in your second paragraph is still a 3-way system that you've chosen to cross at ~200 Hz, not really a subwoofer. Nothing wrong with that but I try to discourage people from using TLs for true subwoofer duty unless they won't mind the sheer size that will usually be necessary for IMO very little, if any advantage. I will use a TL every chance I get because the sound from a TL-based system really is good.
Because you're about 20 years my junior, you had an advantage in being able to use computerized tools through much more of your working life. I never even touched a computer keyboard until 1995, then retired 8 years later. I like having a computer, the internet, this hobby and these forums, but my pertinent abilities and knowledge lag behind many others. Asking me to use unfinished software with bugs and to apply corrections factors first isn't likely to have good results.
Paul
Because you're about 20 years my junior, you had an advantage in being able to use computerized tools through much more of your working life. I never even touched a computer keyboard until 1995, then retired 8 years later. I like having a computer, the internet, this hobby and these forums, but my pertinent abilities and knowledge lag behind many others. Asking me to use unfinished software with bugs and to apply corrections factors first isn't likely to have good results.
Paul
Paul, think we only got off on the wrong foot. If you don't want or need sub tl then that's fine. Don't blow it off because you personally see no reason for one. I assumed incorrectly that you had experience with LATL to make an informed opinion. If not simply reading the thread should have someone with your experience level up to speed in no time.
The current design I'm working on requires a upper extension upto ~200. This is then handed off to identical drivers in an MTM. By removing the low frequency energy from the mid drivers I'll eliminate doppler / FM distortion, at the same time will reduce the difference in acoustic character and the timbre remains the same. So I figured might as well discover what all could be done, what are the variables, how do they affect each other. This was after reading most of the links Charlie posted (thx C
Now I have stated the software has issues, it is beta after all. Never seen a beta software without issues. It has limitations we'd like to see included etc. When schmeet comes back to planet earth hope he'll have the time to resolve. Until then we wait, he's done a great job so far IMO and many others agree.
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