Just a few more notes - any design is a balancing act between the desired frequency response and tuning vs size vs excursion vs power handling. With high excursion drivers of this type that only have moderate power handling, if you want to use up all the usable excursion within the limits of the rated power handling you need a very large box with a very low tuning.
And although I said it before, this is important. These sims will NOT match measurements unless you adjust the sim to account for the large voice coil, which effectively reduces motor strength. At 431 liters as shown this box is already too small and/or tuned too high to use up all the usable excursion, when you adjust Bl to make the sim a bit more realistic it's going to be WAY too small. The alignment tables are a good guide but were not made to account for drivers of this type.
And also you could use the t/s parameters as measured at data-bass as these might be more accurate than the published specs. Or you could look around avs forum to see if other users have measured it. Published specs are not always accurate.
Also, in the last post I listed Cyclops as 340 liters and Submaximus as 1075 liters. Those are external dimensions which include the wood. The 430 liter tl as simulated was internal measurement not including wood. And just to repeat one more time - it's really too small, it should be larger. In fact ALL the designs mentioned (Cyclops, Submaximus and the simulated tl) would all benefit from being larger, in some cases quite a bit larger.
And although I said it before, this is important. These sims will NOT match measurements unless you adjust the sim to account for the large voice coil, which effectively reduces motor strength. At 431 liters as shown this box is already too small and/or tuned too high to use up all the usable excursion, when you adjust Bl to make the sim a bit more realistic it's going to be WAY too small. The alignment tables are a good guide but were not made to account for drivers of this type.
And also you could use the t/s parameters as measured at data-bass as these might be more accurate than the published specs. Or you could look around avs forum to see if other users have measured it. Published specs are not always accurate.
Also, in the last post I listed Cyclops as 340 liters and Submaximus as 1075 liters. Those are external dimensions which include the wood. The 430 liter tl as simulated was internal measurement not including wood. And just to repeat one more time - it's really too small, it should be larger. In fact ALL the designs mentioned (Cyclops, Submaximus and the simulated tl) would all benefit from being larger, in some cases quite a bit larger.
Too late to edit but that should say orange. The design details are output in orange.
(Yellow is the stuff you don't want to mess with unless you really know what you are doing and have a really good reason.)
Oops, another mistake, I really should pay attention to what I'm doing. The actual line length (in orange) is 492.1 cm, not 502. 502 is the effective length.
The sims I did used 502 but the 10 cm difference doesn't make any appreciable difference in the sim. I just wanted to clear up any confusion I may have caused and make sure that you knew the outputs were in orange so that's the dimensions you would use in a sim and in a build. The effective length is only given as extra info about the mouth effect adding a bit of virtual length, not something you need to know really for sim or build purposes.
thanks Just A Guy,
I posted the work my friend did but i didn't know that it did not show the formula. the terms or abbreviations were things he named them like "opening" which refers to the area of the port. the video we based the formula on was based off of the Jon Risch design process. in the video he broke it down and simplified it. the 2 Y= numbers were the length of the port and the frequency cross.
I originally was going to build a ported enclosure called the Full marty that is a proven design but My cabinet maker butchered the enclosures and i became frustrated and started looking at other options and for a different cabinetmaker.
I am not researching TL's because of a "garbage claim". I first heard a tl enclosure over 20yrs ago it a pickup truck with a single 8" woofer that blew my mind. I do not have a ton of chances to audition speakers with this design. the "garbage site" i found the formula we used, it was on youtube and it's title was "Transmission line speaker box math made easy" by Backyard Amusement. it didn't seem like bad information but again everything I read comes off as confusing, the pages that have been mentioned to me to read start right off the bat with terms that are not already mentioned so i was lost before i even started. I may have to wait this out until my head is clear, my Wife has been in the hospital with pneumonia for over a week and my head probably isn't clear. I will try to get everything that i do understand on paper so i can make something of it.
I posted the work my friend did but i didn't know that it did not show the formula. the terms or abbreviations were things he named them like "opening" which refers to the area of the port. the video we based the formula on was based off of the Jon Risch design process. in the video he broke it down and simplified it. the 2 Y= numbers were the length of the port and the frequency cross.
I originally was going to build a ported enclosure called the Full marty that is a proven design but My cabinet maker butchered the enclosures and i became frustrated and started looking at other options and for a different cabinetmaker.
I am not researching TL's because of a "garbage claim". I first heard a tl enclosure over 20yrs ago it a pickup truck with a single 8" woofer that blew my mind. I do not have a ton of chances to audition speakers with this design. the "garbage site" i found the formula we used, it was on youtube and it's title was "Transmission line speaker box math made easy" by Backyard Amusement. it didn't seem like bad information but again everything I read comes off as confusing, the pages that have been mentioned to me to read start right off the bat with terms that are not already mentioned so i was lost before i even started. I may have to wait this out until my head is clear, my Wife has been in the hospital with pneumonia for over a week and my head probably isn't clear. I will try to get everything that i do understand on paper so i can make something of it.
Yeah, having a seriously ill loved one does tend to preoccupy us to the point of distraction, so strongly recommend 'taking a breather' for now and hope she has a speedy recovery.
'We' will still be here once you're clear headed enough to 'spell out' what is 'stopping you in your tracks', allowing us to educate you as required one point at a time as you progress since this really does seem to be a pretty complicated/intimidating 'science'/'hobby' until at some point in the learning curve it starts making sense; then you wonder why it seemed so complicated as the fundamentals of the 'physics of the situation' really are quite simple, just the underlying math is complex, but the software programs do all that for us math challenged types.
GM
'We' will still be here once you're clear headed enough to 'spell out' what is 'stopping you in your tracks', allowing us to educate you as required one point at a time as you progress since this really does seem to be a pretty complicated/intimidating 'science'/'hobby' until at some point in the learning curve it starts making sense; then you wonder why it seemed so complicated as the fundamentals of the 'physics of the situation' really are quite simple, just the underlying math is complex, but the software programs do all that for us math challenged types.
GM
Yes, learning while a loved one is in the hospital can be very difficult.
While some of us make this seem easy, the ones that know what they are doing have studied this stuff for years.
Anyway, the video "Transmission Speaker Box Math Made Easy" is unfortunately garbage. And ironically there's a lot more math in that video than the REQUIRED single formula in MJK's alignment tables. I didn't see the part where he talked about 4 chambers and ports (none of that exists in straight tl design) I only watched the first minute or so, and he mentions this webpage.
http://www.t-linespeakers.org/design/classic.html
So I read that page, it's a lot quicker than watching the video. In the video he says all his calculations came from this webpage. This is the old way of designing tls and the statement "The classic transmission line bass enclosure has never been completely and successfully modeled such that it can be built from a pat set of equations." is simply untrue.
The most important information on that page is right at the top in red - Editor's Note: This methodolgy is obselete and here for historical purposes. And it gives a link to an updated page.
Transmission Line Speakers Read Me
And on this page it talks about MJK's work and links to the same MJK website that we have been telling you about, the site with the Alignment Tables article and spreadsheet.
So now we have gone full circle and are right back at MJK's Alignment Tables.
WRT your tl experience 20 years ago, a tl will not perform significantly better than a ported box. If it had been a ported box in the pickup 20 years ago it would have performed in similar fashion (unless the "impressive" part was massive undamped tl peaks emphasizing certain notes, which is a design flaw, not a feature).
The Full Marty I believe is even bigger than the Cyclops, so it would be a naturally better choice, maybe your best option. If there is any way to salvage the enclosure that is definitely where I would start, after all, it's a big ported box, it's exactly what you need and you already paid for the wood.
Take care of your family first, the info is all here and it's not going anywhere.
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