im really late into the TH game, and i think im doing something wrong, and if im not, i need to learn how to fold/build this thing! this was my attempt at implementing the driver from a home theatre style ported box i never use for home theatre, into something a little more house party friendly.
this is with an ascendant audio atlas 15 driver (no longer in production
) on the low q setting, under 500 litre box(i think around 470 but for some strange reason the program isnt telling me anymore...help anyone?),
anyway, what am i doing wrong? cause this seems too good to be true( more than 105 db/w from 40-150hz in 1pi loading?!
).
if im not doing anything wrong, how do i build it?
this is with an ascendant audio atlas 15 driver (no longer in production
) on the low q setting, under 500 litre box(i think around 470 but for some strange reason the program isnt telling me anymore...help anyone?), anyway, what am i doing wrong? cause this seems too good to be true( more than 105 db/w from 40-150hz in 1pi loading?!
).if im not doing anything wrong, how do i build it?
Attachments
The inputted driver's specs are ludicrous for a 15" sub driver, especially when compared against these: http://www.soundsolutionsaudio.com/forum/index.php?showtopic=8323
It seems to be just some inputting errors though, so go back and input its Vas, Fs, Qes, Qms and let HR calc Cms, Mmd, BL, Rms to try again.
Also, the Lrc, Lpt, Atc inputs serve no purpose by themselves, so review the HELP file to see what you can do in the 'TH' mode with the bottom six fields.
Regardless, if you're pleased with your original sim, then it at least gives you a set of specs to try and find something 'close enough' to work as predicted. By extrapolation, it also gives you an idea what BW the Atlas works best in.
WRT folding, the object is to preserve the expansion through the bends. Otherwise, how you fold it up is your choice as there's no one 'right' way AFAIK.
GM
It seems to be just some inputting errors though, so go back and input its Vas, Fs, Qes, Qms and let HR calc Cms, Mmd, BL, Rms to try again.
Also, the Lrc, Lpt, Atc inputs serve no purpose by themselves, so review the HELP file to see what you can do in the 'TH' mode with the bottom six fields.
Regardless, if you're pleased with your original sim, then it at least gives you a set of specs to try and find something 'close enough' to work as predicted. By extrapolation, it also gives you an idea what BW the Atlas works best in.
WRT folding, the object is to preserve the expansion through the bends. Otherwise, how you fold it up is your choice as there's no one 'right' way AFAIK.
GM
ok, i have another design with the type of response i would like to achieve. but i cant figure out for the life of me how i would design this on paper, how do i put a horn around a bend, and have it keep a smooth expansion rate? it seems every sub i design is a colume, i want more of a box, but folding the 1st half 2 times seems to complex.
this program told me how i can make a 285cm long tapered tube that will give me the performance i want.
the more i poke around in this program the more i feel this is all way over my head, help me out guys, what am i doing wrong?
check out that frequency response with 2v applied, i must be doing something that defys the laws of physics again, this just seems impossable.
this program told me how i can make a 285cm long tapered tube that will give me the performance i want.
the more i poke around in this program the more i feel this is all way over my head, help me out guys, what am i doing wrong?
check out that frequency response with 2v applied, i must be doing something that defys the laws of physics again, this just seems impossable.
Attachments
That seems correct for the driver.
Not sure why this seems impossible.
That is a 600 Lt box with a 15" 13mm xmax driver. Thing would be to try to even out those 2 humps at least by half. Then if you corner loaded it should flatten out the rest of the way. Down into the upper 30 Hz region at 130 DB region. One hella house party sub. Though I go back to it being BIG. This isn't something you will throw into a car.
Van , perhaps depending on build.
Here's is a chart of a TH Mini clone I built
Mini Clone 2 The spike at the 200Hz isn't that profound in real life. I have 2 of those in my basement
and they sound great. That is 101 Lt each. Here is a 106 Lt version with inductance to get it flatter.Mini Clone
Th key to Live Sound is that of Max SPL
and you should measure at 2 Pi (which mine are BTW).
Not sure why this seems impossible.
That is a 600 Lt box with a 15" 13mm xmax driver. Thing would be to try to even out those 2 humps at least by half. Then if you corner loaded it should flatten out the rest of the way. Down into the upper 30 Hz region at 130 DB region. One hella house party sub. Though I go back to it being BIG. This isn't something you will throw into a car.
Van , perhaps depending on build.
Here's is a chart of a TH Mini clone I built
Mini Clone 2 The spike at the 200Hz isn't that profound in real life. I have 2 of those in my basement
and they sound great. That is 101 Lt each. Here is a 106 Lt version with inductance to get it flatter.Mini Clone
Th key to Live Sound is that of Max SPL
and you should measure at 2 Pi (which mine are BTW).
ahhhhhhh i read the hornresp help file a couple more times and now see that my thinking about this is very wrong, i seem to have a much better grasp of what the various parameters mean. and using a pen and some paper seem to have folded it to the best of my abilities (asked dad for some math help).
i will be building this unless anyone has anything else to add!
sorrry for being such a noob at this guys
i will be building this unless anyone has anything else to add!
sorrry for being such a noob at this guys
Attachments
http://www.diyaudio.com/forums/attachment.php?s=&postid=1598913&stamp=1220191730
What folding scheme did you use?
What folding scheme did you use?
one extremely similar to that one, i dont know if its 100% right though, i doubt it is, started with a 545 litre box, chose my width, and made it 105x105cm, so about 550l, then proceeded to try and place panels inside so that the surface area/distance remained as constant as possable. pretty much just fancy trial and error.
i havent been able to find a site with a step by step of someone folding their horn, but im sure theres some tips and tricks im missing.
im starting to greater understand the parameters now! s1-s2 is distance from the throat to the centre line of the driver, and 23-24 is centreline-mouth(is this corret?), and then s2-s3 is the big distance i need to"fold" to fit my size and shape of box yes?
i was previously under the impression that these controlled horn segment sizes, as opposed to that AND driver positioning.
once again, really sorry for the onslaught of questions and impossable simulations!
i havent been able to find a site with a step by step of someone folding their horn, but im sure theres some tips and tricks im missing.
im starting to greater understand the parameters now! s1-s2 is distance from the throat to the centre line of the driver, and 23-24 is centreline-mouth(is this corret?), and then s2-s3 is the big distance i need to"fold" to fit my size and shape of box yes?
i was previously under the impression that these controlled horn segment sizes, as opposed to that AND driver positioning.
once again, really sorry for the onslaught of questions and impossable simulations!
xstephanx
I simplify things by doing the throat and mouth to correct proportion and then just make sure the folds are expanding. I don't sweat that they are 100% exact. Also if you notice in jbell's diagram, corner wedges are missing. After lots of reading it just isn't needed. Though I would block brace those joints.
Also look up the Apache MK 1 and MK2.
Which JBells is close to.
I simplify things by doing the throat and mouth to correct proportion and then just make sure the folds are expanding. I don't sweat that they are 100% exact. Also if you notice in jbell's diagram, corner wedges are missing. After lots of reading it just isn't needed. Though I would block brace those joints.
Also look up the Apache MK 1 and MK2.
Which JBells is close to.
reagrding expansion rate: ok! that makes things alot easier!
i realised that s1-s2 can be a little shorter(down to 20cm for a 15" driver) as can s3-s4, so ive made them as short as possable (as this gives best response)
to get the line length i want in the volume i want, my best bet is to make one like j bells, however eliminating the first little expanding section so its just a big spiral.
maybe i can have this drawn up by tonight and built by tomorrow.
my deadline for this project(yes theres a deadline) is feb 14th, i plan to throw a little shindig in my living room(10x25'), and if the sims are correct its gonna be a pretty loud little shindig
also, if i use an edgeways 2x4 to brace the mouth(its going to be 90cm high, 50cm wide), will i need to factor that into my mouth area calculations? i get this feeling that it wont make much of an impact causeof the wavelengths this thing will be dealing with, but i could be wrong.
i realised that s1-s2 can be a little shorter(down to 20cm for a 15" driver) as can s3-s4, so ive made them as short as possable (as this gives best response)
to get the line length i want in the volume i want, my best bet is to make one like j bells, however eliminating the first little expanding section so its just a big spiral.
maybe i can have this drawn up by tonight and built by tomorrow.
my deadline for this project(yes theres a deadline) is feb 14th, i plan to throw a little shindig in my living room(10x25'), and if the sims are correct its gonna be a pretty loud little shindig
also, if i use an edgeways 2x4 to brace the mouth(its going to be 90cm high, 50cm wide), will i need to factor that into my mouth area calculations? i get this feeling that it wont make much of an impact causeof the wavelengths this thing will be dealing with, but i could be wrong.
xstephanx
For your purposes, No it wont matter. At that size I would brace it.
I assume its 35" tall by 20" wide. So a "+" brace would be good. Though I wouldn't use a 2x4. I would make something from the scraps you will have.
Should be able to make it in a day or 2.
If you don't have a table saw, you can build using only 90 degree cuts.
Even if you need to physically angle a board, that is fine. Just fill gap with caulking. You can even "step" the sections so there aren't any angles at all. Long as the throat, mouth, and length are correct and each segment is expanding. You will be good to go.
I will already predict the Cops being called.
Less you don't have neighbors. Or are in a a basement.
For your purposes, No it wont matter. At that size I would brace it.
I assume its 35" tall by 20" wide. So a "+" brace would be good. Though I wouldn't use a 2x4. I would make something from the scraps you will have.
Should be able to make it in a day or 2.
If you don't have a table saw, you can build using only 90 degree cuts.
Even if you need to physically angle a board, that is fine. Just fill gap with caulking. You can even "step" the sections so there aren't any angles at all. Long as the throat, mouth, and length are correct and each segment is expanding. You will be good to go.
I will already predict the Cops being called.
Less you don't have neighbors. Or are in a a basement.
Flipc
youre going to laugh, but as a teenager in suburbia, i am surrounded by old people with poor hearing, even when me and my friends would jam in the garage, with guitar amps cranked, ive never once had a noise complaint. although well see about 130db at 40hz in the living room...those long waves have a bad habit of going through barriers, and that room has two huge bay windows(one floor to cieling)
i have a table saw, and also a good circular saw, which i prefer to use with a saw board 90% of the time, i find that the coupling between the board and the saw is usually alot more rigid not to mention longer) than the fence on an entry level table saw.Not to mention i dont feel safe around table saws, if it was a milling machine on the other hand
caulking will be used, and i will brace the mouth in a cross with scraps, as per your reccomendation(with a little bit of thought its better than my idea)
Don, that method is what i tried to do last night, my approximation is made by calculating the line length so far, and making sure it corresponds with the surface area between the end of the board and the wall at the turn(does that make sense?)
thank you guys so much for all the help, its been too long since ive had an exciting speaker project on the go!
youre going to laugh, but as a teenager in suburbia, i am surrounded by old people with poor hearing, even when me and my friends would jam in the garage, with guitar amps cranked, ive never once had a noise complaint. although well see about 130db at 40hz in the living room...those long waves have a bad habit of going through barriers, and that room has two huge bay windows(one floor to cieling)
i have a table saw, and also a good circular saw, which i prefer to use with a saw board 90% of the time, i find that the coupling between the board and the saw is usually alot more rigid not to mention longer) than the fence on an entry level table saw.Not to mention i dont feel safe around table saws, if it was a milling machine on the other hand
caulking will be used, and i will brace the mouth in a cross with scraps, as per your reccomendation(with a little bit of thought its better than my idea)
Don, that method is what i tried to do last night, my approximation is made by calculating the line length so far, and making sure it corresponds with the surface area between the end of the board and the wall at the turn(does that make sense?)
thank you guys so much for all the help, its been too long since ive had an exciting speaker project on the go!
oh i dont think ill be able not to, at 585 litres this thing aint gonna be tiny!
also, i see alot fo tapped horns have a plate infront of the driver, with a hole that is < SD, is that supposed to be the same measurement as s-1? or do i not need it? whats going on with that thing?
things are slowly assembling in the basement for construction....caulking....coarse thread drywall screws... circ saw, only thing thats really missin is OSB!
also, i see alot fo tapped horns have a plate infront of the driver, with a hole that is < SD, is that supposed to be the same measurement as s-1? or do i not need it? whats going on with that thing?
things are slowly assembling in the basement for construction....caulking....coarse thread drywall screws... circ saw, only thing thats really missin is OSB!
OH and I wasn't suggesting you use OSB.
Unless you want to test first. That was for just a guy. Cheap way to build a test box. You want to use really good plywood. I would say MDF but at that size the weight saved from plywood will offset the cost.
As far the "have a plate in front of the driver"
goes. In HornResp look at your schematic diagram. See the area at the throat?
See how the driver is partially covered?
That is what this is. Sometime also it will be a compression chamber
before actual horn. But that is up to your design. The schematic gives you the dimensions. Though I wish you didn't have to mouse over things to get them. The compression is part of the throat so must be correct as possible.
Unless you want to test first. That was for just a guy. Cheap way to build a test box. You want to use really good plywood. I would say MDF but at that size the weight saved from plywood will offset the cost.
As far the "have a plate in front of the driver"
goes. In HornResp look at your schematic diagram. See the area at the throat?
An externally hosted image should be here but it was not working when we last tested it.
See how the driver is partially covered?
That is what this is. Sometime also it will be a compression chamber
before actual horn. But that is up to your design. The schematic gives you the dimensions. Though I wish you didn't have to mouse over things to get them. The compression is part of the throat so must be correct as possible.
you lost me a little there my schematic doesnt really look like that, the circles seem contained on either side. are you talking about how the "sides" of the horn create a chord going through the circle? and then the area of the opening infront of the driver would be equal to the area contained within the chords? this seems to be the only reasonable number i can generate out of that schematic
also, the OSB is due to cost, im out of school and currently still looking for a job, and this is only to hold me over at some houseparties until i build a real PA system(happening before the summer). in other words, the goal of this deisgn isnt so much great quality as great quantitiy between the critical range for electronic music (mainly electro/fidgit house) so as much energy as i can get between 40 and 120hz. before i stumbled on this tapped horn idea i was going to build a 6gth order bandpass, with 40 and 80hz tunings(holy groupdelay!) so id tend to think even an OSB TH would be better.
the osb is 15$ a sheet, the fir plywood is 40(!) they also have spruce plywood for 20 a sheet, but it has lots of voids in the plys, and i think id lose more SPL to that than i would losing it to some somewhat flexy OSB.
also ive heard a couple times that OSB is good for subwoofers, lots of people build IB manifolds out of it too.
mdf is a big no no, im not looking forward to the idea of a 200 lb+ box...
my schematic doesnt really look like that, the circles seem contained on either side. are you talking about how the "sides" of the horn create a chord going through the circle? and then the area of the opening infront of the driver would be equal to the area contained within the chords? this seems to be the only reasonable number i can generate out of that schematic also, the OSB is due to cost, im out of school and currently still looking for a job, and this is only to hold me over at some houseparties until i build a real PA system(happening before the summer). in other words, the goal of this deisgn isnt so much great quality as great quantitiy between the critical range for electronic music (mainly electro/fidgit house) so as much energy as i can get between 40 and 120hz. before i stumbled on this tapped horn idea i was going to build a 6gth order bandpass, with 40 and 80hz tunings(holy groupdelay!) so id tend to think even an OSB TH would be better.
the osb is 15$ a sheet, the fir plywood is 40(!) they also have spruce plywood for 20 a sheet, but it has lots of voids in the plys, and i think id lose more SPL to that than i would losing it to some somewhat flexy OSB.
also ive heard a couple times that OSB is good for subwoofers, lots of people build IB manifolds out of it too.
mdf is a big no no, im not looking forward to the idea of a 200 lb+ box...