Ladies and Gentleman, I'm looking for help...
I've bought some Fostex FE167E drivers and im now trying to design a cabinet to put them in. Let me add that im a beginner!
I was originaly intending to use the fostex recomended enclosure but ive been told that it maybe too small. Plus ive noticed bob brines uses a larger enclosure (his smallest is 24L i think) and ive been told from anouther site of someone using a 21L enclosure with success.
So ive decided to use a 21 L enclosure, make it tall and thin (for aesthetics).
I entend to use baffle step correction compensation too.
Ive attached a pic of my plans so far and im looking for criticism, help, ideas, etc....
Any help will be much appreciated.
Thanks.
Wella
I've bought some Fostex FE167E drivers and im now trying to design a cabinet to put them in. Let me add that im a beginner!
I was originaly intending to use the fostex recomended enclosure but ive been told that it maybe too small. Plus ive noticed bob brines uses a larger enclosure (his smallest is 24L i think) and ive been told from anouther site of someone using a 21L enclosure with success.
So ive decided to use a 21 L enclosure, make it tall and thin (for aesthetics).
I entend to use baffle step correction compensation too.
Ive attached a pic of my plans so far and im looking for criticism, help, ideas, etc....
Any help will be much appreciated.
Thanks.
Wella
the pic
the pic
the pic
An externally hosted image should be here but it was not working when we last tested it.
Attachments
Hi,
the tuning and all looks alright.
I think you got messed up with internal/external measures of the speaker? 560*170*220 should be internal right?
Have a look here for some inspiration. (should be ~20l+ as well)
I built the 15l-recommended and well the tuning is alright but yes for most recordings a bit on the thin side when it comes to bass.
I´ll be either complementing with stereo subs or building a ML-TL ala Bob Brines FT1600. Building a stand for a bookshelf or building a bigger speaker in the first place is no big difference is it?
greets&happy listening
the tuning and all looks alright.
I think you got messed up with internal/external measures of the speaker? 560*170*220 should be internal right?
Have a look here for some inspiration. (should be ~20l+ as well)
I built the 15l-recommended and well the tuning is alright but yes for most recordings a bit on the thin side when it comes to bass.
I´ll be either complementing with stereo subs or building a ML-TL ala Bob Brines FT1600. Building a stand for a bookshelf or building a bigger speaker in the first place is no big difference is it?
greets&happy listening
Greets!
Hmm, tall and thin, eh? Since even most old vinyl has strong content to 40 Hz, this seems the 'no-brainer' Fb choice to me, so using your 374 cm^2 (~57.97"^2) CSA (cross sectional area):
L = 50.375"
zdriver = 17.375"
zport = bottom exit
rp = 1.5"
Lp = 2"
Space it up off a massive plinth as required to get it to ear level. With 2-3 ohms series resistance/BSC it should be solid to 40 Hz at modest SPLs if not placed too far out into a large room.
GM
Hmm, tall and thin, eh? Since even most old vinyl has strong content to 40 Hz, this seems the 'no-brainer' Fb choice to me, so using your 374 cm^2 (~57.97"^2) CSA (cross sectional area):
L = 50.375"
zdriver = 17.375"
zport = bottom exit
rp = 1.5"
Lp = 2"
Space it up off a massive plinth as required to get it to ear level. With 2-3 ohms series resistance/BSC it should be solid to 40 Hz at modest SPLs if not placed too far out into a large room.
GM
ok you lost me there,
Sorry GM but im new to this and you kind of lost me... Infact you completerly lost me...
Hmm, tall and thin, eh? Since even most old vinyl has strong content to 40 Hz, this seems the 'no-brainer' Fb choice to me, so using your 374 cm^2 (~57.97"^2) CSA (cross sectional area): The cross sectional area of what is 374 cm^2. Are you saying that it has to be tall and thin or that it doesnt. Im sorry but without understanding the math your "no brainer" isnt clear to me...
L = 50.375"
zdriver = 17.375"
zport = bottom exit
rp = 1.5"
Lp = 2"
: Yep you got me there too im afraid. Im now 100% lost
Sorry for my ignorance, im very new to this but wanting to learn.
Paul
Sorry GM but im new to this and you kind of lost me... Infact you completerly lost me...
Hmm, tall and thin, eh? Since even most old vinyl has strong content to 40 Hz, this seems the 'no-brainer' Fb choice to me, so using your 374 cm^2 (~57.97"^2) CSA (cross sectional area): The cross sectional area of what is 374 cm^2. Are you saying that it has to be tall and thin or that it doesnt. Im sorry but without understanding the math your "no brainer" isnt clear to me...
L = 50.375"
zdriver = 17.375"
zport = bottom exit
rp = 1.5"
Lp = 2"
: Yep you got me there too im afraid. Im now 100% lost
Sorry for my ignorance, im very new to this but wanting to learn.
Paul
I guess from your picture GM thought you like the enclosure to be tall and thin.
The values given mean:
L: inner lenght of the enclosure
zdriver: position of the driver measured from the top
zport: position of the port measured from the top(here:50.375")
rp: radius of the port
lp: lenght port
Cross-sectional-areawide*depth)
(S0/SL in the drawing below)
have a look here for a better understanding:
(and the whole webpage if you wish:http://www.quarter-wave.com/)
http://www.quarter-wave.com/Models/Box_App_Notes.pdf
greets
The values given mean:
L: inner lenght of the enclosure
zdriver: position of the driver measured from the top
zport: position of the port measured from the top(here:50.375")
rp: radius of the port
lp: lenght port
Cross-sectional-area
wide*depth)(S0/SL in the drawing below)
have a look here for a better understanding:
(and the whole webpage if you wish:http://www.quarter-wave.com/)
http://www.quarter-wave.com/Models/Box_App_Notes.pdf
greets
Greets!
No need to apologize! I see Jens explained what it all means. Your first post 'sounded' like you had at least some knowledge of speaker design and since you had done some research I assumed you had at least been exposed to MJK's MathCad WS and many of the various pipe designs already documented on the various forums/personal websites.
Studying everything on MJK's and Bob Brine's site is a great start!
No, it doesn't, but you both stated a desire for and depicted a tall/thin design, but in reality it's a typical ~small box speaker with a massive 'stand' attached. My suggestion OTOH is a true tall/thin pipe design that will perform somewhat better down low one optimized with either some series resistance and/or BSC and typically 'sounds' subjectively 'tighter'.
Hmm, this indicates to me that you're really not interested in learning about speaker design or building a true tall/thin (pipe) speaker, but just looking for some validation of your design, which Jens has already done, so build and enjoy.
GM
No need to apologize! I see Jens explained what it all means. Your first post 'sounded' like you had at least some knowledge of speaker design and since you had done some research I assumed you had at least been exposed to MJK's MathCad WS and many of the various pipe designs already documented on the various forums/personal websites.
Studying everything on MJK's and Bob Brine's site is a great start!
No, it doesn't, but you both stated a desire for and depicted a tall/thin design, but in reality it's a typical ~small box speaker with a massive 'stand' attached. My suggestion OTOH is a true tall/thin pipe design that will perform somewhat better down low one optimized with either some series resistance and/or BSC and typically 'sounds' subjectively 'tighter'.
Hmm, this indicates to me that you're really not interested in learning about speaker design or building a true tall/thin (pipe) speaker, but just looking for some validation of your design, which Jens has already done, so build and enjoy.
GM
Build GM's design. It would be hard to beat for that driver.
You can build the downfiring enclosure like this:
Or you can put it on stilts, like this:
Since the port diameter is 3", I believe as long as you give at least 3" clearance below, it ought not change the tuning of the enclosure much if at all.
I am a proponent of "wide and shallow" enclosures, as it lowers the baffle cutoff frequency. I have also listened to a pair of the Jordan JX92S in the VTL enclosures, and found the stereo imaging excellent.
You can build the downfiring enclosure like this:
Or you can put it on stilts, like this:
An externally hosted image should be here but it was not working when we last tested it.
Since the port diameter is 3", I believe as long as you give at least 3" clearance below, it ought not change the tuning of the enclosure much if at all.
I am a proponent of "wide and shallow" enclosures, as it lowers the baffle cutoff frequency. I have also listened to a pair of the Jordan JX92S in the VTL enclosures, and found the stereo imaging excellent.
I like all these mltl designs and made a pair myself
from some measures graciously provided by GM.
It's not clear if yours is the triangular version of
the Jordan TL or a triagular mltl. How and
where is the port located? Downfiring out bottom?
How long?
Mine is a 6 in. extended out the bottom. The driver
is the modest but hard working Fostex FE127e.
from some measures graciously provided by GM.
It's not clear if yours is the triangular version of
the Jordan TL or a triagular mltl. How and
where is the port located? Downfiring out bottom?
How long?
Mine is a 6 in. extended out the bottom. The driver
is the modest but hard working Fostex FE127e.
The sketch is just a mock-up for an MLTL with trapezoidal cross-sectional area, downfiring vent, and raised on stilts. The bottom piece would ideally be something heavy, like concrete or what, for stability.loninappleton said:
My "logic" is that if the height of the stilts is at least as large as the diameter of the vent, the tuning of the enclosure ought not change (or in any event would be LOWER than designed, which is better than the opposite).
The basic concept is a wall-hugging design that toes in the speakers roughly 45deg, as recommended by Messr Jordan. The base could even be offset by about 3/4", to clear any floor moulding, ensuring closest wall-hug. Just keep the wall between the speakers relatively free of clutter for best stereo imagery.
explanations
Morning all,
I did write that last message in rather a rush so probably didnt come over too well.
I have found MANY referances and things to read up on while ive been researching this enclosure and i have found the mathcad files and intend to have a play. I havent had a chance yet cause im at work on an oil rig in the middle of the north sea and they dont like you installing programs on there PC's ! I get to go home today (weather permitting (sunshine makes lots of offshore fog!))after 2 weeks so i intend to try them out while at home.
GM, can i ask are you saying to stay with a small port but to have it downwards firing or to have the bottom open as a large port?
Ill be back next week with lots of questions about how the hell to use mathcad.
Thanks
Wella
Morning all,
I did write that last message in rather a rush so probably didnt come over too well.
I have found MANY referances and things to read up on while ive been researching this enclosure and i have found the mathcad files and intend to have a play. I havent had a chance yet cause im at work on an oil rig in the middle of the north sea and they dont like you installing programs on there PC's ! I get to go home today (weather permitting (sunshine makes lots of offshore fog!))after 2 weeks so i intend to try them out while at home.
GM, can i ask are you saying to stay with a small port but to have it downwards firing or to have the bottom open as a large port?
Ill be back next week with lots of questions about how the hell to use mathcad.
Thanks
Wella
Hi,
have a look at this thread.
http://www.diyaudio.com/forums/showthread.php?threadid=32055
I don´t claim these links are essential discussions but read a few of those carefully and you´ll have a good start with mathcad.
(+of course Martin´s site itself and Bob Brines)
Besides the forum is full of advice and designs made with mathcad from the pro´s. Always good to "re-simulate" in order to understand the changes talked about in some discussion.
I got many different designs for the FE-167E in my mathcad folder which I have from Bob Brines site, this and other forums.
Can make them into jpg´s if you want and send them over.
Those include TL´s, BR´s and a voigt pipe (cain abby clone;see forum)
greets&happy reading
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