Based on the factory specs., tuning to 85.71Hz will give you a maximally flat TL (viz. flattest performance over the widest BW), below which you'll have a shallow roll-off blending into the room providing it has decent gain.
Ron designed the Dallas II very tightly to the FE206E. It'd need changing for the Seas to work optimally; the driver needs a rather larger volume to work in for a start. You may get away with it from the POV of liking the results, but it won't be accurate to the design criteria.
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Too little information to go on. The Seas needs a relatively large volume, so for e.g. I make an optimal Alpha TL as being 36.722in long with a pipe CSA of 324in^2 & damped 1.9lbs ft^3 (dacron).
No, it's a myth that low Q drivers are required for back horns. Since like any back load they are only useful over a limited BW, in practice a driver with a < 250Hz mass corner is preferable. The Seas is at 167.6Hz, so better than a lot from this POV.
No, it's a myth that low Q drivers are required for back horns. Since like any back load they are only useful over a limited BW, in practice a driver with a < 250Hz mass corner is preferable. The Seas is at 167.6Hz, so better than a lot from this POV.
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Not well enough for me. The ~85Hz tuning frequency of this box is about right for a maximally flat BW TL with the Seas unit, but the cabinet doesn't have sufficient volume, so you'd likely end up with a big peak at Fb until damped to ~aperiodic levels, by which point you will have lost most of the horn's gain.
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Thanks for answer
it is nice to get help to take away some ideas and narrow down the search for a good enclosure for this driver.it seems that the driver needs a large enclosure. And right now i use it in a 90L bassreflex tuned to 32hz and it performs good.
But i realy want to extend the performance in the lower region thats why
i think horn is the way to go.
The Jerico is a suggestion that has come up ,but will it perform any better than the dallas horn?
or is there other constructions that will perform better?
The one thing i am shure of is that the answer will appear in this thread.
Because of the level of competance i see inn here.
I used the 0,82mh and 6,8omh resistor it may be to much damping because
it looses some of the energy in the top.
so i think i will try a smaller inductor and resistor on it to move the damping higer in frequency
I've seen a lot worse in response terms for a widebander of this type. Looking at what Seas publish (which is of a higher resolution than you get from, say, Fostex or Tang Band, plus they haven't expanded the dynamic range as far, which has the effect of masking deviations on a graph), 15 degrees off axis should put it relatively flat. Their measures were taken as a 60 litre closed box rather than an IEC standard baffle, so the drop at ~280Hz is possibly uncorrected step-loss.
Right, the Seas needs a large box (by the standards most people are used to these days) to 'breath.' It may benefit from horn loading in the LF, assuming you have sufficient room for the kind of box size it'll need.
Assuming we're talking the original Jericho, Ron designed Dallas II to improve on its performance; with the 206 it's the superior box. With the Seas, I doubt there'll be much in it, but they'll both be quite a way from the original intentions (translation: I doubt it'd work too well).
Right, the Seas needs a large box (by the standards most people are used to these days) to 'breath.' It may benefit from horn loading in the LF, assuming you have sufficient room for the kind of box size it'll need.
Assuming we're talking the original Jericho, Ron designed Dallas II to improve on its performance; with the 206 it's the superior box. With the Seas, I doubt there'll be much in it, but they'll both be quite a way from the original intentions (translation: I doubt it'd work too well).
This was what i was afraid of they are both to small.
How big a construction do you think we are talking about before it makes sense trying it?
And do you think a big vented reflex construction are easier to get right.
i know it's a lot of questions so i hope you bear with me
I was referring to the 115cm X 43.8cm X 50cm "Jericho" HobbyHifi put the Exoitics in 4/'08 and don't know any more about it, just wanted to keep the wheels in motion.
Hobby HiFi Lautsprecherbausätze: Jericho 08 mit Seas Exotic F8
I'm happy to read you're pleased with what you're seeing of this driver. Leaves me feeling optimistic for a proper design at some point.
Hi Joni
so you are going to something like the JE-Lab open baffle ?
look here: Open Baffle
I know abot a "modern version" for Hemp driver, called "Hemp Ventana".
Can't find a link - maybe others do ?
Regards
Jörn
edit:
http://bazsielektron.atw.hu/Hang Box/HEMP Acoustics F.U.N. - Ventana.pdf
Jordan JX92S OB with a Goldwood GW-1858 Woofer in an H Frame Project
using a plexyglass for the fullrange can have a decent WAF ....
using a plexyglass for the fullrange can have a decent WAF ....
...well, i can think of twelve ways to ask for one - Moose SoundsAll i need now is a good BVR or BLH construction
Hi nikko
this is, what we call "Horn-reflex" (in Germany, maybe everywhere too ?)
please look here:
: Acoustic Design Wohlgemuth
on the right, small pic middle, you'll find a plan
and a (german) text - the pictures and graphs should speek for thereself.
[URL=http://img6.imageshack.us/i/gradientseas8fr.jpg/][IMGDEAD]http://img6.imageshack.us/img6/8004/gradientseas8fr.jpg[/IMGDEAD][/URL]
Black: original Gradient AX8
Red: Seas FA220
Take the AX-8 plan and graph's.
It's a 73l Box with a short conical horn.
I simulated the box also with the Seas FR.
this is, what we call "Horn-reflex" (in Germany, maybe everywhere too ?)
please look here:
: Acoustic Design Wohlgemuth
on the right, small pic middle, you'll find a plan
and a (german) text - the pictures and graphs should speek for thereself.
[URL=http://img6.imageshack.us/i/gradientseas8fr.jpg/][IMGDEAD]http://img6.imageshack.us/img6/8004/gradientseas8fr.jpg[/IMGDEAD][/URL]
Black: original Gradient AX8
Red: Seas FA220
Take the AX-8 plan and graph's.
It's a 73l Box with a short conical horn.
I simulated the box also with the Seas FR.
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