So, I got to looking at some Fostex drivers this morning, much to Mrs. Annan's dismay, and I came across the 225K. The response in the higher end seems much smoother than my 206Es and, while I realize this would need a tweeter, it looks like a fine driver, based solely on the SPL response.
Now, Kofi don't know nuthin' 'bout boxin' no drivers, so I looked for a recommended enclosure for these and it appears that Fostex only has a bass reflex design they recommend. I was hoping for a back-loaded horn. Well, actually, I was hoping for a quick resolution to the Syria - Lebanon thing, but a horn'll work too.
Also, my searchifying turned up ungatz on any other recommeded encosures for these, hence the need for another Kofi Original Post(tm).
So my questions are as follows:
1. What's wrong with this driver? Why aren't people talking about it on the fora (forums pl.; cool, right?)? Is it just because of the required tweeter or are there other Thiele / Small issues that make this undesirable?
2. If this is an OK driver for an SET setup, could I use it in a horn or not?
3. Anyone have experience with this driver and the 206E that could let me know what they liked / disliked in comparison?
4. Anyone with experience in Syrian - Lebanse relations that needs a job with lots of international travel?
Help a brother, will ya?
Kofi
Now, Kofi don't know nuthin' 'bout boxin' no drivers, so I looked for a recommended enclosure for these and it appears that Fostex only has a bass reflex design they recommend. I was hoping for a back-loaded horn. Well, actually, I was hoping for a quick resolution to the Syria - Lebanon thing, but a horn'll work too.
Also, my searchifying turned up ungatz on any other recommeded encosures for these, hence the need for another Kofi Original Post(tm).
So my questions are as follows:
1. What's wrong with this driver? Why aren't people talking about it on the fora (forums pl.; cool, right?)? Is it just because of the required tweeter or are there other Thiele / Small issues that make this undesirable?
2. If this is an OK driver for an SET setup, could I use it in a horn or not?
3. Anyone have experience with this driver and the 206E that could let me know what they liked / disliked in comparison?
4. Anyone with experience in Syrian - Lebanse relations that needs a job with lots of international travel?
Help a brother, will ya?
Kofi
Hi Kofi,
I've wondered about the 225K as well and like you, searching the 'net and fora hasn't turned up much. But! I may have some information that may interest you, and some that is completely useless.
Question:
1) What's wrong with this driver? There aren't any 'proven' designs on the net. This tends to eliminate it from general use. It's hard to go out on a limb and spend a couple hundred bucks (for me) on drivers that might not be what I am after.
2) If this is an OK driver for an SET setup, could I use it in a horn or not?
Probably; Maybe. Again, without anyone having any experience with it, it's hard to know for sure. It does look suitable for a back horn, or even a midrange front horn. That would be cool!
3) Unfortunately, I don't have any hands-on experience with the ff225. I have built a set of the BLH for the 206e, so, no help there.
4) Anyone with experience in Syrian - Lebanse relations that needs a job with lots of international travel? 'Fraid not. Although I could use a bit of travel!
So, now for the (possibly) useful stuff. I snagged the set of books that Madisound offers, "Nagaoka Tetsuo's Special Technique to Design the Original Speakers" (catchy title, hey?) when they first came out. In the books, there are about three bajillion different enclosure designs, mostly for Fostex drivers. When I say your post, I thought, "Gee, there has to be at least ONE BLH for the ff225k in there!".
Alas, there wasn't.
BUT! There were a handfull of other designs that used the driver. So, check them out:
Sorry, the pictures in these links are a bit too detailed to be considered "fair use", so we've put them to bed until permission from the publisher can be obtained... dhaen
I know that I am breaking copyright, &c, yadda yadda, by posting these. If you like them, get the books. If only for the design that looks like a huge robot!
-Hans
I've wondered about the 225K as well and like you, searching the 'net and fora hasn't turned up much. But! I may have some information that may interest you, and some that is completely useless.
Question:
1) What's wrong with this driver? There aren't any 'proven' designs on the net. This tends to eliminate it from general use. It's hard to go out on a limb and spend a couple hundred bucks (for me) on drivers that might not be what I am after.
2) If this is an OK driver for an SET setup, could I use it in a horn or not?
Probably; Maybe. Again, without anyone having any experience with it, it's hard to know for sure. It does look suitable for a back horn, or even a midrange front horn. That would be cool!
3) Unfortunately, I don't have any hands-on experience with the ff225. I have built a set of the BLH for the 206e, so, no help there.
4) Anyone with experience in Syrian - Lebanse relations that needs a job with lots of international travel? 'Fraid not. Although I could use a bit of travel!
So, now for the (possibly) useful stuff. I snagged the set of books that Madisound offers, "Nagaoka Tetsuo's Special Technique to Design the Original Speakers" (catchy title, hey?) when they first came out. In the books, there are about three bajillion different enclosure designs, mostly for Fostex drivers. When I say your post, I thought, "Gee, there has to be at least ONE BLH for the ff225k in there!".
Alas, there wasn't.
BUT! There were a handfull of other designs that used the driver. So, check them out:
Sorry, the pictures in these links are a bit too detailed to be considered "fair use", so we've put them to bed until permission from the publisher can be obtained... dhaenI know that I am breaking copyright, &c, yadda yadda, by posting these. If you like them, get the books. If only for the design that looks like a huge robot!
-Hans
just curious kofi are you unhappy with the 206 or is it simply pe (parameter envy) my 206 are in a pair of Rons Dallas II blh and when I first had them in the topss were really annoying and I got panicky.I had a heap of mods lined up too tackle this.thankfully
1) I was slow in the uptake and
2) I listen to a lot of music which had the twofoldd benefit of massaging my lugs and also properly breaking in the driverrs at the same time.now they are very good.
whats my point? firstly are your 206 properly broken in and are the in a properly designed cabinet ie blh
by the way I always enjoy your posts cheers fergs
1) I was slow in the uptake and
2) I listen to a lot of music which had the twofoldd benefit of massaging my lugs and also properly breaking in the driverrs at the same time.now they are very good.
whats my point? firstly are your 206 properly broken in and are the in a properly designed cabinet ie blh
by the way I always enjoy your posts cheers fergs
Hi,
Try to look here:
http://gallery.audioasylum.com/cgi/view.mpl?UserImages=21168&session=
http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=72315&highlight=ff225k&r=&session=
http://boozhoundlabs.com/ff225k/
I think that the biggest problem with this driver is that it has xmax of 0.3mm so you can't expect much bass comming out of it.
Good luck Martin
Try to look here:
http://gallery.audioasylum.com/cgi/view.mpl?UserImages=21168&session=
http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=72315&highlight=ff225k&r=&session=
http://boozhoundlabs.com/ff225k/
I think that the biggest problem with this driver is that it has xmax of 0.3mm so you can't expect much bass comming out of it.
Good luck Martin
HWV said:
Assuming that the FF225N is the same as the FF225K, it doesn't make much sense to use a 2.2uf cap on the tweeter, does it?
9K?
Assuming that the FF225N is the same as the FF225K, it doesn't make much sense to use a 2.2uf cap on the tweeter, does it?
Looking at the PDF, 9k is just under where the driver response drops off the chart. Not a completely bad place to hand-off to a tweeter! It is a good place to start, anyway.
I'm sure the details would be much clearer (for me anyway) if I could read Japanese. Ahh, back to school I go!
-Hans
Looking at the PDF, 9k is just under where the driver response drops off the chart. Not a completely bad place to hand-off to a tweeter! It is a good place to start, anyway.
I'm sure the details would be much clearer (for me anyway) if I could read Japanese. Ahh, back to school I go!
-Hans
That's why we're asking the questions. I see you're in my camp.
Wow! Thanks so much for scanning these! I love the concepts here, but I'm still wary that there may not be enough feedback for me to venture forth and buy 'em. Apologize if I sound like I've had a few, but I have a cold and I went to my local Irish pub and had a few hot whiskeys and a few cold ones and, well, you know the rest...
I love fat girls. I really do.
That's the booze talkin'.
That's no good. And its been brought up before. The popular myth here is that these drivers have an xmax that actually exceeds the .3mm Fostex discloses, but its certainly an issue, since I want some bass.
I am not unhappy with the 206 at all. I like it quite a bit, but I would like to get rid of some of the peakiness in the mids if possible. Also, I have almost no experience with BLHs other than the ones I built for the 206E (I actually built the horn enclosures for the 208EZ to accommodate the 206E at the recommendation of BrianGT). I have, however, performed some modifications to these myself, including M J King's BSC circuit and installing Dave's (Planet 10's) phase plugs.
I must say that the phase plugs have really released the highs and now the 206Es sound better without the BSC circuit than with it. However, I would like to have some speakers that are a bit flatter / smoother overall. Again, I'm not dissatisfied with the 206Es, I'd be glad to recommend them to anyone, but I am looking for an 8" driver that can come close to doing it all, and these initially looked like they fit the bill.
I have thousands of hours on these and I really like them a lot. Again, using the 208EZ BLH design for these and I would wholeheartedly recommend them to anyone. Except Jacques Chirac. He's more of a bass reflex guy.
So, if I wanted a set of full range 8" speakers (or 6"?) that would provide a reasonably smooth response, could do the bass, had >94dB SPL, could propose Iraqi constitutional amendments, and would work in a BLH for a reasonable price, where would I be? The Afterlife, maybe? Do I already have these in the 206Es, maybe, and I'm just getting greedy? Hey, if it needs a tweeter, I'm down.
Down with the tweeter.
Word.
Hey man, what do I know? Nothing. That's what I know.
A little advice for your reasonably drunk and ill UN Secretary General, here, please?!? Hey, I can actually give you some advice: Did you know that Bushmills is smoother than Jameson? Well, it is. Had a few of each, so I speak from very recent experience. Wanna know which one pukes up better? I may have a hard time discerning, but I'll do my best for the DIYAudio community.
Youguyzarethebest. Iloveyouman. Woohooooparteeeewooo!!!!
Kofi
fergs1 said:
Fergs,
Forgot to ask-- what modifications did you make? I have installed Dave's phase plugs and I would consider some cone treatment, but I'd like to know what you did to yours.
Kofi
greetings kofi, in a word nought unless you count the 6 X 1 in disk of styrene foam glued onto the back magnet as per rons suggestion . this actually tamed some of the midrange forwardness and with the highs settled and house trained the only thing I'm considering is the phase plgs(hands don't fail me noww!) mainly to increase the sweet spot widen the soundstage. I listen to mainly classical and jazz on vinyl but if I was lostening to pop rock all day esp on cd I think i would find the 206 fatiguing.what do you liisten to?btw there's a pic of my 206 with thee foam disk on it in the fullrange driver site. you access thee gallery thru the forum and bring up last uploads, thheres a few Dallas II 's there, mines the one with the fairy lghts. I'd exhaust all other poss b4 putting damar on the cones. takke care fergs
fergs1 said:
An externally hosted image should be here but it was not working when we last tested it.
I don't know if James lets people deeplink (it is in my cache so i'm going to see it) so here is the link
http://fullrangedriver.com/gallery/displayimage.php?album=4&pos=38
and more...
http://fullrangedriver.com/gallery/displayimage.php?album=4&pos=40
http://fullrangedriver.com/gallery/displayimage.php?album=4&pos=41
http://fullrangedriver.com/gallery/displayimage.php?album=4&pos=42
dave
Well now... that's a mod. Haven't tried that one.
Mostly chain gang music and early 80's sitcom themes. Love Boat, Fantasy Island, Joannie Loves Chachi. That sort of thing.
Well, actually, that was a lie. I listen to a lot of jazz, some soul, if you want to call it that (is Screamin' Jay Hawkins considered soul?) and a little r-n-r for good measure. Never got into classical since I was forced to play it as a child. Rrrrrrrr....
Dave-- WHOA! That's quite a hunk of styrofoam you got there! Won't that change the volume at the throat, or is that the idea?
Kofi
I've been tormented byt the 225 too in my past. As mentioned, the highs roll off about right for a tweet, which I was planning on using anyway. I posted various tormented questions asking if anyone had hear one-nope..
Ended up getting the FE208 Sigma, because it was new, looked cool, and they dropped the whizzer cone so it also made sense to use with a tweeter. But I was THIS close to getting the 225.
The x-max is what put me off, but as you say, the response curve is exemplary. In my open baffles which cross over on the low end at about 180 hz, the 208 doesn't appear to move much at all, so the 225 might have worked also...
Ended up getting the FE208 Sigma, because it was new, looked cool, and they dropped the whizzer cone so it also made sense to use with a tweeter. But I was THIS close to getting the 225.
The x-max is what put me off, but as you say, the response curve is exemplary. In my open baffles which cross over on the low end at about 180 hz, the 208 doesn't appear to move much at all, so the 225 might have worked also...
kofi thats actually my driver. the idea is two fold, decrease the compression chamber channging the cut off fq and styrene absorbs mid and hf stopping them going down the horn but doesn't mess with the bass as stuffing can.its an easy reversibble mod unlike the damar so give itt a go. if it works too good halve the thickness of the foam. cheers fergs
The restorative properties of Mr. Rourke's "Smiles, everyone! Smiles!" may prove to be the key to conflict resolution here. Don't knock it. If it worked for the indentured servants on Fantasy Island, it could be the ticket in the middle east.
Hmmm... just a feeling right now, but maybe its time for me to take one for the team. Note that this is just a thought, but I could take the plunge on the 225 and lean on you geeks to help with some modeling. You know: you think, Kofi do.
I have a Mac now (thanks for the advice, Dave-- love it) and I have been using FuzzMeasure to work with SPL measurements. They're rough measurements to be sure, since I'm using the internal mike on the iBook, but they get you in the ball park (cricket field, for those overseas).
Any thoughts on this?
Will do. I'll give that a shot this weekend.
Thanks again for all the advice and let me know what you think of my idea.
Kofi
Kofi Annan said:
Yeah, I'm all about you taking one for the team (go team!). The 225 does look like a pretty nice driver, it does seem funny the 206/207 get so much attention and the 225 gets none. Such a low Qts though, seems like you might have a tough time pulling much bass out of it. You could use series resistance to get the Qts to a point where it would work well in an MLTL or something. Or you could try and shoehorn it into an already existing BLH design. Either way I'll be interested to hear what you think of the driver.
take care
Joe
Well, I haven't decided on it yet. I'm hoping for someone to propose a design they think would work well. I guess I could try the Boozhound method, but I'm hoping for some clearer direction.
I really think this driver should sound good and I haven't met a Fostex yet that I couldn't squeeze ample bass out.
So, any of you geeks got some ideas for box-i-fying the 225K?
Kofi
Hmm. Bass per se shouldn't be a problem from these drivers. They certainly go low enough in themselves. What is more of a problem is excursion -what you won't be able to do is go for massive decibel figures, their Xmax is too limited.
Two rough ideas for existing cabinet types until I get chance to run some numbers, and one (with variations) which should work fine:
1) You could try a version of Nelson Pass' J Lo double horn. The existing enclosure should work passably, though I suspect there'd be a dip circa 150Hz using the Fostex driver in the cabinet as is without any mods to the dimensions.
2) Ditto the Fostex factory enclosure for the FE208ESigma should be another option, albeit with some dimensional modifications.
3) Wild card: not everyone likes them, but I do! A large version of Terry Cain's Bigger Is Better TQWT we've been discussing here over the last few days. Try these dimensions: (external, assuming 3/4" material): Total Line length: 178". Cabinet height: 89". Cabinet Width: 8 1/2". Cabinet Depth: 14 3/4". End the internal baffle 6 1/4" from the floor of the cabinet and 6 1/4" from the internal front and rear walls. Driver height from base: 45" (actually, 49" would be better, but this would be too far above the normal listening height. 45" shouldn't be too far off-axis -just enough to counter the fractional rise in the response) Stuff to taste. This is just the original box, which works quite well with the 225Ks smaller brother, the 165K, scaled up for the larger driver. Increasing the cabinet depth a bit to dive the driver a little more breathing space could bring rewards; taking it out to around 16 1/4" (external) and ending the internal baffle 7" from the floor and 7" from the front and rear walls might work. I wouldn't take it further though -I doubt the driver could shift much more air with safety.
Cheers
Scott
Two rough ideas for existing cabinet types until I get chance to run some numbers, and one (with variations) which should work fine:
1) You could try a version of Nelson Pass' J Lo double horn. The existing enclosure should work passably, though I suspect there'd be a dip circa 150Hz using the Fostex driver in the cabinet as is without any mods to the dimensions.
2) Ditto the Fostex factory enclosure for the FE208ESigma should be another option, albeit with some dimensional modifications.
3) Wild card: not everyone likes them, but I do! A large version of Terry Cain's Bigger Is Better TQWT we've been discussing here over the last few days. Try these dimensions: (external, assuming 3/4" material): Total Line length: 178". Cabinet height: 89". Cabinet Width: 8 1/2". Cabinet Depth: 14 3/4". End the internal baffle 6 1/4" from the floor of the cabinet and 6 1/4" from the internal front and rear walls. Driver height from base: 45" (actually, 49" would be better, but this would be too far above the normal listening height. 45" shouldn't be too far off-axis -just enough to counter the fractional rise in the response) Stuff to taste. This is just the original box, which works quite well with the 225Ks smaller brother, the 165K, scaled up for the larger driver. Increasing the cabinet depth a bit to dive the driver a little more breathing space could bring rewards; taking it out to around 16 1/4" (external) and ending the internal baffle 7" from the floor and 7" from the front and rear walls might work. I wouldn't take it further though -I doubt the driver could shift much more air with safety.
Cheers
Scott
That's good news. I'm not looking for massive decibel figures either. Well, not that massive, anyway. These aren't going to wind up at Carnegie Hall or anything, just Kofi's living room.
Now we're getting closer! Could this be modeled in Martin King's brilliant MathCad worksheets? I dunno how ta uze dem, but maybe i cud lern.
Thanks so much for the advice and, as always, I'll need a bigger push in the right direction here. Actually, I need for someone to bring me to the exact spot and rub my face in it for hours until a psycho-physical osmosis is created that translates the physical world into psychological sublimations that will then penetrate the cerebrum and stimulate the hippocampus as to evoke the physical concept into an abstract codification that we'll call "Psycho-Osmotics" which will then yield in the abstract, logical confines of the mind a complete representation of the design along with all related theora and principles related to its electrical and acoustical behavior.
Or, a drawing would help. Actually, a drawing might be better, now that I think about it.
Kofi
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