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Old 25th May 2004, 10:24 AM   #1
navin is offline navin  India
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Default fostex FW208N and FF85K

I have posted this before but got no response. maybe because it was buried inside another thread....

my investigations with full range drivers (a la Jordan JX125-JX53) have led me to Fostex (via the FE103).

What do you guys think of a system using a FW208N and a FF85K? A system on the lines of the Jordan JX125/53.

My aphrehensions:
1. the FW208 cost $150 the FF85 $30. I am loathe to spend 80% on a driver that will cover at most 4 octaves (30-60-120-250-500) and $30 on a driver that will cover the more critical human voice (500-1k-2k-4k-8k-16k) and beyond.

2. Anyone have any opinions on either or both of these drivers? I'd prefer to use a sealed or TL but seems to me the FW208N (with a Qts on 0.2 and a Fs of 29) is better suited for bass reflex right? Also is the Ff85 recomended for use on an open baffle. it's Qts is 0.47.

3. Are these drivers well matched say as well matched as the above mentioned JX125/53? Can anyont think of other alternates (for a wide range 2 way)?

lastly here are the links...
http://www.fostexinternational.com/d.../pdf/ff85k.pdf
http://www.fostexinternational.com/d...pdf/fw208n.pdf
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Old 25th May 2004, 09:28 PM   #2
Greg B is offline Greg B  United States
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Quote:
What do you guys think of a system using a FW208N and a FF85K? A system on the lines of the Jordan JX125/53.
It's workable. FWIW though, the official Fostex recommendation for the FW208 is the FT48 midtweeter crossed at about 1300hz. They had a schematic in the old Madisound Fostex PDF catalog.

Personally, with the FF85K, I'd be more inclined to use a good 10" or 12" paper driver in a sealed box or maybe BR or TL - along the lines of the old wharfedales. Either way could work though.

You'd need to pad the FF85 a bit with the FW208 because of the baffle step.

Quote:
My aphrehensions:
1. the FW208 cost $150 the FF85 $30. I am loathe to spend 80% on a driver that will cover at most 4 octaves (30-60-120-250-500) and $30 on a driver that will cover the more critical human voice (500-1k-2k-4k-8k-16k) and beyond.
Unfortunately, this is kind of how it goes. Good woofers cost more than good mids or tweeters, etc. If you want to save some money, Zalytron has a bunch of Focal woofers on sale. I've use the FF125k as a midrange with a focal 10W something and integration was perfect.

Quote:
2. Anyone have any opinions on either or both of these drivers? I'd prefer to use a sealed or TL but seems to me the FW208N (with a Qts on 0.2 and a Fs of 29) is better suited for bass reflex right? Also is the Ff85 recomended for use on an open baffle. it's Qts is 0.47.
Have not heard the FW208, but I've used many fostex drivers and they've all been excellent. The FF125 was both extremely detailed and musical. Some folks have said the FF85 is the best mid/tweeter they have heard.

AFA open baffle vs sealed, it depends on your space. I prefer sealed as a rule, but OB might be good if you have a well damped room with carpet and clutter, etc.

Re: the FW208, yes, the specs definitely indicate bass reflex. My fave enclosure for drivers similar to this by far is the tower BR or ML-TL. This is a short (for example, 30-40") TL meant to fill out the midbass of a low Q driver while allowing better bass extension and a lower tuning. Works very well and has none of the boxy sound of a 'bad' BR.

Quote:
3. Are these drivers well matched say as well matched as the above mentioned JX125/53? Can anyont think of other alternates (for a wide range 2 way)?
With the low crossover point, it makes it easier. The most surefire thing is to take the fostex recommendation at face value and use the FT48. Like I said, my gut feeling for a good match with the FF85 would be a larger either vintage or good prosound wideband woofer. Probably a ribbed cone type. JBL D123A for example.

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Old 26th May 2004, 01:11 AM   #3
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Take a look at the recent thread about the fe107e. It's the shielded version of the fe103. I chose the fe107e because the manufacturer's frequency response curve for it is smoother than that of the fe103.

GM suggested a tower design, and I said, what the heck. I've got prototypes running with a subwoofer. See the thread about the XLS 10".

I haven't decided just how much I like the small towers. I think I hear a little bit of "shouty" stuff in female vocals that I don't hear with my Ariels. (Unfair comparison of course. The Ariels cost more to build than the small towers and subwoofer combined, and the Ariel box is elaborate.) I say I think I hear stuff. I have not done an A/B comparison yet. One audiophile friend is quite impressed with the little towers. Another is, perhaps out of politeness, less commital.
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Old 26th May 2004, 04:54 PM   #4
Greg B is offline Greg B  United States
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Cool, I used to have some FE103 based speakers in my office too (when I had and office... ).

They are quite good, but IMO the FF85 would be better for this particular application: ie, as a wide BW mid/tweeter. The FF series is a step up in clarity etc, based on my experience with the FF125.

BTW, AFA 'shout', the FE series responds very well to tweaks and cone doping. Send me an email if you want my 'secret' tweaks, or just search the 'fullrange forum' archives.

I wouldn't worry about your audiphile friend. People with a certain investment in their rigs will hear what they want to hear. A cheap FR driver will often beat fancy audiophool stuff. An aquaintance of mine in Palo Alto replaced his B&W with some speaks I made from well tweaked radio shack FR drivers, and considers it an improvement.

GB
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Old 26th May 2004, 09:43 PM   #5
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Quote:
Originally posted by Greg B
Cool, I used to have some FE103 based speakers in my office too (when I had and office... ).

They are quite good, but IMO the FF85 would be better for this particular application: ie, as a wide BW mid/tweeter. The FF series is a step up in clarity etc, based on my experience with the FF125.

BTW, AFA 'shout', the FE series responds very well to tweaks and cone doping. Send me an email if you want my 'secret' tweaks, or just search the 'fullrange forum' archives.

I wouldn't worry about your audiphile friend. People with a certain investment in their rigs will hear what they want to hear. A cheap FR driver will often beat fancy audiophool stuff. An aquaintance of mine in Palo Alto replaced his B&W with some speaks I made from well tweaked radio shack FR drivers, and considers it an improvement.

GB
Sure, I'd love to see the tweaks. Check your email.

I found the "shout" problem. (I screwed up.) See the other thread. The system now sounds really good.
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Old 27th May 2004, 07:24 AM   #6
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Greg, Dave,

Thanks a LOT! Everything you guys say is being logged in my mental bible at my age how of it stays there is questionable though.

I did consdier the 103 and i think the 85 will have better dispersion and less beam only because it is smalller. also the 103 might need some help in the upper registers. Dave (from Victoria) for example is considering mating the 103s with a ribbon (JP2?).

The ML-TL looks promising. I have made bass reflex before and done well it can sound good but like i said i have done bass reflex before.

The reason I chose the FW208N is because of WAF. Even the 208 would require a box that is 25 liters and that is pushing it. The larger drivers like the D123 wold require larger boxes. Are there any other alternates to the FW208 that wold work in a 25 liter (or smaller) box and be a good match for the FF85.

The reason I did not choose the FT48 is that I am trying to hae a simple single element 1st order XO as low as possible (300Hz if possible but under 500Hz for sure) so that the entire vocal range and above is managed by one driver.

my backup is a Jordan JX125/53 system however I am a bit aphrensive about the metal cone drivers jordan makes. have any of you compared jordan to fostex?
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Old 27th May 2004, 07:35 AM   #7
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BTW for the center and rears I was hoping to use the FF125K in a 9-10 liter box if the FF85K is used for the fronts or else the JX92 with a 125/53 front.
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Old 27th May 2004, 09:15 AM   #8
Greg B is offline Greg B  United States
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I think the FF85 is a good choice since you will be using it essentially as a mid tweeter. I'd think you'd do a bit better in the treble clarity department. BTW, the FE103 doesn't need a tweeter. It reaches up there just fine.

Assuming you stick with the FF85k... you'll want to cross over at least two and preferably 3 octaves above the Fs, so 500 at a bare minimum, and I'd recommend 800. The reason is the impedance peak at Fs will screw up the highpass, and it just won't work right. You can cheat this a bit by putting the driver in an aperiodic subenclosure to smooth the impedance a bit. You could also use a series notch filter, but you probably don't want to go there.

It's a good idea to put the crossover at the baffle step. This lets you kill two birds with one stone. Probably will be ~800 hz or so with typical 25l boxes.

AFA cheaper subsitute woofers. I guess I'd stick to plain paper. Maybe a Seas H333 in a sealed box?

The FF series isn't shielded BTW, and the FF125K has a hulking big magnet since it's a horn driver. For this reason it has rising response, and will need a passive filter in a BR. Mine sounded best with a simple ~.7mH 20g choke in series.

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Old 27th May 2004, 10:28 AM   #9
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Quote:
Originally posted by Greg B
I think the FF85 is a good choice since you will be using it essentially as a mid tweeter. I'd think you'd do a bit better in the treble clarity department. BTW, the FE103 doesn't need a tweeter. It reaches up there just fine.

Assuming you stick with the FF85k... you'll want to cross over at least two and preferably 3 octaves above the Fs, so 500 at a bare minimum...

It's a good idea to put the crossover at the baffle step. This lets you kill two birds with one stone. Probably will be ~800 hz or so with typical 25l boxes....

AFA cheaper subsitute woofers. I guess I'd stick to plain paper. Maybe a Seas H333 in a sealed box?

The FF series isn't shielded BTW, and the FF125K has a hulking big magnet since it's a horn driver....Greg B
Boy you are fast. I cant think that fast.

Is the FF85K better than the JX53 in your opinion?

The Fs of the 85k is about 122Hz. I was hoping to XO about 460Hz. the reason for this....

The baffle of the proposed speaker was to be about 10" wide (250mm) and about 40" (1m) tall.

the top 7" (just so I can use 2 hf units in vertical array) will be open baffle and the bottom 33" would be a sealed box

the sealed box (or bass reflex or ML-TL as may be required) would be about 25 liters.

now for a baffle that is 250mm wide the baffle step (-3db) is about 460Hz (115/W from http://www.trueaudio.com/st_diff1.htm).

Since I intend having 2 amplifiers and a PLLXO (passive line level XO) I could compensate for baffle step by increasing the bass amp gain.

finallly the H333 in a 25 liter sealed box would give a Qtc on 0.7 and a F3 of 65Hz a bit high for my tastes. any other alternates?
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Old 27th May 2004, 10:59 AM   #10
Greg B is offline Greg B  United States
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OK, I didn't realize you were biamping. You can crossover wherever then, limited only by how much SPL capbility you want, and you don't need a driver 3-4 db more sensitive than the FF85 either.

I haven't heard jordans so I couldn't tell you. You may want to ask on the full range forum. At that level of driver quality, it becomes a personal taste thing.

F3 @ 65 is better than it sounds with sealed boxes, 12db rolloff and all.

Off the top of my head, the Focal 7C on sale at Zalytron. I bet it would do ~40 hz in a 25l ML-TL. I have the 8C and it's solid to ~30 in room. Focal drivers are very neutral and 'hifi' though. Fostex tend to be equally detailed (or better) but just a touch 'romantic' sounding. My gut feeling is the JS53 might mesh better with the former.

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