Thoughts and opinions about Fostex FF85WK

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Hi everyone!
I am very new in this forum and I am very excited already.
I have only build car subwoofers and (car) door/kicker panels in the past and this is going to be my first attempt to home HiFi DIY.
I have read the past few days quite a few threads and have settled on the FF85WK in a FAST configuration.
Which woofer you think would be best to cover the 40-150/300Hz? I need it to be fast and tight but I don't need it to play really low as I plan to also use a subwoofer below 60-80Hz
I plan to build 3 of those for L,C,R, plus 2 or 4 more (probably different ones) for surrounds (the surrounds can be larger so I can use them full range) in a home theater system .
I am also thinking about using two drivers, one facing forward and one facing upwards and experiment with room acoustics and maybe try a spherical reflector on the top driver (idea stolen from the Duevel speakers) and make them omni-directional.
Going omni-directional with full range drivers is also my plan for the surround speakers.
My current HiFi system is a Naim CD3, Nait 3, Naim IBL which is fine but lacks bass and it is not really suitable for HT (and I can't find a matching center speaker anyway)
I have an Arcam Xeta2 surround processor/3channel amplifier but plan to buy an old unused Pioneer VSA 2014IS I found (new boxed, previously at 830euros now a bargain at 200euros clearance price) to power them.
The system will be used 80% movies 20% music but that may change if I really like how they sound with music.
In the past I had a pair of Klipsch HeresyII which I really liked when I first heard them playing through a low power tube amp but it was less enjoyable with the Naim amplifier so I sold it. Too bad though because I sold it before I find something else that I like more.
Since then I cannot find a speaker that i really like because every speaker I hear sounds either too slow or too thin or dull.
I like fast and tight low end and I appreciate extended LF response but I also like lifelike voices and airy highs. High frequency extension is really low on my priorities ( I seem to hear much less above 14-15k) but I don't think I can tolerate mid high harshness.
My biggest problem will be driver availability in Greece.
I can only buy drivers available in Europe so I would prefer a suggestion for non-American woofers.
For now I plan to get only a pair of FF85WK, brake them in for a few days, and try them in a cardboard box to see if I like their sound in mid-highs.
I have high hopes for those little drivers but if they don't meet my expectations I can use them in the car as dash speakers.
 
I would like to stay under 150euros/pair BUT I can appreciate the value of a high quality driver if it is vastly superior. I am a big VFM fan though so if I can find something that comes really close and costs less than half I will chose that.
Paying double for 10% improvement is what I want to avoid.
Size can be anything between 6 and 10 inch as long as it can be housed in a relatively small enclosure preferably under 45lt (sealed?).
 
Excellent for small sealed bass unit.

A less expensive but actually much better for a small sealed bass unit for FAST application upto 300-500 Hz would be the Dayton Audio RSS265HF-4 10" Reference HF Subwoofer 4.
This has mildly lower efficiency and higher Qts than the SEAS L26, making it actually better for a small sealed unit.
 
I found both the Dayton and the Seas but it sems that both go well above the intended budget.
They both look like high quality drivers though.
The cost could be justified if they would serve as subwoofers but I don't know if a subwoofer with a 300hz cross is a good idea.
The initial plan was to get a pair of woofers to cover the 40-150/300Hz area of the front speakers, cut them off at 80Hz for home theater use and let one good 12" sub take over for the bottom two octaves.
When playing music i could just swich off the sub if bass is too much and let the main speakers play full range. (I find HT and music to have different requirements from subwoofers.)
I'll keep them in mind though.
 
Can you get SB acoustics there? They have some 8" woofer for something like $75 each USD.

You should move some of your budget into more subs than just 1. I use 4 x 12" subs for music and its excellent. Multiple subs smooth the bass modes. And gives additional output for HT use.
 
frugal-phile™
Joined 2001
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We really like the FF85wk (of 22 pair thru here, something like half have been sucked up for internal use).

We have used it (or its precursor) with SDX7, EL166, Peerless 830870 with proven results, next up is the Silver Flute W14,

I would avoid subwoofers, you want a good midbass for your application. There are a ton of very good candidates. The problem is not a matter of availability but wading thru them all to find something most suited to your applicationYou want something that produces decent bottom, and goes up to at least 1kHz (higher doesn't hurt -- the Peerless goes up somewhere north of 5 kHz) with any breakup modes well above that.

SEAS, Peerless, Vifa, Monacor, VIFA, SilverFlute, SB Acoustics, probably some there i haven't even heard about (don't forget obscure former east block manufacturers). Some vintage units will probably work fine -- i have some 12" Fosters in the queue.

dave
 
Dave, my decision on the FF85WK was heavily influenced by your comments, however the only woofer available from the ones you tried is the Peerless but I don't think I want to rely on a 4"woofer for my purposes.
I have found some in my price range that I am considering (I raised the budget to approximately 200euros/pair).
Precision Devices PD.8BM20
Visaton W200 S-8
SB Acoustics SB23NRXS45-8
Seas CA22RNY

Dayton RS225-8


Has somebody tried any of them?
 
I forgot to mention that the setup will be used in a 17sq/m room and that I have not really decided on what I am going to use to power the woofers.
Perhaps a used low cost power amplifier (Rotel RB850/960 or similar if I can find one) or a professional 4channel power amplifier that I will also use to power the subs.
The FF85WKs will be driven from the AV amplifier so all I can do to cross them is use the build in High Pass of the amplifier (which I believe is <100Hz) plus a simple first order passive filter around 300Hz. The woofer can be crossed with a line level passive crossover unless I end up with a plate amplifier with a build in crossover or a two way electronic crossover..
Cost elevates quickly though.

Perhaps I could live with the high sensitivity Precision Devices 8" and a passive crossover as a more cost effective solution but even though the manufacturer says that it will work in a 20lt enclosure I run it through WinIS and it showed 331lt for a sealed enclosure. Perhaps I did something wrong? I don't know.

Also the Seas driver has 91db sensitivity and it may be suitable for a passive crossover.
I am only considering a passive crossover if it can be made simple. If not it may not worth trying.
 
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Dave I just saw that on another thread you mentioned the Mark Audio CHP-70 and you also provided a link to a european store.
When I was making my decisions I couldn't locate a store that carries MA speakers so I didn't even consider them.
How does it compare to the FF85WK in mid-highs?
If it is about equal I may change my plans as these could be used with a 100Hz crossover and a sub and avoid the Sub+woofer+fullrange config I was thinking.
In that case I can replace the FF85WK with the MA CHP-70 and go straight for a pair of 10 or 12 inch subs.
However I have the impression that if I stick to my original plan I will have better dynamics and higher SPL.
 
frugal-phile™
Joined 2001
Paid Member
Dave I just saw that on another thread you mentioned the Mark Audio CHP-70 and you also provided a link to a european store.
When I was making my decisions I couldn't locate a store that carries MA speakers so I didn't even consider them.
How does it compare to the FF85WK in mid-highs?
If it is about equal I may change my plans as these could be used with a 100Hz crossover and a sub and avoid the Sub+woofer+fullrange config I was thinking.
In that case I can replace the FF85WK with the MA CHP-70 and go straight for a pair of 10 or 12 inch subs.
However I have the impression that if I stick to my original plan I will have better dynamics and higher SPL.

The FF85 & the Alpair 7.3 (maybe alpair 6.2m -- 6.2p has a soft top (on purpose)) are in the same league mid/top, A7 has the edge and goes much lower. CHP/EL70 don't equal them mid/top, but go lower, are very good, and depending on your room and how much quantity of bass you need, a sub may not be needed. The CHP gen 1 that rumoh has a killer value.

dave
 
Dave I am going after a Home Theater system.
The room is 17sq/m but I don't think I can get away with no sub. Do you think that such a small driver can give me the dynamics I want if I let it handle frequencies lower than 300Hz?
Remember that in my mind I have the dynamics of the Klipsch Heresy II.
That's what I am after and with the addition of a subwoofer I hope I am going to have some serious bottom end as well that the Klipsch was lacking.
Fast, tight, extended but controlled bass combined with lifelike vocals and airy highs is my goal and I expect to get it by choosing the right components for the job.
I may have to change my plans completely and go let's say for an Alpair 12.2 if that's what I need to get the dynamics I want but i will do that only if I can get top class mids-highs from them.
Till now I thought that the combination of a smooth sounding full range driver handling everything from around 300Hz up and a more powerful larger woofer should give me the results I am looking for but it seems that if I can't make it work with a passive crossover it is going to cost a lot more than I was hoping for.
That's why I am also looking for alternative solutions.
So till now I have these possible combinations in my mind:
1) Fostex FF85WK + 8" woofer with passive crossover. Plus one or two 12"subwoofers.
2) Mark Audio Alpair 7.3 covering the entire range from 80Hz up + 2X12"subwoofers
3) Mark Audio Alpair 12.2 + 2X12"subwoofers.

What do you think?
 
Geez you're in a tough situation given your constraints for budget and cross over. I'd be tempted to run a larger 4" full ranger that can hit 100hz sealed. The rest those on top of 12" subs and use the cross over in your avr. I'm personally running a 3" tang band crossed at 300hz to an 8" silver flute using a minidsp. Then that is crossed to 4 12" subs at 90hz using my avr. The other night I watched the new batman movie at theatre levels (but without the theatre crappy sound) and the speakers held on. In the past I've run my EL70 down to 90hz and let the subs take over from there, and no, the dynamics are not the same. But at 120hz it probably would have been closer. But then you're faced with localization issues.

I'd be tempted to do the FAST method if I were you, but it might get a bit expensive. Maybe look at cheaper woofers. The silver Flute W20RC-08 would probably make a good sensitivity match after baffle step compensation. And cost a whole lot less than some of these others.
 
Thanks for the contribution Tuxedocivic.
Your setup is somehow similar to what I am after.
My initial plan was to get 3XFF85WKs and 3X6-10 inch woofers (with 8" being the best compromise between price/performance/enclosure size) for L/C/R and 2XFF225WK to use as full range surround speakers (I also had some ideas about making them omni-directional).
One or two 12" subs were going to be added afterwards to add some low end punch.
At first I had in my mind a simple passive XO for the 8"+FF85WK but after reading some threads I figured out that it would be quite difficult to find a woofer that will match easily with a simple XO and I had to go the Bi-amp way.
At first I didn't gave it too much thought and thought OK I'll just do that; but after a while it became obvious that this was going to exceed my budget a long way.
That's when I started looking for alternative solutions.
Unfortunately I cant find the Silver flutes anywhere but I have found at least two 8"drivers that may be suitable.
It is the SEAS CA22RNY that has 91db sensitivity, and the PRECISION DEVICES PD.8BM20 with 92db sensitivity. I have not heard any one of them and I have not make an enclosure simulation to see if I can actually get them to work in a relatively small enclosure.
If I can get them to work with a simple passive XO I will save enough money to afford better subs and get 2 of them.
 
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