Implementation of Fostex FF85wk

[TubaV]

Playing around with different woofers to be used with my Fostex ff85wk. Can I use it open baffle like several of Martin J King's projects or is it still best in some kind of MLTL or BR perhaps integrated into my woofer box design? Thanks for any and all suggestions.

 

[adason]

depends on the crossover you are planning to use
if you cross it high, no need for elaborate enclosures, they are there to extend low fr

 

[joensd]

As long as you free the ff85 from bass duties you are free to decide which enclosure you go for.
Depends more on room, bass need, application, SPL and the woofers you want to use.
I suppose you have them already?
Active or passive xo?

Anyway, this is one nice full range driver with sweet treble.

 

[vinylkid58]

Can I use it open baffle like several of Martin J King's projects or is it still best in some kind of MLTL or BR perhaps integrated into my woofer box design? Thanks for any and all suggestions.

Yes, but you need to pick one config. that suits you and your room.

jeff

 

[TubaV]

Thanks for the replies. I will be doing passive and crossing high around 3000 or even higher. Room is not too big and I listen with tube amplification in a 7 foot triangle not real loud. Experimenting with SB 5" and Peerless 6.5" both sealed.

 

[joensd]

crossing high around 3000 or even higher

Then I don´t understand your initial question!
Why would you put the FF85 in a ML-TL (which sure sounds nice and can be easily crossed to a woofer) if you want to cross it at 3k?
The woofers would be nice in a ML-TL though.
(but I personally would in any case cross at 400Hz max. to keep the fullrange character)

 

[planet10]

We did a version of the MJK passive baffle with the FF85k and Eminence Alpha 15. The FF85 worked wnderfully, i was not so thrilled with the woofer.

As Jeff suggests, both woofer & midTweeter should be OB, or both be in a box.

Baffle was made of a surplus meeting tabletop cut in half.

dave

 

[chrisb]

My oh my, but that takes me back a decade or two

And yes, several of the MLTL combos of FF85WK and Silver Flute, Peerless and even old SDX7 made for much more satisfying and placement friendly systems, IMHO.

 

[vinylkid58]

My oh my, but that takes me back a decade or two

Good times eh Chris?

jeff

 

[chrisb]

Thankfully this forum affords numerous opportunities to reminisce upon that era, and regret countless missteps and inept & inappropriate pronouncements documented along the way.

 

[christiang]

Baffle was made of a surplus meeting tabletop cut in half.

dave

This made me laugh!

COVID-19 work-from-home consequence?

--Christian

 

[chrisb]

Preceded the current era by at least a decade.

 

[planet10]

Long before covid.

People came to the event. Hugged and shook hands.

dave

 

[Bigun]

I would recommend Open Baffle for the FF85k with a crossover placed a bit higher, e.g. 500Hz, then support with ML-TL woofer to give best of tradeoffs concerning bass impact, size and room placement.

 

[adason]

"As Jeff suggests, both woofer & midTweeter should be OB, or both be in a box."

Why? I made a lot of speakers like basszilla with fullrange on open baffle and woofer in closed box. Why you make up rules where there are none?

 

[planet10]

I would recommend Open Baffle for the FF85k with a crossover placed a bit higher, e.g. 500Hz, then support with ML-TL woofer to give best of tradeoffs concerning bass impact, size and room placement.

IIRC the MJK passive OB crosses the midTweeter over at about 450 Hz. It works well and th espilt XO deals with the baffle response.

dave

 

[christiang]

Long before covid.

People came to the event. Hugged and shook hands.

dave

Oh well. Still made me laugh. I was picturing a BC Chainsaw Massacre, with those airport guy earmuffs...

The 'baffles' on these pipe monsters I built for a friend ca. 2000 (MLTL, although I did not know this term back then) were hacked from melamine kitchen top. Woofers are modified vintage Radio Shack 40-1197 with added mass and white glue coating (carefully avoided the fabric surround). Surprising amount of bass in a small appartment! Tweeter heavily padded down so efficiency is best studied by speleologists...

--Christian

 

[KCHANG]

I have tried my FF85wks in various configurations that use helping woofers. An image of the current configuration is shown below.

Each FF85wk is in a sealed enclosure that is concealed in a 24"-diameter papier mache sphere, which sits on a bass module with two 8" woofers. This configuration produces the best sound I've gotten from those small drivers. I am very satisfied with the sound. To me, they are "as good as it gets" for systems using tiny fullrange drivers.

Kurt

 

[planet10]

Have you tried with the woofers closer to the FF85?

dave

 

[Vix]

Kurt, do FF85wk neally need such big balls?