I’m busy right now building Metronomes for the Fostex F120A’s I bought last summer. However, I just bought a pair of Fostex FF85K drivers for a micro-Fonken build later this summer. Usually I put new drivers on OB (i.e. an old board) to check them out & get an idea of how they will sound, but I was afraid of hurting these little guys.
Others have put their drivers into cardboard boxes to check them out--not a bad idea! Just need to figure out how big a box I need. So I got out David Weems’ “Designing, Building, and Testing Your Own Speakers” and calculated a ported box for he FF85K. Works out to 1.77 liters and the port...Hey, that’s pretty much what I’d have if I cut the bottom off a 2 l soda bottle, glued a piece of wood to it, and added a bit of fiber fill!
So here it is: the FF85K Sprite!
(Note that Sprite is a brand of lemon-lime soda here in the USA.) Photo below shows The Sprite perched atop the Fonkens I built last summer.
How does it sound? Not bad. Especially considering that the drivers are fresh out of the box and the ‘cabinets’ are fresh out of the re-cycling bin. (But I do expect that the micro-Fonkens will be considerably better.)
Cheers, Jim
Others have put their drivers into cardboard boxes to check them out--not a bad idea! Just need to figure out how big a box I need. So I got out David Weems’ “Designing, Building, and Testing Your Own Speakers” and calculated a ported box for he FF85K. Works out to 1.77 liters and the port...Hey, that’s pretty much what I’d have if I cut the bottom off a 2 l soda bottle, glued a piece of wood to it, and added a bit of fiber fill!
So here it is: the FF85K Sprite!
(Note that Sprite is a brand of lemon-lime soda here in the USA.) Photo below shows The Sprite perched atop the Fonkens I built last summer. How does it sound? Not bad. Especially considering that the drivers are fresh out of the box and the ‘cabinets’ are fresh out of the re-cycling bin. (But I do expect that the micro-Fonkens will be considerably better.)
Cheers, Jim
Attachments
I heard the FF85K Sprite speakers this afternoon at Jim's house. Running with a sub to fill in the very bottom, these little drivers sounded great. I was extremely impressed. If they were not out of stock at Madisound there would probably be a pair on their way to me right now. I can visualize quite a few two way speaker designs that would be a bargain to build and perform way better then they should using these drivers.
MJK said:
When i started working on FF85 i was worried about being able to sell them for what i'd have too... after i heard them i knew it was only a matter of getting sufficient people to hear them... and now with the Audience A3 double the cost of my version, they seem a real bargain.
Cal & i were talking about an array of 4 per side (like the Jordan, Bandor stacks that have lead to the A3) with woofers on the bottom -- this just after he heard uFonken. I was chatting with someone the other day, and he was speculating about whether the elevated HF of the A3 had something to do with countering the combing issues of multiples of these... FF85 seems to have a similar rise at the top (and you could buy an array of 4 stock ones for not much more a pair of A3).
I wonder if Madisound has had a bump in sales.
dave
MJK said:
Have you seen the Tysen thread?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=144099
dave
Just to chime in I made a pair of the uFonkens a while back. I needed some computer speakers at work. These are the perfect size to sit on the the desk. I have been listening to them for over a month now about 8 hours a day. These sound great. No fatique at all listening to them. The reason I have not posted pictures because they are still in plywood. I have not had a chance to veneer them. I will soon hopefully. But if anyone needs a computer speaker or is looking at a speaker in the 3" range these are the ones to get.
John
John
The FF85k's are now broken in and sounding amazing! As noted above MJK came over to check out the F120a Metronomes, but took time out to have a listen to the Sprites. While the Sprites may look butt ugly and have no WAF, they sound GREAT!
That doesn't mean that I have abandoned the micro-Fonkens--those are under construction. On the other hand, my enthusiasm for the FF85k has me planning two, more extensive builds for next summer using this very special driver.
So little time. So many speakers to build...
That doesn't mean that I have abandoned the micro-Fonkens--those are under construction. On the other hand, my enthusiasm for the FF85k has me planning two, more extensive builds for next summer using this very special driver.
So little time. So many speakers to build...
Hi ped,
I tossed out the calc. I did based on the Weems book, but a quick visit to Madisound for their link to an on-line calculator yielded the following:
V(box)= 1.82 liters
F(box)= 104 Hz
Ripple= 0.02 dB
F(3)= 96 Hz
Port D= 1.06"
Port L= 2.59"
Port area= 0.83 sq. in.
Not identical to what I figured out from Weems, but close enough.
Cheers, Jim
I tossed out the calc. I did based on the Weems book, but a quick visit to Madisound for their link to an on-line calculator yielded the following:
V(box)= 1.82 liters
F(box)= 104 Hz
Ripple= 0.02 dB
F(3)= 96 Hz
Port D= 1.06"
Port L= 2.59"
Port area= 0.83 sq. in.
Not identical to what I figured out from Weems, but close enough.
Cheers, Jim
kazoo said:
uFonkens in Macassar Ebony, along with Kingrex T20U amp & power supply - and iMac..
An externally hosted image should be here but it was not working when we last tested it.
http://homepage.mac.com/tlinespeakers/FAL/box-plans/microFonken-0v9-map.pdf
"John, out of curiosity:
what amp are using, and are you driving them from the computer sound-card, or higher up the food chain? (i.e. outboard USB DAC, etc)?"
Chris,
Nothing fancy running them. I have a Philips micro system that is a 5 disk changer. So I listen to CDs mostly but it also has an AUX IN that is plugged to the computer to listen to MP3s. The computer has a standard sound card. One thing that amazes me is the sound stage on these, especially the channel seperation. It could be how close I am sitting, but I do like the way these sound.
John
what amp are using, and are you driving them from the computer sound-card, or higher up the food chain? (i.e. outboard USB DAC, etc)?"
Chris,
Nothing fancy running them. I have a Philips micro system that is a 5 disk changer. So I listen to CDs mostly but it also has an AUX IN that is plugged to the computer to listen to MP3s. The computer has a standard sound card. One thing that amazes me is the sound stage on these, especially the channel seperation. It could be how close I am sitting, but I do like the way these sound.
John
What type of demping material should i use in uFonkens and how?
I'm listening to them without any demping material, the sound has got some king of sreaming side.
I have been listening ff85k for about a year in closed box and 18W8531 in vented box with XO around 1k hz, now i'm building uFonkens and SP95
SS and fostex are a bad match.
The bass from uFonkens is just right.
Thanks.
I'm listening to them without any demping material, the sound has got some king of sreaming side.
I have been listening ff85k for about a year in closed box and 18W8531 in vented box with XO around 1k hz, now i'm building uFonkens and SP95
SS and fostex are a bad match.
The bass from uFonkens is just right.
Thanks.
Attachments
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.