Fostex FE107E speakers

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I bought 2 from Madisound this week and have built the box shown in plans on the site, tuned to 93HZ. Do I need any sort of BSC or do I go with out? They show nothing but hook up the driver direct. This is my first FR project. It is for a sonic T AMP. What will I have next week when I test them out?

Thanks

Bob
 
You may want to use BSC. I am a firm believer in it! Others consider it heresy.

However...

Start by breaking in the driver for a couple hundred hours. The sound will change the most in the first 40 hours (in my experience anyway.)

Then tweek the stuffing in the cabinet.

Then decided on BSC. If you aren't already aware of it, check out the BSC calculator Martin provides at quarter-wave.com. I would ignore the zobel network. The inductor will define the frequency hinge point and the resistor will control the amount of adjustment. You might want to buy a number of Mills resistors to try, or use an L-pad to make an adjustable BSC--another suggestion found it Martin's site. I find that a change of only 0.5 ohms makes a significant difference. Too much resistance & the sound becomes totally lifeless; too little & the sound is 'extremely detailed' but quickly becomes painful & causes headaches.

Just my $0.02, As always: YMMV

Cheers, Jim
 
I built these and am amazed at their performance. I plan another FR project. So, which drivers? I like small so I guess 4-5". Does anyone make test available to aid selection? I want to place them on a 16' wall, with a sub to cover the low end. I can cross over, up to 180hz or so, as needed. I might use the crossover in my WHS which has all my music on it. Just use the onboard sound card and the HT antilogue outs. I can't find what the crossover point is.

The FE108E Sigma looks charming but is it any better than the FE126? And do either have advantages over the FE107 I like so much.

I would like something to put in an unobtrusive box that is tall enough to make stands unnecessary. Tall and thin, but not 5' tall! Wife does not want them to MAKE a Statement. She rolled her eyes at the Frugle Horn.

Thanks for your comments

Bob Howell
 
16" wall--sounds like you have a large room.

I built a pair of Metronomes w/ FE108eSigma drivers. I love them! But I don't think they'll cut it in a big room. The room I have the Mets in is 14' 8" X 13' 2" w/ cathedral ceiling. If you think the 108 has enough output to satisfy you, then the small foot print and modest height should work for your wife. My wife thinks they are cute. ;)

Cheers, Jim
 
Well, my daughter loves the new speakers and the BR box I built from the plans Fostex provides. These are up against the wall run with a small sub with f3=35.

I am thinking of making a Frugalhorn for her drivers, or a Suzy Chang. Which ever she likes. What would be the difference, or improvement over the BR box they are now in; is it worth the effort? The base extension seems to be the big point but I have a sub for her.

I could just leave them there and get a pair of FE126e-127e and make a horn design for me to experiment with.
 
I also use subs w/ my FR speakers. Being careful to set their XO's low enough so as to avoid mid-bass bloat. Both the FE108eSigma Mets and the FE127e Fonkens reach down to 40 Hz in my rooms (which appears to be lower than most folks get.) Still, for a truly satisfying listening experience, I find I need a system to get down to 30 Hz.

Different cabinets will exhibit different characteristics. Most folks here will say that the Fostex recommended enclosures don't get as much performance out of a driver as other, newer designs can. I would say that both the Met and the Fonken will provide better imaging and sound stage than the Fostex BR cabinet. The double mouth MooseBVR designs will provide a slightly different perspective, but will again improve on sound stage and imaging. As always, YMMV.

Cheers, Jim
 
Jim Shearer said:
... the FE127e Fonkens reach down to 40 Hz in my rooms


planet10 said:


In my wildest dreams i never would have expected a set of Fonkens to go that low. Initial estimates based on impedance curves was about 70 Hz. Later measurements pushed that down a bit.

dave

I seriously doubt that your Fonkens are going that low. They do go low enough to capture the harmonics of the double bass and (moderately low) piano. Your ears and brain reconstruct the missing fundamental and trick you into thinking that the 40Hz fundamental actually exists. This phenomenon is helped by the fact that the harmonics are stronger than the fundamental in low plucked instruments.

Bob
 
Dave & Bob,

I checked the Fonkens using a Stereophile test CD and a RS spl meter: I find that the output is the same at 40 Hz as at 200Hz. There is a bump in between due to a room mode at about 80 Hz. Is there something else at 40 Hz? I have no way to know.

In the interest of full disclosure, I must point out that:
1) I use a Sansui 4000 SS receiver and added a BSC (1 mH inductor, 5.5 ohm resistor)

2) I lined the cabinets w/ 0.5" PE acoustic barrier foam (rather than the recommended felt.) Otherwise, the cabs are made as close to the specs as I could manage.

Does this make any measurable difference? I have no idea. :scratch1:

All I know is that in my room with my equipment, the Fonkens do WAY MORE than even the most optimistic estimates.

Cheers, Jim
 
frugal-phile™
Joined 2001
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I have measured the Fonkens in my room, and they measure much lower than any expectation (blue curve) and almost as low as Jim is getting... they go almost as low as the push-push SDX7 TLs but don't have nearly the weight or apparent extension. My room is quite large, i could easily see a more "normal" room having more gain.

Measurements taken outside by a 3rd party show extension to 55-60 Hz and an expected 6 dB of bafflestep loss.

Fonken-inRoom-Measures.gif


upper limit of my current measuring kit is about where the measure starts plummeting.

dave
 
Had another thought about the Fonken performance:

I carefully finish ALL SURFACES, inside & out. I have heard that speakers sound better if they are completely finished/sealed, but I have no data one way or the other. It seems to me that this would make the cabinet more dimensionally stable, but it may also affect resonance(s.)

Cheers, Jim
 
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