My Fostex FE108E Sigma project..

[Taperwood]

There're here!!! It's like Christmas again. Sweet looking drivers. Nice and heavy.

I would like to document this project as I go to share with others and to keep as a record for myself (if that's okay with everyone?). I plan to do a lot of prototyping and testing.

First, break-in. Tonight, I will cut some baffles out of MDF and mount the drivers. I will use the 10w amp for my computer speakers to drive them. This way, I can run the drivers day and night with all kinds of voice and music.

Question: I understand volume is important to breaking in, but how loud? That's one thing I can't seem to find.

Doug

[pinkmouse]

To run drivers in, I usually wire them out of phase, stack one on top of the other, and run 15Hz sinewave from a frequency generator at just under Xmax for 4-12 hours or so. That keeps the noise to a minimum, and seems to work well. Just keep an eye on the temperature, though in free air, and with no loading on the cones, they shouldn't dissipate too much energy.

[Corloc]

I put my fe206e's into cardboard boxes with holes cut into the top and pillows in the bottom. Hooked them to my old onkyo reciever and let them play for a few weeks. I just used the volume level that wasn't disturptive to the household. It work just great.

Near as I can tell the mechanical parts of the driver just need a little exercise to loosening up. I had the drivers running for two weeks this way (about 336 hours), and I haven't detected any differance in sound quality over the next year. O' and I listen to my setup for 5 to 10 hours a day.

Anyway, I am intrested in your new project. I have my eyes on the 108 or 168 for new project. What cabinet are you looking to build?

Chris

[planet10]

108ES is a lovely driver... i'm just hoping someday to see an alnico version...

dave

[Josephjcole]

Please keep us posted as to your results. I've quite enjoyed my 108's, they are now in thier third pair of speakers, a two way with a 12" eminence. At some point I'ld like to try them in front horns, but I'm quite happy with them just the way they are for now.
Joe

[Taperwood]

Thanks everyone.

I put them in a MDF open baffle last night and will play them 24/7 for the next week or two. I have them in my basement office, where I use my Yamaha 3" speakers. The difference in sound is quite dramatic. The 108's also reveal a lot more background noise from the amp, so I am going to have to be careful what I ultimately hook them up with.

They sound really nice. A little thin, but I expected that, and, of course, no bass at all. Right now, Horowitz is playing Chopin. I do notice a dramatic improvement in the midrange and upper midrange compared to the Yamahas. Yes, vocals do sound a LOT better.

As for an enclosure, I am ultimately shooting for a Buschhorn, but I have so many ideas floating around in my head that it will be some time before I actually build something permanent. I want to experiment with the sound of open baffles, tubes, pipes, X baffles, concentric rings. The ideas just keep coming. The Replikon (sp?) looks really cool, and now I wonder what that sounds like. My wife likes Terry Cain's Abbys, so maybe I can come up with a smaller version (the "Babby").

I won't have anything specific to add to this thread for a week or two. Until then, here's a picture of the break-in baffles. The foam is to protect the finish from the screws I used. I will not use the Fostex screws until I put the drivers into their final enclosure.

Doug

[Josephjcole]

Originally posted by Taperwood
As for an enclosure, I am ultimately shooting for a Buschhorn, but I have so many ideas floating around in my head that it will be some time before I actually build something permanent. I want to experiment with the sound of open baffles, tubes, pipes, X baffles, concentric rings. The ideas just keep coming. The Replikon (sp?) looks really cool, and now I wonder what that sounds like. My wife likes Terry Cain's Abbys, so maybe I can come up with a smaller version (the "Babby").

Let us know how the experimentation goes. Although I will say from personal experience, that the fostex 108es is quite limited as an open baffle driver. It has such a small x-max that it's limited to either low level play back, or an extra large tweeter on an open baffle. Quite a nice driver though despite it's limitations.
Joe

[robertG]

Lovely driver! Break-in time is very very long and mine got better every passing day. I sold them to get a pair of FE168EZ. Dub reggae is the best break-in music with heavy bass beat and sizzling highs.
Back loaded horns are the best way to go if you intend to use them full-range on their own. You might find the Bushorn a bit boomy while the Fostex design seems better balanced in my opinion.
Great driver! If you plan to use it with a SS amp, try a non-inductive resistor in serie (in between 4 and 10 Ohms). Best $5 tweak for the money.

[kiang]

I agree - the 108 is a fantastic little driver.
I have built some horns with them - very pleased with the results
My T Amp project feels just right for them.

http://www.auricles.com/new_page_9.htm

[planet10]

Originally posted by robertG
You might find the Bushorn a bit boomy while the Fostex design seems better balanced in my opinion.

If anything the B-Horn doesn't extract enuff bottom out of the 108, but what is there is very good.

The Fostex horn i'm working on still doesn't sound right (not with 108ES thou)

dave