[KnyazHM]

Hi,
What speakers will be better? More interestingly? What differences in a sound?

Fostex FE206E+T90A in
http://www.fostexinternational.com/docs/speaker_components/pdf/recom_enclose/206e_enclrev.pdf
or
Fostex FE208EZ+T90A in
http://www.fostexinternational.com/docs/speaker_components/pdf/recom_enclose/208ez_enclrev.pdf


Thanks

[sts9fan]

Whats better?

[chrisby]

to paraphrase sts9fan "what's better mean ?"

better than what - a B0$e clock radio, or each other?

Having built / assisted in more than a few BLH of various designs, including several of the Fostex Nagaoka family for FE166ESR / FE206ESR and others, I'd suggest you consider other designs types as well - such as some of Scott Lindgren's excellent

double front mouth Olson type manifolds;
http://www.frugel-horn.com/spawn-plans.html

or more recently;
 
http://www.wodendesign.com/fostex.html


The big Fostex BLH boxes consume a lot of material (don't even think about MDF unless you want to hire a moving crew  ), are time consuming and fiddly to build, and I've heard several other and less complicated BLH enclosures (including several of the Scott's designs in above links)  that sound more balanced and exhibit less colorations. 

[Mariusz]

Hey Chris

What are the main sonic, performance differences between Sachiko and Wooden-design Vulcan? What's the presentation like? Did you hear both designs in similar listening space?
Mainly interested in rear bass loading and its interaction with room boundaries?

[chrisby]

OK, I haven't heard either of those, but if Scott doesn't mind my extrapolating my experience with Saburo/Valiant* ("equivalent" versions for FE126)  - I found the more recent Woden design to dig a bit deeper and cleaner in the lowest octave, less colored in upper midbass and with a much larger/spacious sound-stage.  I also preferred the imaging from the Valiant, but my build also included an elliptical supra-baffle.

The listening venue was this August's VI DIY audio fest at casa Dlugos - IIRC amp used was Dynamutt ( triode mode on the Fostex?)   This is an open space plan with far more cubic volume than any of mine, and most importantly, a ceiling that slopes quite steeply from less than 6ft at front end to at 16ft? at rear wall.

In my 2 channel AV system at home the Valiant fills the 320 sq ft room with a bigger soundstage than FE167E in Fonken enclosures, but with a slight sacrifice of precise imaging and bass articulation.  No matter how well the speaker system might be engineered or executed, sooner or later the room takes control - and every room can be different.  If I ever get off my ass and set up my new Denon HT receiver, I might get a bit more enthused about "upgrading" to at least 3 channels & powered woofer(s)  - or maybe not         


I'll let the designer of both attribute which of those sonic impressions could be related to differences in geometry line length / rear vs front mouth / curved vs straight mouth profile - but my money's on rear mouth & boundary loading contributing quite a bit to the performance in the lowest couple of octaves.



* note that the Saburos were built by Fleming Anderson, and the Valiant by myself from the plans originally intended for Mark Audio drivers.  After experience with several drivers in  prototypes of the new FH3, I couldn't resist wanting to try the FE126E in the "Maeshowe" and liked it from the start.   

[Mariusz]

Thanks for your generous insight on both designs. 

...............
It's certainly difficult to predict speaker-in-room response, especially lower frequencies which are far more difficult to control. 
Upper bass..., up to subsonic frequencies are less concerning and can be address with speaker placement or with more aggressive approach, such as room acoustic treatments.

From my experience with Saburo or Sachiko designs, I would assume more flexibility as far as in-room-placement is concern. 
I also enjoy that in-your-chest rumbling bass of front mouth loading.

Could you share your experiences regarding placement challenges and difference between front and rear mouth loading?
-stereo separation of the lower notes
-diffused v.s direct bass
-soundstage
-imaging

Cheers
Mariusz

 

[chrisby]

Could you share your experiences regarding placement challenges and difference between front and rear mouth loading?
-stereo separation of the lower notes
-diffused v.s direct bass
-soundstage
-imaging

Cheers
Mariusz

that's going to be a bit harder, since I don't have regular access to both types of designs with same driver and have to rely on vagaries of "selective / acoustic memory"  (I've never been good at taking notes during listening sessions)

But from the best that I can recall, the Saburos (or for that matter Aengus' curvy Harveys with FE127e) seemed to trade better stereo separation of lower notes / direct bass (which I'd probably refer to as "articulation / definition") for overall diffuse bass / ambience / soundstage size.  As well, I've found the sweet spot for mid-upper range imaging precision and depth of field to be smaller for front mouth vs rear mouth designs ( whether single or dual).

Funny that sometimes your impressions / opinions aren't quite concrete until you're asked to express them verbally / in writing.  Now that I've been thinking about it, I'd say that regardless of what others might consider deficiencies of impact / scale, for me the overall performance of rear mouthed enclosures of this general category is simply "more whole/organic". 

Of course in my own 2 systems, due to domestic acceptance factor* the "daily driver" speaker systems are not horns at all, and YMMV, caveat ad nausea.        

* is there an emoticon for pxxxy whipped?

[mp9]

Of course in my own 2 systems, due to domestic acceptance factor* the "daily driver" speaker systems are not horns at all, and YMMV, caveat ad nausea.        

* is there an emoticon for pxxxy whipped?

that would be would this, 

[KnyazHM]

What recommended cap value for T90A with FE206E and FE208EZ?

[chrisby]

that would be would this, 

definitely the no-no part

thanks for making my day

[Badwater]

What recommended cap value for T90A with FE206E and FE208EZ?

My suggestion is to pick a series of cheap caps of various sizes from 1 uf down to .33 uf wire them up and give them a listen.  After you decide which works best pick up better quality cap of your choosing. For me I ended up using 0.68 up with my Fostex FE166-ESR BLHs.

[adamt]

I have built both (sort of). The 206 was in the standard box, and the 208 was in the bigger D58es box. The 206 is more immediate and exciting, it really drops your jaw. But it can be fatiguing from the whizzer cone, and unless you are prepared to live with that / enable them / built your hifi components around the speakers, it will eventually grate you and wear you out. I ended up having to change.It also has bad hump around 100hz that is hard to get rid of.
The 208 by comparison is darker, but more even over the frequency range with a lush midrange. It specialises in mid range and hf with the horn tweeter. Not as deep in the bass. Much easier to live with, and I am now 2.5 years into mine with no regrets. Wish I had picked this one first. Better build quality on the driver too and no whizzer to cause angst.

I use a 0.47uf cap in series which works best for me. 0.68,1.0 were too bright. I reakon 0.40 is optimal, but its not a standard available size. I use Quality caps SA which are a bit softer. I found the solens too bright

Hope this helps you

[chrisby]

adam - it's not clear from this post if you tried swapping drivers between cabinets and found any significant differences between the boxes themselves?

what you describe is consistent with my experience with standard and sigma series in much smaller sizes - almost independent of enclosure type

[adamt]

Chrisby

i didnt get to swap drivers between boxes unfortunately.

The Fostex designs (which are variations on Nagaoka designs) seem to have a bass hump by virtue of the ever expanding box shapes (really a transmission line rather than a horn).

The best bit of advice i picked up was to put some wool batting in the first section of the line (ie not in the compression chamber, but in the tunnel behind it). I found this damped the peak.

The biggest improvement came from changing drivers rather than fiddling with the box. The sigma series are a different beast than the fe series, and I am very happy I traded up. They have taken about 2 years to fully settle down, but I now love the sound.

I think all the hype about the FE206E was to do with the cost/music ratio rather than an honest long term assessment of livibility. I got sick of fiddling and moved on.