Original enclosures for Fostex 103's

[airframe]

I searched full range drivers and haven't found much mention about the enclosure suggestions from Fostex, is there a reason ? Will they sound pretty good? Has ANYbody built these ?? Am I just wasting my time??

My first build, I have a NAD 3020e amp that will power these, just want a small bookshelf units that will compliment this amp. Room size is about 10 x 16. I've selected 103's because they can be used in so many different enclosure types but for now I'll do these. Already have the 3/4" MDF and will use 1/2" apple wood front.

http://www.fostexinternational.com/docs/speaker_comp/pdf/recom_enclose/103e_encl.pdf

 

[planet10]

We built the Fostex horn, it sucked. Probably the best existing box for the FE103 that satisfies your criteria is Tony G's Solo 103.

http://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Solo-103_copy.pdf

This thou is for the older FE103. I just got a pair of FE103e and will be working thru to something in the Fonken family for them.

dave

 

[airframe]

Ooops sorry should have said what enclosure on that page , looking at bass reflex unit at the bottom. And yes the new versions of 103's at Solen.

 

[chrisb]

I've had enough experience building more than one of the Fostex factory recommended enclosures for various drivers to offer the opinion that you could do much better than this particular BLH design for the FE103E .




To name a few:

Buschorn MKI (originally designed by Dr Busch for a 3" driver, but easily modified to fit the FE103E or even FE126 - I've built this for both the FE108ESigma and FE126 );


http://homepage.mac.com/tlinespeakers/FAL/box-plans/buschhorn-Mk2.gif

Tony Gee's Solo 103;

http://www.humblehomemadehifi.com/Solo103.html

Scott Lindgren's Vampyr;

http://homepage.mac.com/tlinespeakers/FH/download/Vampyr-map-1v1-010109.pdf

GM's MLTL;

http://www.diyaudio.com/forums/showthread.php?postid=535015#post535015

and for bipole;

http://homepage.mac.com/tlinespeakers/FAL/box-plans/BD-pipes-drawing.gif

This last design was my first serious entry in the crazy world of Single Driver designs, and I've built probably a dozen pair with vintage Foster alnico precursors to the FE103, as well as NOS and used RS 40-1197. Still somewhat limited at the extremes of SPL and bass extension, but in the right system can deliver a helluva soundstage, and definitely benefits from a powered woofer, XO'd between 100-120 IIRC


p.s.:

It looks like Dave beat me tuit, but for someone looking for a range of designs, particularly one not requiring stands, the list above still stands

edit: After reading your reply above, the question remains as to whether you're specifically looking at the little BR for simplicity of construction, or space requirements. By the time you consider the footprint and expense required for many little monitor designs (the Fonken stand-mounters included), a floorstanding enclosure can start to make sense - and they often deliver more extended LF response.

 

[airframe]

A little of both Chrisb, I guess, has the BR given by Fostex been built? So far I got $6 of MDF, I'll spend maybe $120 to get the Fostex here, some binder posts and the Apple wood on the front and of course my time. At the end maybe $140 Cdn. The questions still remains on the viability of the BR's. No doubt there are better enclosures out there but for size, lack of complexity, cost is the difference going to be apparent to the average listener like me? Are you going to notice it with Gordon Lightfoot, Simon & Garfunkel or Jimmy Buffet ?? We can all search for the holly grail of speaker enclosures ( so far I think that will be the BIB that I will eventually build) but for now has anyone come up with any real issues on the BR's, lets face it the average speaker out there is a BR enclosure of some sort !!

 

[Cal Weldon]

is the difference going to be apparent to the average listener like me?

Yes.

Are you going to notice it with Gordon Lightfoot, Simon & Garfunkel or Jimmy Buffet ?? [/B]

3 of my favourites, with Jimmy (two t's) Buffett at the top of the pack. I run my Foster 10F3's in a BVR cabinet with a helper woofer in a separate cabinet with a plate amp. Very nice combo.

 

[airframe]

Cal, way to big, WAF very much in the red !!

 

[HareBrained]

Hmmm, if you haven't bought the drivers yet, why are you set on the FE103?

There are some other options out there that you may want to consider. The Mark Audio CHR70 for one. Cost will be less and you'll be very happy with their performance (I am). They're available in CA from creativesound.ca.

 

[airframe]

Hmmm gona have to look at those ??? Thanks, didn't think the cost was less actually! Anyone else try these in a simple BR yet

 

[chrisb]

Mark, FWIW, I've built a variation (i.e. revised aspect ratio of dimensions and additional bracing) of the Fostex recommended enclosure for the FE167. Compared to 2 other designs by Dave & Scott, (Fonken 167 and Demitri) it severely limited the driver's performance. I'm too lazy to experiment if that would be the case for every driver I might find interesting.

Our only enclosure built to date for the new Mark Audio drivers was a 6 litre sealed box for driver break-in for the CHR70 , and Henkjan's MLTL for the Alpair5. It's my intuition that the full potential of these drivers is not yet realized with these simple boxes.

Next up is the Lotus^2 for CHR70, but as circumstances limit my construction time, previously committed projects will delay completion of that one for at least a couple more weeks.

A final observation, based on several of my own earlier experiments - considering the investment in drivers and your labour, I'd definitely recommend baltic birch plywood for any of the contemplated enclosure designs. I've used it exclusively for the past 3 years now, even including boxes for my car install buddy.

 

[Bob Brines]

IMO the Fostex recommended box for the 167 is a reasonably good implementation as an HT satellite crossed ~100Hz. the too small box limit excursion which is a good thing for HT. Remember that Fostex markets the FExx7E line as "AV"

My personal recommendation for the 167 in a BR is 24l tuned to 60Hz.

Bob

 

[chrisb]

IMO the Fostex recommended box for the 167 is a reasonably good implementation as an HT satellite crossed ~100Hz. the too small box limit excursion which is a good thing for HT. Remember that Fostex markets the FExx7E line as "AV"

My personal recommendation for the 167 in a BR is 24l tuned to 60Hz.

Bob

Fair enough, Bob; the 167 does work quite well in exactly that implementation - of course, the exact number and XO to woofer(s) is up to the user.

 

[airframe]

Hare Brained

other options out there that you may want to consider. The Mark Audio CHR70 for one.

SO what small enclosure would be good for these, bookshelf style, don't want any x overs, plane simple etc... Any suggestions

 

[Bob Brines]

Hare Brained
SO what small enclosure would be good for these, bookshelf style, don't want any x overs, plane simple etc... Any suggestions

Well, I think I did! Understand that the 167 is not going to produce meaningful bass in a small BR. If you can accept F3=60Hz, then go for it. Otherwise, you will have to cross to a sub or go to a much larger cabinet.

Bob

 

[HareBrained]

SO what small enclosure would be good for these, bookshelf style, don't want any x overs, plane simple etc... Any suggestions

I put my CHR70 into a dual-chamber bass reflex. Dimensions are 21.5"x8.5"x5" with a net internal volume of 8.1L. Port tuning is ~50Hz and F3~45Hz. No xover. You could do anything from 5L on up. I chose the largish volume because I'm not using a sub and I needed to raise the driver 15" above my desktop. You could even do a 4L sealed (predicted F3~80Hz) if you're using a sub. I'm thinking of building a sealed enclosure just to hear how it sounds.

I'm also impressed by the SPL of the speakers. They can become very loud if needed, and the DCR-style enclosure is great for controlling excursion. The DCR could be made as small as 7L and still have a sub-50Hz F3.

Now, since I'm using these for near field listening, I don't need, or have, any BSC. You may need to do something if your situation requires it. But that would the situation for any speakers.

 

[airframe]

Thanks Hairbrained for your suggestions.

I'd still like to hear from the fans of the FE103E's on 6-7 liter BR enclosures, what can I expect for F3? These will not be near feild just in a smaller room no sub planed. Still like the 103's because of all the different cabs that has been built with them.

 

[chrisb]

Thanks Hairbrained for your suggestions.

I'd still like to hear from the fans of the FE103E's on 6-7 liter BR enclosures, what can I expect for F3? These will not be near feild just in a smaller room no sub planed. Still like the 103's because of all the different cabs that has been built with them.

It seems that your potential application may have changed? If these are to be used not near-field, but in a small room with no sub, then you might well be better served considering the FE127E. (and extra inch in girth can certainly make a difference)

There have been more than a few different cabs designed for them, and in case it wasn't mentioned before, I've built at least half a dozen of them myself - 3 of the Fonken designs, Mileva, Brynn, monopole and bipole MLTL. For my money, it's at least as flexible in terms of potential enclosures as the FE103E, with better performance in the lower octaves. I have 2 systems with FE127E, one at approx 220 sq ft, and the other at 340 (2 channel video) - neither system is ever taxed beyond 90dB, and they are are quite satisfying without subs.

 

[planet10]

I'd still like to hear from the fans of the FE103E's on 6-7 liter BR enclosures, what can I expect for F3? These will not be near feild just in a smaller room no sub planed. Still like the 103's because of all the different cabs that has been built with them.

80 Hz, but really easy to exceed xMax.

will work in a mFonken w port length reduced to 10.3 cm, bass to 95 Hz, not quite as much problem with excursion.

dave

 

[Andrewbee]

I'd still like to hear from the fans of the FE103E's on 6-7 liter BR enclosures, what can I expect for F3?

I'm with Dave, you may get ~80Hz out of them but they will not be loud and you will easily exceed xMax, I think its a bad idea to run them this way.

The FE-103 IMO works better in a smaller cab, somewhere around ~5 Litres. You give up a little bass but you pick up dynamics and superior cone control. I have been listening to a pair of BS-10's for a few months and they sound really good and are a very simple build.

I still believe the FE103 is best served in a horn enclosure (not the Fostex recommended one) but thats another story.




http://www.zillaspeak.com/ZillaSpeakFostex103-RS1197.asp

Second to last plan on the page

 

[HareBrained]

When I was researching FR drivers, before settling on the CHR70, I considered the 103 because of the relatively inexpensive cost but everything I found pointed to the 103 being a niche product within a niche area. If you do decide to use it, there are significant compromises you have to live with. Personally, I needed more SPL and bass then the 103 offers, and I am using them near field. If you feel that you're aware of the compromises and it's acceptable, the 6-7L size is fine for the 103, and you should continue. If you're still uncertain, everyone and everything points to no bass or SPL from the 103, even in a horn and you should look at another driver.