Noob questions re Fostex 103e

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TonedeafDIY

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Joined 2005
#1
My Fostex 103e BLH cabs are coming on well now (just the sides to fit now after I put cables in.
I have some questions though.
I know the drivers will need breaking in, what's the best way to do this, time etc?
Should I tape the basket on the drivers and will I notice? I have used my trusty router to chamfer the inside of the baffle.
The cabs are made of MDF, I know its been commented on re BLH construction (I can get MDF precision cut and supplied at work for free😀 ). Should I treat this internally in any way or am I not likely to notice in the real world?
Oooh! and can I use phase plugs with the 103e and will I notice.
Sorry for the myriad of questions, its all a bit new to me.
Cheers
Paul
 
#4
I built a pair of these just recently out of plywood. I was expecting better than I got (after earlier listening to just the raw drivers in a simple OB) and asked similar "tweaking" questions in the FullRangeDriver forum here http://fullrangedriver.com/forum/viewtopic.php?id=436

I did notice what I thought was a slight difference after the drivers ran in for only 5 or 6 hours.

The Planet10 website advises against using phase plugs with the FE103E described here http://www.planet10-hifi.com/FE127.html because for the FE103E/126E/127E family; "the way that the lead-in wire is connected to the voice coil is such that it is far to easy to kill your driver during clean-up after the removal of the dustcap."
 
#7
Just buy the drivers, you won't be sorry. I made a pair several years ago and still use them on a semi-regular basis. I only use them semi-regularly because I can't stop making speakers.

They are an incredible imaging speaker. They won't play your AC/DC very well, but accoustic jazz is stunning as is the female voice. These speakers still amaze me everytime I listen to them. Add a smal sub when you can and you will be very happy.

Gary
 
#9
Cal, I've been thinking about using these in a different way. Would you care to share what you have added to the 103's for highs and lows.

Thanks for your any help you could give and pictures would be even better.

Gary
 
#10
TonedeafDIY - I didn't mean to sound discouraging. I like the FE103Es a lot. They have great imaging but struggle with deeper bass and louder volumes (no surprise for a 4" driver). Since I listen to blues rock and alternative music mostly they can't keep up. However they sound great with acoustic music and seem much better suited to small rooms.

I found the Fostex 103 BLH design to be a difficult cab to build. All of the cuts (there are a lot!) require precision to get the internal horn path correct and stay consistent between both speakers. IMO the Fostex recommended BR version for the 103 is just as good sounding and a lot easier and less expensive to build.

I like the FE167Es much more but they're are roughly double the price. I have these drivers in a Bob Brines FB-16 which I think is a great design.

I also have a pair of FE126Es which seem to sound excellent out of the box but I haven't built cabs for them yet - I'm not happy with the Fostex cabs for this driver. After my build experience with the 103 BLHs I'm not anxious to try a cab design like Ron's A126 yet although if you can get around its looks it appears to be a great design.

My recommendation - start with the FE103s and build a BR or TQWT. If you can afford the FE167E jump to that driver and put them in a BR or TL design.
 
#11
holdent said:
The Planet10 website advises against using phase plugs with the FE103E described here http://www.planet10-hifi.com/FE127.html because for the FE103E/126E/127E family;
Click to expand...

I thought i'd updated that page. The FE103e is OK to install plugs in. With Andrew chimimg in, that is at least 2 people who have done it successfully.

We built the Fostex FE103 horn and weren't very happy with it. A buschhorn II is a better bet. The RonHorn A126 with an FE126 is even better -- quite a bit better. And if i have the same success tweaking the FE126 as the FE127 i did earlier this week it will be even better yet.

dave
 
#12
Holdent, thanks for the advice. These were meant as a first foray into speaker building and as such intended to be cheap but worth the effort.
As I have said, I can get MDF precision cut at work so that chore is spared me! I did not think the cabinets were that bad to build, they went together well and with little effort. Patience was another thing.
I'll see how these go and move onto something more capable as funds allow.
Cheers
Paul
 
#13
ejfud said:
Cal, I've been thinking about using these in a different way. Would you care to share what you have added to the 103's for highs and lows.

Thanks for your any help you could give and pictures would be even better.

Gary
Click to expand...

Hi Gary,
I run a Coral version of the F103 from 1K to 10K, first order.
I added an old Foster tweeter for the top, XO at 10K first order.
I added an MCM poly woofer for a midbass, XO 100 - 1000Hz
I have the TB W6-1139 with drone cone and plate amp all in one neat little package.

This is the back
 

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#15
Those look very cool! Does the FE103 sound good as the midrange? Is the sub and passive in the same cabinet or isolated.

I wish I had a better understanding of schematics and electronics in general so I had an idea of what you are talking about in the crossovers. I really think the FE103 would be great in this role. I just don't have the ability to make the crossovers.

I have 2 pairs of the old Foster 103's at my disposal for a project like this, but my lack of knowlegde has held me back. I was thinking of using a super tweeter and a small sub to make a quazi 3 driver system. Any thoughts?

Thanks again for the great pictures.

Gary
 
#19
planet10 said:

The FE103e is OK to install plugs in. With Andrew chimimg in, that is at least 2 people who have done it successfully.

We built the Fostex FE103 horn and weren't very happy with it. A buschhorn II is a better bet.
dave
Click to expand...

I'm curious about the shape of phase plugs—most of them seem to taper to points. If they "essentially halve the distance from one edge of the cone to the other", does the point of that tip, in effect, put a hard-edged point of diffraction around that halved-cone?

Would a phase plug with a domed-top sound better?

(I have the FE103e in MDF zigmahornets. The dustcap of one was mod'ed by little fingers, so I've been thinking about phase plugs for both. And, either plywood Buschhorn IIs or a set of mini-BIBs are going to be their next homes.)
 
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