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Fostex 167E distortion [message #21264] Fri, 26 August 2005 13:05 Go to next message
Dave is currently offline  Dave
Messages: 27
Registered: May 2009
Chancellor
After being extremely pleased with the midrange of a pair of Fostex 127E BR speakers I built I decided to try a pair of BR 167E's. These don't have the magic in the midrange that the 127E's do. There seems to be a distortion in the upper midrange, highest octaves of the human voice and the electric guitar. I never had this problem with the 127E's even when new. I am not using BSC on either speakers.

Re: Fostex 167E distortion [message #21265 is a reply to message #21264] Fri, 26 August 2005 15:26 Go to previous messageGo to next message
Bob Brines is currently offline  Bob Brines
Messages: 186
Registered: May 2009
Location: Hot Springs Village, AR
Master
Try using a BSC, something like 1.5mH||4-6 ohms. I've never had a problem with the upper mid-range of the FE167E. The FE127E has a serious hump in the frequency response 5-10K Hz. I find the FE127E unlistenable without a zobel to bring down the rising FR.

Bob


FE127e [was] Re: Fostex 167E distortion [message #21269 is a reply to message #21265] Fri, 02 September 2005 14:04 Go to previous messageGo to next message
lon is currently offline  lon
Messages: 760
Registered: May 2009
Illuminati (2nd Degree)
Bob,


What do you suggest for the FE127e problem?


I have the FE127e's in GM designed MLTL.

Re: FE127e [was] Re: Fostex 167E distortion [message #21270 is a reply to message #21269] Sat, 03 September 2005 06:24 Go to previous messageGo to next message
Bob Brines is currently offline  Bob Brines
Messages: 186
Registered: May 2009
Location: Hot Springs Village, AR
Master
I'm real sensitive to spitting, sibilant speakers. A zobel helps when a driver has a rising FR like the FE127E. Try 8 ohm and 2.2 uF.

Right now I'm trying to find a good cabinet for a pair of FE127E's I have laying around. I've looked at all of the MLTL variants, BR's and the Fostex standard DBR. Nothing is going to go below 70 Hz and max power handling will be in the 1/2 watt range -- 85dB max undistorted. The only use I can see for a "full-range" application is computer speakers, and 24x9x9" is a bit big for my computer desk. I'm thinking that the right application for this driver is as a mid-tweeter over a 10" or 12" woofer and crossed at 300 Hz or so.

The best of the lot is indeed the Fostex DBR. However, the dip at 150Hz is just hinted at in the Fostex FR plot. Running the numbers through MJK's spreadsheet shows the dip to be a very sharp 20dB hole. AT 150 Hz, that should cause notes to drop out! Anyone build the standard DBR?

Bob

Re: FE127e [was] Re: Fostex 167E distortion [message #21272 is a reply to message #21270] Sat, 03 September 2005 12:25 Go to previous messageGo to next message
lon is currently offline  lon
Messages: 760
Registered: May 2009
Illuminati (2nd Degree)
Building anything fresh for me is going to be a problem since
I've developed some joint problems.

So my other question is what would be a good upgrade for the
FE127e that would be plug and play for my MLTL?


FX200 has been mentioned by GM as a drop in replacement.


Overall I'm sold on the MLTL config. The boxes have nothing
inside and I extended the port tube to 6". Original calls
for much less to attain very low frequency but the elongated
port brings the harmonics up to where all stringed instruments
like double bass and piano sound superb.


I will be interested to see what you come up with for these.

I originally got the FE127e's for computer speakers. But they
sounded better than the off brand mains I had so I started to
build with them.

The previous bookshelve speaks had junk in them near as I
can figure but the workmanship is great. I have some
blank baffles made to tinker with some other speaks for those.
Measures are very close to what Jim Griffin uses for his
Jordan BR.

Re: FE127e [was] Re: Fostex 167E distortion [message #21273 is a reply to message #21272] Sat, 03 September 2005 21:12 Go to previous messageGo to next message
GM is currently offline  GM
Messages: 114
Registered: May 2009
Viscount
>FX200 has been mentioned by GM as a drop in replacement.
=====
Greets!

I believe you meant FX120........

That said, assuming you didn't get carried away cutting out the mounting holes, the new CSS 125S is a slightly smaller, but still drop-in once you drill new mounting holes, and sims better overall in your cabs than either the Fe127E or FX120. I gather from your remarks that strong bass isn't desired, so you may have to either extend the vents to 8" or damp them to suit.

GM


Re: FE127e [was] Re: Fostex 167E distortion [message #21274 is a reply to message #21273] Sat, 03 September 2005 22:37 Go to previous messageGo to next message
lon is currently offline  lon
Messages: 760
Registered: May 2009
Illuminati (2nd Degree)
Hi Greg,

Thanks for responding. And yes I must have meant what you said.

The CSS would be an interesting experiment.

And I still have (or can get more 2" pvc.


Bob's comments notwithstanding, the FE127e in the MLTL
made me a believer. This is stereophile sound on a true
budget:

Particle board shelving, pvc and a bit of glue.

I did make some grilles out of a piece of 3/8 in
particle board and some stretchy doubleknit fabric
from my old bell bottoms... (just kidding.) Grilles
look good though for being a cut and paste job.


Maybe the CSS 125's will go on deal.


One of us on here was saying they were overrated IIRC.


Over at Full Range Driver Forum there has been some
talk about a Tangband model -- 1346 (whatevs) that is showing
potential for full range builds as well.




Re: FE127e [was] Re: Fostex 167E distortion [message #21275 is a reply to message #21269] Sun, 04 September 2005 15:38 Go to previous messageGo to next message
moray james is currently offline  moray james
Messages: 51
Registered: May 2009
Baron
Have a look at Onur Ilkorur's site at this address http://www.yildiz.edu.tr/~ilkorur/. Onur has a great design for the fe127e which can also be used for the fe126e as well. Not to mention his Singular design which he says kicks butt with a Tannoy in wall dual concentric that hits 27 Hz. and plays as loud as a PA system with no distress. Regards Moray James.

Something new on the radar [was] Re: FE127e [was] Re: Fostex 167E distortion [message #21277 is a reply to message #21273] Mon, 05 September 2005 14:11 Go to previous message
lon is currently offline  lon
Messages: 760
Registered: May 2009
Illuminati (2nd Degree)
Hi Greg and all,


Adire has a driver on pre-order called the Extremis 6s.
It's getting favorable recognition over the CSS released
product. Any news on that?


A fresh thread is called for... I'll go to the top and make
one.

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