Hi diy'ers
I just wanted to report, that I've built the fostex-recommended basreflex-design for the fe126e. The background for this report is the general lack of information for fe126e-designs.
Before I started, I wondered whether I needed a parallel notch filter to dampen the 6,5 kHz peak - but decided to give it a listen first.
I've no previous experience with full-range driver, but was afraid that it could be nasale and with too much energy is the upper frequencies.
To put it short, I had absolutely nothing to worry about: the sound is very balanced, delicate - and with an extreme musical timing and natural amount of details - you definitely won't get bleeding ears - I just kept listening to cd's all night long (and today too). The tonality is musicality is absolutely setting a very high standard.
The only backdraw is off course the limited bass, but I don't feel I'm missing anything, according to the timing and quick response overall.
My cd/amp/cable setup is very neutral, and in the $6000-league. I've scrapped my other speakers (at $1400/pair).
The fe126e-design is at $200/pair, including enclosures.
I just wanted to report, that I've built the fostex-recommended basreflex-design for the fe126e. The background for this report is the general lack of information for fe126e-designs.
Before I started, I wondered whether I needed a parallel notch filter to dampen the 6,5 kHz peak - but decided to give it a listen first.
I've no previous experience with full-range driver, but was afraid that it could be nasale and with too much energy is the upper frequencies.
To put it short, I had absolutely nothing to worry about: the sound is very balanced, delicate - and with an extreme musical timing and natural amount of details - you definitely won't get bleeding ears - I just kept listening to cd's all night long (and today too). The tonality is musicality is absolutely setting a very high standard.
The only backdraw is off course the limited bass, but I don't feel I'm missing anything, according to the timing and quick response overall.
My cd/amp/cable setup is very neutral, and in the $6000-league. I've scrapped my other speakers (at $1400/pair).
The fe126e-design is at $200/pair, including enclosures.
Wow. Bested some high dollar ones and scrapped em, eh?
Can I have em? Just kidding. Good for you.
I wonder if anyone participating in the 127E "reference TL" thread has any comparative experience. Have you looked thru that thread? MarkMc might have some info for you.
Thanks for posting.
Can I have em? Just kidding. Good for you.
I wonder if anyone participating in the 127E "reference TL" thread has any comparative experience. Have you looked thru that thread? MarkMc might have some info for you.
Thanks for posting.
johnb said:
Well, I bought some cheap bookcases - the MDF was necessary for the sides of the enclosures (the one side is glued on the original back of the bookcase, the other is glued on a frame just inside the enclosure.
Well, it's not exactly a boom box. Fostex recommends a 11,5 cm long port (Ø 5 cm). I played around with boxplot - see below:
Well, -3 dB at 200 Hz, -5 db at 150 hz, flat until 61 Hz, rolloff. It must be possible to come up with something better.
This is better. Port length = 4,3 cm, -3dB at 150 and 80 Hz, with rise to 0 db at 90 Hz. I still don't like the -3 dB at 150 Hz, so here we go again:
Port length = 3,2 cm, -3 dB at 80 Hz.
...And the sound? Well, the last solution is absolutely the best - you can feel the bass in the floor + a very coherent sound. Try it!
Well, -3 dB at 200 Hz, -5 db at 150 hz, flat until 61 Hz, rolloff. It must be possible to come up with something better.
This is better. Port length = 4,3 cm, -3dB at 150 and 80 Hz, with rise to 0 db at 90 Hz. I still don't like the -3 dB at 150 Hz, so here we go again:
Port length = 3,2 cm, -3 dB at 80 Hz.
...And the sound? Well, the last solution is absolutely the best - you can feel the bass in the floor + a very coherent sound. Try it!
Now with Shoe polish!!!
I couldn't decide which finish to end up with - so I grabbed a black and brown shoe polish, keeping the DIY-style.
Advantages: no toxic fumes from the paint, dries in 5 minutes, price.
Actually the result is far better than the picture: the brown is pretty close to cherry wood, the black looks like some kind of nubuck.
Feedback are welcome.
Regards
Juspur/Innowatt.dk
I couldn't decide which finish to end up with - so I grabbed a black and brown shoe polish, keeping the DIY-style.
Advantages: no toxic fumes from the paint, dries in 5 minutes, price.
Actually the result is far better than the picture: the brown is pretty close to cherry wood, the black looks like some kind of nubuck.
Feedback are welcome.
Regards
Juspur/Innowatt.dk
I've received a few questions about the enclosure: basically it's a 30 x 30 x 17 bookshelf, bought at a local timberyard. They also cut out the sidebaffles for the speakers - so it's pretty simple.
I glued the one sidebaffle to the original back of the bookshelve, made a frame app. 1 cm inside the enclosure, to attach the other sidebaffle to (I glued that on too).
Finally I cut the speaker and port holes with a drilling machine, followed by a compass saw.
Oh yeah - and the speaker posts on the back, wiring and inserting the port Ø 5 cm, length 3,2 cm - that's it - enjoy.
Regards
Juspur
I glued the one sidebaffle to the original back of the bookshelve, made a frame app. 1 cm inside the enclosure, to attach the other sidebaffle to (I glued that on too).
Finally I cut the speaker and port holes with a drilling machine, followed by a compass saw.
Oh yeah - and the speaker posts on the back, wiring and inserting the port Ø 5 cm, length 3,2 cm - that's it - enjoy.
Regards
Juspur
Oh, I forgot: please dampen with acoustilux - I used a 50 x 25 cm piece, folded into an "M" (seen from above)
Double parallel notch filter
Okay, I've listened to the 10 thumbs for a while - and a parallel notch filter is a must - actually I've added two parallel notch filter for each speaker (the one filter after the other - meaning the two filters are in series).
Why two filters? Well, basically one filter lowers the peak 3 db
I used the parallel notch filter calculator found on http://www.carstereo.com/help/Articles.cfm?id=19 .
There's also a good explainiation of the basics of parallel notch filters.
I added the filters, because on axis you get "beamed" by the sound - one parallel filter dampened the peak significantly, but two filters in series is definitely a hit. The sound is EVEN more enjoyable than before - and on axis is actually the preferred listening position, with a VERY precise soundstage.
The values for the filter? Here they comes:
R = 2,7 ohm
L = 0,12 mH
C = 4,7 uF
This is for one filter. For two filters for each speaker, you'll need four of each components described above.
Theoretically, with the filter on, you've achieved 80-15000 Hz +/- 2 dB (but I haven't measured it).
Finally I consider converting the speaker into a closed enclosure (the "bass" isn't changed, when I stuff the ports with socks, but the transients are getting better - phenomenally soundstage.
That's it for now - DIY regards, Jesper
Okay, I've listened to the 10 thumbs for a while - and a parallel notch filter is a must - actually I've added two parallel notch filter for each speaker (the one filter after the other - meaning the two filters are in series).
Why two filters? Well, basically one filter lowers the peak 3 db
I used the parallel notch filter calculator found on http://www.carstereo.com/help/Articles.cfm?id=19 .
There's also a good explainiation of the basics of parallel notch filters.
I added the filters, because on axis you get "beamed" by the sound - one parallel filter dampened the peak significantly, but two filters in series is definitely a hit. The sound is EVEN more enjoyable than before - and on axis is actually the preferred listening position, with a VERY precise soundstage.
The values for the filter? Here they comes:
R = 2,7 ohm
L = 0,12 mH
C = 4,7 uF
This is for one filter. For two filters for each speaker, you'll need four of each components described above.
Theoretically, with the filter on, you've achieved 80-15000 Hz +/- 2 dB (but I haven't measured it).
Finally I consider converting the speaker into a closed enclosure (the "bass" isn't changed, when I stuff the ports with socks, but the transients are getting better - phenomenally soundstage.
That's it for now - DIY regards, Jesper
I'm crazy
Yea, I know i'm crazy, i'm in the process of making a pair, too. Just want to share, thanks.
http://home.comcast.net/~tpham1218/Bookshelf/bookshelf.htm
Yea, I know i'm crazy, i'm in the process of making a pair, too. Just want to share, thanks.
http://home.comcast.net/~tpham1218/Bookshelf/bookshelf.htm
As long as you are using two identical notch filters, please consider using one parallel filter wired in series and follow that with a series filter wired in parallel.
You will have to adjust the resistor values, but this will allow for a smoother impedance curve on both sides.
Good designing and good building,
Mark
Hi Mark
Thank you for the advice - and I guess you're right. I've just removed the notch filters, because the sound simply became boring with the filters on... and I prefer the filter-less sound, by far.
A major sound improvement was achieved by adjusting the tuning frequency to 111 Hz - this means that the frequency curve is almost rular-flat from 500 Hz - 120 Hz. Peak 120 Hz-100 Hz (+2 dB)
The sound enhancement? Instruments now have a natural body, where before they were a bit on the lean side.
It is achieved by removing the port, leaving a hole Ø 61 mm, length 14 mm.
Thank you for the advice - and I guess you're right. I've just removed the notch filters, because the sound simply became boring with the filters on... and I prefer the filter-less sound, by far.
A major sound improvement was achieved by adjusting the tuning frequency to 111 Hz - this means that the frequency curve is almost rular-flat from 500 Hz - 120 Hz. Peak 120 Hz-100 Hz (+2 dB)
The sound enhancement? Instruments now have a natural body, where before they were a bit on the lean side.
It is achieved by removing the port, leaving a hole Ø 61 mm, length 14 mm.
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