SunRa said:
well, i think Scott is right.
i´ve tried OB´s with my FE168eSigmas before i build the BiB´s for them. i had some
great moments with the OB´s but overall they didn´t work out right. some music
was really breathtaking, but others was really not, and i need a speaker, which is
good with all kinds of music.
me thinks, that a speaker, that is designed for horns is no good for OB´s,
the Qt is just too low.
and such a small driver wouldn´t work without a woofer, and i don´t wanna mess
around with that, for me one speaker must be enough, i´m a purist whith the term
"fullranger"
cherrio, Mirko
I didn't mean to sound too drastical. I was just thinking about the FE138ES-R as an extraordinary midrange driver. At least that is what it seems to be. And in order to exploit this capability it occured to me that OB might be the way. There are some examples .. Mr.'s King open baffle, the 4.5" Feastrex in OB published by Mr. Olsher. I agree that there is now way runing a small fullrange driver alone in OB but with proper integration it just might be.
Regarding monopoles, I don't reject the idea of a monopole but the problems related to monopole implementation (box resonance, impendance peaks, difractions, room modes) . Of course with some experience and very carefull design most of these problems can be overcomed, and a number of superb design by you or planet10 are prooving this.
And I must agree there is something very apealing in using fullrange drivers. Too bad this time is not that easy to have the best from both worlds (OB and fullrange)
DaveCan said:Mirko, are those other speakers in the pic BIB's ? Maybe an inverted BIB for these new drivers could work well, they sure are easy enough to build and offer great sound.. Dave
Hey Dave, you truly are fast responding...
yeah, you´re right, they are BiB´s with Fe168eSigma´s, and i´m really happy
with them, and i think that it´s true what they said over in in the BiB-thread,
about that the BiB and the 168-sigma´s are a perfect match. i´m still
amazed how powerful they sound and how low they can go.
but it´s also true, that the BiB´s are a bit rough in the mids and highs.
and i don´t wanna spoil that sweet AlNoCo-sound of the eS-R´s with a
enclosure, that ads heavy ripple to the upper frequencies (although the bass
really would be amazing..)
and so the easy to build BiB is sadly out of the race...
greetings, Mirko
Too bad that all the specs needed are not published, maybe they could slide into the Ron designed A126, or the A126 could be modded to work for the 138esr drivers? Better driver height with the A126 over the Frugal IMO..
Perhaps someone could design a cab with driver height as the first equation to start a design with, perhaps 33''-37'' or? at driver center then go from there... Thats how I'd do it if I had the skills of enclosure design... Dave
Perhaps someone could design a cab with driver height as the first equation to start a design with, perhaps 33''-37'' or? at driver center then go from there... Thats how I'd do it if I had the skills of enclosure design... Dave
Hey Dave, thanks for all your nice ideas
yeah, Ron´s horn are truly amazing , but i think if i would really build a BLH for
my esr´s i would likely go for the frugel´s, because it´s such an elegant design
and they look really neat, and i like the idea of the open-source-project.
and for me the driver height wouldn´t be much of a problem.
----------------
well, i searched the web for the lost data the last two days, but again
i found nothin
and i got a headache from all the kanji-letters,
i´m not able to read.... it seems that really no one had more than the specs
we had seen on the PDF already.
the es-r didn´t exist on the Fostex-international-site, and Fostex.jp had a redesign
last week, when you click inquiry-button, they come up with a telephone-number,
you can´t even email them asking for help, and i really don´t belief that Fostex-
international would help for japan-only items.
isn´t there any guy from japan or someone who´s more familiar with the japanese
language here in the forum, who would be so kind in helping out and doing some
more decent searching for the lost data ??
yeah, Ron´s horn are truly amazing , but i think if i would really build a BLH for
my esr´s i would likely go for the frugel´s, because it´s such an elegant design
and they look really neat, and i like the idea of the open-source-project.
and for me the driver height wouldn´t be much of a problem.
----------------
well, i searched the web for the lost data the last two days, but again
i found nothin
and i got a headache from all the kanji-letters,i´m not able to read.... it seems that really no one had more than the specs
we had seen on the PDF already.
the es-r didn´t exist on the Fostex-international-site, and Fostex.jp had a redesign
last week, when you click inquiry-button, they come up with a telephone-number,
you can´t even email them asking for help, and i really don´t belief that Fostex-
international would help for japan-only items.
isn´t there any guy from japan or someone who´s more familiar with the japanese
language here in the forum, who would be so kind in helping out and doing some
more decent searching for the lost data ??
...me again... 
i had some weird thoughts about the lost data lately...
first the specs we have for the FE138Es-R:
Zn = 8Ω
Re = 6,9Ω (i´ve measured)
Fs = 60 Hz
Sd = 82,35cm²
Qts = 0,27
Mms = 5g
SPL = 91,5dB/w(1m)
is there something else missing besides the Vas ??
...and here´s my thought: if we didn´t have the Vas, wouldn´t it be ok, to just guess
it ?? i mean, all the 5inch-drivers from Fostex (Fe126e/127e, F120A, FF125K, etc)
have a Vas from 9,1l to 9.9l, and Fostex won´t build a driver with some weird specs,
so, what if we assume that the Vas for the es-r is something around 9 or 10 liters ??
... if you think, that complete nonsense, feel free to give a goot spanking, it´s just that
i´m getting quite desperate about that malicous issue...
cheers, and have a nice day... Mirko
i had some weird thoughts about the lost data lately...
first the specs we have for the FE138Es-R:
Zn = 8Ω
Re = 6,9Ω (i´ve measured)
Fs = 60 Hz
Sd = 82,35cm²
Qts = 0,27
Mms = 5g
SPL = 91,5dB/w(1m)
is there something else missing besides the Vas ??
...and here´s my thought: if we didn´t have the Vas, wouldn´t it be ok, to just guess
it ?? i mean, all the 5inch-drivers from Fostex (Fe126e/127e, F120A, FF125K, etc)
have a Vas from 9,1l to 9.9l, and Fostex won´t build a driver with some weird specs,
so, what if we assume that the Vas for the es-r is something around 9 or 10 liters ??
... if you think, that complete nonsense, feel free to give a goot spanking, it´s just that
i´m getting quite desperate about that malicous issue...
cheers, and have a nice day... Mirko
Hi Mirko --
If I had to guess based on the numbers Fostex supplied, I'd go around 12.5 litres.
Of course that's only a guess, based on the Fs, Qts, and Efficiency supplied by Fostex. If you were able to test for Fs and Qes, along with Fostex's SPL #, we'd be able to come up with a better estimate of Vas. Of course if you could test for Fs and Qes, you could probably manage to test Vas as well...
Regards,
John
If I had to guess based on the numbers Fostex supplied, I'd go around 12.5 litres.
Of course that's only a guess, based on the Fs, Qts, and Efficiency supplied by Fostex. If you were able to test for Fs and Qes, along with Fostex's SPL #, we'd be able to come up with a better estimate of Vas. Of course if you could test for Fs and Qes, you could probably manage to test Vas as well...
Regards,
John
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nullspace said:
Hi John,
thanks alot for your effords, it´s much appreciated.
i didn´t even know that missing T/S-parameters can be re-calculated.
MJK´s MathCad-sheeds truly are amazing, if ever i had the brains to use them...
and, yeas, sadly i didn´t have any speaker-testing-equipment,
and i also think that the specs provided by Fostex can be trusted, so IMHO you
more substantial "guess" of the Vas of 12.5l is really close to the real vaue.
regards,
Mirko
Thanks alot for your help, Tom
...now we have two values for the Vas, but wich is the right one ??
i think none of the two is the exact right value,
but it´s good that the two calculation came out with so near conclusions,
12,5l and 13,5l aare not so far away, so maybe the true Vas is somewhere in between...
cheerio, Mirko
...now we have two values for the Vas, but wich is the right one ??
i think none of the two is the exact right value,
but it´s good that the two calculation came out with so near conclusions,
12,5l and 13,5l aare not so far away, so maybe the true Vas is somewhere in between...
cheerio, Mirko
A word of warning: don't kid yourselves about the Fostex specifications being especially accurate. They aren't always. My matched FE167Es and FE126Es are significantly off the advertised parameters, and I'm not alone in finding this.
To use Vas as an example, in the former case, it's 50% lower than claimed, and although that will increase under realistic conditions, it's not going to shift to that kind of extent. Troel Gravsen measured his own 126s with Vas ~120% lower than claimed (average 4.05 litres as against the claimed 9.95), while Zaph found departures from the claims with his FE166ES-Rs and FF165Ks. So best keep in mind, whatever you do, you're going to have to have to have some fudge-factor in it.
To use Vas as an example, in the former case, it's 50% lower than claimed, and although that will increase under realistic conditions, it's not going to shift to that kind of extent. Troel Gravsen measured his own 126s with Vas ~120% lower than claimed (average 4.05 litres as against the claimed 9.95), while Zaph found departures from the claims with his FE166ES-Rs and FF165Ks. So best keep in mind, whatever you do, you're going to have to have to have some fudge-factor in it.
Scottmoose said:
Keep in mind that T/S is a curve, not a single number. The measures Scott has are ones i measured yet for modeling purposes i use the factory specs (ie Fonken fanily) and get pretty much what i expect. Fotunately they tend to change in a direction that keeps your box size similar.
T/S will also change depending on the weather. I was just commenting today on the problems a manufacturer from the coast would have demoing his BR in Denver at RMAF.
T/S also change as you turn up the wick.
It is important to make your design tolerant... why i avoid pure BR and sealed boxes.
dave
Likewise, unless I have more accurate data to go on. Most of the cabinets I tend to do have some latitude built into them for just these reasons, along with the impact of the rest of the system (, particularly the amplifier) on the driver. It's just a warning really to avoid potentially counter-productive over-refinement. Good enough is good enough. Perfect is a pain in the neck & usually not worth the extra hassle.
Thank you, Scott and Dave, for your adwises, i really appreciate your
words of wisdom. it reminds me of one important thing, which i almost
forgot: i do know nothing about speaker-design...
Well, you know, i am addicted to this Audio-stuff for almost 25 years now
and only had 6 different speakers ( 1 was a comercial speaker, 2 i designed myself,
1 was a kit, and the other 2 i build out of plans from the net)
i mean, i understand most of the design theory´s, but you have to consider
so much differnt things for designing a good speaker.... i don´t get it.
for me, designing tube-amps is so much easier, electricity is pure mathematics,
all things you need to consider in amp-design can be put down to a few basic
equations.
cheers, Mirko
words of wisdom. it reminds me of one important thing, which i almost
forgot: i do know nothing about speaker-design...
Well, you know, i am addicted to this Audio-stuff for almost 25 years now
and only had 6 different speakers ( 1 was a comercial speaker, 2 i designed myself,
1 was a kit, and the other 2 i build out of plans from the net)
i mean, i understand most of the design theory´s, but you have to consider
so much differnt things for designing a good speaker.... i don´t get it.
for me, designing tube-amps is so much easier, electricity is pure mathematics,
all things you need to consider in amp-design can be put down to a few basic
equations.
cheers, Mirko
Second Impressions
Hi Folks,
well, one week has past since i posted my first impressions of the es-r´s.
Time for an update.
now they have played for nearly 30 hours, and they are really beginning
to flex their muscles. the colourations of the HF have improved alot, on some CD´s
they´re nearly inaudible. and i happily welcomed some bass, there´s not much,
(there will never be with them in these test-boxes) but i can hear even really deep
tones. Speed and dynamics have improved, too, and they even sound a bit louder
than last week. what makes me think that the claimed SPL of 91,5dB is a bit
conservative, i believe that the es-r`s are not much quiter than my old 168-sigma´s,
which should have 94,5dB, and those 3dB is a huge difference ( hey Scott, now i see what
you mean about the accuracy of T/S-specs..)
and to come to a conclusion: when you leave the bass aside, the es-r´s are yet much
better than my 168-sigmas´s in every aspect.
cheerio, Mirko
Hi Folks,
well, one week has past since i posted my first impressions of the es-r´s.
Time for an update.
now they have played for nearly 30 hours, and they are really beginning
to flex their muscles. the colourations of the HF have improved alot, on some CD´s
they´re nearly inaudible. and i happily welcomed some bass, there´s not much,
(there will never be with them in these test-boxes) but i can hear even really deep
tones. Speed and dynamics have improved, too, and they even sound a bit louder
than last week. what makes me think that the claimed SPL of 91,5dB is a bit
conservative, i believe that the es-r`s are not much quiter than my old 168-sigma´s,
which should have 94,5dB, and those 3dB is a huge difference ( hey Scott, now i see what
you mean about the accuracy of T/S-specs..)
and to come to a conclusion: when you leave the bass aside, the es-r´s are yet much
better than my 168-sigmas´s in every aspect.
cheerio, Mirko
It's too bad and really odd that the vas isn't published for these drivers, you'll never get an accurate picture of what these drivers will sound like till their in a proper enclosure... Maybe someone could get the full specs from the Japan site... Maybe cdwitmer from the Feastrex thread could find out? Dave
DaveCan said:It's too bad and really odd that the vas isn't published for these drivers, you'll never get an accurate picture of what these drivers will sound like till their in a proper enclosure... Maybe someone could get the full specs from the Japan site... Maybe cdwitmer from the Feastrex thread could find out? Dave
Hmm... sounds like a good idea ! Does someone has his email-addy ??
Ping cdwitmer: if you read this, can i convince you in any way to help us out ??
i would really appreciate it, if you could do some searching or
maybe make an inquiry at the fostex-site.
Scottmoose said:Naturally, Vas, especially for a small driver with a big motor & a delicate cone has to be the hardest parameter to measure accurately. Nothing like making life easy for people huh?
yeah, but i really can´t believe that the guys at Fostex didn´t measure it !!
they just don´t tell us, because of pure sadism, like: "we give you the best driver
we can think of, but we won´t make it too easy for you"