I did it
Made these two baffles from an old table top. No waf to consider, just me and my dog. Definitely an odd shape
Don't know how good the "edge" software is but following are a few pic.s
The baffles needed to be down on the floor to reinforce the bass.The system is very revealing source, studio or live.
Perhaps the driver in the middle of the baffle might sound better with a mid bass emphasis before drop off.
cheers
doggy
Made these two baffles from an old table top. No waf to consider, just me and my dog. Definitely an odd shape
Don't know how good the "edge" software is but following are a few pic.s
The baffles needed to be down on the floor to reinforce the bass.The system is very revealing source, studio or live.
Perhaps the driver in the middle of the baffle might sound better with a mid bass emphasis before drop off.
cheers
doggy
Attachments
Hi doggy!
I have question regarding the BLH in the back on the photo. Looks like modified FE206E in its recommended horn. Could you tell us what kind of midifications you did to that FE206E (looks like you cutted off the weezer
) and of course how it compares to that supravox.
Thanks alot Martin
I have question regarding the BLH in the back on the photo. Looks like modified FE206E in its recommended horn. Could you tell us what kind of midifications you did to that FE206E (looks like you cutted off the weezer
) and of course how it compares to that supravox.Thanks alot Martin
Probably what I do and say will be frowned upon by those with more common sense.
When I got the 215 from France in 2001, they recommended 2 enclosures which is on the french supravox site. I built the tqwt. Looking at the plans , what I failed to do was stuff the top end properly. So in consequence the sound did not satisfy for long. There is also a stuffed box with a air gapped front baffle that looks interesting. The design looks old.
The Driver on the open baffle has come to life, it works very well, especially enjoyeable are live venue recordings. But no doubt this is the magic of open baffle also. The bass is less, but I live in the midrange.
I saw that in Germany the rtf64 bicone was priced less than the 215 signature.The rtf is 98 db efficient, qt.s about .40 the signature 93 db.
The blh has more prominent bass, but I need to stuff the chamber more to clean up the sound-the ob being used as a reference.
Yes, I confess. I did d-wizzer the fe208e and also added a fair amount to the back of the cone, added a cork inset after experimenting with phase plugs.I was just fed up with the in your face sound.
The 215 on the baffle sound great.
I wonder, does anyone know of other fullrange candidates for ob that are more affordeable?
Cheers and happy ears
doggy 
When I got the 215 from France in 2001, they recommended 2 enclosures which is on the french supravox site. I built the tqwt. Looking at the plans , what I failed to do was stuff the top end properly. So in consequence the sound did not satisfy for long. There is also a stuffed box with a air gapped front baffle that looks interesting. The design looks old.
The Driver on the open baffle has come to life, it works very well, especially enjoyeable are live venue recordings. But no doubt this is the magic of open baffle also. The bass is less, but I live in the midrange.
I saw that in Germany the rtf64 bicone was priced less than the 215 signature.The rtf is 98 db efficient, qt.s about .40 the signature 93 db.
The blh has more prominent bass, but I need to stuff the chamber more to clean up the sound-the ob being used as a reference.
Yes, I confess. I did d-wizzer the fe208e and also added a fair amount to the back of the cone, added a cork inset after experimenting with phase plugs.I was just fed up with the in your face sound.
The 215 on the baffle sound great.
I wonder, does anyone know of other fullrange candidates for ob that are more affordeable?
Cheers and happy ears
doggy
Technically speaking, the Supravox 215 are better than Fertin : the first clue for this is that Supravox publish very detailed measurements for their drivers : it means they must be proud of them. IMHO a manufacturer who's not proud to show nice graphs doesn't sell nice products (though Fostex do sell good drivers with minimal specs).
Then, the frequency responses of Fertin show a very very uneven frequency response, with peaks which very often hide resonnances visible on a CSD (resulting in colorations and "messiness").
If you look at Supravox's CSDs I think you will hardly find better drivers. I have 165GMF, and measurements I took where exactly the same as Supravox's.
I have been a fullrange lover for 2 years, but I discovered that the good coherence was at the expense of limited SPL, distorsion, and extension.
For example, adding a FT17H supertweeter to a 165GMF gives a better result than using the 165LB fullrange. Add a sealed sub and roll the 165 at 65Hz and you can increase the SPL of 6~10dB (and extension down to 25Hz)
Also, if you stick with high Q drivers, you get less "punch" on transcients (see or model impulse responses to see what I mean).
Why use open baffle when sealed offers you the possibility to use a smaller enclosure, have more bass, have no resonnances on the wall behind, and use lower Q drivers ? Use a large enough box, with very solid non parallel walls and smart stuffing inside to get a "box sound free" enclosure : works amazingly good !
Don't wanna break the magic, but measurements are the only trustable information when you cannot hear things by yourself.
If I were you, I'd use a Supravox 215RTF (or 215-2000 if you can afford) with a supertweeter (FT96H or T90A) and a 15" woofer (light cone and high BL), active filtered if possible. It costs less than a Fertin driver and must definetely be better !
I think fullrange is a good way to begin in audiophile audio, but if you want to go serious for not too much, multiway-sealed-active is the only solution.
Then, the frequency responses of Fertin show a very very uneven frequency response, with peaks which very often hide resonnances visible on a CSD (resulting in colorations and "messiness").
If you look at Supravox's CSDs I think you will hardly find better drivers. I have 165GMF, and measurements I took where exactly the same as Supravox's.
I have been a fullrange lover for 2 years, but I discovered that the good coherence was at the expense of limited SPL, distorsion, and extension.
For example, adding a FT17H supertweeter to a 165GMF gives a better result than using the 165LB fullrange. Add a sealed sub and roll the 165 at 65Hz and you can increase the SPL of 6~10dB (and extension down to 25Hz)
Also, if you stick with high Q drivers, you get less "punch" on transcients (see or model impulse responses to see what I mean).
Why use open baffle when sealed offers you the possibility to use a smaller enclosure, have more bass, have no resonnances on the wall behind, and use lower Q drivers ? Use a large enough box, with very solid non parallel walls and smart stuffing inside to get a "box sound free" enclosure : works amazingly good !
Don't wanna break the magic, but measurements are the only trustable information when you cannot hear things by yourself.
If I were you, I'd use a Supravox 215RTF (or 215-2000 if you can afford) with a supertweeter (FT96H or T90A) and a 15" woofer (light cone and high BL), active filtered if possible. It costs less than a Fertin driver and must definetely be better !
I think fullrange is a good way to begin in audiophile audio, but if you want to go serious for not too much, multiway-sealed-active is the only solution.
Youyoung21147
I would like to comment some of your statements on
the Fertin drivers.
First, I agree with you that in this hi-fi jungle, it's really
difficult to have an opinion on a product without having
heard the product yourself (this is the golden rule).
but I disagree when you say that (measurements are the
only trustable info when you cannot hear things yourself).
How many products have great specs and frequency plots
buy just sound bad? I guess by your comments that
you haven't heard the Fertin in OB or TL.
As for prices, if we look at the Fertin 20EX:
-900U+200transportation(most USdestination)
Taxe and duties.
-Supravox-1240USor1340+transportation
(this is from their web site)
Consider that the 20EX doesn't need a tweeter. This could
also add to the cost.
Now , you must also compare the quality of the product
to have a good idea of the price versus quality.
If it were that easy,we would just look at the measurements.
They're wouldn't be any reviewers and so many different
products, just perfect measurements and we would all be
happy.
I would like to comment some of your statements on
the Fertin drivers.
First, I agree with you that in this hi-fi jungle, it's really
difficult to have an opinion on a product without having
heard the product yourself (this is the golden rule).
but I disagree when you say that (measurements are the
only trustable info when you cannot hear things yourself).
How many products have great specs and frequency plots
buy just sound bad? I guess by your comments that
you haven't heard the Fertin in OB or TL.
As for prices, if we look at the Fertin 20EX:
-900U+200transportation(most USdestination)
Taxe and duties.
-Supravox-1240USor1340+transportation
(this is from their web site)
Consider that the 20EX doesn't need a tweeter. This could
also add to the cost.
Now , you must also compare the quality of the product
to have a good idea of the price versus quality.
If it were that easy,we would just look at the measurements.
They're wouldn't be any reviewers and so many different
products, just perfect measurements and we would all be
happy.
I confess I haven't heard the Fertin drivers, but those will need some frequency response compensation (I've once seen a commercial design using this driver, and it had a very very complicated filter). The graphs visible here
http://www.spectrumaudio.de/breit/fertinFLB20D40S.html
shows it obviously.
It is more expensive than the 215RTF64 (not the 215-2000).
I have usually found a big correlation between measurements and audible qualities : a measured bump in the frequency response is always traduced by a tonal change.
A ringing in a CSD always hides some "messiness" of a driver.
Measured distorsion (especially in the bass region) means some extra not natural tones.
But I agree with you : there is always a "something" you cannot measure and makes a driver sound great or not !
I usually trust this kind of measurement :
CSD+FR+distorsion
http://www.spectrumaudio.de/breit/fertinFLB20D40S.html
shows it obviously.
It is more expensive than the 215RTF64 (not the 215-2000).
I have usually found a big correlation between measurements and audible qualities : a measured bump in the frequency response is always traduced by a tonal change.
A ringing in a CSD always hides some "messiness" of a driver.
Measured distorsion (especially in the bass region) means some extra not natural tones.
But I agree with you : there is always a "something" you cannot measure and makes a driver sound great or not !
I usually trust this kind of measurement :
CSD+FR+distorsion
With respect to Supravox, I'm not sure if their published T/S parameters are particularly accurate, and the enclosure designs that I've looked at (the TQWTs for example) are very poor for the specified drivers. Nor are these published parameters generally as complete as the Fostex listings -I don't, for example, see Voice Coil Inductance refered to, while it is in many of the newer Fostex units. As for the Fertin's, I'll reserve judgement until I've heard a pair, and measured them.
Why choose an open baffle, Youyoung, when you can get an 'unboxy' sound with a correctly designed sealed / vented / TL enclosure? Simple; dipole radiation pattern.
Dipoles, unless rammed against a wall, will actually excite fewer room modes than a monopole, not more, due to the energy propagation. About 30% less goes into room excitation than a monopole. Have a look at this; particularly the boundaries: http://www.kettering.edu/~drussell/Demos/rad2/mdq.html note how in the dipole and quadrupoles the boundaries ar emuch calmer.
For more on dipoles, visit Siegfried Linkwitz site at www.linkwitzlab.com for all you'll ever need on the subject. Of course, you're quite right that you get less LF due to the progressive acoustic cancellation, but you hand over to dedicated LF drivers to do that anway. Martin King has an impressive new OB project on his site, and dipole worksheets that you might find an interesting read -I know you use his software, right?
Regards
Scott
Why choose an open baffle, Youyoung, when you can get an 'unboxy' sound with a correctly designed sealed / vented / TL enclosure? Simple; dipole radiation pattern.
Dipoles, unless rammed against a wall, will actually excite fewer room modes than a monopole, not more, due to the energy propagation. About 30% less goes into room excitation than a monopole. Have a look at this; particularly the boundaries: http://www.kettering.edu/~drussell/Demos/rad2/mdq.html note how in the dipole and quadrupoles the boundaries ar emuch calmer.
For more on dipoles, visit Siegfried Linkwitz site at www.linkwitzlab.com for all you'll ever need on the subject. Of course, you're quite right that you get less LF due to the progressive acoustic cancellation, but you hand over to dedicated LF drivers to do that anway. Martin King has an impressive new OB project on his site, and dipole worksheets that you might find an interesting read -I know you use his software, right?
Regards
Scott
You're right about the Fertin 20S needing a compensation in the
hihgher frequencies. I have one pair in box that I'll use with
a tweeter in or around 7khz. I doubt if the entry line Supravox
could be used without a tweeter. I know that the
Fertin 20EX in TL our Ob doen't need a tweeter. But here
we're talking of a driver 3 times the price of a 20S.
As for OB versus TL; the air pressure inside a box will
cause a decrease in dynamic ( the longer the wave , the longer
the cone movement and the more back pressure on the cone that
will prevent it from moving freely, not to mention by
the coloration that this backwave brings to the sound).
This will also be heard in the bass(compress and less precise
sound).
To do OB correctly , you need a driver that has
a strong motor like a fieldcoil paired with a light cone.
These 2 characteristics(no backwave with a strong motor)
will give you precision and dynamism that you won't
find in a box speaker.
But you need a driver with a resonance capacity of 70hz
or lower.
This has a price, limited bass. You'll get good bass,
if you want deep bass, then big woofers + amp needed.
hihgher frequencies. I have one pair in box that I'll use with
a tweeter in or around 7khz. I doubt if the entry line Supravox
could be used without a tweeter. I know that the
Fertin 20EX in TL our Ob doen't need a tweeter. But here
we're talking of a driver 3 times the price of a 20S.
As for OB versus TL; the air pressure inside a box will
cause a decrease in dynamic ( the longer the wave , the longer
the cone movement and the more back pressure on the cone that
will prevent it from moving freely, not to mention by
the coloration that this backwave brings to the sound).
This will also be heard in the bass(compress and less precise
sound).
To do OB correctly , you need a driver that has
a strong motor like a fieldcoil paired with a light cone.
These 2 characteristics(no backwave with a strong motor)
will give you precision and dynamism that you won't
find in a box speaker.
But you need a driver with a resonance capacity of 70hz
or lower.
This has a price, limited bass. You'll get good bass,
if you want deep bass, then big woofers + amp needed.
I have remeasured my self some 165GMF and both the FR and T/S where precisely matched. Moreover, each pair of driver is appaired and comes with individual T/S sheet.
For sure ! Those things where so ugly that they have removed them
Very interesting point of view. The Linkwitzlab website is very well documented. I go there very often to grab information.
I will one day try large OB to see what it is worth. I must confess I'm a bit prejudiced against OB dipole because I once built a very small one for 3" speakers and it was catastrophic
And also because it theorically adds delayed signal (due to room boundaries) to the ideal point source radiation. But as we never listen in semi-anechoic chambers, it is possible that less room modes excitation becomes more important than delayed echoes.Yup I've seen that. It looks impressive, but it is not the kind of thing I'm about to be able to put in my bedroom
I rather use his software to design vented boxes (or used to, since I only use now sealed boxes + active filtering)
This is no fair comparison
!Vented enclosures always have "box sound" simply because a part of the sound... comes from the box ! Vented enclosures have higher group delay and poor impulse response (I could measure that).
In fact I was only saying that a large and deep and overdamped sealed enclosure could lead to a "pure sound", i.e sound that only comes from the driver, without backwaves coming back through the cone (hence the non-parallel wall I mentionned). A good sealed box has no box sound. It is the nearest from the ideal "point source"
But it isn't dipole, and doesn't have its advantages in a normal environment. I should definetely try dipole for my next system and report the results here
Very well said
Fullrangers are never able to cover the 50-20Hz with level. Nothing is worth a good 15" 
youyoung21147,
what I meant is that in Open Baffle, from what I heard with
the Fertin 20EX fieldcoil, is that with this driver alone, you
get decent bass(some people are satisfied with this).
If you want to really go down , then add 15 inch woofers.
But , if you like very good bass with a Fertin 20Ex in a
Transmission Line cabinet , then it's possible to get (36hz-21khz).
But here , they must increase the size of the cabinet
in order to go lower than 50Hz.
This, for me, would be considered fullrange.
Strada, Ebénisterie & Musique, from France builds
different TL with the Fertin20EX and the one I mentioned
above is listed 11000.00euros. There in Paris. They also
make 2 other fullrange TL with the Fertin20EX.
what I meant is that in Open Baffle, from what I heard with
the Fertin 20EX fieldcoil, is that with this driver alone, you
get decent bass(some people are satisfied with this).
If you want to really go down , then add 15 inch woofers.
But , if you like very good bass with a Fertin 20Ex in a
Transmission Line cabinet , then it's possible to get (36hz-21khz).
But here , they must increase the size of the cabinet
in order to go lower than 50Hz.
This, for me, would be considered fullrange.
Strada, Ebénisterie & Musique, from France builds
different TL with the Fertin20EX and the one I mentioned
above is listed 11000.00euros. There in Paris. They also
make 2 other fullrange TL with the Fertin20EX.
Here is the big problem : fullrange can be very good, but when you wan true fullrange, the price becomes huge.
For less than 11000€ you can build a 4-way system with TAD compression drivers, Fostex supertweeters, low-midrangers from Supravox, Fostex or even Fertin and excellent woofers from TAD, Precision Devices or RCF.
I honestly think it cannot be worst than the Fertin alone !
Siegfried Linkwitz in his Orion uses several drivers, because he has probably found that ideal fullrange is impossible.
But I don't blame fullrangers : I lived with a pair of FX-120 in a ML-TQWT for more than two years and they still provide me very much pleasure listening to them.
But when you want both big and refined sound, fullrangers show their limits...
I have just bought some F120A drivers and mounted them on an open baffle (see "Fostex F120A measurements").
Scottmoose : you were right saying the open baffles excited less room modes : measurements don't exhibit as crazy peaking as I would have expected !
On the downside, I must say I have been a bit disapointed by imaging, especially on the voices : these seem to come from a bit everywhere whereas in a closed box they are right at the center of the soundstage. I assume it is a consequence of the low-midrange leaking through the damping and reflecting on the walls.
Maybe it is possible to correct for this ?
Scottmoose : you were right saying the open baffles excited less room modes : measurements don't exhibit as crazy peaking as I would have expected !
On the downside, I must say I have been a bit disapointed by imaging, especially on the voices : these seem to come from a bit everywhere whereas in a closed box they are right at the center of the soundstage. I assume it is a consequence of the low-midrange leaking through the damping and reflecting on the walls.
Maybe it is possible to correct for this ?
Both drivers are pointed right toward the listening point, because the F120A is flat only on-axis.
I think the speakers are still too near from the rear and side walls, and they are not completely damped.
I didn't do a precise phase-adjustment either. I will soon do it and report the results.
Cheers !
I think the speakers are still too near from the rear and side walls, and they are not completely damped.
I didn't do a precise phase-adjustment either. I will soon do it and report the results.
Cheers !
Right, it's mostly a positioning thing I suspect. Dipoles need a bit more room than monopoles, but as you've found out, it's nothing like as bad as some people would have you believe. Some soft cloth like a curtain covering the wall behind them can also work wonders if you can't pull them away any further. Also, depends on the size & height of your baffle of course.
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