I'm getting closer to constructing my first pair of speakers. My FE206Es arrived a little while ago, but due to uni obligations I've yet to have time to build a cabinet for them. In the meantime, they've been burning in in an approximate open baffle. They sound okay, but not great.
The design which has captured my attention the most is Onur's double horn. The only problem is that it's relatively untested compared to other designs.
I personally have no skill in horn design, so I was wondering if more talented members could tell me if Onur's double horn looks like a design which should work well
The design can be found here:
http://www.yildiz.edu.tr/~ilkorur/speaker/fostex_fe206e.htm
Thankyou
(also if anyone has any first hand experience with this design i'd LOVE to hear it)
The design which has captured my attention the most is Onur's double horn. The only problem is that it's relatively untested compared to other designs.
I personally have no skill in horn design, so I was wondering if more talented members could tell me if Onur's double horn looks like a design which should work well
The design can be found here:
http://www.yildiz.edu.tr/~ilkorur/speaker/fostex_fe206e.htm
Thankyou
(also if anyone has any first hand experience with this design i'd LOVE to hear it)
hmmm.... Marco likes them better with 207 (and i just bought a pair of those)
Onur has been doing some innovative work, i know Moray had some good things to say about some of his designs that he tried.
dave
Onur has been doing some innovative work, i know Moray had some good things to say about some of his designs that he tried.
dave
It works. I checked a few months back in MathCad. It's really a sort of Replikon with a couple of mouths. Technically, it's more a TL, or big-vent reflex, as Martin or GM would say, than a true 'horn' -it's none the worse for that though. Most are, until you get to Kleinhorn size. These hybrid TLs / BR designs with short, rapidly flaring vents do seem to work very well in some cases. As Dave advises, I'd stick with the 207. 1/2 space response graph generated in MathCad below.
Best
Scott
Best
Scott
Attachments
Well... i dont have FE207Es! Does this enclosure seem unsuited to the FE206E then? Maybe i should use the dallas II instead? I like the look of Onur's design, but if it's just a fancy BR then i suppose it WOULD be more suited to FE207E (as i understand, fostexs ending in "6" are suited to horns whereas ones ending in "7" are suited for BRs)
Not at all. Just add a touch of series resistance to the 206 and you'll be in business. You can either do it via a resistor, or a highish resistance cable. Magnet wire is ideal -24AWG or similar. If you want 'proper' hifi cable, then Van Den Hul's carbon wire will be just the ticket.
I would redesign such that the front were flush, or put absorbing material on the baffle projections. Early reflections are bad for fidelity. I suppose the time and image smear caused by these early reflections will be diminished by the beaming fullrange, but it exists nonetheless.
There is a certain class of DIYers that like formulaic designs. I say not designing your own enclosure takes all he fun out of it. Designing an enclosure requires a chain of decisions, why would you accept someone else's?
There is a certain class of DIYers that like formulaic designs. I say not designing your own enclosure takes all he fun out of it. Designing an enclosure requires a chain of decisions, why would you accept someone else's?
Scottmoose said:
Hm I don't think i'd be happy with that. Although it's silly, lately i've fallen for the idea of having a horn. I wouldn't be happy knowing that all I have is a fancy BR. No matter how nice it sounds, this would bug me. Silly I know, but I'm silly.
For the horn fans.. yes i do hope to make a front horn sometime in the future! A rear horn is just my introduction to horns
Ron E said:
I agree that designing your own is the ultimate, but at this stage I'm too newbie for this. I want to build someone else's design/s to get used to the building process, and then I will try to design my own. I have to learn a lot about horn design before I can even start to think about designing my own. In the meantime, my fe206e needs a cabinet!
Also, there's no real point in designing my own cabinet if i dont have anything to compare it against. If i build a cabinet of a well regarded designer, and then design my own, I will be able to compare the sound of my own design against theirs to see if mine is any good. Unfortunately at the moment I dont have any reference point, which is why I want to build a well regarded cabinet instead of taking a risk on a new one (like onur's which is relatively untested).. since i have no reference, i have no way of knowing if the fe206e is living up to it's potential in the cabinet
Thanks for your comments so far. Based on them, I think i will probably have to move away from onur's sexy design and build the Dallas II instead. Since i like onur's design so much, I may consider buying a pair of fe207e's after I build my dallas
The Dallas II is also a hybrid.
It's basic physics really: to generate low frequencies, a horn has to have a huge mouth. Like this: http://www.passdiy.com/pdf/KleinHorn.pdf Note that despite their monster size, even these don't exactly pluge the depths: they go about as low as, say, the Dallas II or one of the Fostex Factory designs.
As most of us will never be in a position to have such a pair of monsters, all the full-range domestic back-loaded horn designs you will see, DIY or commercial, use some form of hybrid loading for the lowest frequencies. Fostex, for example, use a series of 1/2 wave resonators, each stage slightly wider than the last (so in the strict sense, they are never horns at all). Most others behave either like a reflex, or a TL, depending on the design methodology choses, and shift to horn loading higher up. There's nothing wrong with either approach -they work very well if properly implemented, so don't worry too much about that!
Hope this helps a bit
Scott
It's basic physics really: to generate low frequencies, a horn has to have a huge mouth. Like this: http://www.passdiy.com/pdf/KleinHorn.pdf Note that despite their monster size, even these don't exactly pluge the depths: they go about as low as, say, the Dallas II or one of the Fostex Factory designs.
As most of us will never be in a position to have such a pair of monsters, all the full-range domestic back-loaded horn designs you will see, DIY or commercial, use some form of hybrid loading for the lowest frequencies. Fostex, for example, use a series of 1/2 wave resonators, each stage slightly wider than the last (so in the strict sense, they are never horns at all). Most others behave either like a reflex, or a TL, depending on the design methodology choses, and shift to horn loading higher up. There's nothing wrong with either approach -they work very well if properly implemented, so don't worry too much about that!
Hope this helps a bit
Scott
I think a useful rear loaded horn will negate the effect of baffle step diffraction. The frequencies involved seem ideal for this application, I think.
I also think that corner loading is worth looking at. You could build a relatively small enclosure that blends with the room corner and extends very low.
I also think that corner loading is worth looking at. You could build a relatively small enclosure that blends with the room corner and extends very low.
Ron E said:
I don't agree on this. I have designed some other enclosures, which I have managed the time alignment the same way as I did with the double horn and in all those cases, the stage became one of the strongest point. The others were the quality of midrange purity and the absence of shouting effect.
However, I think that these kind of enclosures, large rear chamber and hyperbolic or exponential horn combination form a pitfall for simulation software depending on T/S parameters. The low end response looks balanced and free of ripple. I think this is deceiving. The reason is, most designs I have examined by reverse engineering don't have a flat low end response. A rise in the 60 to 100 Hz region is common. Making it flat may cause listeners to feel less bass. I, on purpose, made a similar design for Coral Flat10s and built the rear chamber just %10 smaller then I have in my previous designs and this caused a rise in 50 Hz to 150 Hz region, which did the trick. Again, placing the speaker unit behind the radiation plane of the mouth improved the midrange purity and staging.
The enclosure will on my web page soon, with some pictures.
/Onur
Attachments
Hi Onur, thanks for joining the discussion
It sounds like i'll be facing a compromise no matter whihc direction i turn (unless i build a super large horn which is beyond my abilities at the moment)
Although I have some faith that onur's design is probably good, it seems that it's tweaked towards the fe207e, and that to make it work well with the fe206e the driver has to be modified with resistors
On the other hand, the dallas II seems to be tweaked towards the fe206e. For this reason (and because it's well tested), i'm now leaning towards the dallas II, since it seems like a more "natural" enclosure for the fe206e; as opposed to onur's horn which is natural for the fe207e and needs a bandaid to work well with the fe207e
I dont like bandaid sollutions very much and i prefer designs whihc were built specifically from day one. since the dallas II is designed specifically for the fe206e (i think), I'm leaning towards it
I dont understand what you're saying here due to my lack of knowledge. Does this apply to my situation, and if so how? or is it just a part of discussion with the others?
It sounds like i'll be facing a compromise no matter whihc direction i turn (unless i build a super large horn which is beyond my abilities at the moment)
Although I have some faith that onur's design is probably good, it seems that it's tweaked towards the fe207e, and that to make it work well with the fe206e the driver has to be modified with resistors
On the other hand, the dallas II seems to be tweaked towards the fe206e. For this reason (and because it's well tested), i'm now leaning towards the dallas II, since it seems like a more "natural" enclosure for the fe206e; as opposed to onur's horn which is natural for the fe207e and needs a bandaid to work well with the fe207e
I dont like bandaid sollutions very much and i prefer designs whihc were built specifically from day one. since the dallas II is designed specifically for the fe206e (i think), I'm leaning towards it
lndm said:
I dont understand what you're saying here due to my lack of knowledge. Does this apply to my situation, and if so how? or is it just a part of discussion with the others?
It was meant as an adjunct to Scottmoose's comments that a horn needs to be large. Whilst this is correct, I was trying to point out that a horn can be made more reasonably.
You say that a rear horn will be just an introduction. A very good one I think. 😉
You say that a rear horn will be just an introduction. A very good one I think. 😉
Flat 10
Hi Onur,
That Flat10 enclosure looks neat. Would watch for updates on both Flat and Beta series on your website... I hope you put up a design for Coral 8" drivers too (I have a pair). The 150Hz-50Hz is the punch/hit region, most backhorn scoop designs have a suckout in the low midrange/bass anyways so it's a good thing to put bit of bump there I think. BTW, most Coral drivers have highish Qts and Fs when actually measured. I'm thinking that the stock/original backhorn designs for the Beta may have some bass anomalies compared to the mulit-ported br designs. Thanks.
*Hi hugz, I apologize for hi-jacking your thread. Good luck on any design you may pursue with the FE206E.
fred
Hi Onur,
That Flat10 enclosure looks neat. Would watch for updates on both Flat and Beta series on your website... I hope you put up a design for Coral 8" drivers too (I have a pair). The 150Hz-50Hz is the punch/hit region, most backhorn scoop designs have a suckout in the low midrange/bass anyways so it's a good thing to put bit of bump there I think. BTW, most Coral drivers have highish Qts and Fs when actually measured. I'm thinking that the stock/original backhorn designs for the Beta may have some bass anomalies compared to the mulit-ported br designs. Thanks.
*Hi hugz, I apologize for hi-jacking your thread. Good luck on any design you may pursue with the FE206E.
fred
Hugz, in case you're a bit lost here, what Indm is saying is related to using the boundary conditions of the room to continue the expansion of the horn.
In a nutshell: imagine a horn hanging in mid air, hundreds of feet above the ground. That is radiating into 'full space.' It will need a very large mouth, as you can imagine.
Now imagine that we have plonked our horn down in the middle of a field somewere. To all intents and purposes, what the horn will 'see' is a boundary under it infinitely wide and infinitely deep. It is now radiating in 1/2 space. Theoretically at least (I stress the 'theoretically' bit), this should allow us to halve the size of the horn mouth, because we can use the reflection from the boundary condition to double the size of the mouth. It's easiest to visualise if you imagine placing a large mirror, face upward, on the floor, in front of your horn. What do you see? A horn mouth that has doubled in size.
Continuing the theme, now imagine a wall that has been constructed directly behind the horn. This halves the space the horn is radiating into once again (yes, you've guessed it: 1/4 space loading), and if you're using a rear-firing mouth firing at that boundary, you can halve the area of the mouth you wish to use once again.
A horn mounted in a room-corner is radiating into 1/8 space. So you can reduce the mouth area by a factor of 8 over what you would have needed had it been hovering somewhere up in the stratosphere. The BIB horns work on this principle, and very effective it is too.
Actually, if memory serves, Onur's horn was designed for the 206, not the 207, which I suspect was prefered due to its higher Q (30AWG magnet wire or a low damping factor amp and this is no longer an issue though). I haven't modelled the Dallas II in MathCad yet -I'll have a go if you like. I seem to remember the plans are over on the full range driver forum, right?
Regards
Scott
In a nutshell: imagine a horn hanging in mid air, hundreds of feet above the ground. That is radiating into 'full space.' It will need a very large mouth, as you can imagine.
Now imagine that we have plonked our horn down in the middle of a field somewere. To all intents and purposes, what the horn will 'see' is a boundary under it infinitely wide and infinitely deep. It is now radiating in 1/2 space. Theoretically at least (I stress the 'theoretically' bit), this should allow us to halve the size of the horn mouth, because we can use the reflection from the boundary condition to double the size of the mouth. It's easiest to visualise if you imagine placing a large mirror, face upward, on the floor, in front of your horn. What do you see? A horn mouth that has doubled in size.
Continuing the theme, now imagine a wall that has been constructed directly behind the horn. This halves the space the horn is radiating into once again (yes, you've guessed it: 1/4 space loading), and if you're using a rear-firing mouth firing at that boundary, you can halve the area of the mouth you wish to use once again.
A horn mounted in a room-corner is radiating into 1/8 space. So you can reduce the mouth area by a factor of 8 over what you would have needed had it been hovering somewhere up in the stratosphere. The BIB horns work on this principle, and very effective it is too.
Actually, if memory serves, Onur's horn was designed for the 206, not the 207, which I suspect was prefered due to its higher Q (30AWG magnet wire or a low damping factor amp and this is no longer an issue though). I haven't modelled the Dallas II in MathCad yet -I'll have a go if you like. I seem to remember the plans are over on the full range driver forum, right?
Regards
Scott
Scottmoose said:
Thanks for that explanation. I was roughly familiar with that concept. What i kinda dont understand is how does having a wall behind the speakers affect the sound? I'm sure I should know this since for all speakers (not just horns) distance from rear wall is important... but i just dont understand how the sound gets BACK there to reflect off the walls. does the sound simply travel through the enclosure?
You're correct that onur's horn was designed for the 206. What i was kinda talking about is that it seems suited to the 207, from what i've heard. But now that I think of it i've only heard 2 things that suggest that... the review on onur's website which says they prefered it with the 207, and someone saying that it's impendence curve looks like a BR. Since the 207 suits a BR more than a 206, i assumed that the cabinet would suit a 207 better. Now that I sit back to reflect, i suspect that i'm half just hyping it up in my head and the reality may differ. In the end i'm just quite concerned about choosing the right design to build, because i have nothing to compare it against if the design is bad, so i'll never know the true potential of the drivers..
If you'd be willing to model the dallas sometime that would be great. The design can be found here in various formats:
http://fullrangedriver.com/gallery/thumbnails.php?album=search&type=full&search=dallas
Imagine you have a straight horn lying on the ground. Slice it in half from throat to mouth by placing a wall down the middle. Imagine the wall is a mirror and you will see what looks like the full horn, but it is only half a horn. It will behave the same as the full horn, including frequency response, except it will only put out half the sound. This is OK as it only needs to fill half the space with sound.
This theory also applies to antennas. For best effect, I like to build the horn mouth right into the corner of the room.
This theory also applies to antennas. For best effect, I like to build the horn mouth right into the corner of the room.
Hi Onur,
That a great looking cabinet for the Flat 10, I look forward to seeing the plans on your website. Can this same cabinet be used for the Beta 10 ? Also as I have the Flat 8 and Beta 8s as well, can the same box be used or must it be scaled down ?
That a great looking cabinet for the Flat 10, I look forward to seeing the plans on your website. Can this same cabinet be used for the Beta 10 ? Also as I have the Flat 8 and Beta 8s as well, can the same box be used or must it be scaled down ?
Another slight sidestep and question for Onur,
Would you say the new 206ES-R would be suitable for the double horn and if not what should be changed in the plans?
(two ES-Rs waiting in their carton boxes to get out y'know...)
Would you say the new 206ES-R would be suitable for the double horn and if not what should be changed in the plans?
(two ES-Rs waiting in their carton boxes to get out y'know...)
Onur said:
Perhaps you just like the immediacy of the early reflections. Try listening (and of course measurements) with and without damping on your "extensions". I guarantee you will see and hear an effect. There is a reason you don't see speakers designed like this, not by professionals, anyway.
Take a nice speaker and set it on a table in front of you, how does it sound now?
We took a bunch of absorbers, which have different absorbing coefficients and listened to the design (for a russian full range unit which is similar to the one I built for Coral) with various kinds of music. Later we have listened to it without any absorbers. It would be a careless act if we didn't try it before publishing plans on my web page as a finished designs.
If we examine the problem in terms of radiation patterns, the directivity of a Full-Range speaker gains importance over 5000 Hz and at that frequency the panel below the speaker is not in the critical radiation space. Besides, I couldn't measure any reflection in the time domain.
If we take the matter from the time alignment and improvement of low frequency response angle, you can see many improvements. The impulse response, starting from the initial input to the sattlement, gets shorter. You can see the mouth response is getting closer to the response comming directly from the speaker unit. I must admit that I do have some worries here. In my previous measurements, the large low frequency peak was away from the peak which belongs to the speaker unit. In such a case, the small reflections, which are close to the first peak, could easily be identified. This, peaks getting closer in the time domain business, may be previenting me to identify any reflections which are very close to the first peak, but doesn't this also mean that they are less audiable as compared to the low frequency signal? On the low frequency improvement front, the indication of things getting better is the clear midrange response. I was very suspicious at the beginning like any other DIYer who is opposed to a enclosure which has a different design, but I am not anymore.
As for the 206ES-R, many enclosure builders are asking about it. I think I will go over it in a couple of days and see what will happen.
/Onur
If we examine the problem in terms of radiation patterns, the directivity of a Full-Range speaker gains importance over 5000 Hz and at that frequency the panel below the speaker is not in the critical radiation space. Besides, I couldn't measure any reflection in the time domain.
If we take the matter from the time alignment and improvement of low frequency response angle, you can see many improvements. The impulse response, starting from the initial input to the sattlement, gets shorter. You can see the mouth response is getting closer to the response comming directly from the speaker unit. I must admit that I do have some worries here. In my previous measurements, the large low frequency peak was away from the peak which belongs to the speaker unit. In such a case, the small reflections, which are close to the first peak, could easily be identified. This, peaks getting closer in the time domain business, may be previenting me to identify any reflections which are very close to the first peak, but doesn't this also mean that they are less audiable as compared to the low frequency signal? On the low frequency improvement front, the indication of things getting better is the clear midrange response. I was very suspicious at the beginning like any other DIYer who is opposed to a enclosure which has a different design, but I am not anymore.
As for the 206ES-R, many enclosure builders are asking about it. I think I will go over it in a couple of days and see what will happen.
/Onur
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