Hi folks, in looking at the FrugalHorn plans, I'm wondering if the FE166E could squeeze in there. Baffle width is just under 7 inches, with internal width of 5.5 inches, and it looks like it could go in there, especially if a supra-baffle is used.
Has anybody tried that, or do you have any thoughts on what the result would be? Thanks in advance -- the FrugalHorn looks like a fantastic design.
Has anybody tried that, or do you have any thoughts on what the result would be? Thanks in advance -- the FrugalHorn looks like a fantastic design.
Hi guys, thank you for the replies to my newb question. It can definitely get in there physically (with the supra-baffle) so I'm guessing you guys are saying it doesn't fit for other more sophisticated reasons.
It seems to have been designed with a lot of flexibility. For example, the chamber has dividers that permit up to 5.4 liters. That's vastly bigger than the chamber on Ron Clarke's A166.
So do you mean that, despite the adjustable size of the chamber, the throat is just impossibly small? In reading the plans, the throat looks to be about 5.5" wide x .75" high = 4.125"^2 (no quite sure of the .75 height from the plans but it looks to be about that).
Looking at the A166, the throat seems to be about 7.9 x 1.3 = 10.27"^2.
What if I simply make the Frugel-Horn's width greater until the throat area equals the value the A166 is using? A longshot of course, but I thought I'd ask in the hope of learning something. Thanks in advance!
It seems to have been designed with a lot of flexibility. For example, the chamber has dividers that permit up to 5.4 liters. That's vastly bigger than the chamber on Ron Clarke's A166.
So do you mean that, despite the adjustable size of the chamber, the throat is just impossibly small? In reading the plans, the throat looks to be about 5.5" wide x .75" high = 4.125"^2 (no quite sure of the .75 height from the plans but it looks to be about that).
Looking at the A166, the throat seems to be about 7.9 x 1.3 = 10.27"^2.
What if I simply make the Frugel-Horn's width greater until the throat area equals the value the A166 is using? A longshot of course, but I thought I'd ask in the hope of learning something. Thanks in advance!
Why not just build the A166? If your just wanting to have fun and play around some, then you can put the 166 in the FH ,but why bother?
To me the FH is a cool little horn that sounds good, and would be a good choice if you just can't get the wife or other to go for anything bigger, or you have a tiny room.
If it were me ,and I'm no designer, I would re-work the FH cab to have the driver at a more reasonable ear height as its basically a floor standing speaker cab that fires at your kneecaps. I always thought that this was a big flaw of the design IMO, but many really like it and of course YMMV..
Btw only my observations ,and in no way do I mean to say the FH doesn't sound good, it does..
Dave
To me the FH is a cool little horn that sounds good, and would be a good choice if you just can't get the wife or other to go for anything bigger, or you have a tiny room.
If it were me ,and I'm no designer, I would re-work the FH cab to have the driver at a more reasonable ear height as its basically a floor standing speaker cab that fires at your kneecaps. I always thought that this was a big flaw of the design IMO, but many really like it and of course YMMV..
Btw only my observations ,and in no way do I mean to say the FH doesn't sound good, it does..
Dave
Hi DaveCan, thanks for your words, especially with regard to driver height. My wife is just fixated on those amazing FH pictures of the flower-like supra-baffles with the voids left open. And now the standard has been set: in her mind, speakers should look like flowers in a vase.
I'm really trying to comprehend the horn theory. It would be fantastic if you could scale a horn in just the width dimension in order to nail the throat size. (This presumes the FH adjustable chamber, and it assumes you can live with whatever the horn's cutoff freq is, of course.)
So that's what I'm wondering: can you scale a horn's width to a larger driver, until the throat area matches that required by the driver?
The equation for throat area I'm using is:
throat area = (2pi * Fs * Qts * Vas) / speed of sound
So throat area is a function of driver params, but the mouth equation is not:
mouth area = (1/size-factor * 4pi)(c / cutoff-freq)^2
Which are from this site:
http://rocketsciencecanada.com/rocketsciencecanada/Sound/Horns/Info_Design.asp
Am I totally missing something obvious? Pardon these newbie questions -- I'm not trying to avoid the work, I'm really stuck after hours and hours. The problem with self-teaching is that I have an idiot for an instructor.
I'm really trying to comprehend the horn theory. It would be fantastic if you could scale a horn in just the width dimension in order to nail the throat size. (This presumes the FH adjustable chamber, and it assumes you can live with whatever the horn's cutoff freq is, of course.)
So that's what I'm wondering: can you scale a horn's width to a larger driver, until the throat area matches that required by the driver?
The equation for throat area I'm using is:
throat area = (2pi * Fs * Qts * Vas) / speed of sound
So throat area is a function of driver params, but the mouth equation is not:
mouth area = (1/size-factor * 4pi)(c / cutoff-freq)^2
Which are from this site:
http://rocketsciencecanada.com/rocketsciencecanada/Sound/Horns/Info_Design.asp
Am I totally missing something obvious? Pardon these newbie questions -- I'm not trying to avoid the work, I'm really stuck after hours and hours. The problem with self-teaching is that I have an idiot for an instructor.
Not generally, because in the process, you're going to change everything else, not just the throat.
Horn theory will only take you so far with most domestic horns, because they have to use a combination of QW & horn actions to fit into a vaguely reasonable cabinet size. See these two posts by GM which list a 'sufficient' number of publications on horns generally: http://www.diyaudio.com/forums/showthread.php?postid=1527960#post1527960
Horn theory will only take you so far with most domestic horns, because they have to use a combination of QW & horn actions to fit into a vaguely reasonable cabinet size. See these two posts by GM which list a 'sufficient' number of publications on horns generally: http://www.diyaudio.com/forums/showthread.php?postid=1527960#post1527960
If the wife really loves the FH with the flower type SB, then why not build it for the driver (s) it was meant for instead of using the 166? If it was me I'd build Ron's A126 instead ,and use Dave's modded 126 driver, and put the flowery Supra Baffle on it if I had to keep the WAF happening The A126 isn't a whole lot larger, better driver height and fuller sounding etc..
As Scott has pointed out you really can't just put any one driver in a horn cab and some other type cabs too that were not designed for it..
All the designs that these guys have worked on and given for the d.i.y.-er , should be built to the letter IMO ,otherwise you have no reference to how the design was suppose to work and sound in the first place..
Dave
The A126 isn't a whole lot larger, better driver height and fuller sounding etc.. As Scott has pointed out you really can't just put any one driver in a horn cab and some other type cabs too that were not designed for it..
All the designs that these guys have worked on and given for the d.i.y.-er , should be built to the letter IMO ,otherwise you have no reference to how the design was suppose to work and sound in the first place..
Dave
Hi guys, thank you again for your help! The lady will have her flower-speaker one way or another.
What got me thinking about scaling, in all dimensions or just width, is the http://www.hornlautsprecher.de site.
Many of the designs have the same "shape" and differ only in HxWxD, with some squishing and stretching -- but still variations on one shape.
Anyway, I'll keep chipping away. Thank you for the advice and the articles! It's a long slog but I guess it will be my personal Mt. Everest -- I can hardly complain that it's hard since the challenge is practically the point. That, and a speaker that looks like a flower which will probably be a plant-stand.
Thanks again guys!
What got me thinking about scaling, in all dimensions or just width, is the http://www.hornlautsprecher.de site.
Many of the designs have the same "shape" and differ only in HxWxD, with some squishing and stretching -- but still variations on one shape.
Anyway, I'll keep chipping away. Thank you for the advice and the articles! It's a long slog but I guess it will be my personal Mt. Everest -- I can hardly complain that it's hard since the challenge is practically the point. That, and a speaker that looks like a flower which will probably be a plant-stand.
Thanks again guys!
It would be kind of neat to poll some women and see what they would appreciate as a compromise enclosure etc ,in the shared listening space.
I think the Frugal Horn and the like would probably be very high up on the list, and also small bookshelf sort of cabs, very high WAF for size etc.
It's funny in that most women love to dance and groove etc( at all age levels), but somehow unlike us men folk, they don't often appreciate their stereo systems as the dominating factor of the room decor, go figure
Wouldn't it be cool if the lady of the house one day said something like, " Ya know honey , your a good man and I'd like to support your interest in music, you can build a pair of speaker cabs any size you want, as long as we can still sit together in the room and have space for when company comes over'' Schwing!!!
Dave
I think the Frugal Horn and the like would probably be very high up on the list, and also small bookshelf sort of cabs, very high WAF for size etc.
It's funny in that most women love to dance and groove etc( at all age levels), but somehow unlike us men folk, they don't often appreciate their stereo systems as the dominating factor of the room decor, go figure
Wouldn't it be cool if the lady of the house one day said something like, " Ya know honey , your a good man and I'd like to support your interest in music, you can build a pair of speaker cabs any size you want, as long as we can still sit together in the room and have space for when company comes over''
Schwing!!! Dave
Hi DaveCan, I say screw WAF and get a listening room which is not shared. That means a spare bedroom or basement, both of which will have great corners for the Frugel-Horns. Yay!
I really want to understand horns, as my amp only has two watts and I love the way inverted or rear-facing horns energize the room, with that open, reflected sound. For all the trouble, I think it's worth it.
That means a spare bedroom or basement, both of which will have great corners for the Frugel-Horns. Yay!I really want to understand horns, as my amp only has two watts and I love the way inverted or rear-facing horns energize the room, with that open, reflected sound. For all the trouble, I think it's worth it.
100% agree with everything you just said and then some..
I'd love to have my own room someday and that is the eventual goal, but not always possible for many.. Also using low watts, (6), and love the way horns work in my room.. Presently using inverted BiB's with fe108ez drivers and pretty happy with the way they sound for such a simple build.. Anyhow happy building and understanding all that horn tech stuff... Dave
I'd love to have my own room someday and that is the eventual goal, but not always possible for many.. Also using low watts, (6), and love the way horns work in my room.. Presently using inverted BiB's with fe108ez drivers and pretty happy with the way they sound for such a simple build.. Anyhow happy building and understanding all that horn tech stuff... Dave
If you have the 166 driver and want to use it then I'd do the A166 ,or if a more simple build is wanted a non- inverted BiB , but use them as designed, ie: corners.. Btw I've never heard a A166 cab but those that have seem to really like it...
It's really a personal thing to compare those cabs, especially if you've only heard them out of their element as designed..
For me if I was to use a 126 driver and had to choose between the cabs you listed then it would be the A126, or an inverted? Bib.. Also I've mostly just listened to the 108 driver and prefer it to the 126 but ymmv.. Also I should say that the last I heard a 126 driver it was not at the point that it has been taken to now with the newest mods and tweaks etc.. With just 2watts the 126 may be your best bet overall for the small driver cabs, the FH, A126 and Bib..
There are more highly skilled people here than myself that could really give you some good advice on which way to go but as for using the 166 in the FH I think most would say don't bother... Now if you want to put the 108 or 126 in the FH then thats a different story, and one with a happy ending.. Dave
It's really a personal thing to compare those cabs, especially if you've only heard them out of their element as designed..
For me if I was to use a 126 driver and had to choose between the cabs you listed then it would be the A126, or an inverted? Bib.. Also I've mostly just listened to the 108 driver and prefer it to the 126 but ymmv.. Also I should say that the last I heard a 126 driver it was not at the point that it has been taken to now with the newest mods and tweaks etc.. With just 2watts the 126 may be your best bet overall for the small driver cabs, the FH, A126 and Bib..
There are more highly skilled people here than myself that could really give you some good advice on which way to go but as for using the 166 in the FH I think most would say don't bother... Now if you want to put the 108 or 126 in the FH then thats a different story, and one with a happy ending.. Dave
Hi guys, just as a footnote, I found this quotation very interesting, from MJK's "Design of a Back Loaded Exponential Horn":
http://www.quarter-wave.com/Horns/Back_Horn.pdf
He's not talking about scaling at all, but rather, mere driver-swapping. Still, it's an interesting read and the first time I felt like I grasped something about horns in quite a while.
http://www.quarter-wave.com/Horns/Back_Horn.pdf
He's not talking about scaling at all, but rather, mere driver-swapping. Still, it's an interesting read and the first time I felt like I grasped something about horns in quite a while.
Hmm. I think you have to be a little careful with that particular paragraph as its easy to take out of context, or even misinterpret.
What I believe Martin is pointing out are:
1) All other things being equal (not that they ever are), the CSA of the driver is neither here nor there. The horn couldn't care tuppence if the driver has a 6in or an 8in diameter cone providing all other performance parameters remain constant. And
2) A horn is a horn, and, say, a 40Hz flare of any kind, taken from a given throat CSA, is a 40Hz flare for that particular throat CSA.
All fine & dandy so far: now we come to the caveat, which is whether or not a particular horn is optimal for a specific driver is a completely different matter. Horn variations can in fact be quite forgiving -more so than a typical modern BR box (which BLHs at any rate are related to), but forgiving and optimal are two different things. If you want to extract the maximum efficiency / performance, then you design it for a specific driver. Here, Keele, Leach etc have done the hard work for you by reworking Webster et al to relate to driver T/S parameters, which allows you to select an optimum throat area etc for your drive unit, rather than shooting in the dark.
What I believe Martin is pointing out are:
1) All other things being equal (not that they ever are), the CSA of the driver is neither here nor there. The horn couldn't care tuppence if the driver has a 6in or an 8in diameter cone providing all other performance parameters remain constant. And
2) A horn is a horn, and, say, a 40Hz flare of any kind, taken from a given throat CSA, is a 40Hz flare for that particular throat CSA.
All fine & dandy so far: now we come to the caveat, which is whether or not a particular horn is optimal for a specific driver is a completely different matter. Horn variations can in fact be quite forgiving -more so than a typical modern BR box (which BLHs at any rate are related to), but forgiving and optimal are two different things. If you want to extract the maximum efficiency / performance, then you design it for a specific driver. Here, Keele, Leach etc have done the hard work for you by reworking Webster et al to relate to driver T/S parameters, which allows you to select an optimum throat area etc for your drive unit, rather than shooting in the dark.
Hi Scott,
Thank you for your very helpful words. I'm still struggling with the very basics.
So is it something like this?
1. Throat area (and chamber) is a function of the driver chosen (balancing bandwith with efficiency) using T/S params.
2. Mouth area is a function of the chosen cutoff frequency (or vice versa). Mouth can be sized down by 4 for wall loading, 8 for corner loading.
3. Line length is ideally 1/2 wavelength of the cut-off frequency.
4. That ends up being too big, so after sizing down the mouth, the next thing to try is sizing the line length to 1/4 wavelength to mix in some TL action.
Is that hopelessly simplistic? Probably so, I'm guessing. Still, I appreciate your help and the occasional friendly shove in the right direction!
Thank you for your very helpful words. I'm still struggling with the very basics.
So is it something like this?
1. Throat area (and chamber) is a function of the driver chosen (balancing bandwith with efficiency) using T/S params.
2. Mouth area is a function of the chosen cutoff frequency (or vice versa). Mouth can be sized down by 4 for wall loading, 8 for corner loading.
3. Line length is ideally 1/2 wavelength of the cut-off frequency.
4. That ends up being too big, so after sizing down the mouth, the next thing to try is sizing the line length to 1/4 wavelength to mix in some TL action.
Is that hopelessly simplistic? Probably so, I'm guessing. Still, I appreciate your help and the occasional friendly shove in the right direction!
You're welcome.
That's the easiest, and most accurate way to do it, if you're aiming to get optimal performance.
Basically, yes. A horn is an impedance matching device (diaphragm to air) ergo, it requires a certain mouth size (which can be reduced by a factor of 2, 4 or 8 depending on what room boundaries are nearby) to achieve proper matching. If the length etc. of the horn is tuned to a lower frequency than the mouth size permits for proper impedance matching, then this is the is the transition point between horn & QW actions.
It varies with the chosen flare profile. For example, a catenoid horn (M=0) needs to be far longer than, say, the equivalent tractrix. But as a ROT, for optimal efficiency, a horn should be at least 1/2 wavelength of the chosen cut-off frequency in length.
In a sense -see note
A little simplistic, but not hopelessly because you're heading in the right direction.
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