I was looking at building some towers for myself and I have decided to go with a full range horn setup. A friend of mine on DIYMobileAudio.com with me posted about his full range setup and he is very impressed with his.
I'm looking for the best Sq possible. I'm going to be running a pair of subs with these so REALLY low end extension isn't a necessity but I'd like these to be able to hold their own with some lower notes.
Driver selection
I'm currently looking at the Fostex 108ESigma drivers. I know a fair amount about speakers but full range is foreign territory to me so I'm having trouble selecting drivers to build a horn for. Are the 108ESigmas a good choice or is there something else I should be looking at? Also, I've looked around and seen some of the eNabled drivers out there and couldn't really tell if it was worth it or not. Can the eNable process be done to the 108ESigma for some improvement? Planet hifi has the FE127eN for something like 240 and I wasn't sure how much the process really improved them. I know the 108ESigma's aren't that efficient but I'm not running a low powered tube amp or something so that wont be a problem. I looked at the Fostex suggested horn enclosure and I'm going to build that unless there is something else that you guys know about that sounds a ton better. I've looked at a ton of stuff and I don't want something that's TOO monstrous like the spawn variants.
My idea is to have each sub in a sealed enclosure on the ground below the horn enclosure and decouple the horn enclosure by way of a spike system on top of the subwoofer like I have pictured below. Is there any reason why this would be a bad idea? I'm just trying to think ahead here. I'm in uncharted waters and I'm trying to get everything planned out right.
Any help offered is appreciated.
I'm looking for the best Sq possible. I'm going to be running a pair of subs with these so REALLY low end extension isn't a necessity but I'd like these to be able to hold their own with some lower notes.
Driver selection
I'm currently looking at the Fostex 108ESigma drivers. I know a fair amount about speakers but full range is foreign territory to me so I'm having trouble selecting drivers to build a horn for. Are the 108ESigmas a good choice or is there something else I should be looking at? Also, I've looked around and seen some of the eNabled drivers out there and couldn't really tell if it was worth it or not. Can the eNable process be done to the 108ESigma for some improvement? Planet hifi has the FE127eN for something like 240 and I wasn't sure how much the process really improved them. I know the 108ESigma's aren't that efficient but I'm not running a low powered tube amp or something so that wont be a problem. I looked at the Fostex suggested horn enclosure and I'm going to build that unless there is something else that you guys know about that sounds a ton better. I've looked at a ton of stuff and I don't want something that's TOO monstrous like the spawn variants.
My idea is to have each sub in a sealed enclosure on the ground below the horn enclosure and decouple the horn enclosure by way of a spike system on top of the subwoofer like I have pictured below. Is there any reason why this would be a bad idea? I'm just trying to think ahead here. I'm in uncharted waters and I'm trying to get everything planned out right.
An externally hosted image should be here but it was not working when we last tested it.
Any help offered is appreciated.
WRT drivers, as you seem to be looking at the 4in - 4 1/2in units, the 108 is a lovely unit, but it's somewhat restricted in output terms & it really does prefer quite a big horn (relatively speaking) to really come to life. The 126&127, especially Dave's upgraded versions, are a little (very much, in the latter case) more forgiving. The upgrades are worth it IMO; they're so heavily modified, they no longer sound like the Fostex base unit, but something much more expensive. One of the more recent comments I dug out: http://www.diyaudio.com/forums/showthread.php?postid=1735016#post1735016
Right, next step. You say you want the 'best' SQ possible; can't say I blame you, don't we all, but you don't say how you define 'best' (it's a bit subjective you know... 
), or your circumstances. Firstly, exactly what amplifier are you running? This will have a bearing on which driver / cabinet will suit you best. FR based systems are all about matching the amplifier / driver / cabinet / room interface. You can make things work if needed via Eq, series resistance etc., but it's usually a better idea to pick the most optimal match to your requirements in the first place.
So much for that -taste? What sort of presentation do you like? How loud will you be listening? How far away? Room size? Is it 'live' or 'dead'? Material to be played (some cabinets are specifically designed for certain genres).
OK, on to BLHs. Most of them will not thank you for sitting them on a subwoofer, as they rely on using the floor boundary condition to double their effective mouth area -& if you remove that, the response will suffer. The Fostex designs are patchy. Some are OK, others less so. The 108 box is passable, but not much more than that. For e.g., you'd be better off with an FE126eN in the Frugel-horn (if you can corner-load them) or Ron's A126 (if a rear wall is available). Both are far superior to the Fostex cabinets. The Spawn range generally features larger designs, but there are some smaller boxes there for the 126 & its 127 stablemate, if you root through the plans page. There's even a reasonably compact double horn for the 108.
Whatever you do, don't rush into a decision. Take your time; it'll save you some in the long run. And BTW, if possible, don't build it out of MDF. Not an ideal material for horns.
Best
Scott
Right, next step
), or your circumstances. Firstly, exactly what amplifier are you running? This will have a bearing on which driver / cabinet will suit you best. FR based systems are all about matching the amplifier / driver / cabinet / room interface. You can make things work if needed via Eq, series resistance etc., but it's usually a better idea to pick the most optimal match to your requirements in the first place. So much for that -taste? What sort of presentation do you like? How loud will you be listening? How far away? Room size? Is it 'live' or 'dead'? Material to be played (some cabinets are specifically designed for certain genres).
OK, on to BLHs. Most of them will not thank you for sitting them on a subwoofer, as they rely on using the floor boundary condition to double their effective mouth area -& if you remove that, the response will suffer. The Fostex designs are patchy. Some are OK, others less so. The 108 box is passable, but not much more than that. For e.g., you'd be better off with an FE126eN in the Frugel-horn (if you can corner-load them) or Ron's A126 (if a rear wall is available). Both are far superior to the Fostex cabinets. The Spawn range generally features larger designs, but there are some smaller boxes there for the 126 & its 127 stablemate, if you root through the plans page. There's even a reasonably compact double horn for the 108.
Whatever you do, don't rush into a decision. Take your time; it'll save you some in the long run. And BTW, if possible, don't build it out of MDF. Not an ideal material for horns.
Best
Scott
Scottmoose said:WRT drivers, as you seem to be looking at the 4in - 4 1/2in units, the 108 is a lovely unit, but it's somewhat restricted in output terms & it really does prefer quite a big horn (relatively speaking) to really come to life. The 126&127, especially Dave's upgraded versions, are a little (very much, in the latter case) more forgiving. The upgrades are worth it IMO; they're so heavily modified, they no longer sound like the Fostex base unit, but something much more expensive. One of the more recent comments I dug out: http://www.diyaudio.com/forums/showthread.php?postid=1735016#post1735016
Right, next step. You say you want the 'best' SQ possible; can't say I blame you, don't we all, but you don't say how you define 'best' (it's a bit subjective you know...
So much for that -taste? What sort of presentation do you like? How loud will you be listening? How far away? Room size? Is it 'live' or 'dead'? Material to be played (some cabinets are specifically designed for certain genres).
OK, on to BLHs. Most of them will not thank you for sitting them on a subwoofer, as they rely on using the floor boundary condition to double their effective mouth area -& if you remove that, the response will suffer. The Fostex designs are patchy. Some are OK, others less so. The 108 box is passable, but not much more than that. For e.g., you'd be better off with an FE126eN in the Frugel-horn (if you can corner-load them) or Ron's A126 (if a rear wall is available). Both are far superior to the Fostex cabinets. The Spawn range generally features larger designs, but there are some smaller boxes there for the 126 & its 127 stablemate, if you root through the plans page. There's even a reasonably compact double horn for the 108.
Whatever you do, don't rush into a decision. Take your time; it'll save you some in the long run. And BTW, if possible, don't build it out of MDF. Not an ideal material for horns.
Best
Scott
For the amplifier I won't be running anything special. I'll be running my Harmon/Kardon AVR147. I don't have much available in the way of Eq but I do have a high pass crossover in the receiver. When I say "best Sq possible" I know that's an impossible task. My taste in drivers this far has been congruent with what Focal offers. Some say they are bright but I rather like the way they sound. Accuracy is much preferred over coloration.
Room size isn't set in stone since I'm likely to move within a few months into an apartment. But, the room size wont be huge. When i actually do listening I listen to mostly jazz. I do really like rock and other stuff to but finding recordings that do a good speaker justice are hard to find.
I thought that the supplied design for the 108 looked a little rough to be honest. What exactly isn't opptimal about it? I was pondering using body filler to round off the areas where multiple pieces of wood are used to create a false curve much like stairs. I was going to smooth out the shape hoping that response would look better after doing so.
My main goal is to find something i will really enjoy sitting down and listening to. I'd rather critique the recording than my speakers.
That's the last thing you should do. The Fostex cabinets, like many of mine, create the flare out of an expanding series of constant CSA pipes. The sharp edges are actually beneficial to / part of this type of enclosure. It's just that in this case, it's not an especially distinguished example -not terrible, but not ideal either; the profile isn't really optimal for the driver, and so on & so forth.
The HK amp is OK, but the small Fostex units won't exactly flatter it, so you'll probably need to look at your cables at least (something resistive like thin magnet wire) to help tweak things.
The HK amp is OK, but the small Fostex units won't exactly flatter it, so you'll probably need to look at your cables at least (something resistive like thin magnet wire) to help tweak things.
did you notice my thread about the Conical horn I built, using the Markaudio Alpair10 :
http://www.diyaudio.com/forums/showthread.php?s=&threadid=137654
http://www.diyaudio.com/forums/showthread.php?s=&threadid=137654
Thanks for the heads up. What do you mean by thin magnet wire? I was sort of under the impression that oxygen free copper wire was all pretty much equal as long as the gauge was thick enough to handle the current going through it. What is the difference?
In the future I'd like to get a nice tube amp of some sort but for now the HK is what I have so I'm sticking with it.
I have been doing TONS of searching and I found that there is an eNable kit of some sort that is sold here on the forum. What exactly is done to the drivers in the process? I read that there is some clay like stuff that goes on the motor structure to prevent resonances and the cone is treated too. Is that all or is there more to it? The kit was like $25 and if it is something I could do myself I'd try it for sure.
Basically, I know that the 127 driver that has been eNabled is leaps and bounds better than it's factory sibling. This is why I'm curious if I started with what I perceive to be a better driver out of the box (108) and eNable it, would that yield better results? I hadn't read anything about people treating the 108 driver; is there a reason for that?
I must say, I'm kinda stuck on integrating a sub into the bottom of the system so I can keep things compact in an apartment. It will also keep the sound stage in front. Is there a horn design that would work better with that idea?
PS: In hind sight I realize I should probably have told you all what I'm listening to right now as a sort of bench mark. Currently, I have a 5.2 (yes i made that up) system that is composed of HSU Research HB-1 book shelf speakers with a center channel and a pair of Peerless 830845 12" XXLS Subwoofers in separate sealed enclosures. When listening to music I run only two bookshelves in stereo with the pair of subs. I like it a lot but I'm intrigued by the idea of full range stuff hoping to find that level of detail and accuracy in music I didn't even know existed.
In the future I'd like to get a nice tube amp of some sort but for now the HK is what I have so I'm sticking with it.
I have been doing TONS of searching and I found that there is an eNable kit of some sort that is sold here on the forum. What exactly is done to the drivers in the process? I read that there is some clay like stuff that goes on the motor structure to prevent resonances and the cone is treated too. Is that all or is there more to it? The kit was like $25 and if it is something I could do myself I'd try it for sure.
Basically, I know that the 127 driver that has been eNabled is leaps and bounds better than it's factory sibling. This is why I'm curious if I started with what I perceive to be a better driver out of the box (108) and eNable it, would that yield better results? I hadn't read anything about people treating the 108 driver; is there a reason for that?
I must say, I'm kinda stuck on integrating a sub into the bottom of the system so I can keep things compact in an apartment. It will also keep the sound stage in front. Is there a horn design that would work better with that idea?
PS: In hind sight I realize I should probably have told you all what I'm listening to right now as a sort of bench mark. Currently, I have a 5.2 (yes i made that up) system that is composed of HSU Research HB-1 book shelf speakers with a center channel and a pair of Peerless 830845 12" XXLS Subwoofers in separate sealed enclosures. When listening to music I run only two bookshelves in stereo with the pair of subs. I like it a lot but I'm intrigued by the idea of full range stuff hoping to find that level of detail and accuracy in music I didn't even know existed.
Henkjan said:
The design looks MUCH simpler than the one I was planning and it's not all that tall. My conversions to inches put it right about 4 feet off the ground with the driver cone sitting about 3 feet off the ground. Do you think this design decoupled on top of a sub would inhibit it's function? The top of the sub where the horn would be spiked would be about 450mm off the ground.
MathCAD predicted responses of aforementioned cabinet
1/ 1/2 space
2/ 1/4 space, front baffle 1m from rear wall
2/ 1/4 space, front baffle 1m from rear wall, cabinet raised 0.45m
Conclusions: the falling response below ~600Hz in the two lower simulations is concurrent with the baffle-step point. The dip in the mid-upper bass is likely to be floor-bounce. I'd would avoid raising them on top of subwoofers, as I mentioned before, as it does the response no favours at all, and probably favour corner-loading, to try to get as much help from the room as possible, if a compensation circuit is not wanted.
1/ 1/2 space
2/ 1/4 space, front baffle 1m from rear wall
2/ 1/4 space, front baffle 1m from rear wall, cabinet raised 0.45m
Conclusions: the falling response below ~600Hz in the two lower simulations is concurrent with the baffle-step point. The dip in the mid-upper bass is likely to be floor-bounce. I'd would avoid raising them on top of subwoofers, as I mentioned before, as it does the response no favours at all, and probably favour corner-loading, to try to get as much help from the room as possible, if a compensation circuit is not wanted.
Attachments
italynstylion said:
The thinner magnet wire will help raise the impedance the receiver will see, effectively dropping the damping factor of the amp some to help create a little more bass output from the Fostex drivers. That's why a lot of people use tube amps or small digital amps with these drivers... They already have low damping factors to begin with.
Also, something like the FE126eN such as I have will blow your current bookshelves out of the water. Not that I'm bashing your speakers, but I do know what these drivers are capable of and with the speakers I have around here, the modified Fostex drivers are blowing them all away.
italynstylion said:
I think the biggest reason for going with a horn design is to get as much usable bass out of these small drivers as possible. Since you have stereo subs, that may not be an issue for you and can mount the horns on top of your subs and still be perfectly happy.
I have my Fe126eN's in aperiodic loaded cardboard boxes which taper off the bass around 150Hz or so. I have them sitting on top of a pair of 3-way towers I built 13 years ago that use 8" Vifa woofers. I have the rest of the drivers in those enclosures disconnected and am only using the Vifa's for bass support. They are crossed over at 120Hz. They blend perfectly with the little Fostex drivers and you would not believe how incredible this system actually sounds, YES, even in cardboard boxes!
That thread that Scottmoose linked to is my thread about the entire project. I have pondered many horn designs, but have finally settled on a large, very heavy one-off bookshelf design of my own. Feel free to read through that thread. There's a lot of great information in there and you can see where and why I changed my plans with these awesome little drivers.
Scottmoose said:
Scott, is that for the horn that I posted or is that for the one that Henkjan posted? Thankyou for running the numbers for me. I didn't expect you to do that but it definitely explains what your talking about.
A question about that; if I may...Is the drop in response due to the fact the horn's mouth fires at the listener and parallel to the ground so the ground being farther from the mouth has a drastic effect? That may have been stating the obvious but I just wanted to make sure.
If that was the case it gives me an idea though. In my quest to learn about this stuff I ran across the BIB site. I didn't really understand how to design that style of horn but I noticed that that "style" or horn enclosure has it's mouth on the top of the enclosure. Would this style of horn be adversely affected if I raised it a touch to put on the sub? I wouldn't think it would be impacted as much but I have no way of knowing and that's why I'm asking you!
How is that style of horn designed? Is the FE126eN that Chops mentioned a strong candidate for that type of horn? I found that driver on their site and the response in the BIB looked decent from what I could tell. Again, I'm not looking for much in terms of response below 80hz, I just want detail and realism.
Interesting, I'll end up getting a different amp sometime so I doubt I'll end up getting any of that wire but if i feel something is lacking I'll check it out. I'm not sure when I'd get a new amp but one day it will happen.chops said:
The subs I'm using are DIYMA R 12's in sealed enclosures. The R12's will play up to 120hz well but I wasn't planning on running them quite that high.
italynstylion said:
The latter.
Not applicable per se as you're refering to the Fostex cabinet, whereas the Henkjan box has the mouth to the rear.
Depends which drop you mean. The gradual decrease seen in the 2nn & 3rd graphs below 600Hz is caused by step-loss. The large dip also seen in these graphs is likely the result of floor-bounce -note that it changes in frequency when the cabinet is raised.
If that was the case it gives me an idea though. In my quest to learn about this stuff I ran across the BIB site. I didn't really understand how to design that style of horn but I noticed that that "style" or horn enclosure has it's mouth on the top of the enclosure. Would this style of horn be adversely affected if I raised it a touch to put on the sub? I wouldn't think it would be impacted as much but I have no way of knowing and that's why I'm asking you!
How is that style of horn designed? Is the FE126eN that Chops mentioned a strong candidate for that type of horn? I found that driver on their site and the response in the BIB looked decent from what I could tell. Again, I'm not looking for much in terms of response below 80hz, I just want detail and realism.
After Terry Cain became ill, it was primarily myself & GM (who also posts here) who picked up the batton for the BIB, and Jeff kindly offered to host a dedicated set of pages for them. The BIB is a Voigt style (it's pretty much the only proper one around) BLH, where total horn length is set to 1/2 wavelength of the desired tuning frequency. You will see on the pages a set of explanatory diagrams, and several Excel sheets which will allow you to design your own with little effort for any driver you feel inclined to use. For those who want to extract the most LF extension from a driver, with a relatively simple box, this is the one to go for.
Can I give you a friendly piece of advice here? Try not to dump your cabinets on top of the subs. It might be space-convenient, but it won't do the sound any favours at all.
italynstylion said:If that was the case it gives me an idea though. In my quest to learn about this stuff I ran across the BIB site. I didn't really understand how to design that style of horn but I noticed that that "style" or horn enclosure has it's mouth on the top of the enclosure. Would this style of horn be adversely affected if I raised it a touch to put on the sub? I wouldn't think it would be impacted as much but I have no way of knowing and that's why I'm asking you!
How is that style of horn designed? Is the FE126eN that Chops mentioned a strong candidate for that type of horn? I found that driver on their site and the response in the BIB looked decent from what I could tell. Again, I'm not looking for much in terms of response below 80hz, I just want detail and realism.
One of the caveats of a BIB is that it needs to load into a corner, or at least a wall/ceiling (or wall/floor) junction.
A 126 BIB is very feasible, but is usually inverted to use the floor instead of the ceiling since it is so short. If your sub was high enuff to boost the short BIB to allow it to use of the ceiling it would work.
Note thou that a BIB can be described as a simple box, that gets the most bass out od a driver, at the expense of some ripple (no free lunch). Since you have the subs seems you would be going to a lot of effort just to throw away the benefit, and still have to live with the compromise.
With the 126 in a situation i'd look seriously at putting the 126 into a lossy/aperiodic "midrange" TL and choose woofers that let you cross up where it starts to fall -- 150-200 Hz would be my guess.
With Sats on top of woofers you need to insure isolation.
dave
After much reading/searching I think I've decided on the following...Tell me if my plan has any holes in it or if there are places it could be improved.
I will be using the FE126eN from Planet HiFi as my driver of choice. It seems to fit the bill for my goals. I don't need bass response that extends that low because I will have subs for that. This driver also seems to have the best reputation of any driver around the forum so it's probably a good choice to start out with.
The design I'll be using is a Frugal Horn Level 3. I decided on this because it's not terribly huge and is designed for the 126 driver. Coincidentally, this design also accommodates the 108Esigma which was the other driver I was looking at. In the future, if i decided to try the 108 I could still use the enclosure and alter the compression chamber.
I think I'm going to design the horn to have the small and medium compression chambers opened up. I read that increasing the CC lowers the filter. I'm not looking for sub bass out of these so I'll go with a medium CC and fill it in as I need. What things are suitable for filling in the CC to make it smaller?
I've also decided to axe the idea of putting these on top of my subs. As many have told me, the idea just isn't optimal for Sq.
I will be using the FE126eN from Planet HiFi as my driver of choice. It seems to fit the bill for my goals. I don't need bass response that extends that low because I will have subs for that. This driver also seems to have the best reputation of any driver around the forum so it's probably a good choice to start out with.
The design I'll be using is a Frugal Horn Level 3. I decided on this because it's not terribly huge and is designed for the 126 driver. Coincidentally, this design also accommodates the 108Esigma which was the other driver I was looking at. In the future, if i decided to try the 108 I could still use the enclosure and alter the compression chamber.
I think I'm going to design the horn to have the small and medium compression chambers opened up. I read that increasing the CC lowers the filter. I'm not looking for sub bass out of these so I'll go with a medium CC and fill it in as I need. What things are suitable for filling in the CC to make it smaller?
I've also decided to axe the idea of putting these on top of my subs. As many have told me, the idea just isn't optimal for Sq.
italynstylion said:
Great choice, however I doubt you'll want to ever switch out the FE126eN for the Sigma 108. As it is, the original Frugal Horn came equipped with the 108, then later upgraded to the stock FE126E. Dave's highly modified FE126eN is years ahead of the stock FE126E. See where I'm headed with this?
Scottmoose said:
I see. I did indeed misinterpret what the plans were saying. What is the trade-off for having the horn run up higher with a smaller CC? Is it just personal taste?
One thing I noticed about the plans that looked a bit odd is that they mentioned that the 126 needed about 2.2L and the small CC was a good place to start. If the small CC is already 2.3L then what is the advantage of making it drastically larger?
chops said:
What you mean is that the Hornshoppe Horn came with FE108eS (started out with FE108S or RS 40-1197), and then upgraded to FE126e.
Stock vrs stock, 108eS does better mids, 126 has 3 dB efficiency, better bottom, and top. The pre-treatment on an FE126e brings the mids to within spitting distance of FE108eS in the mids, and i agree with chops on stock brs fully treated, pretreat is maybe a 1/4th the difference between stock & fully treated, being closer to a stock one.
dave
Italyn,
Given that you really don't want to give up your bass, perhaps a horn isn't the best solution for you. You could still stick with full-range and perhaps build some Fonkens with matching subwoofer stands...
Note that the fonkens pictured are designed for the FE127e while the frugelhorn is designed for the FE126e. They look the same, but each requires different enclosure characteristics.
Given that you really don't want to give up your bass, perhaps a horn isn't the best solution for you. You could still stick with full-range and perhaps build some Fonkens with matching subwoofer stands...
Note that the fonkens pictured are designed for the FE127e while the frugelhorn is designed for the FE126e. They look the same, but each requires different enclosure characteristics.
chuyler1 said:Italyn,
Given that you really don't want to give up your bass, perhaps a horn isn't the best solution for you. You could still stick with full-range and perhaps build some Fonkens with matching subwoofer stands...
Note that the fonkens pictured are designed for the FE127e while the frugelhorn is designed for the FE126e. They look the same, but each requires different enclosure characteristics.
That could be an option as well.
Another question, if I may....
Can the triangular prism deflector that sits behind the horn mouth be altered at all? Keeping the angle the same, could I extend the sides to make it a bit bigger? The face that faces the wall is 10.25inches but could I make that face something like 15inches while keeping the same angle on the point facing into the horn mouth?
Of course, the reason I ask is because I'm mulling over ideas of where to put the subs. That deflector is almost big enough to house a 12" sub. Would putting a sub in there kill it's purpose? I had imagined making it so that I could mount the sub on the top of the deflector in the triangle face. I would make the area that is as high as the horn mouth, the internal chamber, filled with sand. Then, the top chamber would be an enclosure for the sub. Would this work?
I have a picture explaining some of the stuff. Please excuse the use of MS paint
An externally hosted image should be here but it was not working when we last tested it.
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