placement
The Buschhorns photos posted by Dave above were formerly in my system, and I got the best sound with them (and all other speakers before and since for that matter) with an apex/diagonal placement
i.e. the plane of the front baffles forming the base of an isosceles triangle, with a room corner as the apex.
While both speakers are at an angle and much further away from the corner than a "standard" corner placement, they are both loading into the same corner and there's some good room gain happening. Also, you only need one decent corner, and in my case while the other corner might be "available" it's over 15 feet away.
In addition, with a bipole (and if you put your ear to the mouth of the Buschhorn, there's quite a lot of energy well into the midrange coming out) you'll get a fair amount of delayed side wall reflections that can contribute to "soundstage"
For an interesting article that graphically represents the placment:
http://www.decware.com/paper14.htm
I'm sure Steve didn't invent this set-up, but it has certainly worked for me for over 5 years.
The Buschhorns photos posted by Dave above were formerly in my system, and I got the best sound with them (and all other speakers before and since for that matter) with an apex/diagonal placement
i.e. the plane of the front baffles forming the base of an isosceles triangle, with a room corner as the apex.
While both speakers are at an angle and much further away from the corner than a "standard" corner placement, they are both loading into the same corner and there's some good room gain happening. Also, you only need one decent corner, and in my case while the other corner might be "available" it's over 15 feet away.
In addition, with a bipole (and if you put your ear to the mouth of the Buschhorn, there's quite a lot of energy well into the midrange coming out) you'll get a fair amount of delayed side wall reflections that can contribute to "soundstage"
For an interesting article that graphically represents the placment:
http://www.decware.com/paper14.htm
I'm sure Steve didn't invent this set-up, but it has certainly worked for me for over 5 years.
Hi Guijs,
I have sent you a mail with a scan, as prommissed, of the original drawing you get with the units. The rest of the plans contains the drawing you will find on the Fostex site and a lot of Japanese
. If you look good in picture number 1 you will see that parts 29 are replaced by 4 parts. Now they fit and there's no place left. It's importend that it fits the side wall for the extra strenght of the compression chamber. I still don't understand the idee of the 6 lose pieces, the only reason I could come up with was that it didn't fit the cutting plan.
A piece of granite would look nice and I think it will work. In the original design you can fill the compartments in the bottem with sand. If your speaker is upside down it isn't possible, it will fall down. With the granite platform you will get the extra weight. I haven't filled the compartments with sand yet. What I last did was put some spikes under it so it stand more stable on the ground ( I have carpet), it was a lot better.
One question: It is possible to line the speakers directly to the listening position? What I mean is if the speakers face straight to the front, so that the don't point directly to the listening possition, You will have a lot of loss in the high frequenty. So you will have to be able to turn the speakers to the inside, directly pointing to the listening possition. Then you can experiment with turning them bit by bit to the outside to get some more depht in the soundstage.
I have sent you a mail with a scan, as prommissed, of the original drawing you get with the units. The rest of the plans contains the drawing you will find on the Fostex site and a lot of Japanese
. If you look good in picture number 1 you will see that parts 29 are replaced by 4 parts. Now they fit and there's no place left. It's importend that it fits the side wall for the extra strenght of the compression chamber. I still don't understand the idee of the 6 lose pieces, the only reason I could come up with was that it didn't fit the cutting plan.A piece of granite would look nice and I think it will work. In the original design you can fill the compartments in the bottem with sand. If your speaker is upside down it isn't possible, it will fall down. With the granite platform you will get the extra weight. I haven't filled the compartments with sand yet. What I last did was put some spikes under it so it stand more stable on the ground ( I have carpet), it was a lot better
.One question: It is possible to line the speakers directly to the listening position? What I mean is if the speakers face straight to the front, so that the don't point directly to the listening possition, You will have a lot of loss in the high frequenty. So you will have to be able to turn the speakers to the inside, directly pointing to the listening possition. Then you can experiment with turning them bit by bit to the outside to get some more depht in the soundstage.
Chrisb,
Thanks for the explanation, I'll read the articles carefully.
Alexander,
Thanks for the scan, I can't read it but the pictures are nice . As you can see on my shelf drawing, there is some space on the enclosure place in the shelf, so I can move it and point directly to the listening position! No problem with that. About the granite, I think it will be the best way since since I can't put the sand bags...
Thanks for the explanation, I'll read the articles carefully.
Alexander,
Thanks for the scan, I can't read it but the pictures are nice
. As you can see on my shelf drawing, there is some space on the enclosure place in the shelf, so I can move it and point directly to the listening position! No problem with that. About the granite, I think it will be the best way since since I can't put the sand bags...To Guijs (and others):
To avoid doubling of my contribution to questions about implementation of 10 cm horns I give this signal to Guijs.
In the thread 'compression chamber size' I have given today some thoughts to your question about 'placing a horn against or too near to a wall'. Go to that thread for more information.
I also asks in relation to that thoughts for some hornparameters for use of the fostex fe108ez, but that's a question that reflects issues of several other threads on diy also. The answers others will give to that specific parameters can be of interest for your decisions on wich cabinetimplementation will be chosen by you.
Greetings.
To avoid doubling of my contribution to questions about implementation of 10 cm horns I give this signal to Guijs.
In the thread 'compression chamber size' I have given today some thoughts to your question about 'placing a horn against or too near to a wall'. Go to that thread for more information.
I also asks in relation to that thoughts for some hornparameters for use of the fostex fe108ez, but that's a question that reflects issues of several other threads on diy also. The answers others will give to that specific parameters can be of interest for your decisions on wich cabinetimplementation will be chosen by you.
Greetings.
The efficiency is roughly 90dB /1w / 1m
so
93 dB / 2 w
96 dB / 4 w
99 dB / 8 w
102 dB / 16 w
Assuming you do not listen at 1 m distance, but at the same time your room is not that big, you probably could get 100 dB - brief -peaks in the midrange (I very doubt you can push that high in the 60 - 100 Hz region without damage - especially with the Bhorn)
so
93 dB / 2 w
96 dB / 4 w
99 dB / 8 w
102 dB / 16 w
Assuming you do not listen at 1 m distance, but at the same time your room is not that big, you probably could get 100 dB - brief -peaks in the midrange (I very doubt you can push that high in the 60 - 100 Hz region without damage - especially with the Bhorn)
try this one:
After several iterations of very basic SET amps, loosely based on a small scale commerical product, I tried both the EL84 and 34 versions of Alex Kitic's designs.
http://www.diyaudio.8m.com/Laf/Lafse2.html
Don't let the modest output power dissuade you from trying these out. With a well implemented power supply and decent OPT, these are very fast and dynamic, which can go a long way to sounding more "powerful" than the math would suggest, while retaining their musicality.
I personally preferred the EL84 design (with extra PS chokes and parallel feed output) quite synergistic with the stellar midrange of the FE108E Sigma in BLH.
To safely operate at sustained SPLs above 90dB, you'll probably need to pre-filter and roll in a pair of bass drivers somewhere in the neighbourhood of 80-120Hz. You could start with a cheap plate amp with adjustable turnover to find the sweet spot, and upgrade later to something like a LM4780 gainclone.
I found that I hardly ran mine at peaks approaching 90dB, so 5-10W of SE (T or P) was quite adequate, and very "creamy"
After several iterations of very basic SET amps, loosely based on a small scale commerical product, I tried both the EL84 and 34 versions of Alex Kitic's designs.
http://www.diyaudio.8m.com/Laf/Lafse2.html
Don't let the modest output power dissuade you from trying these out. With a well implemented power supply and decent OPT, these are very fast and dynamic, which can go a long way to sounding more "powerful" than the math would suggest, while retaining their musicality.
I personally preferred the EL84 design (with extra PS chokes and parallel feed output) quite synergistic with the stellar midrange of the FE108E Sigma in BLH.
To safely operate at sustained SPLs above 90dB, you'll probably need to pre-filter and roll in a pair of bass drivers somewhere in the neighbourhood of 80-120Hz. You could start with a cheap plate amp with adjustable turnover to find the sweet spot, and upgrade later to something like a LM4780 gainclone.
I found that I hardly ran mine at peaks approaching 90dB, so 5-10W of SE (T or P) was quite adequate, and very "creamy"
Guij: I listen to a wide variety of stuff incl. prog rock, jazz, orchestral, etc. These little drivers do an excellent job of sorting out the textures and nuances of the music. FWIW, they also go louder than my FE167E's, 'though I'm no headbanger. Aside from limited bass, you can't go wrong. Don
Hi there!
Interesting post. I am about to build
the Fostex recommended enclosure for the fe108ez as well. I'll build it out of 16mm MDF. I got the pieces cut in a "Baumarkt", that's a chain of hardwarestores in Austria where you usually buy tools and bathtubs and stuff like that...the MDF and the cutting cost me around 60$ (51EUR) for both enclosures (~4 m^2) and looks really staight, rectangular and accurate. We'll see...
The next step will be that I will slightly sand (240 grain) the surfaces that were cut, because there the fibres are not so compact (the fibres are ripped by the saw); sanding closes the surface. But I certainly won't sand the edges, don't worry...
Then I will "soak" every single piece with some undercoat (I don't know if the translation is correct; primer is another possibility), to seal off the MDF. Probably I'll use some 2-component undercoat because these can be spray-painted afterwards. The procedure should be like coat, let it dry for at least 12h, slightly sand (just smooth the surface, 240-280 grain), coat again, dry, slightly sand.
If one likes a coloured primer can be used, so later scratches in the paintjob are not that nasty...
Then I'll glue everything together with some waterproof glue.
People have told me that this (waterproof) is important becuase the pait could dissolve or reject from a surface where some glue is on. (it can dissolve the glue, not the surface...)
I hope you guys can give me some advice for the assembly, I've read something about some japanese instructions....please.
I'm not sure if I'll use nails or srews or just glue alone (shoul do fine, there's a lot of surface due to the many parts), but if, there is some levelling (again, not sure about the translation...) to be done because noone would want to see nails or scewsheads under the paint.
Well, then there's the paintjob...no idea yet. Maybe spraypaint and some clear coating.
The sand will most probably be put in some kind of bag to avoid a mess.
So, after sharing my thought, I've got a few questions:
What will you be using as dampin material? Filt mats, that white stuff (don't know the name, like glass-whool),...?
How will you mount the driver? Directly to the wood or with one of these brass rings or ?
Do you think it's clever to direct-mount the speaker-cables to the driver or should i install a connection-port?
And for piece #29: There would be enough space in the cutting plan to make them whole pieces (two per speaker), right? I have no idea why they are cut into tinier pieces and don't fit the width...
What do you think about making round edges (pieces 3,4,5,6,12,...) and round corners inside of the enclosure, could this reduce unwanted resonances? There are sure a lot of parallel planes inside...
Well enough this time.
c u , dave
Interesting post. I am about to build
the Fostex recommended enclosure for the fe108ez as well. I'll build it out of 16mm MDF. I got the pieces cut in a "Baumarkt", that's a chain of hardwarestores in Austria where you usually buy tools and bathtubs and stuff like that...the MDF and the cutting cost me around 60$ (51EUR) for both enclosures (~4 m^2) and looks really staight, rectangular and accurate. We'll see...The next step will be that I will slightly sand (240 grain) the surfaces that were cut, because there the fibres are not so compact (the fibres are ripped by the saw); sanding closes the surface. But I certainly won't sand the edges, don't worry...
Then I will "soak" every single piece with some undercoat (I don't know if the translation is correct; primer is another possibility), to seal off the MDF. Probably I'll use some 2-component undercoat because these can be spray-painted afterwards. The procedure should be like coat, let it dry for at least 12h, slightly sand (just smooth the surface, 240-280 grain), coat again, dry, slightly sand.
If one likes a coloured primer can be used, so later scratches in the paintjob are not that nasty...
Then I'll glue everything together with some waterproof glue.
People have told me that this (waterproof) is important becuase the pait could dissolve or reject from a surface where some glue is on. (it can dissolve the glue, not the surface...)
I hope you guys can give me some advice for the assembly, I've read something about some japanese instructions....please.
I'm not sure if I'll use nails or srews or just glue alone (shoul do fine, there's a lot of surface due to the many parts), but if, there is some levelling (again, not sure about the translation...) to be done because noone would want to see nails or scewsheads under the paint.
Well, then there's the paintjob...no idea yet. Maybe spraypaint and some clear coating.
The sand will most probably be put in some kind of bag to avoid a mess.
So, after sharing my thought, I've got a few questions:
What will you be using as dampin material? Filt mats, that white stuff (don't know the name, like glass-whool),...?
How will you mount the driver? Directly to the wood or with one of these brass rings or ?
Do you think it's clever to direct-mount the speaker-cables to the driver or should i install a connection-port?
And for piece #29: There would be enough space in the cutting plan to make them whole pieces (two per speaker), right? I have no idea why they are cut into tinier pieces and don't fit the width...
What do you think about making round edges (pieces 3,4,5,6,12,...) and round corners inside of the enclosure, could this reduce unwanted resonances? There are sure a lot of parallel planes inside...
Well enough this time.
c u , dave
Congratulations!
This driver is a really good choice!
MDF is not so good to construct the horns, but since you plan to seal the fibers, then it should be as good as birch plywood.
You will see that MDF "drinks" a lot!
Now, two things about the sealant:
1. Make sure it is compatible with the glue you will use;
2. Probably best would be to mask the areas where the glue will be applied, before sealing the MDF. Glue needs to soak a little in the MDF for tight bond (especially on the edges).
I would suggest that to do all construction work, except the last side panel, without sealant. Then when everything is glued and dried, apply as much sealant as it will absorb. Shellac is a very good product (but incompatible with urethane paints - test before!!) to seal wood. If it does not work, use a compatible product such as a sanding primer (2 or 3 coats).
For construction you can use glue alone, if you have plenty of clamps of different sizes. If not, you can use glue and brad nails (you probably can rent one along with a small compressor - works wonder and cost little).
For damping material, if you can afford it, use only high wool content felt (usually 95% wool) 10mm thick. Depending on wool content and thickness, it can absorb up to 80% of frequencies centered at 520Hz with nice roll-off. This stuff is MUCH better than any fiberglass material.
I do not know where you are located, but gemmeaudio.com in Canada sells the 10mm wool felt.
Several pieces are smaller than what they could be on the Fostex plan (this is to use every possible waste bits). You can use full width panels.
If you can afford the brass rings, use them. They provide mass loading on the driver frame and it improves sound focus. Plus it gives you a bit more compression chamber volume for you to tweak.
Sand should definitely be put in bags. Make sure the sand is dry (one hour at 100 or 200 degree in the oven should make it dry). You alson can use pebbles, rocks, ball bearings, etc. Anything dense, inert and heavy will do. Some people will pour melted paraphine on pebbles to make them "stick" together.
I'm not sure about the rounding edges on internal parts. Some people say it should be done to reduce turbulence while some other say you should leave them square to induce surface turbulence (which acts as a "lubricant" for air flow).
I would leave them as is, but then again I might be wrong because i did not do any turbulence analysis of the design.
Good luck with your project and I'm pretty sure you will be blown away by the performance of this little driver!
This driver is a really good choice!
MDF is not so good to construct the horns, but since you plan to seal the fibers, then it should be as good as birch plywood.
You will see that MDF "drinks" a lot!
Now, two things about the sealant:
1. Make sure it is compatible with the glue you will use;
2. Probably best would be to mask the areas where the glue will be applied, before sealing the MDF. Glue needs to soak a little in the MDF for tight bond (especially on the edges).
I would suggest that to do all construction work, except the last side panel, without sealant. Then when everything is glued and dried, apply as much sealant as it will absorb. Shellac is a very good product (but incompatible with urethane paints - test before!!) to seal wood. If it does not work, use a compatible product such as a sanding primer (2 or 3 coats).
For construction you can use glue alone, if you have plenty of clamps of different sizes. If not, you can use glue and brad nails (you probably can rent one along with a small compressor - works wonder and cost little).
For damping material, if you can afford it, use only high wool content felt (usually 95% wool) 10mm thick. Depending on wool content and thickness, it can absorb up to 80% of frequencies centered at 520Hz with nice roll-off. This stuff is MUCH better than any fiberglass material.
I do not know where you are located, but gemmeaudio.com in Canada sells the 10mm wool felt.
Several pieces are smaller than what they could be on the Fostex plan (this is to use every possible waste bits). You can use full width panels.
If you can afford the brass rings, use them. They provide mass loading on the driver frame and it improves sound focus. Plus it gives you a bit more compression chamber volume for you to tweak.
Sand should definitely be put in bags. Make sure the sand is dry (one hour at 100 or 200 degree in the oven should make it dry). You alson can use pebbles, rocks, ball bearings, etc. Anything dense, inert and heavy will do. Some people will pour melted paraphine on pebbles to make them "stick" together.
I'm not sure about the rounding edges on internal parts. Some people say it should be done to reduce turbulence while some other say you should leave them square to induce surface turbulence (which acts as a "lubricant" for air flow).
I would leave them as is, but then again I might be wrong because i did not do any turbulence analysis of the design.
Good luck with your project and I'm pretty sure you will be blown away by the performance of this little driver!
Those Brass Rings from Fostex are too expensive!!! Would a solid metal DIY ring, do the same job? Why the Brass rings are so expensive?
The FE108ez arrived on monday for me, and they are amazing. I'll start building the Fostex recommended enclosure next week.
Thanks for all the Help guys, this topic really, really help.
The FE108ez arrived on monday for me, and they are amazing. I'll start building the Fostex recommended enclosure next week.
Thanks for all the Help guys, this topic really, really help.
Hi, I just completed a pair of backloaded horns using the F206e.I experimented with a super tweeter but didn,t notice much of an improvement.These are excellent speakers with this cabinet design but sound best with tubes.I found too much harshness and shout with solid state.Don't require much power as well.10-15 watts.Currently running them with an Eico HF-81 and they sound awesome.EL84 output tubes.
Guijs said:
Because they are a company who wishes to make money, and this is a very good way of making some more.
To be fair economies of scale do come into this -they won't make / sell vast numbers of these brass rings, so that will push the price up. They're beautifully machined too. You want real extortion? Look at the prices of their plasic grills. Your wallet will scream for mercy, whilst you scratch your head and wonder how moulded plastic can cost so much.
A solid metal DIY ring will do the same job if made out of brass, which is not a particularly expensive metal. A change in metal type would affect the resonant quality though. I'm not a metallurgist except when talking about bronze and iron-age swords, which are another of my interests (well, I am a military historian!), so I'll let someone else work that one out. From my sword-making experience, I would favour bronze myself, but that's just me. The resonant frequency will shift, of that I'm sure, but which way would depend on the metal, how much is used, and which drivers you're using etc.
Best
Scott
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.