| jasonlky |
Hi,
Just want to share my DIY Horn speakers based on the Dallas III and Fostex FE206E. You can read it here. Tell me what you think....
Jason:D |
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| ronc |
Add 1-4 ohms series resistance to taste.
ron |
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| jasonlky |
Hi Ronc,
Thanks for the design. The speakers are really good and as long as I am off axis with the speakers toed out, I don't notice the shout inherent in these speakers.
What does the 1-4ohm resistance do?
Jason |
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| Cal Weldon |
| Nice looking horns Jason. |
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| hm |
hello ron,
is the thickness of the side walls enough ??
nice work, good looking |
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| ronc |
is the thickness of the side walls enough ??
Based on the spacing of the internal supports, yes. However more bracing would be better.( Texas sayin " if more is better then too much is enough)
I ran the side loading sims on a structural loading program that was modified from a building enclosure program
that was altered for internal pressure fluctuations. (blow into a square box and measure the deflection of the sides)
What does the 1-4ohm resistance do?
It will bring up the LF response by raising the Qes which in turn raises the Qts. With the efficency of the 206/Dallas you will be hard pressed to notice any difference in efficency.
Again, tune to your personal desires.
ron |
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| ronc |
I just noticed in your pics the wires hanging out from the driver flange.
ANY leaks in the flange to baffle surface will affect LF performance. The driver flange should be totally sealed with something on the order of silicone sealant.
ron
(the hardest thing you can do is to make something simple)
Now I am not sure if the Dallas III was actually designed by Ron himself
Yep! |
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| jasonlky |
1. I will try the 1-4ohm resistors and report back as to what works for me.
2. The speakers are all sealed up so there is no way for me to add additional support/bracing unless I cut it open.
3. Yes the pictures do show that the wires are stickin' out and there is no proper seal. That said I very satisfied with Well, I have not installed the binding posts and I have also been asked to try the Coral 8A-40 in these cabinets. Once I have done all this, I shall seal up the cabinets.
4. I guessed that Ron did not design the Dallas III, but after cross referencing the measurements with the Dallas II, all measurements seem to line up. What I am not sure about is if the radiused corners will change the parameters and this the sound all that much....
Jason:D |
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| ronc |
I guessed that Ron did not design the Dallas III, but after cross referencing the measurements with the Dallas II, all measurements seem to line up.
I believe i did, unless it was a drug induced flashback (happens sometimes). My mind is still strong, however as i get older its more analytical and i spend much more time doing the actual math/physics and less dreaming, Maybe there is a downside to getting older, you lose imagination.
ron
I have also been asked to try the Coral 8A-40 in these cabinets.
I designed these cabs specifically for the 206, i cannot garrentee the results with any other driver. |
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| TerribleT |
Nice work. The Dallas design is beautiful. I have a pair of 206Es and I was considering building the Sachikos. Does anyone out there care to comment on the Dallas III's design versus the Sachikos'?
Regards,
David |
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| ronc |
The Dallas design is beautiful.
I have no idea about that. Its functional to a given degree.
ron |
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| jasonlky |
Ronc, sorry for misunderstanding. Thank you again for the very functional design of the Dallas III horns, I love em to bits. I do understand that the cabs are designed for the 206, but since the corals are such versatile speakers, I'd just like to listen to them in this setup. Plus I am geting the Corals on loan for free... so no harm in trying.
The Dallas III is indeed a beautiful design. I am not so hot for the Dallas and Dallas II though. Here is the side profile fo the Dallas III showing the internal structure... |
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| jasonlky |
And here is the Dallas II for comparison. For ease of build, the Dallas II wins hands down. But for both functionality and good looks... choose the Dallas III.
Presenting the Dallas II. |
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| ronc |
and the Dallas III... much more attractive, but does the radiused corners affect the parameters and so the sound.... negatively?
Nope! just a gain in efficency because there is less turbulance in the wavefront as it traveles. Down side is a slight increase in mids coming thru the mouth. However the actual horn action begins a slow roll off at 247 hz and ends at around 400 hz. From there the baffle action takes over (overlaps with the horn roll off) and as the frequency increases finally hands off to the driver. The absolute lowest frequencies are a TL action which blend into the lowest horn action at around 120 hz. The higher frequency TL ripples are then blended with the horn action. This results in a smoother mid bass.
However if the drivers are not totally air tight and sealed to the CC then there will be a definate loss in LF response.
ron |
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| jasonlky |
@ronc, thanks for the expalnation. I breathe a little easier with the knowledge that the decision I made on looks first did not have a negative outcome in terms of the sound.
Roger that on the air tight seal required for good LF response. I will do that as soon as I have the Corals tested in the cabs.
Question: During the build, I tried my best to follow all measurements as closely as possible. But for an amateur like me, it isn't always easy to get everything accurately down to the last milimeter. WHat is the allowed tollerances with regards to the various measurements in the DallasIII? Since I do not have a frame of reference for the Dallas III/Fostex 206, I cannot tell if the speaker sounds as you would have "intended".
Jason:D |
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| jasonlky |
I have just got my grubby hands on a pair of Coral 8A-40s. Really old and dirty!! I will be plugging them into the Dallas III. Interesting to see how they work out.
Jason |
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| hartgas |
greetings from the netherlands.
i have decided to build a pair of dallas III to match a soon to be mine 2A3 pair of monoblocks.
http://www.dhtrob.com/projecten/magique_1_en.htm
i think this could be a good combination and enter into the realms of the singledriver experience.
dhtrob who build this one plays these amp's using Phy drivers from france.
this, if is the ultimate in his opinion in an open baffle.
for me this would be an option but for the wifey not!!
so my friend who is an excellent carpenter will help me to build your dallas III design.
first i wanted to build the frugal horns, but my livingroom is a rather L-shaped room and from what i read i get more bass with the dallas's and also the wifey likes the optics dallas better, so do i for that matter
i am no expert on electronics so i will stick to your plan on how to build and try refrain from any diversions.
i couldn't find the plans for the dallas III on the frugalhorn site, they look very similar to the dallas II but with all corner excess taken off, is this true?
i like the look of the fostex 208 es but i read they need an extra tweeter, is that so?
so i will try and get my hands on dave's 206 EN
greetings
~joris
--
coffee over soup anyday |
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| planet10 |
| quote: | Originally posted by hartgas
i couldn't find the plans for the dallas III on the frugalhorn site, they look very similar to the dallas II but with all corner excess taken off, is this true? |
No plans for the Dallas III were ever released. It is a "smoothed" version of the Dallas II that Ron & Tony (layertone) worked on. Ron's plans were eaten by Windows. Tony may have them still.
dave |
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| OzMikeH |
| quote: | Originally posted by planet10
........ Ron's plans were eaten by Windows......
dave |
I know that feeling well.
I've had a bad day. That comment helped me laugh about it.
Your timing is almost psychic.
There is some information on it here:
http://fullrangedriver.com/gallery/search.php
type in Dallas.
there is a sketch there that could be printed to scale. |
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| TerribleT |
Hello,
Nice construction. The wood looks pretty thick. What type of material was used to construct the Dallas?
Regards,
David |
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| jasonlky |
@hartgas, we are similar type of DIYers, just stick to plans and try to refrain from diversions. About the DAllASS III's WAF (Wife Acceptance Factor), they are rather LARGE speakers in both th visual and audio sense, so unless you have a large room to fill... again both visually and audio wise, best to opt for something smaller. The Dallas III plans can be found on www.fullrangedriver.com's gallery section. Good luck in your pursuit and keep us updated.
@David, I got some local plywood for the construction. A mold was created and the plys were glued in layers with the help of the mold. It was finally finished off with a birch veneer.
Update: the Corals are sitting pretty in my cupboard, have not found the time to install them in the Dallas III cabs as yet. I'll try to do it this weekend.
Cheers,
Jason:D |
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| ronc |
The Dallas was designed with my original programming, things have advanced from then.
As i look on it now its fairly antiquated.
ron |
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| hartgas |
i just talked with my woodworking companion.
in the drawings of the dallas II we saw the thickness of the material is 14 mm
that seems very thin and flimsy to us.
is there any difference between plywood and solid wood? what about veneered MDF/HDF
@jason,
i saw on the design for the phy drivers, the OB's that mr salabert is using spruce instument wood and into some sort of sandwichfilled with sand. so instead of creating a dead box he is using thin wood and using the box as a resonator as done with musical instruments, any thought on that?
didn't you go for a thick baffle or is that integrated?
@ron
you said things developed from there and seems antiqutated, feel free to enlighten us.
thanks sofar with all the info
greetings
~joris |
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| Scottmoose |
Yes. Depends on what type of wood.
People do seem to get obsessed over resonance. Remember, assuming the material is stiff enough for the purpose in hand, it doesn't matter if it rings like a bell if the natural resonance frequency of the panels is above the operational passband of the cabinet. That's why CRS is ideal for many cabinets. Personally, I don't like MDF / HDF. Not stiff enough, it kills you, and its resonant frequency is right where you don't want it, so you either need to use far more bracing than plywood requires, or double up the panels to push resonance down, below the cabinet's passband. Which has its own problems, like energy storage & slow decay time etc. Not good.
I'm not Ron, but his software & ability to plot wavefronts, and the different actions, has improved greatly since Dallas was designed (as if it wasn't good enough to start with) -current state of the art are his Austin enclosures. |
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| hm |
Hello,
my experience shows
18 mm birch multiplex and
soft fibre board is the best
material mix for horns. |
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| ronc |
you said things developed from there and seems antiqutated, feel free to enlighten us.
Well , first off a sound wave is spherical in nature, a wave travelling thru a medium is a very complex set of actions, there are energy exchanges (much beyond the inverse square law) that have to do with heat production or a transfer of one form of energy to another. As a wave encounters a reflection medium there is an exchange of energy, as it reflects the wave front changes shape. Its fairly endless.
I have some thoughts on the subject in the FR forum in the articles section. If you ever have insominia , please dont count sheep, just read my posts ( i hear they are reading my posts to patients in the hospital before an operation, cuts down on the cost of putting them out).
ron |
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| don9146 |
| quote: | Originally posted by ronc
The Dallas was designed with my original programming, things have advanced from then.
As i look on it now its fairly antiquated.
ron |
Does this mean we will see a Dallas IV anytime soon?
:D |
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| planet10 |
| quote: | Originally posted by don9146
Does this mean we will see a Dallas IV anytime soon?
:D |
I'm guessing that if/when it comes it will be A206.
dave |
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| vmps |
| quote: | Originally posted by jasonlky
@hartgas, we are similar type of DIYers, just stick to plans and try to refrain from diversions. About the DAllASS III's WAF (Wife Acceptance Factor), they are rather LARGE speakers in both th visual and audio sense, so unless you have a large room to fill... again both visually and audio wise, best to opt for something smaller. The Dallas III plans can be found on www.fullrangedriver.com's gallery section. Good luck in your pursuit and keep us updated.
@David, I got some local plywood for the construction. A mold was created and the plys were glued in layers with the help of the mold. It was finally finished off with a birch veneer.
Update: the Corals are sitting pretty in my cupboard, have not found the time to install them in the Dallas III cabs as yet. I'll try to do it this weekend.
Cheers,
Jason:D |
hi Jason
how do the corals sound? |
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| ronc |
I'm guessing that if/when it comes it will be A206.
Right on! Slightly different expansion rates, a bit wider and will not need a SB(its sort of built in). Second pass showed a 34 hz bottom frequency, corner loaded. just working out the structural patterns. This will require external bracing stringers so WAF leaves the scene. Room should be on the larger volume. Flea amps would work very well.
I gave up on the Houston, it was just too complicated for a build.
Sorry i havent been more active, but the demands from work is very great.
ron |
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| jasonlky |
Its time to breathe new life into this thread....
@Ron, I look forward to the next speaker design from you. I would certainly build it since I know what you are capable of.... In the mean time I have tried the resistors in series with the speakers and did not care for them. The 206 and Dallas III seem good enough without them. Thanks for the suggestion though. By the way with an air tight seal the speakers seem to breathe better down low.
Coral 8A-40
Well I have finally found some time to listen to the Coral 8A-40s that Yeo of diyparadisewas kind enough to lend me. The looong version can be found in my diy audio blog.
The short version....
The Coral 8A-40 are very competent speakers but not enough to replace my Fostex FE206E. I understand that many here would disagree with me, Yeo especially but these are what my ears tell me. For the money, the Coral 8A-40 are truly unbeatable, that is if you can still find them. But for a few more dollar bills, the Fostex FE206E is better. Here a pic showing the magnets of both drivers, the FOstex FE206E is full 3 times larger and heavier than the Coral 8A-40.
Jason :)
ps - I managed a quick listen to Yeo's Hedlunds. They play LOUD and FAST!!! I am amazed at how well the Coral Beta 6 performed. The hedlunds look physically larger due to its height, but its a single fold design while the Dallas III is a double fold design, as such they are both very similar in size. And from what I can see the Hedlunds are a simpler build compared to my Dallas III simply because with the Hedlunds, there is only a single fold to contend with, while on the Dallas there are 2 folds to work on. |
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| ronc |
And from what I can see the Hedlunds are a simpler build compared to my Dallas III simply because with the Hedlunds, there is only a single fold to contend with, while on the Dallas there are 2 folds to work on.
If you look at a true horn profile its a inconstant change(M factor) in area as the wave expands. Due to the fact that DIYers would have trouble making curves all i did was to break up the curves to point expansions. 3 sections gave me greater control over the expansion rates than 2. If you want simple then use a BIB, to me if properly designed so that there is no direct reflection back to the mouth and an outboard filter chamber is used and there is a greater final end expansion then it will outperform the Hedlunds by a great margin and be a much more simple build. Trust me, it will go lower with less distortion and be the same relative height.
ron |
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| jasonlky |
| quote: | Originally posted by ronc
I'm guessing that if/when it comes it will be A206.
Right on! Slightly different expansion rates, a bit wider and will not need a SB(its sort of built in). Second pass showed a 34 hz bottom frequency, corner loaded. just working out the structural patterns. This will require external bracing stringers so WAF leaves the scene. Room should be on the larger volume. Flea amps would work very well.
ron |
Hiya Ron.... This design that you are currently working sounds real interesting, a 34Hz bottom end is not to be messed around with. Just as I was ticking off my checklist, I came accross corner loading. I do have a very large bedroom to fill, problem is corners are very far apart, what do your sims tell you about rear wall loading?
| quote: | Originally posted by ronc
If you look at a true horn profile its a inconstant change(M factor) in area as the wave expands. Due to the fact that DIYers would have trouble making curves all i did was to break up the curves to point expansions. 3 sections gave me greater control over the expansion rates than 2. If you want simple then use a BIB, to me if properly designed so that there is no direct reflection back to the mouth and an outboard filter chamber is used and there is a greater final end expansion then it will outperform the Hedlunds by a great margin and be a much more simple build. Trust me, it will go lower with less distortion and be the same relative height.
ron |
I did consider building a BIB before I settled on the Dallas III, but was caught up by its inherent ripple effects and the requirement for corner loading. I obviouly did not know how to properly design one, so BIBs went out the window...
Jason :) |
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| DaveCan |
| I'm no cab designer, but I've thought for a long time that the BIB cab could be a good start to something better, with a tweak here and a tweak there... Care to take it on Ron? Dave:) |
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| ronc |
I have kinda lost interest in Big BLHs. Complexity/cost/size is the sticker. Trying to make a single driver BLH (despite the enclosure size) is a series of comprimses.
I have been very impressed with Martins 2 way OBs. I do like the OB sound,however they lack the bottom end of either a properly designed BLH or a woofer.
IMHO a BVR suppling up to 240 Hz and either an OB or horn/waveguide from there to the top is a good answer. The OB/BVR is a very simple/cost effective build and for normal listening SPLs will perform in an adequate manner. Many many builds are established around this principal like Basszilla,Altec Mdl 14/19 (except they use a compression driver/horn and XO in the critical range) ect. ect. The BVR IMO is the best comprimise of a BLH and a BR, extended BW and a simple build. Just add an OB for the upper range (horn/waveguide if so inclined or have the talent) and be done with it. Bi amp and you will have a system that will be hard to outperform and be very cost efficent.
ron |
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| GM |
Yeah, I came to this conclusion back in '67 and never looked back. All my simple pipe horn builds were strictly woofer horns, though XO's could be as high as 500 Hz. In Nov. '69 I experienced bi-amping, active XOs combined with acceptable performance SS power and how to do CD horn EQ, so bye-bye expensive PIA tube systems. In June '70 I learned about separate subs systems, so for me the 'circle' was complete until digital delay and most recently, 80 Hz Unity concept horns, reducing the 'circle' back to a nominally two way system.
GM |
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| Scottmoose |
| Yeah. That's why I've ended up trying to simplify everything as far as I possibly can of late. The more complicated things get, the more variables there are. And more to go wrong. |
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| ronc |
Yeah, I came to this conclusion back in '67 and never looked back
I am slow Greg, (a Texan) so it takes me longer.
Yeah. That's why I've ended up trying to simplify everything as far as I possibly can of late. The more complicated things get, the more variables there are. And more to go wrong.
Thus my (actually my Mentor) motto "the hardest thing you can do is to make something simple".
I have learned that in industrial design that simple is better. Once you start to make something complicated that unknown variables enter and the system becomes unstable. Too many engineers depend on correction or control by computers. To the young today its easier to correct for design flaws by puter correction rather than design correctly in the first place. When i first entered the field all we had was analog, yes we had to work harder to find an answer but there are still systems in use that i designed over 30 years ago. All this sums up to what i learned from my mentor.
1. Make it simple.
2. Make it cost effective.
3. Make it easy to build.
4. Make it easy to operate.
5. Make it reliable.
ron |
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| hm |
very good I agree complet:
"I have learned that in industrial design that simple is better. Once you start to make something complicated that unknown variables enter and the system becomes unstable. Too many engineers depend on correction or control by computers. To the young today its easier to correct for design flaws by puter correction rather than design correctly in the first place. When i first entered the field all we had was analog, yes we had to work harder to find an answer but there are still systems in use that i designed over 30 years ago. All this sums up to what i learned from my mentor.
1. Make it simple.
2. Make it cost effective.
3. Make it easy to build.
4. Make it easy to operate.
5. Make it reliable." |
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| bobmar |
I thought the single driver concept was pretty simple. Complexity and comprimises is the designers problem. As far as construction, once I got the full size drawing made[ and accurate] the work of cutting and glueing wasn't too bad. A lot of work really, but the reward was there in the end.
Ron, i wish you'd get back to the 206 Austin and turn it loose on us. The 166 A is fine speaker design..The instruments sound correct and the lower end is presented like a finely carved statue. We do our part, you do yours. Times a wasting.
Bob |
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| ronc |
very good I agree complet:
Good ! Thats a first. The point i am trying to make is like this.
Over 50 years ago Kodac produced an automatic film developer that has sold in the millions to hospitals, industrial applications ect ect. The basic design hasent changed but now has digital info displayed. Its still the same basic design.
A good design will last when all of us are dust. But we have to come up with the basic workable good design.
ron |
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| ronc |
I thought the single driver concept was pretty simple. Complexity and comprimises is the designers problem. As far as construction, once I got the full size drawing made[ and accurate] the work of cutting and glueing wasn't too bad. A lot of work really, but the reward was there in the end.
Ron, i wish you'd get back to the 206 Austin and turn it loose on us. The 166 A is fine speaker design..The instruments sound correct and the lower end is presented like a finely carved statue. We do our part, you do yours. Times a wasting
HAHA! Sounds like my everyday. (Hindu accent) " Mr Ron your project is behind schedule for the love of Gandi please find an answer, i need a full report within one hour". Thus is my life.
ron
Complexity and comprimises is the designers problem.
There was once a physicist statement about a nuclear propulsion system that would take mankind to mars, it was stated " thats an engineers problem". |
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| Scottmoose |
Yep, that figures. Even as a simple naval historian, I run across that kind of thing on a regular basis. Either in history, or within my own department. :rolleyes: Anyway, couldn't agree more with what you & Greg say.
BTW Ron -I've almost got that box idea we were talking about worked out. It was trying to find a suitable driver that held things up a bit. I'll get the basic plan over to you in the morning so you can see if it or some modification will be suitable for intended purposes. |
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| ronc |
It was trying to find a suitable driver that held things up a bit.
Thats the major problem. its finding a LF system that hands off to a higher frequency system with a given SPl of both systems.( In football or rugby i want Scott,GM,Dave,Mk,Chris on my team) i dont deal well with inadequate performance.
ron |
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| Scottmoose |
| Probably, but the high Vas will mandate a BIG box. |
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| nigelwright7557 |
| quote: | Originally posted by jasonlky
Hi,
Just want to share my DIY Horn speakers based on the Dallas III and Fostex FE206E. You can read it here. Tell me what you think....
Jason:D |
Wow that is a work of art !
Makes my folded horn designs look ancient ! |
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