Guangui,
This looks like a Weems horn design - they can be very good but this is the smallest I have seen it - did you use a calculator online to design dimensions? It should sound nice. I think damping here will be polyfill stuffing in the triangle closed end and felt if you have it in the top area to line surfaces directly behind driver and top wall and 4 inches or so of top of back wall to reduce reflected sound. Use polyfill stuffing to taste after the driver little by little probably no more than 2 inches past the driver towards open end as it will really attenuate bass from such a small driver. I don't think you need anything in the main chamber before the terminus.
This looks like a Weems horn design - they can be very good but this is the smallest I have seen it - did you use a calculator online to design dimensions? It should sound nice. I think damping here will be polyfill stuffing in the triangle closed end and felt if you have it in the top area to line surfaces directly behind driver and top wall and 4 inches or so of top of back wall to reduce reflected sound. Use polyfill stuffing to taste after the driver little by little probably no more than 2 inches past the driver towards open end as it will really attenuate bass from such a small driver. I don't think you need anything in the main chamber before the terminus.
Yes, I used a calculator (MH). The curiosity was simply too much. I've always seen them at a larger scale. There is always a first time, and an interesting project. The calc. gives me the port dimensions based on a cylinder (round), so I replicated the area in a rectangular port. I will start working on it. We'll see how they turn out, and will compare the sound to the uFonken. It will have to be an "ear" comparison, as I have not purchased the mic and software to do so. Any recommendations, as far as analytical software goes? Don't want the latest bells & whistles, just a simple one that works.
The sound will be very different than a uFonken. I would imagine much more bass efficiency and extension. The measurement stuff is easy, buy a Panasonic wm61a capsule from Digikey for $2 ea, get several, wire them to a 3.5 mm jack and cable from an old cheap pair of headphones (follow guides online do search for wm61a and measurement) plug into your mic jack and you have a flat mic from 20 to 20 khz. Download the holmimpulse software. There is a thread on it and how to use, it even has a calibration curve for this mic.
As I think was mentioned before what you have drawn is a "Weem's Pipe", which is a variation of the "Voigt" pipe. My personal experience with both is that the driver is on the wrong side of the "Weem's Pipe". If you do the modeling, you will see that the driver needs to be farther down, toward to vent. That puts the vent on the back of the cabinet, which may or may not be a good idea depending on room placement.
Bob
Bob
I think you are right Bob, if you place the driver on the other side and add a horn expansion to the terminus you end up with something like this
:
http://www.diyaudio.com/forums/full-range/227460-fh3-inspired-foam-core-mini-build.html
I love the sound from mine. The W3-881si can probably work here too.
That's one of the advantages of rear-firing ports or horns, the wall boundary enhances the bass even more. If you flip the port to the back and have room for a horn, the bass enhancement is even better. I think you can use the design I have in the above thread for the Tang Band, the drivers are close enough in size, but it wouldn't hurt to order some TC9FD's on the next order from PE or Madisound
, it is only $2 more than W3-881wsi
.
, it is only $2 more than W3-881wsi
.
Thanks for the tip on the VIFA...I see them all the time, but the specs have never convinced me, maybe I'm looking them the wrong way. Anyways, in March I will be placing an order with Madisound for FF85WK's, so will add a pair of the VIFA to try.
I think you are right Bob, if you place the driver on the other side and add a horn expansion to the terminus you end up with something like this
http://www.diyaudio.com/forums/full-range/227460-fh3-inspired-foam-core-mini-build.html
I love the sound from mine. The W3-881si can probably work here too.
Nice! Besides sounding good, like you mentioned, they also look great! For my intended purposes it won't work, but basically because a lack of space on the desk. Though you have given me an idea...What if a horn was designed for either the front port, or driver? This will be a fun project.
Guangui,
Thanks. They do look pretty cool and elegant with the smooth curves. The Vifa's ended up working real well here and I get nice bass down to about 60 Hz and the rear firing horn reflected off a wall lets it fill the room nicely. I recently moved these from a much larger rec room to my smaller study and the sound really improved because, let's face it, 3.5 inch drivers were not meant to fill big spaces.
You mean add a horn flare to the front firing port of your earlier Weems pipe design?
Thanks.
They do look pretty cool and elegant with the smooth curves. The Vifa's ended up working real well here and I get nice bass down to about 60 Hz and the rear firing horn reflected off a wall lets it fill the room nicely. I recently moved these from a much larger rec room to my smaller study and the sound really improved because, let's face it, 3.5 inch drivers were not meant to fill big spaces.You mean add a horn flare to the front firing port of your earlier Weems pipe design?
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Mine will be for my home office, 10' x 9' x 8' ceiling height, and will be placed on top of my desk, almost against the wall, and at each side of a 21" screen.
Yes, a horn flare. I will attach with tape at first, and if it works, then I will permanently attach, using glue.
1st of all...Thanks Planet 10!...
For those who have never tried doing a DIY speaker, this is one that it is easy to do, inexpensive, and sound really, really, good!
For the last two weeks (mainly waiting on parts) I have been working on a pair of uFonken, designed by Planet 10 Hi-Fi. These speakers are meant to be done with 12mm thick (3/8" to 1/2" nominal) wood. I purchased the wood, and before I started cutting I tried 3/16" thk. (20" x 30" sheet make one pair) Foam Core, which I had at home. Bought 3/8" thk. wool from the local upholstery shop, and poly-fill (not used). The complete build with all the materials at hand takes about 1-1/2 hours, for the pair.
The design is for the Fostex FF85WK 3" full range driver, but since this driver will not be available in stock until mid-March I ordered a pair of W3-881SI from PE. The 881's are about 1/4th the price of the 85's. Well I installed the banana connectors, welded 18 AWG Pure Copper cable to the drivers. Sealed the drivers with silicone, and voila! My speakers were done.
How they sound, unbelievably awesome, and no break-in yet. I have spent the last three hours hearing to all kinds of music: New Orleans Jazz, Latin Jazz, Classic, Classic Rock, Latin Pop, Salsa, New Age, 80's New Wave, Female Jazz Singers...You get the picture. These speakers are crazy good for a $30.00/pair build. I'm sure some other designs might be better (working on a TL for the same driver), but these Onkens (uFonken) fit the bill nicely. These are desktop speakers for my PC.
For those of you who don't know Salsa, on Pandora just type "El Gran Combo de PR", and get the station. There is bass, horns, group vocals, nice vocal solos, percussion; even if you don't understand the words, just try it. Salsa shines in these speakers.
I placed them on top of a dining table, spaced them about 2' at first, then at 3'. My seating position was in the middle at a little over 2', which is more or less the same as in my desk. Sound was smack in the center of the soundstage, soundstage was wider than expected (wider than the 3' from speaker to speaker), great imaging, sound a little forward (not overwhelming, actually I like a little laid back, but liked the dynamics of this trait), the mid-range was wonderful, the highs not harsh, and the lows more than expected (no measurements, but I believe well in the low 70 Hz range), and great details, which is expected from a full range driver. Headroom was not as full as I would have liked, but this is a 6" high speaker with 3" drivers; wonder how they sound with the intended driver. And this amazing sound was using a Dayton DTA-1 T-Amp, and an IPhone, without external DAC, playing Pandora. The sensation is difficult to explain until you get immersed in such a project, and hear them.
Again, try this build, it will be the best $30.00 you have spent on speakers. These will make a great addition to your office, small room/bedroom, and/or PC.
For those who have never tried doing a DIY speaker, this is one that it is easy to do, inexpensive, and sound really, really, good!
For the last two weeks (mainly waiting on parts) I have been working on a pair of uFonken, designed by Planet 10 Hi-Fi. These speakers are meant to be done with 12mm thick (3/8" to 1/2" nominal) wood. I purchased the wood, and before I started cutting I tried 3/16" thk. (20" x 30" sheet make one pair) Foam Core, which I had at home. Bought 3/8" thk. wool from the local upholstery shop, and poly-fill (not used). The complete build with all the materials at hand takes about 1-1/2 hours, for the pair.
The design is for the Fostex FF85WK 3" full range driver, but since this driver will not be available in stock until mid-March I ordered a pair of W3-881SI from PE. The 881's are about 1/4th the price of the 85's. Well I installed the banana connectors, welded 18 AWG Pure Copper cable to the drivers. Sealed the drivers with silicone, and voila! My speakers were done.
How they sound, unbelievably awesome, and no break-in yet. I have spent the last three hours hearing to all kinds of music: New Orleans Jazz, Latin Jazz, Classic, Classic Rock, Latin Pop, Salsa, New Age, 80's New Wave, Female Jazz Singers...You get the picture. These speakers are crazy good for a $30.00/pair build. I'm sure some other designs might be better (working on a TL for the same driver), but these Onkens (uFonken) fit the bill nicely. These are desktop speakers for my PC.
For those of you who don't know Salsa, on Pandora just type "El Gran Combo de PR", and get the station. There is bass, horns, group vocals, nice vocal solos, percussion; even if you don't understand the words, just try it. Salsa shines in these speakers.
I placed them on top of a dining table, spaced them about 2' at first, then at 3'. My seating position was in the middle at a little over 2', which is more or less the same as in my desk. Sound was smack in the center of the soundstage, soundstage was wider than expected (wider than the 3' from speaker to speaker), great imaging, sound a little forward (not overwhelming, actually I like a little laid back, but liked the dynamics of this trait), the mid-range was wonderful, the highs not harsh, and the lows more than expected (no measurements, but I believe well in the low 70 Hz range), and great details, which is expected from a full range driver. Headroom was not as full as I would have liked, but this is a 6" high speaker with 3" drivers; wonder how they sound with the intended driver. And this amazing sound was using a Dayton DTA-1 T-Amp, and an IPhone, without external DAC, playing Pandora. The sensation is difficult to explain until you get immersed in such a project, and hear them.
Again, try this build, it will be the best $30.00 you have spent on speakers. These will make a great addition to your office, small room/bedroom, and/or PC.
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1st of all...Thanks Planet 10!...
For those who have never tried doing a DIY speaker, this is one that it is easy to do, inexpensive, and sound really, really, good!
the lows more than expected (no measurements, but I believe well in the low 70 Hz range), and great details, which is expected from a full range driver. Headroom was not as full as I would have liked, but this is a 6" high speaker with 3" drivers; wonder how they sound with the intended driver.
am glad I have ordered 6 more speakers... I will try them on ufonken in 1/2" plywood in near future (midst of moving...). Very helpful.
gychang
The fact that foam core has air trapped in its wall might contribute to making it a neutral material, and helps with sound wave damping. Now, back to finishing my foam enclosure TL's for the same driver.
OK, so I am building the "Weem's". I need help in determining if I should line or just stuff with poly-fill in the "V" enclosed area. What are your recommendations? Should I totally line, except for port area? Or, just stuff, and maybe use a little wool liner behind the driver and on the top of the enclosure?
* The port has been changed to the back.
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