I could post that (after the design is ironed out), but I doubt you'll be able to chop it further for smaller printers (but who knows?). Getting the pieces glued together straight won't be easy with something shaped like this. The tabs and screw holes work well for connecting the two pieces, but I don't see a way to do that for 4 pieces.
Drivers, I don't really know the cost. The TF0410MR midrange drivers are inexpensive if you get them through a bulk order from Celestion, but can cost about 5x that if ordered in smaller quantities from the few places that sell them. Woofers (https://www.parts-express.com/faitalpro-6fe100-6-professional-midrange-midbass-woofer-8-ohm--294-1150) can be priced at Parts Express, DNA-360tweeter from DIYSoundGroup (Erich might be able to get you the midranges, too, but I don't know if he has any to sell anymore). Crossover parts won't be cheap, there will be some big inductors.
Drivers, I don't really know the cost. The TF0410MR midrange drivers are inexpensive if you get them through a bulk order from Celestion, but can cost about 5x that if ordered in smaller quantities from the few places that sell them. Woofers (https://www.parts-express.com/faitalpro-6fe100-6-professional-midrange-midbass-woofer-8-ohm--294-1150) can be priced at Parts Express, DNA-360tweeter from DIYSoundGroup (Erich might be able to get you the midranges, too, but I don't know if he has any to sell anymore). Crossover parts won't be cheap, there will be some big inductors.
100ppi in the woofer holes.... so much for that idea
I got a chance to play a little today. I took apart 4 of those 100ppi foam paintbrushes and put them in the output holes of the wooferes (with horn assembly in a cabinet). Here are photos of tweeter, midrange, woofer responses, all on-axis, with and without the foam:
Result: Basically, nothing for the midrange or the tweeter. But the woofers are down about 2dB. So, nothing much good happens with it. There is some few dB reduction of a peak at the upper end of the woofer's response but not worth it I don't think.
Unrelatled, but the midranges sound bad for some reason, even just with sine sweeps, like the cones are rubbing against something. I'll have to pull the off and see if there are some plastic or glue blobs sticking up and getting into things there.
I got a chance to play a little today. I took apart 4 of those 100ppi foam paintbrushes and put them in the output holes of the wooferes (with horn assembly in a cabinet). Here are photos of tweeter, midrange, woofer responses, all on-axis, with and without the foam:
Result: Basically, nothing for the midrange or the tweeter. But the woofers are down about 2dB. So, nothing much good happens with it. There is some few dB reduction of a peak at the upper end of the woofer's response but not worth it I don't think.
Unrelatled, but the midranges sound bad for some reason, even just with sine sweeps, like the cones are rubbing against something. I'll have to pull the off and see if there are some plastic or glue blobs sticking up and getting into things there.
Found the source of the midrange scratchiness -- some glue had seeped up and put in bump in the mounting surface for one of them. A little time with a file and all sounds clean now.
I tossed together a quick crossover (in simulation, using measured responses), doesn't look like it will be too hard or complicated. I have to first get a set of off-axis and on-axis curves, though, to be able to optimize for directivity. Might have time in the next few days (if not, then probably not for a while).
I tossed together a quick crossover (in simulation, using measured responses), doesn't look like it will be too hard or complicated. I have to first get a set of off-axis and on-axis curves, though, to be able to optimize for directivity. Might have time in the next few days (if not, then probably not for a while).
Do you think it would be feasible to place a coentrant horn such as this atop a mid-bass module similar to one such as seen here: diysoundgroup mid-bass module
1/4 lambda of a 250Hz crossover is just over 13", so I was wondering if perhaps one could utilize the small syns' waveguide-to-array trick with a pair of the drivers as seen at the above link.
1/4 lambda of a 250Hz crossover is just over 13", so I was wondering if perhaps one could utilize the small syns' waveguide-to-array trick with a pair of the drivers as seen at the above link.
It could probably be done. Though, frankly I don't worry too much about pattern down in the 250Hz range, everything gets modal (bumps of pressure varying in all directions) just from the room reflections down there.
The waveguide-to-array trick does need the woofers to be behind the waveguide, though, as they have to blend in as the waveguide directivity goes away and the woofers' centers of radiation have to be spaced about (and preferably a little less) than the width of a waveguide to do that with similar radiation pattern
The waveguide-to-array trick does need the woofers to be behind the waveguide, though, as they have to blend in as the waveguide directivity goes away and the woofers' centers of radiation have to be spaced about (and preferably a little less) than the width of a waveguide to do that with similar radiation pattern
bwaslo have you thought about using 8" or even 10" drivers as bass drivers? Since you can design your own waveguide you could accomodate them easily. That way you would gain 3-4 decibels and would not need to bring down a lot mid and high freqeuncies.
To keep the price down eminence woofers are not that much more then the faitals.
I would really love to see a 95-96 decibels speaker like this, and would build it! But 90 decibels is a bit low for who loves high volume and triode amplifiers.. specially considering all the efficiency thown away in the midrange ad highs. Well, if it was for me I would even go with 12"
To keep the price down eminence woofers are not that much more then the faitals.
I would really love to see a 95-96 decibels speaker like this, and would build it! But 90 decibels is a bit low for who loves high volume and triode amplifiers.. specially considering all the efficiency thown away in the midrange ad highs. Well, if it was for me I would even go with 12"
One of the "neat" things about the Synergy concept is that the output level scales in a hurry.
Do you want a moderate level of output? If so, use one or two midranges and one or two woofers.
Do you want a cosmic amount of output? If so, use twice as many drivers.
Take to the extreme, you get the Jericho horns.
There's no free lunch though:
1) As the horn starts to turn into swiss cheese, diffraction becomes a problem
2) The weight gets crazy in a hurry. Some of the Jericho horns are over 400lbs.
3) It gets expensive.
Thing that blew my mind is how SMALL some of the Jericho horns are.
True, this Jericho horn exists. But the newer ones aren't a whole lot bigger than a Danley SH-50! They're just really really heavy and really expensive. Sizewise, they're amazingly compact.
Do you want a moderate level of output? If so, use one or two midranges and one or two woofers.
Do you want a cosmic amount of output? If so, use twice as many drivers.
Take to the extreme, you get the Jericho horns.
There's no free lunch though:
1) As the horn starts to turn into swiss cheese, diffraction becomes a problem
2) The weight gets crazy in a hurry. Some of the Jericho horns are over 400lbs.
3) It gets expensive.
Thing that blew my mind is how SMALL some of the Jericho horns are.
True, this Jericho horn exists. But the newer ones aren't a whole lot bigger than a Danley SH-50! They're just really really heavy and really expensive. Sizewise, they're amazingly compact.
I think for most houses a speaker like the one build by Bwaslo but with 8" woofers would be acceptable, expecially considering the fact that they can be attached to the wall, so nothing in the middle of the room.
I am looking for something like that to build next year when I'll move with my longtime girlfriend. Unfortunately there won't bd much space for bigger speakers since it is a small appartement.. I was dreaming of 18" woofers all around the room and a synergy for midhighs but I guess I have to wait for that..
I am looking for something like that to build next year when I'll move with my longtime girlfriend. Unfortunately there won't bd much space for bigger speakers since it is a small appartement.. I was dreaming of 18" woofers all around the room and a synergy for midhighs but I guess I have to wait for that..
I'm a tube guy myself, so I can sympathize.
I built a pair of 88 Specials from diysoundgroup, each uses a pair of custom 16-ohm 8" drivers. The cones are hemp and the efficiency is high; the 88 Special is 98.5dB @2.83V/1M. There is an air vent for the voice coil but no shorting rings to my knowledge. I prefer these new drivers to the purple ones originally used. They would be good candidates since the DNA-360 used here are only available from DIYSG.
I briefly discussed with Erich at DIYSG whether the custom 4" midranges used here could also be made in a higher efficiency, 16-ohm iteration and he said they probably could but I think he's already got his hands full.
Regardless, I'm still gathering the drivers so I can follow along and build as-is. I'm honestly grateful Bill is going to cook up a passive crossover, even if the efficiency is a little lower than ideal (for me).
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bwaslo have you thought about using 8" or even 10" drivers as bass drivers? Since you can design your own waveguide you could accomodate them easily. That way you would gain 3-4 decibels and would not need to bring down a lot mid and high freqeuncies.
To keep the price down eminence woofers are not that much more then the faitals.
I would really love to see a 95-96 decibels speaker like this, and would build it! But 90 decibels is a bit low for who loves high volume and triode amplifiers.. specially considering all the efficiency thown away in the midrange ad highs. Well, if it was for me I would even go with 12"
Well, I've thought about it, but a few problems. The printer is about maxxed out on how big a horn I can make in two halves, and this horn couldn't really accommodate two 8 inchers. I could maybe go to 1/4 horns for a bigger result, but then attaching them square could get to be a problem (it's already tricky with cutting the horn in half -- the mounting surfaces for the midranges and woofers have to be flat, and the CD throat has to be smooth). Also, my room is about maxxed out on how large a speaker I could deal with other than experimentally. Remember that going to bigger woofers also means bigger boxes needed behind them. The Faital 6" woofers I use now give about 94dB sensitivity, but if you call them "4 ohm speakers" (since the impedance dips down to 3 ohms, the the average is about 8), then that puts efficiency at 91. But 25W per channel plays them plenty loud for my purposes without clipping.
It also helps that the speaker is designed to be used up against a wall, so the efficiency or sensitivity is "real" as opposed to what happens when designs are made to be out in the room (and in-the-way).
I have played with making a Unity "stub" (mounts CD and mids) that can be expanded by plywood pieces easily. I even have several designs I've printed, with thought that maybe Erich could get them injection molded. But as Erich proved to me, I didn't really understand injection molding and my designs would need some changes to be made injection-moldable in any practical sense. Maybe this winter when I'm sitting by a fire I'll see if I can adapt what I have. With that, I forsee a 6ft high (!) horn, about 4ft wide, 3ft deep horn with 10" woofers -- that one would be in the "experimental" category, to say the least. But the same "stub" could be used to make smaller horns of course. (Legal concerns about the incomprehensible Unity/Synergy patent situation may keep this from happening, though, as no one really wants to invest what it takes to get an injection mold made only to get a cease-and-desist order...)
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BTW, I have a crossover going for the printed waveguides. They sound very good (I say that with caveats to NEVER TAKE A BUILDER'S OPINION ON SOUND OF HIS OWN SPEAKER ). I still may do some "voicing" on them, I have a bit of a "house curve" applied, balancing between sometimes-bright and sometime-plummy depending on the recording. The crossover got more complicated than I hoped, as I worked to flatten the response, get good off-axis behavior, and keep the impedance well-behaved.
I hope to get some measurements posted at some point (other than in my basement) but the weather here is Oregon lately is too damn hot and now too smoky (bad air quality from forest fires up by the WA border). I'll post crossover and cabinet design and waveguide STL when I get a chance to get it all together and cleaned up. I don't expect a lot of people building these, though, as its a big job. None of the steps are really difficult at all, but there area a LOT of steps. And getting the waveguides printed by a commercial house could get expensive, they have to be printed densely (not much infill) and hot (for strength), and probably have to be done with a large nozzle (not what most 3D hubs use).
). I still may do some "voicing" on them, I have a bit of a "house curve" applied, balancing between sometimes-bright and sometime-plummy depending on the recording. The crossover got more complicated than I hoped, as I worked to flatten the response, get good off-axis behavior, and keep the impedance well-behaved.I hope to get some measurements posted at some point (other than in my basement) but the weather here is Oregon lately is too damn hot and now too smoky (bad air quality from forest fires up by the WA border). I'll post crossover and cabinet design and waveguide STL when I get a chance to get it all together and cleaned up. I don't expect a lot of people building these, though, as its a big job. None of the steps are really difficult at all, but there area a LOT of steps. And getting the waveguides printed by a commercial house could get expensive, they have to be printed densely (not much infill) and hot (for strength), and probably have to be done with a large nozzle (not what most 3D hubs use).
The 3D hub issue is definitely the one I'm most apprehensive about. There is enough of them here in the Bay Area that I can probably find one that I can walk into and discuss what the print is for. I just would prefer a finished print I could look over before paying for.
If you end up going to a commercial printer definitely consider laser sintered nylon. The cost is basically the same as any SLS resin method, but the toughness is incredible. The finish is like 100-200 grit sandpaper, but otherwise finish is very good with no warping or other weirdness. Far better than any FDM method PLA for example. Shapeways does it, and I see at 3Dhubs some others do it with HP's new machine.
First, I'm loving this thread. The idea of printing a synergy design like this gives me some hope that I can have one playing in my living room someday.
What I wanted to add was a recent experience in getting a quote from a 3d print house. I designed a very basic short horn for a 10-inch driver. It had an octagonal shape and instead of cutting this thing I thought it would be easier to print. Because of the angles. So got a quote. The horn was about 12in x 12in, and the cost to print was $500 a piece. Whaaa!
I thought... dang, I could buy a whole printer for that much money. And print it myself.
What I wanted to add was a recent experience in getting a quote from a 3d print house. I designed a very basic short horn for a 10-inch driver. It had an octagonal shape and instead of cutting this thing I thought it would be easier to print. Because of the angles. So got a quote. The horn was about 12in x 12in, and the cost to print was $500 a piece. Whaaa!
I thought... dang, I could buy a whole printer for that much money. And print it myself.
There are some 3D printing aggregators out there that cost about 25% as much as Shapeways. And Shapeways seems to get more expensive every year. You can also find plenty of people on Craigslist that will print things for you.
Having said that, this is a DIY forum, buy a printer already! My prints cost well under $5 a print.