Thanks!
The open back reduces the possibility of low bass, even though I'm using 2 8" woofers. I chose ~120 Hz as XO to bass-boxes, as that gave reasonable distortion up to 95 dB (1 m).
Only built 1, another (larger project) came up:
/Anton
Hey guys, it seems like this page is extremely long, and I have a project that might be complex. I'm busy with a big project, in which I want to include 4x custom height speakers, and I'm looking into making those heights also horn loaded. Preferably also a multi-sourced horn like the rest of surround.
Crossover: Active (miniDSP HD) with 500hz xover in a 2-way.
Should go as low as 40hz (-6dB)
Driver: I'll be using a Faital PRO HF200 2" compression driver.
Size restriction: 65cm height and 40cm depth, width can be up to 80cm
Weight: max 25kg (3kg will already be taken by the driver)(crossovers dont have to be in the cabinet)
Is there any existing horn I can use to modify to a multisource horn? The adapters etc I'll make myself? And is this project reasonable or do I need to adjust some specs?
Crossover: Active (miniDSP HD) with 500hz xover in a 2-way.
Should go as low as 40hz (-6dB)
Driver: I'll be using a Faital PRO HF200 2" compression driver.
Size restriction: 65cm height and 40cm depth, width can be up to 80cm
Weight: max 25kg (3kg will already be taken by the driver)(crossovers dont have to be in the cabinet)
Is there any existing horn I can use to modify to a multisource horn? The adapters etc I'll make myself? And is this project reasonable or do I need to adjust some specs?
A Faital HF200 is going to be tricky. Most of the designs published here have been based on using a crossover in the neighborhood of 1500Hz, give or take half an octave.
The Faital, with a bandwidth of 500Hz-16khz is a bit of an odd choice.
Not saying it won't work, but using it in the published designs will be a bit of a waste.
The Faital, with a bandwidth of 500Hz-16khz is a bit of an odd choice.
Not saying it won't work, but using it in the published designs will be a bit of a waste.
its the 2" throat that is the problem. Since they are height speakers, I'd say make your self a high aspect ratio rectangular conical horn with one horizontal flare flat against the ceiling and a 10 or 12" woofer hanging from the bottom horizontal flare and cross them over at 500 Hz. Should be a piece of cake.
The faital is known to be extremely well suited for 500hz, as long as you dont use it at PA levels (Cornscala Style D | Critesspeakers.com). Reason to pick it for the height channels is because I'm trying to reach "maximum" timbre matching. Impossible to mount my mains, but as I'm using active crossovers I thought I could get pretty close if I'd use the same drivers in the height channels as in the ground level speakers.
Also, I might be able to make that crossover point higher. Depends on the mains. Will have to check that first. Would 700hz make it a bit more easier to achieve?
Hmm, I'm not sure I get what you mean. If you just putting a horn top of a cabin, I'm already considering doing that (with a 15" or 12"
), but I wanted to check if it might not be possible to make it synergy horn instead. The closer I get to my mains, the better. Have been considering a front loaded horn, but they don't go very low and I'm trying to hit the "THX requirements", which are 40hz -6db. Again, I'm not really expecting anything, but would be very cool if it was doable.
One of the things that I believe that wasn't said yet is that the advantage of using a two-way multiple-entry horn (MEH) design (2" compression driver) that crosses over at 500 Hz to a pair of woofers is that the advantages of the MEH are diminishing due to the lack of directivity gain for the woofer below 500 Hz in such a small "bookshelf-sized" horn, such as the ones used in this thread. You will get woofer loading from the horn as if it is slot loaded, but directivity gain or horn gain--probably not so much below ~400 Hz. You'll have to focus on MEH room placement near room corners or on the wall-ceiling boundary to recover a little directivity gain in the woofers' operating band.
The MEH approach is good in terms of point source effect and the smallish overall size of placing the woofers on off-axis ports on the horn, but note that you'll probably be giving up woofer efficiency is due to using very undersized off-axis ports for the woofers...or alternatively, you use something like 10:1 compression ratio for the woofer/off-axis port area (or lower), then you'll be giving up some vertical and horizontal off-axis polars at the frequency corresponding to the beginning of the 1/4 wavelength of the ports from the horn throat. I would view the tradeoff in that fashion: woofer efficiency vs. a fairly narrow frequency off-axis polar dropout at 1/4 wavelength measured from horn throat.
While you can put gratings with multiple round holes of smaller diameter over the off-axis ports to reduce this polar dropout effect, this technique will again begin to compromise woofer efficiency. Note that the loss of directivity at a fairly high frequency (400-500 Hz) of the "bookshelf-sized" horn will compromise clarity of the entire assembly, when you compare the MEH with a typical 2" compression driver/straight-sided horn plus ported woofer box under the horn, I think that you will still be gaining something from the MEH approach.
There are a few reasons to go for a small MEH (2-way) vs. a conventional hybrid ported box/treble horn design, some of which are discussed here. I believe that it's still worth the extra effort. Getting the exact horn and drivers together that work is something that is doable, but there may be a little cut-and-try involved before a successful design is arrived at. Are you up for such a process?
Chris
The MEH approach is good in terms of point source effect and the smallish overall size of placing the woofers on off-axis ports on the horn, but note that you'll probably be giving up woofer efficiency is due to using very undersized off-axis ports for the woofers...or alternatively, you use something like 10:1 compression ratio for the woofer/off-axis port area (or lower), then you'll be giving up some vertical and horizontal off-axis polars at the frequency corresponding to the beginning of the 1/4 wavelength of the ports from the horn throat. I would view the tradeoff in that fashion: woofer efficiency vs. a fairly narrow frequency off-axis polar dropout at 1/4 wavelength measured from horn throat.
While you can put gratings with multiple round holes of smaller diameter over the off-axis ports to reduce this polar dropout effect, this technique will again begin to compromise woofer efficiency. Note that the loss of directivity at a fairly high frequency (400-500 Hz) of the "bookshelf-sized" horn will compromise clarity of the entire assembly, when you compare the MEH with a typical 2" compression driver/straight-sided horn plus ported woofer box under the horn, I think that you will still be gaining something from the MEH approach.
There are a few reasons to go for a small MEH (2-way) vs. a conventional hybrid ported box/treble horn design, some of which are discussed here. I believe that it's still worth the extra effort. Getting the exact horn and drivers together that work is something that is doable, but there may be a little cut-and-try involved before a successful design is arrived at. Are you up for such a process?
Chris
As I long as I dont have to make my own horn (like a mold ) , I'm more than up to the task! Would love a good project. Some cutting and trying is the fun part. Also, there is no hurry or the heights. Soon I'll have the time to read up on everything horn/MEH related, and how to use software/calculations to design it. Giving up some efficiency is definitely not a problem. They are height speakers, and will only be used for that. That 40hz -6db point would be amazing, as it's THX certified, but I might prefer a "good MEH" above that exact spec. Everything up to -3db 60hz will do fine. Also, I know I might be happy with anything else, but whats the point of a project if it all comes easy? I'll focus on my exams first, and get back to you on it Chris (didnt want to bother you all the time with all my questions, which is why I asked here first )
) , I'm more than up to the task! Would love a good project. Some cutting and trying is the fun part. Also, there is no hurry or the heights. Soon I'll have the time to read up on everything horn/MEH related, and how to use software/calculations to design it. Giving up some efficiency is definitely not a problem. They are height speakers, and will only be used for that. That 40hz -6db point would be amazing, as it's THX certified, but I might prefer a "good MEH" above that exact spec. Everything up to -3db 60hz will do fine. Also, I know I might be happy with anything else, but whats the point of a project if it all comes easy? I'll focus on my exams first, and get back to you on it Chris (didnt want to bother you all the time with all my questions, which is why I asked here first )some quotes from Bob Crites:
"This may be the driver we have all been searching for as an HF driver for a 2-way. I have run this driver at high power (around 100 watts per channel) for quite awhile with no problems crossed at 400hz in a Cornscala. The Cornscala does not need to cross that low, but the test proved the Faital Pro HF200 drivers should be safe crossed at 400hz in a Khorn.
This is a 2 inch exit driver with standard 4 bolt mounting arrangement for mounting on a standard 2 inch inlet horn.
The frequency response looks very good to almost 20khz."
" The only other driver that I thought could do this before the Faital driver was the TAD 4002 at around $2500.00 per pair!!!"
I think those are excellent drivers and can be used down quite low as needed for a 2-way Synergy. I don't think there is any argument about that.
As I said before, perhaps too tersely, is that the difficulty will be with finding an appropriate horn. The K-402 that Cask05 used is an exemplary horn but its also huge and hugely expensive. But finding a smaller horn with a 2" throat that doesn't beam at HF and doesn't honk might be a problem. I haven't looked but I also haven't stumbled across one in other searches. There may be some legacy horns around but if they are diffraction horns I would be cautious about using them.
I was suggesting you make a wooden conical horn for your application but before you do that you need to figure out what the appropriate directionality would be. Also determine what range of frequencies it needs to cover. I don't think it would need to extend much below 80 Hz because its hard to perceive directionality at those frequencies. A 15" woofer would certainly get you to 40 Hz with EQ, but its volume requirements would mean a fairly large box hanging from the ceiling. If you only need 100 Hz, the box can be considerably smaller and contain only an 8" driver.
Also I suspect that wide response up to 8 Khz or so might be sufficient for a height speaker, in which case you don't need to worry about beaming. After all that is decided you can use BWaslo's Synergy_calc_v5.xls to design an wooden conical horn whose parts can be cut out on a table saw. Study a couple of the Synergy threads on this forum. Perhaps then my original post will make more sense to you. I was visualizing a wide but not very tall Synergy horn with your HF200 at the throat and a single woofer on the low side, although I guess you could flip it around, cut a hole in the ceiling and have the woofer box between the ceiling joists.
As I said before, perhaps too tersely, is that the difficulty will be with finding an appropriate horn. The K-402 that Cask05 used is an exemplary horn but its also huge and hugely expensive. But finding a smaller horn with a 2" throat that doesn't beam at HF and doesn't honk might be a problem. I haven't looked but I also haven't stumbled across one in other searches. There may be some legacy horns around but if they are diffraction horns I would be cautious about using them.
I was suggesting you make a wooden conical horn for your application but before you do that you need to figure out what the appropriate directionality would be. Also determine what range of frequencies it needs to cover. I don't think it would need to extend much below 80 Hz because its hard to perceive directionality at those frequencies. A 15" woofer would certainly get you to 40 Hz with EQ, but its volume requirements would mean a fairly large box hanging from the ceiling. If you only need 100 Hz, the box can be considerably smaller and contain only an 8" driver.
Also I suspect that wide response up to 8 Khz or so might be sufficient for a height speaker, in which case you don't need to worry about beaming. After all that is decided you can use BWaslo's Synergy_calc_v5.xls to design an wooden conical horn whose parts can be cut out on a table saw. Study a couple of the Synergy threads on this forum. Perhaps then my original post will make more sense to you. I was visualizing a wide but not very tall Synergy horn with your HF200 at the throat and a single woofer on the low side, although I guess you could flip it around, cut a hole in the ceiling and have the woofer box between the ceiling joists.
Compare the data sheets, you will see that is pretty much true. I would guess the only difference is in the driver's internal throat adapter. If I recall corrrectly, the HF200 is slightly deeper because it needs more depth to expand out to the wider throat. For a Synergy, the HF140 is a better choice.
Also re' the data sheets, you will see that Faital has some drivers in the family with titanium diaphragms and others with polyester. The Titanium diaphragm drivers go lower; the polyester drivers are smoother up at the very top.
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Hmm yeah, my original idea was to cross it @80hz because of the directivity, but then I saw the THX specs, and I thought: why not see if it's possible. That said, I rather have a good sounding synergy from 80hz. Not sure about the upper limit though. Height channels are also full range, so 8khz point seems a downgrade. But everything is a compromise ofcourse. I'll have a look around to see if there are some opinions on it.
In my non horn design I calculated a 15", which works both in size and weight. I got some pretty sturdy mounts (up to 40kg, although I dont dare go even near that. I would rather hit like 25-30 kg tops).
About building my own horn.. would rather not do that, because I think that's a step too far for my skills. I'll definitely have a look though! I know some locals who can make it for me with the appropriate plans. Also, the horn I was considering using for the height channels is the very small (but awesome) Klipsch K510 2" horn (with mumps). I already have 1 pair, so would only need to find another (not easy to find or cheap).
If you have K-502s in hand you can readily see how large a woofer will fit on them and then what extension you will get. 8 Khz is about where some 2" throats will start to beam. Is using them, then you might take care to aim the horn at your LP. But if the horn has mumps or you add them with modelling clay it will retain a nice wide beam at HF.
I wouldn't take the extremes of the ranges that THX states for height drivers too seriously. Atmos specs allow bouncing the height signal off the ceiling and you know their is very little directivity in those solutions. Similarly, what would be the point of a 20 Khz source panning across the ceiling?
The weight issues for a woofer hanging on a ceiling are serious though. My TD15H boxes weight over 100 lbs and I wouldn't dare hang them up. Implement a multisub solution on the floor and/or stacked in a corner and I think you can limit yourself to 8" wooders in ceiling speakers boxed with 12 mm plywood.
re' not making your own horn
Faital makes smaller horns for their 1.4" CDs and I think at least one of them is synergized earlier in this thread. If you could switch to HF104 you could use one of the Faital horns - the constant directivity horn, not the tractrix
I wouldn't take the extremes of the ranges that THX states for height drivers too seriously. Atmos specs allow bouncing the height signal off the ceiling and you know their is very little directivity in those solutions. Similarly, what would be the point of a 20 Khz source panning across the ceiling?
The weight issues for a woofer hanging on a ceiling are serious though. My TD15H boxes weight over 100 lbs and I wouldn't dare hang them up. Implement a multisub solution on the floor and/or stacked in a corner and I think you can limit yourself to 8" wooders in ceiling speakers boxed with 12 mm plywood.
re' not making your own horn
Faital makes smaller horns for their 1.4" CDs and I think at least one of them is synergized earlier in this thread. If you could switch to HF104 you could use one of the Faital horns - the constant directivity horn, not the tractrix
The horn is on its way from Canada (of Belgium), but when it arrives I'll do some measurements. It is supposed to be a very good horn (very good polar control etc) for it's size. I bought it from someone who had both the K510 and K402 and was very very happy with the K510 compared to the K402. For the moment I'm gonna use it on some of my ground speakers, and I still want to start out with something cheaper to test it out. So first I need a good horn to start with.
I looked on the faital site, and I do see the horn you mention. I'll have a look on the thread here too, but I didn't find anything conclusive at the moment. Could you maybe give some direction on what to look for in a horn? So a 1,4" CD horn would be better? What are some of the other specs that might make a good synergy horn?
I think for a home theater you want a constant directivity horn to cover multiple seats.
To take a CD horn and make it a synergy, it needs to have at least one nearly flat side to which you can epoxy a woofer.mounting board
There are more such horns available with 1.4" throats than with 2" throats, witness the Faital horns. There are even more horns with 1" throats (e.g. SEOS) but those require a 3-way Synergy solution.
What to look for? constant directivity, absence of diffraction slot, a good size and a 1.4" or 2" throat
To take a CD horn and make it a synergy, it needs to have at least one nearly flat side to which you can epoxy a woofer.mounting board
There are more such horns available with 1.4" throats than with 2" throats, witness the Faital horns. There are even more horns with 1" throats (e.g. SEOS) but those require a 3-way Synergy solution.
What to look for? constant directivity, absence of diffraction slot, a good size and a 1.4" or 2" throat