Like that, but the bass reflex ports should be near the mouth of the horn, located near the corners where they are small relative to the percentage of horn surface, like on the DSL SM-60F.
The SM-60F is a three-way, the outer ports visible are bass reflex, the inner are the exit holes for the offset 8" drivers.
Ultimately, you will want to use two 8", but one could certainly get you started, and you can add the second when you save some $$.
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I don't think this spreadsheet does elliptical profiles. The blue and red traces represent the profile at the inner and outer edges of one petal of a petal horn (facets).
The horizontal and vertical profile of an Iwata horn will be different lengths when they are at different widths. Jmmlc re spreadsheet.
BMS 5" coax. 5cn140 is the mirange and highs. Faital Pro 8s are the low end...will have to see which ones they are.
AllenB, that's what I'd found too.
Ok, so based on Art's information, I've cobbled together a small drawing as a proof of concept. It's not to scale, but I imagine that rather than worrying about a specific port, I can use the chamber of the enclosure itself as one, provided I can get the tuning right.
Would this make sense?
The yellow areas of the horn are a guess at where the ports would go.
Ok, so based on Art's information, I've cobbled together a small drawing as a proof of concept. It's not to scale, but I imagine that rather than worrying about a specific port, I can use the chamber of the enclosure itself as one, provided I can get the tuning right.
Would this make sense?
The yellow areas of the horn are a guess at where the ports would go.
I could be wrong, but wouldn't you want the hole (for the mid or woof) closer to the tweet ?
That way you can be 1/4 wavelength away of the crossover point.
But that matters if you are doing a 6db or a 24db............
That way you can be 1/4 wavelength away of the crossover point.
But that matters if you are doing a 6db or a 24db............
[FONT=Arial, sans-serif]UnaHm, i believe it's possible to calculate the Synergy like speakers in Hornresp with offset driver. My apologies for linking the wrong spreadsheet for Iwata.
Some more horn questions. For a given mouth dimension and driver, the horn that presents more load will "flatten out" the response of the driver? In patternflip. Could the loss of patterncontrol in the vertical plane introduce honk? For in example a 300 Hz Iwata. Crossover at 600 Hz, flip / loss of pattern at 1000 Hz. Means honk / distortion / homs/ cooties/ loss of loading the driver / things you will hear and don't want? Or just funky response in the vertical plane. A good answer saves me lot's of trouble, i am a bit stuck on cnc routing Iwata's....would like to prevent them saying just HONK.
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Some more horn questions. For a given mouth dimension and driver, the horn that presents more load will "flatten out" the response of the driver? In patternflip. Could the loss of patterncontrol in the vertical plane introduce honk? For in example a 300 Hz Iwata. Crossover at 600 Hz, flip / loss of pattern at 1000 Hz. Means honk / distortion / homs/ cooties/ loss of loading the driver / things you will hear and don't want? Or just funky response in the vertical plane. A good answer saves me lot's of trouble, i am a bit stuck on cnc routing Iwata's....would like to prevent them saying just HONK.
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If it's beginning to lose control.... Jmmlc indicated they should be crossed above the point of pattern loss, just like a round horn. After all the trouble we go to in sizing a horn I wouldn't count on the possibility of bonus Hz and would build it to work above a given frequency.
No, as Norman mentioned, you want the mid output to be within 1/4 wavelength of the HF output, so the speaker ports (in general) should be located as close to the HF driver as possible.Ok, so based on Art's information, I've cobbled together a small drawing as a proof of concept. It's not to scale, but I imagine that rather than worrying about a specific port, I can use the chamber of the enclosure itself as one, provided I can get the tuning right.
Would this make sense?
The yellow areas of the horn are a guess at where the ports would go.
Placing the mid ports as you have would cause off axis lobing as the path lengths change appreciably compared to the crossover wavelength.
Use the existing DSL speaker in post #344 as a proof of concept..
If you want to add bass reflex ports (which are a completely different set of holes than the offset driver port holes, which are oval shaped in the SH95), add them near the horn mouth.
The relationship between chamber size and port length and area determine the tuning frequency (Fb, or Helmholtz resonance).
I think I'd misunderstood your original guidance. It did look at bit strange when I was drawing it, as all of the Synergy horns I've seen on this forum and elsewhere follow what you and Norman have said...the right way 🙂
I think I've misused some terms as well. I wasn't really imagining a proper implementation of reflex, but more to use the chamber as back-loaded horn to match the output from the front of the driver, on the other side of the enclosure.
Is that appropriate? It seems that from your responses I'd need to actually create a funnel and tube that would take the output pressure from the back of the cone, and direct it to the ports on the other side of the case...more like the first 'Synergy' picture I'd made on the last page.
I suppose I was trying to reduce the complexity of the design 😉
So is this really the sanest one to do for this intent? I'll look at the Danley cabinet again too 🙂
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unaHm,
The horn is to small to pick up the low frequencies comming out of the port. That's the reason it is placed near the end of the mouth. So it does not effect the horn shape. The pic above will give problems in a critical area of the throath of the horn.
The horn is to small to pick up the low frequencies comming out of the port. That's the reason it is placed near the end of the mouth. So it does not effect the horn shape. The pic above will give problems in a critical area of the throath of the horn.
An externally hosted image should be here but it was not working when we last tested it.
But please do read the High sound quality synergy thread that is going on. I could be off. I only remember reading somewhere that even a small round over of the holes for the mid (Alpha 8) can mess up the response. Imho a synergy is hard to get right. Are you no longer into to the straight horn? Your mockup with cardboard looked very promising. I think a two way with 2 straight horns will be the easiest to get right.
edit- forgot the holes for the midwoof.
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??? It's because you want them delayed in time just like the mids, mid-bass drivers referenced to the HF.
GM
From this picture a page back posted by unaHm i got the impression he was trying to hornload the output of the port by placing them as far back in the horn as possible. As i said, i could be off (and i stand corrected) i am not an Synergy or horn expert. I only understand that putting a bassreflex port that close to the troath is not a good thing. I do recommend unaHm to read a lot more about the Synergy Horn if he would like to go the Synergy way. There is as far as i understand a logic behind the tiny dimensions of the holes for the mid in the Synergy.
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Why? Historically, 6th order horns have the vents in the throat, presumably due to the old time design theory that the vent needed to be as close as practical to the driver to maximize vent gain BW.
The Unity/Synergy concept OTOH is about getting proper alignment to create a point source from multiple ones.
GM
Thanks for the 6th order horns, did not know them. Did a google 🙂 Just to check how far i am off understandig the Synergy. The holes / throath's / compression rate is high to mess up the hornprofile as little as possible?
The drawing I've done is just a guess for now, or at least a proof of concept.
Maybe I've misunderstood Art's directions in post #344, and he meant that I could build that Synergy design, but only put one of the mid drivers in there (in my case the Alpha 8).
This would leave one side blank, and I presume, open.
I didn't really intend on a bass reflex design in the standard sense (tuning the back chamber to get Bass boost); it was more that I was trying to make it look like there were two drivers by aligning the output from the back of the speaker with the front.
The 'port' certainly wasn't an engineered design, just something I threw together 🙂
Maybe I've misunderstood Art's directions in post #344, and he meant that I could build that Synergy design, but only put one of the mid drivers in there (in my case the Alpha 8).
This would leave one side blank, and I presume, open.
I didn't really intend on a bass reflex design in the standard sense (tuning the back chamber to get Bass boost); it was more that I was trying to make it look like there were two drivers by aligning the output from the back of the speaker with the front.
The 'port' certainly wasn't an engineered design, just something I threw together 🙂
Sorry to double-post (again!), but would removing the top driver from this design be what your describing Art, and leave the rest of the enclosure intact until another par of Alpha 8s come along? 🙂
An externally hosted image should be here but it was not working when we last tested it.
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