Thanks very much Beau - that's another feature of HornResp that I'd not yet found 🙂
According to Bill's instructions, if I added another driver it seems that what I'd need to do is open the port holes where the speaker would go, and change the volume of the chambers. Dare I say it, if this was successful enough, maybe I'd never need to!
Edit: Hmm, I've just entered the same values as you have there, and my response is really different. The wizard for me says 'Offset Driver Horn Loudspeaker Wizard', rather than just 'Horn Loudspeaker Wizard'. I imagine that your response looks nice because HornResp is calculating for a straight horn driver placement.
Still, it's food for thought, and I can probably tweak things a bit until I can get close!
According to Bill's instructions, if I added another driver it seems that what I'd need to do is open the port holes where the speaker would go, and change the volume of the chambers. Dare I say it, if this was successful enough, maybe I'd never need to!
Edit: Hmm, I've just entered the same values as you have there, and my response is really different. The wizard for me says 'Offset Driver Horn Loudspeaker Wizard', rather than just 'Horn Loudspeaker Wizard'. I imagine that your response looks nice because HornResp is calculating for a straight horn driver placement.
Still, it's food for thought, and I can probably tweak things a bit until I can get close!
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It's not really been possible to improve the response from the first SPL graph shown on the last page. Bill did explain in his PDF that this was par for the course, and EQing would be necessary to make the response curve flatter.
I'm tempted to use his design of the CoSyne horns, but what's nagging at me is the lowest frequency for pattern control. He's set the CoSynes to be effective down to 385Hz.
I was thinking of going a little bit lower, say, 200-250Hz or so, which would make the size of the Synergy horn I had in mind smaller. With that in mind, how low do I need to go in terms of pattern control, because is there a given point where it really doesn't matter any more? 🙂
I'm tempted to use his design of the CoSyne horns, but what's nagging at me is the lowest frequency for pattern control. He's set the CoSynes to be effective down to 385Hz.
I was thinking of going a little bit lower, say, 200-250Hz or so, which would make the size of the Synergy horn I had in mind smaller. With that in mind, how low do I need to go in terms of pattern control, because is there a given point where it really doesn't matter any more? 🙂
With a wide angle conical horn, you can cut the size considerably and it will still have the same cut off frequency, though pattern control loss will go higher.
If corner mounted, the pattern is limited to 90 degree regardless of the horn mouth size.
Good point Art! Well, If I can limit the horizontal dispersion to 90 degrees, that would be a good place to start - at least it fixes one dimension! 🙂
So, if I made a design that was intended to be corner-loaded, without it actually exiting from the corner of the room, what needs to be taken into consideration? I remember earlier on in this thread that it was advised to consider the enclosure in a 1xpi space instead.
However, if the source of the Synergy horn is as small as it can be (e.g. a certain percentage of the design is the wall itself), what value (or percentage) do I need to consider in order to calculate it within a 0.5xpi space?
So, if I made a design that was intended to be corner-loaded, without it actually exiting from the corner of the room, what needs to be taken into consideration? I remember earlier on in this thread that it was advised to consider the enclosure in a 1xpi space instead.
However, if the source of the Synergy horn is as small as it can be (e.g. a certain percentage of the design is the wall itself), what value (or percentage) do I need to consider in order to calculate it within a 0.5xpi space?
You would need to consider it no longer corner loaded 😉.
Also, the corner only limits the horizontal dispersion, the vertical dispersion will diffract around to the corner, unless you built into the wall/ceiling corner, in which case your sound image would come from the ceiling.
If you are not actually building in to the corner, just design for free space.
Thanks for clarifying! I suppose that designing for the worst-case scenario is the best bet, and any boundaries that it gets attached to is only going to improve things!
Don't forget to check the acoustical impedance as the wider horns will unload at a higher frequency. This doesn't change with a larger mouth (and fixed throat size and angle).
Thanks for clarifying! I suppose that designing for the worst-case scenario is the best bet, and any boundaries that it gets attached to is only going to improve things!
Edit: Increasing the length of S2-S3 made a difference. It's going to be a big horn though!
I'm not sure if WAF is a factor now, as we've been re-organising, so I have a place that means she doesn't have to look at them day-in, day-out 🙂
AllenB: Thanks for identifying that. I suppose at some point there's going to be a compromise that has to be met. I'm not that fussy on the dispersion angle, but where I'll have to make decisions is between the dimensions, and how flat a response I can get.
Edit: Increasing the length of S2-S3 made a difference. It's going to be a big horn though!
I'm not sure if WAF is a factor now, as we've been re-organising, so I have a place that means she doesn't have to look at them day-in, day-out 🙂
AllenB: Thanks for identifying that. I suppose at some point there's going to be a compromise that has to be met. I'm not that fussy on the dispersion angle, but where I'll have to make decisions is between the dimensions, and how flat a response I can get.
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Increasing the length and leaving the horn mouth the same size makes the horn go lower, and since the dispersion (wall angle) is less, increases on axis sensitivity.
If length is no longer an issue, going to around a 50 degree included wall angle would be a good choice if it is wide enough for coverage of the intended listening area.
You will find increasing the conical horn size, but retaining the same wall angle does very little to frequency response, though a larger mouth will provide pattern control to a lower frequency.
In typical domestic room sizes, a mouth of around 30 x 30 inches gives pattern control down low enough that further increase in size won't make much difference, as the modal response will tend to take over.
This has been my experience also until the baffle gets beyond ~42" H x ~50" W where a pair typically starts becoming a virtual offset ~30-35 Hz sound wall depending on room size.
GM
GM
yup, not all of us need to reinvent the wheel.
But I admit, I sometimes have to go against the grain and see for my self.
Part of this hobby is the learning, and figuring stuff out later.
I need to thank everyone for their experience.
Without their input, it would otherwise cost a tremendous amount of time, effort, and money.
Norman
But I admit, I sometimes have to go against the grain and see for my self.
Part of this hobby is the learning, and figuring stuff out later.
I need to thank everyone for their experience.
Without their input, it would otherwise cost a tremendous amount of time, effort, and money.
Norman
I want to extend my thanks to all of the advice that has been explained in this thread...thanks gentlemen!
Sorry I've not responded to the thread for a couple of days. Yesterday my wife had a baby, so we've been a bit pre-occupied 🙂
Art, thanks for the ideas with regards to 'using the walls'. I'm not sure how long the horn can be as the room I'm in isn't huge, but I like the rule of thumb with regards to a 30"x30" mouth. When I have a chance, I'll play a bit more with Bill's spreadsheet to see what values it spits out for horn length.
If I'd not been as scared by the Synergy horns before (and found Bill's design), I think I would have made his CoSynes. Still, I have a couple of good drivers, so we'll see how it goes!
Thanks again everyone!
Dan
Sorry I've not responded to the thread for a couple of days. Yesterday my wife had a baby, so we've been a bit pre-occupied 🙂
Art, thanks for the ideas with regards to 'using the walls'. I'm not sure how long the horn can be as the room I'm in isn't huge, but I like the rule of thumb with regards to a 30"x30" mouth. When I have a chance, I'll play a bit more with Bill's spreadsheet to see what values it spits out for horn length.
If I'd not been as scared by the Synergy horns before (and found Bill's design), I think I would have made his CoSynes. Still, I have a couple of good drivers, so we'll see how it goes!
Thanks again everyone!
Dan
Ok. 30 x 30 inches would give me pattern control to about 305Hz, and at 90 degree dispersion, both horizontally and vertically, gives a horn depth in Bill's spreadsheet of about 11.4 inches.
Code:
FILL IN Values that have GREEN background below (see photo): (metric equiv):
ThetaW = 90 [degrees], horizontal coverage angle (90)
ThetaH = 90 [degrees], vertical coverage angle (60)
Fc = 305 [Hz], lowest frequency at which horizontal pattern control to be kept (385)
td = 1.414 [inches], side of HF throat (square, needs shaping to round. For 1" driver use 0.707") 0.03591567183134 [meters]
kk = 25306 [Hz*deg*m], Keele's constant 25306 nom.
ratw = 0.65 ratio of final horizontal first expansion width to overall horiz width, 0.6 to 0.7 (0.65)
L12in = 1.5 [inches] synergy port distance from throat (adjust to get vals for HornResp Sim) 0.03810007620015 [meters]
T = 0.465 [inches] board thickness -- USE MEASURED VALUE. 0.01181102362205 [meters]
Overall Size (inside and outside horn): Values to use in HornResp Simulation (for Synergy horns):
width L= 30.246 [inches] 0.7682 [meters] S1 = 10.13 [cm^2]
height J = 30.246 [inches] 0.7682 [meters] S2 = 116.70 [cm^2] Con12 = 3.81 [cm]
depth M = 11.396 [inches] 0.2895 [meters] S3 = 2493.60 [cm^2] Con23= 19.57 [cm]
S4 = 5902.01 [cm^2] Con34 = 5.57 [cm]Haha, very true! It's wonderful being a Dad for the second time 🙂
Both of them seem to have really good hearing, so I want to make a system that turns them into audiophiles from a very early age 😉
Both of them seem to have really good hearing, so I want to make a system that turns them into audiophiles from a very early age 😉
All of mine love music...too bad our current house doesn't have the room for a good proper horn system. I should buy a cheap class D amp and put my Edgarhorns in here and out of storage. Maybe when I don't have to buy diapers any longer I can do that.
And congrats on the new little one!
And congrats on the new little one!
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