I'm in !!! awesome !
Need those with flat sides for synergy builds...even if like you say, no stellar performance.
The sound of closely co-located drivers on a synergy horn is making me rethink how much stellar measurements really matter.
I mean, my CDs on commercial horns like the xt1464 measure sooo much better than in any straight walled conical synergy i've built.
But the overall sound, the integration with the frequencies below the CD, is so much better with the conical syn...well, i have to go with the total sound, and to an extent say what the heck to the CD-range measurements...
Not an entirely tongue in cheek comment I presumeFor corners, shouldn't we be doing "roll-forward"?
I got to thinking just that during the time I built these, and I can say there was no problem.. in this case. I'm not convinced that rolling forward is the way to go. The energy that is headed for a reflection probably ought to be eased out of the picture, beginning with rolling back.
Attachments
For corners, shouldn't we be doing "roll-forward"?
yep unless the driver was inside the room corner. I'm thinking freestanding "easy to build" and potentialy large horn made from plywood with basic diy speaker shop (garage) tools
Last edited:
Wow, you certainly could.
My contractor friends have confirmed my suspicion that 'architectural speakers' are what people want these days. ie. in-wall speakers that you cannot see. I've been trying to think of how to do in-wall with the 45 degree 'cross fired' angle for a while. It would be the way to go.
My contractor friends have confirmed my suspicion that 'architectural speakers' are what people want these days. ie. in-wall speakers that you cannot see. I've been trying to think of how to do in-wall with the 45 degree 'cross fired' angle for a while. It would be the way to go.
Think of it this way: as the wave leaves the source does it encounter any changes in slope, i.e. 2nd derivatives. If not then no diffraction. What is shown above does precisely that. The wave never encounters a slope change so this source would be free from any diffraction - until it met with room obstacles, which surely it must. But what is shown is very hard to implement - requires a wall reconstruction. And then there is the woofer. I'd put in three as close to the corner as possible (but there now, these will diffract.) Ideal solutions are nice, but usually have "gotcha"s and impracticalities.
I'm excited to see the thread take a turn in the 3-walled direction. I've also played around with that idea and performed some experiments which were promising. It has been on my to-do list to implement something but 2020 got in the way.
RE: squishing the drivers into a corner, I want to go with an offset solution where the tweeter (possibly planar) is mounted on only one of the walls. The other two walls would then reinforce it with virtual sources that increase the apparent size to 4 x. The effect this has on directivity could be partially mitigated with absorbing material.
From a diffraction POV this solution is benign (the walls are like periodic boundary conditions - minimal boundary effects). Polars will not be symmetrical but I'm not convinced this matters a great deal.
Question is which of the 3 walls is best to mount the tweeter on. My first inclination is to mount it vertically so that the horizontal polars are absolutely consistent. I currently use upward firing full range drivers in my living room with EQ with pleasing results for causal listening. Exposed ceiling rafters provide a (probably helpful) scattering effect for this setup, but will cause headaches for a 3-corner/vertex mounted horn.
Any major flaws in my thinking?
RE: squishing the drivers into a corner, I want to go with an offset solution where the tweeter (possibly planar) is mounted on only one of the walls. The other two walls would then reinforce it with virtual sources that increase the apparent size to 4 x. The effect this has on directivity could be partially mitigated with absorbing material.
From a diffraction POV this solution is benign (the walls are like periodic boundary conditions - minimal boundary effects). Polars will not be symmetrical but I'm not convinced this matters a great deal.
Question is which of the 3 walls is best to mount the tweeter on. My first inclination is to mount it vertically so that the horizontal polars are absolutely consistent. I currently use upward firing full range drivers in my living room with EQ with pleasing results for causal listening. Exposed ceiling rafters provide a (probably helpful) scattering effect for this setup, but will cause headaches for a 3-corner/vertex mounted horn.
Any major flaws in my thinking?
If I'm not mistaken, another solution may be a segment of a spherical cap, loaded with a CBT array.
The first pic here illustrates that.
The second and third illustrate how it might look if there was a waveguide in there instead.
I think the latter solution would probably be preferable, because it's REALLY difficult to get CBTs to behave above 10khz or even 5khz really. You can get them to measure flattish with a lot of EQ, but when you're applying 12dB of EQ to bring the top end up, it really makes your output suffer.
The first pic here illustrates that.
The second and third illustrate how it might look if there was a waveguide in there instead.
I think the latter solution would probably be preferable, because it's REALLY difficult to get CBTs to behave above 10khz or even 5khz really. You can get them to measure flattish with a lot of EQ, but when you're applying 12dB of EQ to bring the top end up, it really makes your output suffer.
Attachments
OK, I can see a point in the corner intergration, i.e. 3-walled, no matter how difficult it would be to actually implement (I'm only surprised nobody objects to placing the source on the ceiling - or even the floor?) but I really don't see any point in the two-walled placement. As far as I can see this would be just worse than a free standing waveguide placed at some (even small) distance from the walls. What we want is to let the sound intensity fall around the waveguide, gradually but quickly at the same time. That wouldn't happen when sticked to the walls as the last pictures show. Quite on the contrary, there will be reflections that wouldn't be there with the free standing device. Besides, and that I see as the biggest risk, there's a non-zero chance of confusing it with an urinal.
Last edited:
Of course there's the risk, but at these higher frequencies you can build something bigger that does more of the support itself.
In return you extend some of the earlier reflection distances. In addition you might do things with the lower midrange that are difficult to do in a more open space.
I don't know about that.
This is a photo of a lower frequency waveguide on the floor in the corner. The driver cutout shown was for an 8" driver. I had calculated it would be marginal but I had it on hand and it was OK with the confined rear space.
It couldn't even cleanly reach 650Hz, which was where it was meant to cross. Getting close to walls makes the way you do it more critical.
Attachments
It will need some re-coding as I've found out that the current meshing algorithm doesn't handle sharp wall joints very well. It should not be a difficult modification but it will take some time. I will try to prepare an ABEC project or some template then. Honestly, my interest in non-axisymmetric waveguides droped immensly since the "discovery" of the latest free standing ones. They are so much more effective!Is there a possibility to try and simulate a mouth flare? I'm thinking making such horn out of plywood with the straight section as in the model but the side panels would be cut a bit longer and then bent (google kerf bending) to form some sort of mouth flare /rollback. It would save many hours of trial and error if it was possible to try with ABEC first
Mabat, that would be awesome for the community, thank you! Given that there are more this kind of DIY horns shown in the forum than axisymmetric ones made in lathe / CNC it would be nice to evaluate the performance so people can perhaps optimize this style of a construction or decide to make an axisymmetric one instead. The appeal for this kind of waveguide is the ability to construct it at home with basic hand tools and it is the easiest way to make a multiple entry horn as mark1000 has been showing lately and others before him.
Axisymmetric is superior but it is hard to DIY. Especially big axisymmetric waveguides get very expensive by money and effort but this kind of sheet horn is pretty much the same effort to make big or small.
Given that there are more this kind of DIY horns shown in the forum than axisymmetric ones made in lathe / CNC it would be nice to evaluate the performance so people can perhaps optimize this style of a construction or decide to make an axisymmetric one instead. The appeal for this kind of waveguide is the ability to construct it at home with basic hand tools and it is the easiest way to make a multiple entry horn as mark1000 has been showing lately and others before him. Axisymmetric is superior but it is hard to DIY. Especially big axisymmetric waveguides get very expensive by money and effort but this kind of sheet horn is pretty much the same effort to make big or small.
Last edited: