Not sure what you mean? Vituixcad diffraction tool makes minimum phase responses, propagation delay removed.
In reality one would measure system with fixed distance and using reference channel, accurate relative timing and phase is preserved. Basically same as diffraction tool output.
As operator you must understand how the measurements were taken, at which distance and what was rotation axis and how any set of responses relate to the simulator coordinate system. Usually simulation is done with listening position in mind, from say 3meters away, ear at tweeter height, toe-in (reference angle) and so on. VCAD coordinate system moves the measurement sets around.
If you simulated baffle with a woofer and then another as back woofer so that the virtual mic was centered on each, you probably need to rotate the back driver coordinates by 180deg and adjust z for what ever box depth you plan. Now the front driver is left at 0.0.0 coordinates and the back driver say z=500 and r=180, 50cm deep box and woofer behind facing out.
If you want to, you could adjust Y coordinate as well, to drop the box (set of measurements) where it would be in reality, below ear height probably. As it is a subwoofer application its not critical.
In reality one would measure system with fixed distance and using reference channel, accurate relative timing and phase is preserved. Basically same as diffraction tool output.
As operator you must understand how the measurements were taken, at which distance and what was rotation axis and how any set of responses relate to the simulator coordinate system. Usually simulation is done with listening position in mind, from say 3meters away, ear at tweeter height, toe-in (reference angle) and so on. VCAD coordinate system moves the measurement sets around.
If you simulated baffle with a woofer and then another as back woofer so that the virtual mic was centered on each, you probably need to rotate the back driver coordinates by 180deg and adjust z for what ever box depth you plan. Now the front driver is left at 0.0.0 coordinates and the back driver say z=500 and r=180, 50cm deep box and woofer behind facing out.
If you want to, you could adjust Y coordinate as well, to drop the box (set of measurements) where it would be in reality, below ear height probably. As it is a subwoofer application its not critical.
Last edited:
It looks to be something like dipole, polars show up to 90deg and strong nulls there. If the chart was showing all the way to 180 deg and look like that it would be cardioid response, null on the back. You can shape it as much as you want as its all virtual and make it fit your application exactly, unless it already is.
If I remember correctly just right click on the chart and untick 90 limit on the popup menu.
If I remember correctly just right click on the chart and untick 90 limit on the popup menu.
Last edited:
This seems to be contradictory. Aren't "directly in the corners" symmetrical?
I have shown that a random placement of subs works a little better than symmetrical. Symmetrical has too many sources trying to control the same mode. But the differences are small enough so as not to be a big issue.
As to numbers, it goes like this; two non-close subs just about halfs the variance in SPL at LFs. Adding a third reduces it a bit more and a fourth a bit less than the third - diminishing returns certainly. You get the biggest bang for the buck from the second sub and less and less thereafter.
Take a look at Amphion’s residential series flagship towers with mechanical cardioid/monopole radiation
https://amphion.fi/products/krypton3/
Cheers. Just wondering what was used and if it was apples to apples.
It does seem like chest feeling is not required to identify a frequency. I don't doubt the preference or that it makes it easier.
...
This was the older paper on speakers vs headphones:
https://www.aes.org/e-lib/online/browse.cfm?elib=16086
Comparison of Subjective Assessments Obtained from Listening Tests through Headphones and Loudspeaker Setups
https://www.researchgate.net/public...device_screening_in_Internet_experiments#pf11
The Headphone and Loudspeaker Test–Part II: A comprehensive method for playback device screening in Internet experiments
The above is only a month old.
https://www.aes.org/e-lib/browse.cfm?elib=19252
A Study of Listener Bass and Loudness Preferences over Loudspeakers and Headphones
Last edited:
I've spent some time now with the horn on top of the mid cabinet. What first surprised me, is that the great distance between the horn and the lowest woofers, did not stop the possibility of a pleasurable listening experience, while playing just the horn and the lowest woofers as a two-way
Proof of concept;
pick any system with sources spread all over and you will find people who are willing to sit there and listen to it.
To me, systems typically sound how they look in terms in placement of drivers. I experimented with XO points and the 15". The horns directivity runs lower than the 15" so its hard to compare. From a very shallow perspective, the system sounds much better crossed at 200hz than it does at 800hz though more eqing would be needed to create a fair comparison. Judging by REWs clarity metric it shows higher clarity from the horn at the listening spot, down to ~400hz, which is where directivity should fall off for this horns horizontal polar.
View attachment 1136978
it took some time to adjust to...just like when the tweeter was above my head. The image, in a sense, is "smaller"? It sounds much tighter now. Image is apart of Locatability
On the bright side, the above is sooo much more aesthetically pleasing to me....I could do a million things to finish that, in a way that I would desire.
Adding Cardioid woofers would be simpler in the above form as well. Pretty much the only thing I would change is getting the horn to ear height which makes room for another pair of 18's...... I'm not sure if that would help the FR....if the woofer closest to the ground gets the best FR....then adding any additional woofers that aren't next to the ground would make it worse...I already have two 18"s along the ground.....I probably should call it good. They say when you add too much of something, things start to get worse. I could just raise the horn to ear height or leave it.
1/48th smoothing, taken at listening point seen in top pic. Theres an issue at the crossover point. Fixable? maybe... I ran out of time to play with it, for tonight. I could see why the MTM would be desirable for a person like me, but like I said, it would also have a lower quality FR. I think the 2 way is where its at for me until I can see why, outside of having a symmetrical bass representation. I'm here more for the FR more than anything, now that headroom is plenty.
Proof of concept;
pick any system with sources spread all over and you will find people who are willing to sit there and listen to it.
To me, systems typically sound how they look in terms in placement of drivers. I experimented with XO points and the 15". The horns directivity runs lower than the 15" so its hard to compare. From a very shallow perspective, the system sounds much better crossed at 200hz than it does at 800hz though more eqing would be needed to create a fair comparison. Judging by REWs clarity metric it shows higher clarity from the horn at the listening spot, down to ~400hz, which is where directivity should fall off for this horns horizontal polar.
View attachment 1136978
I thought of this comment over the past week of experimentation....having the horn above my head took some time to get use to, but eventually my brain accepted it. After concluding that the ppsl was equal to the mid 15" in sound quality up to the XO point. After testing XOs between the horn and 15", finally I moved it out of the way to configure what is the best performing configuration yet.
it took some time to adjust to...just like when the tweeter was above my head. The image, in a sense, is "smaller"? It sounds much tighter now. Image is apart of Locatability
I am confident that I know why the image is perceived as tighter now, and its based....around the idea that the 2 sources are closer together. What "closer together" means to me is; Localization of the 2 sources into a smaller area. The problem is my singers are now in the floor or tiny people...or I'm on a balcony but lacking all the other auditorial cues of being so...what does being in the balcony even sound like lol! Like most people, after enough time, I will acclimate, but the question is, is this ok? The horn is pointing slightly up.
On the bright side, the above is sooo much more aesthetically pleasing to me....I could do a million things to finish that, in a way that I would desire.
Adding Cardioid woofers would be simpler in the above form as well. Pretty much the only thing I would change is getting the horn to ear height which makes room for another pair of 18's...... I'm not sure if that would help the FR....if the woofer closest to the ground gets the best FR....then adding any additional woofers that aren't next to the ground would make it worse...I already have two 18"s along the ground.....I probably should call it good. They say when you add too much of something, things start to get worse. I could just raise the horn to ear height or leave it.
1/48th smoothing, taken at listening point seen in top pic. Theres an issue at the crossover point. Fixable? maybe... I ran out of time to play with it, for tonight. I could see why the MTM would be desirable for a person like me, but like I said, it would also have a lower quality FR. I think the 2 way is where its at for me until I can see why, outside of having a symmetrical bass representation. I'm here more for the FR more than anything, now that headroom is plenty.
I do think there is merit in the MTM and the Synergy is yet more proof that centralization of the sound sources are desirable even beyond the capabilities of a 2way. I think that the disconnect with some people is how they chose to define their experiences. Also their is likely an approach to listening that we may not always consider. For example, my approach to listening is up close and in the 0 axis.
I wonder what you think there is to gain with the mtm. The symmetrical expression of the spectrum below the tweeter is desirable but if my predictions are correct, the upper woofer will have a worse FR than the one that is next to the floor. I would chose to loose the benefits of the MTM in order to keep the benefits of a 2way with a floor adjacent woofer.
Are there other ideas of woofer placement, that involve placing a woofer at a certain height to maximize its FR?
So far, my thoughts are that I can likely raise the height up 4" inches and then the horn will be pointing at the sweet spot, on the vertical axis, while being pitched up slightly. I personally would prefer it to point straight at me at ear height, but aiming up from slightly below seems to be ok....being pitched slightly up, might lesson the floor reflections? I may try and figure out a way to add cardioid woofers, and add equivalent volume for the additional woofers. Or maybe I can find a way to add volume, so that when I split the volume between the woofers, it will still be a good amount.
Last edited:
I've had a crossover where I could just discern the differing location of the mid, but the crossover itself was carefully balanced. It was not a deal breaker, it was a very good crossver. I disagree that Synergy is superior. As Dr Geddes says...
Hi Camplo,
Sure there is merits (and drawbacks) to every approach.
I'm totaly in agreements with you about preferences playing a huge role in accepting a system rendering too.
I started listed the merits (i see) of vertically aligned pairs of loudspeakers but it's already been discussed in here somewhere burried in the 500 pages of this thread...
So i'll rather focus on some points:
_the rendering you seems to like: close to loudspeakers and on axis ( for the last i don't get it: you use horn right? Isn't there some issues on axis and isn't some benefits to be a bit offset'ed? This is the case with the one i own).
Mtm are often disimissed by people finding them too much 'forward' in rendering, closer to headphone.
By your choice of setup i think it could work for you.
_your room.
You have a somewhat low ceiling height iirc. By having an MTM arrangement you mitigate floor and ceilling bounce. Rather than one wide q notch you have two 'narrower' q ones.
Of course it'll depend from your listening point/loudspeaker location, the freq at which you crossover etc,etc,...
I see the different spatial location of woofers as a step in the 'good' direction wrt what happen below Schroeder frequency too. It's crude, not as evolved as a multisub approach but still i think it can have merits.
Last but not least you talk about predictions.
How i see things (from my couch on the other side of the planet) is: you have the drivers loaded into their boxes, access to enough amps and things to generate a xover, then it's only a matter of implement a stereo setup with a ppsl/horn one side, an mHm the other and compare ( better if the room have a simetrical layout). It'll give a real idea if there is something to be gained or not even with the different diameters drivers ( you already assesed the difference in sound quality between both isn't this much an issue overall and you could use dsp to give close enough behaviour of low end on both system - linkwitz transform on the 15", hp on the ppsl, etc).
Reality rather than prediction.
That said i won't be the one who'll have to move things around to set up the test...
What i mean is why not try things if they can be implemented ( without it being too complex to set up) rather than thinking about them..