One would be a measurement that shows the difference in summation while the other (the sticking head in speaker part) is a purely subjective conclusion.
That being said, pretty sure 'Patrick' has said something along those lines as well, but it made more of a lasting impression to read it from the man himself.
That being said, pretty sure 'Patrick' has said something along those lines as well, but it made more of a lasting impression to read it from the man himself.
I own a pair, and have installed several more of those and plenty of other Danley products. The acoustic origin and acoustic centre are both at the apex of the horn, but the transition to far-field radiation condition occurs farther out than that. This is relatively easily seen with a measurement taken on-axis, anechoically, moving the mic outward.
The trick is that you can’t hear the sound coming from the individual drivers’ openings, but that doesn’t mean you’re in the acoustic far field.
Don’t get me wrong, they are much better for source coherency in the near-field than other speaker types of the same size, and the transition occurs closer to the cabinet grille than you’d expect (and much closer to the grille than a direct radiating device), but there are some laws of physics that even Tom can’t break completely.
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Hmmm how to answer this question....The response gets tuned with eq, very low xmax in the bass region, mid region, etc?
I don’t believe VituixCAD is capable of this type of simulation. From what I can tell, the plots are generated by purely analytical methods. The effect of source location on the baffle is likely done in a similar way to the equivalent tool in Tolvan’s Basta! and Edge software, which uses a cluster of theoretical point sources arrayed across the defined (flat) surface area.
However, since you seem to be pretty handy with Fusion360, I think you’d perhaps find a lot of answers to your questions by spending some time learning how to import your CAD models into Akabak. That would let you simulate these sorts of driver arrangements, among other things. The ‘simple’ method is to export your CAD model as separate STEP files, in predefined chunks or slices to make up the subdomains in the BEM, and then generate meshes with Gmsh.
If you make an extra STEP file that only contains small disc elements in the centre of any driver cutouts, then you can use the element number of that mesh to locate virtual diaphragms in Akabak. For normalised directivity polar maps, you don’t even need to do the lumped element part for the T/S parameters, but that’s also available if you want to experiment with different drivers, and you can make plots that only have certain cones driven if you want to isolate the effects of individual sections of the box.
At the very least, it might keep you busy for a while and let you investigate the effects of things on your own
This was my desk for a good while before shows started again. We did the oak veneer ourselves, on horns that were specially finished in invisible bondo and staples. The Apex Intelli-Power amp was on demo, nice match for them though.
I don’t have them at my house sadly, but I will gladly do some measurements at various points within the horn when I'm next over at my company's office. Or, it might be when I can schedule some acoustic model verification time at a venue that we installed this fetching pink set into a few years back.
I've also got SH96HO, SM80 and SM80M, SH95, J3-94, SM60F, SH46, and others if you'd rather see one of those? Oh, and these beauties live not so far from me...
You might say I am 'familiar with the product'
give me a couple of weeks. It's on the (long) to-do list, but I was already planning to do some near-field and far-field measurements on various boxes to try out the EASERA TDS module and some other FIR-related ideas I've had recently.@camplo it seems you've moved away from the idea, but I also have a set of DIY monitors which use horizontal side-by-side dual 12" Volt drivers for the LF there. I'm not about to do a full horizontal polar measurement on a turntable, but I could perhaps try to do some 'around the listening position' sweeps to give you an idea of what happens in a room with that arrangement. Of course, Akabak models would achieve that too, if you're game. A simple cabinet model with a pair of 15" cones in it doesn't take long to make or calculate.
I'd normally feel bad for the derail, but this thread has been all over the shop already.
Kyle, it's awesome you have those resources to use and play with. Thanks for posting about it. And yep, this thread goes everywhere !
May i ask your take on the "sound of your head in the SH-50 horn"?
I've DIYed a number of similar size MEHs, and have never had all that strong of a 'the speaker disappears with my head in it feeling'.
I always mainly get the impression all the sound comes from the CD's exit, without being able to hear/identify sound from the other drivers.
So i'm always curious what folks say here.
Maybe the closest to not localizing at the CD has been with a 60x60, which is the narrowest pattern I've trier. I have the impression that greater horn depth may strengthen the phenomenon.
May i ask your take on the "sound of your head in the SH-50 horn"?
I've DIYed a number of similar size MEHs, and have never had all that strong of a 'the speaker disappears with my head in it feeling'.
I always mainly get the impression all the sound comes from the CD's exit, without being able to hear/identify sound from the other drivers.
So i'm always curious what folks say here.
Maybe the closest to not localizing at the CD has been with a 60x60, which is the narrowest pattern I've trier. I have the impression that greater horn depth may strengthen the phenomenon.
camplo ... this link may have been posted here already.
https://www.usound.in.ua/graphs/It can give you a rough idea of what to expect from the side by side driver arrangement.
https://www.usound.in.ua/graphs/It can give you a rough idea of what to expect from the side by side driver arrangement.
Vituix can do rotation and tilting of drivers.
"Horizontal rotation R [deg] and vertical inclination T [deg] of drivers are also supported. Rotation R [deg] is positive to counter-clockwise from top view, and inclination T [deg] is positive to up".
For turning the drivers inwards with an air mass in between Vituix isn't going to give the whole answer, and Akabak would be better.
camplo my guess would be that if the response disappears from rotation that you have set it up in such a way that one driver is totally cancelling the other. Did you add some positive and negative X to reflect the position of the drivers when rotated?
Hello Camplo
Can't you set them up with the 18" slots facing the sides so they are not as obstructed. Your crossover is 80 Hz shouldn't be a problem integration wise. I would more concerned about getting something like flow noise like from the much smaller "port" at high volumes. Concern could be completely unfounded, just a thought. Rotate the 18's 90 degrees in this picture you posted.
Rob
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Yes sir, that did not help, I'm not sure why, The whole polar map disappeared not just for the side woofers.....I ended up Starting with the diffraction tool and taking the virtual response from 90 and-90 degrees....then when I placed the drivers I moved X.
I eventually came to conclusion that the direct energy aspect should be my concern if thats the idea that I am pushing....I speculated that having the output on the front baffle is likely the best option for that goal though I cannot accurately speculate what happens as far as direct energy is concerned with side by side crossed low.
I checked the Velocities in HornResp, at max volume the peak throat particle velocity is 4.5m/s....15-17ms equates to port noise if I remember correctly.Hello Camplo
Can't you set them up with the 18" slots facing the sides so they are not as obstructed. Your crossover is 80 Hz shouldn't be a problem integration wise. I would more concerned about getting something like flow noise like from the much smaller "port" at high volumes. Concern could be completely unfounded, just a thought. Rotate the 18's 90 degrees in this picture you posted.
Rob
Also in hornresp, if I close a a csa past the driver to "1" I still get decent output. My guess is that its just a limitation of the sim.
To model the the new bassbin, I still used an offset horn....922 s1-s2 about 55cm long to s3 set at 322, which is the csa of the transition, then next the csa and length of the final chamber.
If I understand things a little better I could also start modelling with room gain...I'm not sure exactly how the room gain is calculated in VituixCad but I know its not the whole picture. I think its just showing the gain from the front two boundaries? So while I am able to see how vertical bass arrays improve the FR....I cannot see (within this program) whats happening with cancellations from wall boundaries, this would help me see how important multiple bass sources are on the horizontal plane I would imagine.
TOmaTO toMAto ...room gain or room modes are much the same and depending on dimensions of said room, it also comes down to wavelength and physical size and whether or not they express the 1/4 1/2 and 1/f relationships as to whether they are additive or destructive which is why bass distribution in any given room is chaotic....
hopefully someone versed in VitiuxCad can help you with specifics of how to implement it...
hopefully someone versed in VitiuxCad can help you with specifics of how to implement it...
Here is a good thread to read
https://www.audiosciencereview.com/forum/index.php?threads/analytical-analysis-room-gain.23211/
The higher the DI the lower the room reflections will be, it's that simple. Higher directivity becomes ever more difficult in a system of limited size. The physical size tends to go up as the DI is increased.
I liked the comment about DIYers buying great looking drivers and THEN trying to make a system out of them. Bad idea. I started with a specific goal and worked backwards from that, finding drivers that fit the design. At first, I was using high-end TAD, but then after a group listening test (blind) it was determined that the drivers themselves had no effect on the perception given identical system designs. So, I went with a much more reasonable set of B&C and never looked back. Drivers are not important, system design is.
I would ignore "room gain" as it is completely dominated by the specific room and "room" modelers are very weak in their analysis, even wrong in many aspects. The rooms modal behavior can only really be determined with in-room measurements and EQ. I know of no simulations (available to DIY) that can do this region correctly. Just make sure that you have enough power and spread out sources and correct in-situ. It's the only way that I know of to get the low end right.