Waveguide modeling

[isaeagle4031]

Is there anyway to sim the effects of a waveguide on a compression driver (or driver in general)? Planning out a build that may use the Dayton 8 or 10" guide.

[Face]

Re: Waveguide modeling

http://www.hornresp.net/

[jhollander]

Re: Waveguide modeling

Seem to recall reading that Horn response is not accurate for small drivers. It would be nice to hear confirmation.

[isaeagle4031]

Re: Waveguide modeling

This is what I recall reading John.

[1100xxben]

Re: Waveguide modeling

http://www.randteam.de/ABEC3/Index.html

[Face]

Re: Waveguide modeling

http://www.randteam.de/ABEC3/Index.html

Yep, there's also http://www.randteam.de/AkAbak/Index.html

[TN Allen]

Re: Waveguide modeling

If anyone does work with WG/driver simulation, and wants to collaborate on design ideas, I'm interested in providing 3D solid/surface modeling and milling prototypes at no cost.

[natehansen66]

Re: Waveguide modeling

What effects are you looking for? R and D team that was listed above also makes AxiDriver......axi-symmetric only. You can model waveguides, enclosures, etc and look at the polar response and the wavefront at selected frequencies. I'm starting to work with it now. Cool stuff .

[winslow]

Re: Waveguide modeling

Hornresp has problems with the HF aspect of drivers because it treats everything as a pure piston, and some predicted response can look worse because of that.

[Pete Basel]

Re: Waveguide modeling

If anyone does work with WG/driver simulation, and wants to collaborate on design ideas, I'm interested in providing 3D solid/surface modeling and milling prototypes at no cost.

I've been thinking that it would be nice to have a WG, similar to what Zaph did, that bolts on:

http://www.zaphaudio.com/hornconversion.html

Zaph did it with a SEAS tweeter, might be nice to have one for the RS28 that bolts right on,
perhaps in place of the faceplate.

[isaeagle4031]

Re: Waveguide modeling

To be honest, I'm not sure exactly what I am looking for. Polar response for sure. Height effects to listening positions. Etc. The design layout I am working on may put the waveguide up as high as 46" from the floor. So being able to sim this will be a great benefit. If I should design the crossovers 9n the tweeter axis, the mids, or even in between.

[isaeagle4031]

Re: Waveguide modeling

I've been thinking that it would be nice to have a WG, similar to what Zaph did, that bolts on:

http://www.zaphaudio.com/hornconversion.html

Zaph did it with a SEAS tweeter, might be nice to have one for the RS28 that bolts right on,
perhaps in place of the faceplate.

Check out Pellegrene Acoustics. Dave has waveguides for the rs28 tweets that bolt on.

[Face]

Re: Waveguide modeling

I've been thinking that it would be nice to have a WG, similar to what Zaph did, that bolts on:

http://www.zaphaudio.com/hornconversion.html

Zaph did it with a SEAS tweeter, might be nice to have one for the RS28 that bolts right on,
perhaps in place of the faceplate.

There will be a SEOS8 that works with the RS28 available soon.

[Pete Schumacher]

Re: Waveguide modeling

I've been thinking that it would be nice to have a WG, similar to what Zaph did, that bolts on:

http://www.zaphaudio.com/hornconversion.html

Zaph did it with a SEAS tweeter, might be nice to have one for the RS28 that bolts right on,
perhaps in place of the faceplate.

You mean like this?




RS28A in the guide




And here's a set of plots for the SEAS 27TBFC in the above guide.



Check my signature for the link to the thread where this is being discussed (8" two way).

I also have custom baffles that fit the PE enclosures that include some nice guides.

[TN Allen]

Re: Waveguide modeling

Mounting the RS 28 without the face plate requires care removing the protective screen, and to maintain the alignment of the coil and magnet. I use an Aluminum sub-plate attached with screws through the tapped holes in the RS 28. The Aluminum plate is then temporarily clamped to the back of the guide. If the mount is permanent, I don't use the Aluminum plate, but use longer screws that are countersunk into the Corian throat ring I mill as part of the guide contour. These screws then go into the tapped holes in the driver body. I've found wood or particle board at the throat back is too easily sanded away when finishing the guide, the Corian, or sometimes a layer of Formica is harder and less easily damaged, maintaining an accurate circular throat.

I don't have a photo of finished guides with the RS 28, only the temporary mounts. There are two additional photos of a Vifa driver attached with 3 screws in the same way I attach the RS 28, or the Usher 9950, which is somewhat similar to the RS 28. The Usher however requires a slightly different Corian ring.

The RS guides are similar in cross section to the guide Pete Schumacher used in the MiniByzantine(?), and if I recall correctly, it has a similar ~3.95" Radius to one of the WGs described on the Zaph website. The Vifa guide is a spiral cross section.

This mounting method produces a simple clean attachment to the guide. This last photo is the Usher 9950, but similar to the RS 28.

Regarding simulations of WGs effect on sound. I suspect one reason there isn't more of this done easily, is that it is more complex than one might think. I've asked about FEA use for this, other than a few graduate thesis, and examples by well financed commercial speaker builders, there really doesn't seem to be much available suitable for DIY use. I may be wrong, in fact, it would be great to find I am, and that there is something available.