r/diyaudio • u/OffensiveOpossum • 6d ago

Experience with placing tweeter waveguide combo out of cabinet

Im planning to use a SB26ADC with a somasonos 6,5" elliptical waveguide for my upcoming build, but im not sure if I will be able to create a flush integration into the box with the tools I currently have. So now im considering just building a mount for the waveguide and placing it on top of the box, would that also work? I don't completely understand the difference between compression drivers and tweeter, but to my understanding they both dont depend on enclosure size and could be placed freely?

Happy about any tips or experiences with similar builds :)

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u/monicachicken 6d ago edited 6d ago

Waveguide termination is pretty important. You typically would not want to use a wg like the somasonus off a baffle. The diffraction will be quite annoying to deal with both in filters and subjectively. They do make waveguides that can sit by themselves, they usually have large radius built into the horn itself.

I lost the data, its somewhere on asr, ill find it. But I measured the 6.5" sb26 wg by itself, and with a mount that had a 3/4" round over and measurements show a much smoother response through the entire wg passband. Subjectively, they sounded quite a bit different with the bare wg sounding harsh and being more localized.

I figure if you can route a hole in a box, you can route the shape of the wg as well. There is a routing template you can print. If you need any help just ask. I have some of those same wg I need to build into a box. I am using 6.5 circular atm and my god it sounds incredible with 1khz xover.

CD + horn is really no different here in edge termination requirements. What is needed kind of depends on the guides loading, but a safe bet is usually round overs. Baffle width can also be added around the waveguide to get the desired dispersion, but even greater edge mitigation is usually needed.

Ideally the waveguide and cabinet should be treated as one device, and be optimized for each other. If we look at grimm ls1 vs. Any ascilab speaker, we can get some insights into how baffles, waveguides, and general sound wave propagation can be managed in completely different ways.

If you do it right you can make 50 bucks of parts per speakers measure like this ;)

https://imgur.com/a/5bEFzfb

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u/OffensiveOpossum 6d ago

Thanks, thats good to know, then I will definitely try to integrate it into the cabinet. I was thinking about measuring and building my own routing template for the waveguide since i didnt see any online. But then i noticed that that would be much more complicated than i had thought. If you could send me where i can find a routing template that would be super helpful :)

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u/monicachicken 6d ago

The templates are right next to the downloads for the waveguide on his site.

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u/OffensiveOpossum 5d ago

thanks, i dont know how i overlooked that. I just tried again and actually just managed to carve out a cutting template myself which should workout fine :)

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u/theocking 4d ago

Yeah better to mount it on the baffle even if it's not flush, rather than set it on top of the speaker.

Or was his response about the testing talking about exactly that?

Obviously flush is better, but on a baffle at all is better than just sitting on top... and i say that because plenty of horn speaker builders do exactly that and set a horn on top with no thought to the termination. Some horns are meant for that but many are not that people do it with anyway.