Read the article and watched the video. Do these speakers use controlled directivity ? Also waveguide technology is used in the AMT not the uniwave?
The Spatial X3 and X5 do use a a waveguide which provides some controlled directivity and constant directivity concepts. The current M3 and M5 models do not appear to do so (Clayton can correct me here, as it appears to be a tweeter with a wide range). To be specific, it appears that the M3 and M5 provide constant directivity but perhaps not controlled as they are not within a waveguide, i.e. very wide dispersion. The previous X1 (Uniwave?) also used a waveguide (
https://theaudiophileman.com/spatial/).
The video and recommended link directly under the video authored by Bill Waslo were specifically for large waveguide and medium waveguide sized speakers. I would strongly recommend reading and rereading it. Particularly read the definitions of constant and controlled directivity (they are different).
Large and medium waveguide based speakers include the JBL M2 (and several other JBL models, including the 7 series, 3 series, Studio series, etc...), all the GedLee models, Buchardt Audio,Kali speakers, etc...That being said some speakers that use coincident drivers (which have tinier waveguides surrounding the central tweeter) such as KEF, Elac, TAD, Kali etc...appear to benefit from this type of toe in as well. Last I discussed with Andrew Jones, he recommended it with his Elac Adantes.
For us fellas who own large waveguides, this idea of toe in is something we have understood for a long time and is always the method of speaker setup recommended by Earl Geddes. Let's put it this way...a properly designed waveguide
ALLOWS you to do this amount of toe in, while non waveguide based speakers do not. The differences are in the imaging specificity that medium and large sized waveguide speakers allow. If you add diffusion to the rear side walls, in my experience, you have all the advantages of open baffle designs (ie soundstage layering) but with imaging specificity which is a waveguide strong suit. Of note, I have made these conclusions after multiple listening session with GR Research NX Oticas and Linkwitz LX series of speakers amongst others. And moreover, contrary to what people have said, there is no real drop in high end response, but one needs to be careful about what one uses at the 1st reflection point on the side walls. For constant and controlled directivity loudspeakers that use these
medium to large waveguides I would experiment with an MLS based diffuser and not use a thin absorber (1 inch or 2 inches). If you are going to use absorption, go for at least 3+ inches. GIK 244 or bigger is fine and/or an Alpha panel (which minimizes absorption in the high end), again at least 4 inches or more.
I have not listened to the X3 and X5 yet but perhaps next week in Florida. I have listened to other speakers that have AMT waveguide based tweeters and they have very good imaging specificity and a clean top end as well.
That being said, it isn't illegal to use these toe in methods with regular speakers but you may not hear any improvement or it may even sound worse; the reason is due to the extremely linear off axis response that medium and large waveguide speakers allow (and even many coincident speakers allow) which is evident when examining early reflections directivity and sound power directivity indices when this information is provided by the manufacturer or garnered from 3rd party measurements.
As usual, the devil is always in the details, but with this toe in method, the cost is essentially free, so give it a try.
Best,
Anand.
