Taking on board the comments about how intrusive issues might be with surface mounting drivers, and doing some digging - I came across https://www.speakerdesign.net/audioXpress/diffraction/diffraction.html.
As it happens I can get F11 equivalent felt in the UK, although its not cheap. How long a square metre would last is another matter.
More concerning was a statement that I haven't bookmarked it seems that DLR made about a flush mounted tweeter in a recess that was too wide, by a millimetre or so, and that also have a measureable effect from the hard edge of the tweeter faceplate.
That concerns me, because I suspect that being able to use a router to cut to 0.3mm either depth or 0.5mm diameter is a stretch for me. And for many CNCs I suspect, not least many tweeters are spec'd at 104+-0.2 - and its not clear if that means 'round but diameter may vary' or 'might not be round - or elipsoid'.
It seems the felt trick only works if its over the discontinuity, which puts it near the dome, which is bad, which suggests a tweeter with a big faceplate, which puts C2C with the mid too far, which is bad.
Anyway: via ebay I came into a partially completed XRK design FAST with RS225 and B80. The baffle is 25mm birch ply and .already cut for drivers. I had to do a bit of roundover to get the B80s to fit with about 1mm interference from teh basket but that's fixed. The 'problem' is that the depth and diameter of the recess seems to match them very well, and these drivers do not have integrated gasket foam.
I have gasket tape (I think its from Monacor, as so much is in Europe) that I have bought from several vendors, and it squishes down 'quite a lot' but there's a limit, and just placing the B80s in the baffles is finger-smooth.
I'm planning to oil the ply rather than veneer. Should I just say 'its a full range and the effect of a little ridge is lessened by the cone and surround' or look for a very thin solution? I don't want to glue the drivers in place - they look handy as midranges or with other woofers.
I've seen liquid gasket solutions, although its not clear how easy to remove medium/low stick ones are, and also gasket paper down to about 0.25mm, or 0.4mm. Do they work?
I know its a full range, but I'd like to have a stock technique that works with 19mm tweeters as well as a worst case, and to have a technique in reserve for failure to get the diameter or depth exactly right per spec, or to find that adding veneer has throw things off and my tweeter is slightly proud with the normal gasket tape. Measuring the diameter before commissioning the cabinet cut is possible, but as I say it might not be round and I'd planned to leave a bit of sl space.
As it happens I can get F11 equivalent felt in the UK, although its not cheap. How long a square metre would last is another matter.
More concerning was a statement that I haven't bookmarked it seems that DLR made about a flush mounted tweeter in a recess that was too wide, by a millimetre or so, and that also have a measureable effect from the hard edge of the tweeter faceplate.
That concerns me, because I suspect that being able to use a router to cut to 0.3mm either depth or 0.5mm diameter is a stretch for me. And for many CNCs I suspect, not least many tweeters are spec'd at 104+-0.2 - and its not clear if that means 'round but diameter may vary' or 'might not be round - or elipsoid'.
It seems the felt trick only works if its over the discontinuity, which puts it near the dome, which is bad, which suggests a tweeter with a big faceplate, which puts C2C with the mid too far, which is bad.
Anyway: via ebay I came into a partially completed XRK design FAST with RS225 and B80. The baffle is 25mm birch ply and .already cut for drivers. I had to do a bit of roundover to get the B80s to fit with about 1mm interference from teh basket but that's fixed. The 'problem' is that the depth and diameter of the recess seems to match them very well, and these drivers do not have integrated gasket foam.
I have gasket tape (I think its from Monacor, as so much is in Europe) that I have bought from several vendors, and it squishes down 'quite a lot' but there's a limit, and just placing the B80s in the baffles is finger-smooth.
I'm planning to oil the ply rather than veneer. Should I just say 'its a full range and the effect of a little ridge is lessened by the cone and surround' or look for a very thin solution? I don't want to glue the drivers in place - they look handy as midranges or with other woofers.
I've seen liquid gasket solutions, although its not clear how easy to remove medium/low stick ones are, and also gasket paper down to about 0.25mm, or 0.4mm. Do they work?
I know its a full range, but I'd like to have a stock technique that works with 19mm tweeters as well as a worst case, and to have a technique in reserve for failure to get the diameter or depth exactly right per spec, or to find that adding veneer has throw things off and my tweeter is slightly proud with the normal gasket tape. Measuring the diameter before commissioning the cabinet cut is possible, but as I say it might not be round and I'd planned to leave a bit of sl space.