Pensil Series for Mark Audio Drivers

[planet10]

Woden Design (Scottmoose) has designed a complete, and consistent set of Pensil Damped Air Couplers for the entire Mark Audio line-up (CHR-70, CHP-70, A6, A7, A10, A12).

Final drawings were OKed by Scott today and i have posted them on the Mark Audio Box Plans page at Planet10-hifi.com.

dave

[Scottmoose]

Just to clarify (in case any misunderstanding about the above lands me in deep trouble): these are official Mark Audio boxes, rather than 3rd party designs. Once Mark has had chance to rework his site, they'll live there, though links are no problem of course.

[sts9fan]

Can one of you guys give a description of what Resonant Air Coupler is? I can't seem to find much information.

Thanks
Kris

[Scottmoose]

See pg.1 of the plans: http://homepage.mac.com/tlinespeaker...ies-291209.pdf

[gazzagazza]

Sounds like a Mass Loaded Transmission line in other words. Does it model in Martin Kings's mathcad sheets?

[Scottmoose]

MLTL is a catch-all term for an almost infinite variety of possible boxes. The Pencils are a specific alignment, with specific objectives.

[Hypoicon]

Question: Just what is the difference between the Pensil r70 and p70, (besides dimensions, of course) and the original pensil? I can't seem to find any discussion of these variants anywhere.

[planet10]

The original Pensil was Mark's design. The r70 & p70 are part of Scott's re-interpretation for the entire line of drivers. R70 is for the CHR-70 metal cone driver, P70 is for the CHP-70 paper cone driver (largely available only in Germany & Japan or directly from Mark)

dave

[Hypoicon]

Originally Posted by planet10

The original Pensil was Mark's design. The r70 & p70 are part of Scott's re-interpretation for the entire line of drivers. R70 is for the CHR-70 metal cone driver, P70 is for the CHP-70 paper cone driver (largely available only in Germany & Japan or directly from Mark)

dave

Thank you very much for the quick answer. I would be curious what the specific objectives (Scott's term) were for these alignments. I am most likely going to build the R70 in the next couple of weeks, so I'm curious what to expect and what to tweak for.

By that I mean, is there a suggested compensation network (like the original pensil)? About what density of stuffing should be used, or should there be any treatment of the interior walls of the enclosure, or should both be used? As I mentioned, I looked around for any discussion and didn't find any on these new versions so I might need to start a thread if I build the R70.

[Hypoicon]

nevermind about the stuffing question, just spotted it in the notes for the design. Oops.