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Pensil Series for Mark Audio Drivers

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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.
 
Specific objectives?

Simple enclosure, easy to tailor to various rooms / systems, relatively flat impedance & a reasonably balanced response down to ~60Hz without requiring compensation circuitry in the vast majority of cases (there will always be some that need adjustments -that's just life. Mostly not though).

By that I mean, is there a suggested compensation network (like the original pensil)?

As in the taller Pencil Mark designed for the CHR? No. Most users should not require any Eq on the Pencils in practice. There are several threads on the Pencil 12; what applies to that basically applies to the Pencils for the smaller drivers.
 
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Pensil-7 newbie questions

Hello,

I'm embarking on my first DIY project and after reading about the FH and tons of other designs, I've settled on the Pensil series of designs for the Markaudio drivers based on:

a) good reviews
b) good looking response graphs
c) build simplicity
d) lots of guys saying that similar looking designs were popular with their wives :)

I do have a couple of pedestrian questions about this design as well as speaker building in general though.

1) How should the removable rear panel of the cabinet attach to the cleats that are there in the design? Are metal screws okay? Is there a better way? I might be missing how "cleats" work, if they work in any particular way at all.

2) General question... Is it best to have a terminal plate for any reason or can you simply mount binding posts directly on the wood of the cabinet?

3) If you did install a terminal plate, is any one location on the cabinet better than any other location? I guess the rear panel is not such a good idea if it is going to be removable but I'm just wondering about the effect on the acoustics internally to the cabinet. In an effort to hide the terminals as best as possible, would it be okay to put the speakers on a set of rubber feet and put the terminals at the bottom or is that really stupid?

4) In this design, does the location of the stuffing matter? I do intend to play around with the stuffing to get the best sound, but I'm wondering if there are any guidelines on this.

5) I don't want to cut any corners... So I'm wondering if there is *any* benefit to including an internal brace on the Pensil-7 design... Or would I be wasting my time?

Thanks a million!

Colin
 
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5) I don't want to cut any corners... So I'm wondering if there is *any* benefit to including an internal brace on the Pensil-7 design... Or would I be wasting my time?

Colin,

If you are not cutting any corners than add braces. We have found that the brace front to back that couples the driver to the back particularily beneficial for downward dynamic range. And with a removable back, it gives an additional place to attach the back.

An example is shown in one of the Pensil12 drwings i believe.

dave
 
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