MA7.3 first impression

[jjl]

I just finished a pair of Mar-Ken7.3 cabinets and I must say that I really like the sound so far.
It is very clear and precise at the suggested low levels, just what I am after with the music I mainly play (classical guitar etc). The bass in somewhat less than my jr149 speakers and not as warm, but I guess it is too early to compare. I do already prefer the clarity of the MA7.3.

My only question with these cabinets is, why is the vent to the rear and not the front. I almost prefer the sound of these speakers from behind. Just a newby question, sorry in advance. Maybe I need to play with room placement some more. Currently I am just playing them in.

Jeremy

[zman01]

Jeremy,

How many hours do you have on the speakers?

[chrisb]

Originally Posted by jjl

I just finished a pair of Mar-Ken7.3 cabinets and I must say that I really like the sound so far.
It is very clear and precise at the suggested low levels, just what I am after with the music I mainly play (classical guitar etc). The bass in somewhat less than my jr149 speakers and not as warm, but I guess it is too early to compare. I do already prefer the clarity of the MA7.3.

My only question with these cabinets is, why is the vent to the rear and not the front. I almost prefer the sound of these speakers from behind. Just a newby question, sorry in advance. Maybe I need to play with room placement some more. Currently I am just playing them in.

Jeremy

I realize that Dave has drafted many more versions of "Ken" family than I've seen, or certainly built, but out of curiosity which design has vents to the rear?


As Zia has already suggested, run them in per Mark's recommendations hours before final assessment:

Small to medium sized speakers are usually lower power designs. The power rating is given in the technical data for each audio driver. For a reliable long service life, please operate your new speakers with care. For the first 100 hours, operate them at very low volumes. After this period, gradually increase the volume to a normal listening level. If you see the cone of the speakers making large movements, immediately turn the volume down. This will protect the speaker and your human hearing from damage. Factory mechanical defects for a period of 1 year.
Excessive hard use (over-driving) and other damage caused during customer use is excluded from our warranty.

[planet10]

The only dMK7.3 that vents out the back is the narrow CGR, and they can be vented out the front, back, top or bottom. The current (free) drawing has 4 versions with wide vented out the side or front, and the narrow venting out the front or back.

THis drawing did go thu a significant number of revisions.

dave

[jjl]

I have only put <10 hours on the speakers so far.

The plan I have is the Slim classic GR dMar-Ken7.3 2v1 as pictured below. Is this not the best design for these speakers?

[planet10]

You have a lot of breakin to go.

That is 1 of the 4 CGRs in the free planset. Choice of wide or narrow and where the vent goes are both aesthetic & room related. The harder to build rectangular & trapezoidal enclosures in the paid planset have an edge -- same tuning but lower diffraction signature & with the trapezoid, the non-parallel sidewalls help with side-to-side standing waves. The CGRs will have a bit fatter bass because the vent is not as constricted.



dave

[chrisb]

Originally Posted by planet10

You have a lot of breakin to go.

That is 1 of the 4 CGRs in the free planset. Choice of wide or narrow and where the vent goes are both aesthetic & room related. The harder to build rectangular & trapezoidal enclosures in the paid planset have an edge -- same tuning but lower diffraction signature & with the trapezoid, the non-parallel sidewalls help with side-to-side standing waves. The CGRs will have a bit fatter bass because the vent is not as constricted.



dave

the traps for any driver (ie Fostex FF125WK as well) would definitely be my choice sonically and aesthetically, but they're not the easiest of builds, particularly for a newbie.

[jjl]

Still enjoying listening to the CG dMar-Ken73 but I have a set of the trap plans now and today went and got the 18mm ply. The joints are not a problem, I make guitars for a living and there is not one square joint anywhere.
It will be interesting to compare the two designs side by side when I finish them.

One question, the rubber seal under the 7.3 (where they are screwed into the baffle), is it sufficient, it appears very thin and am I looking for a perfect seal at this point.
If I need to make the rebate with a perfect base then I will use something other than a router or at least finish the joint better.
Thanks

[chrisb]

Originally Posted by jjl

Still enjoying listening to the CG dMar-Ken73 but I have a set of the trap plans now and today went and got the 18mm ply. The joins are not a problem, I make guitars for a living and there is not one square joint in any of them.
It will be interesting to compare the two designs side by side.
One question, the rubber seal under the 7.3 (where they are screwed into the baffle), is is sufficient, it appears very thin and am I looking for a perfect seal at this point.
If I need to make the rebate with a perfect base then I will use something other than a router.
Thanks

FWIW, while the cutting is not easier, I like to inset the back panel and stop the beveled port spacer blocks short by that depth - I think it makes for a more reinforced joint.



Mark's integral super-gaskets are thicker than they first appear and are more than sufficient

How exactly would you cleanly mortise the rebate if not by hand-held router/ CNC? Clearly I'm spoiled by having access to the latter for most of my machining, but occasionally ( after hours or on weekends) I'll need to do one by hand. For those I use a router with large diameter top bearing mortising bit and MDF pattern. It takes longer to jig up and align/ clamp the pattern in place than it does to actually route the rebate.

[planet10]

Originally Posted by chrisb

Mark's integral super-gaskets are thicker than they first appear and are more than sufficient

If you have ever seen the back of a Mark Audio drier without the super-gasket, imagine an additional injection molding step that fills the web and leaves an external gasket. The 2 raised rings are the same concept as those used in the solid rocket boosters of the shuttle.

dave