Topic: Modded Superlux MA-90 Mount for Four Mic Rig

[stevetoney]

I thought people might be interested to read about what I did to make up a IMHO cool mount for my planned four mic recording rig once I get my refurbed capsules back from Schoeps.

I had been jonesing for a Grace Spacebar since they first came out, then a couple months ago Mark Burgin turned me onto these Superlux MA-90's.  At $104 each, these are about 1/3 the price of the Spacebar and have almost the same functionality.  Other than the fact that they were backordered, the only problem I saw with the MA-90 was that they are kinda wide for my everyday normal taping needs.  OTOH, I want to have the wider spacing option available to me when desired.  So, the logical solution was to order two of them and do some basic modding.  Here are some pictures of the modding that I did and the end results.

First I had to wait a month or two for the MA-90's to get off backorder.  Once they did, I ordered two of them and they arrived in a few days...





Here are a couple of pictures of what these looked like straight out of the box.






Notice that there are 'wings' at the tips of each bar that prevent the posts from sliding off.  So two basic mods were necessary to make these bars function the way I want them.  First I wanted to shorten one of the bars so that it's not so bulky and heavy to take to shows.  So, I used a hack-saw to hack both ends off of one of the bars.  Once I did that, the posts slid right off the ends.

(Note that the posts click through a series of detente's spaced one cm apart on the bar, so the posts don't slide completely freely along the bar.  Although with the 'wings' in place, it's impossible to lose the posts, I don't anticipate losing posts being an issue after the wings have been removed, especially since there's a bottom thumbscrew that fastens the post down tightly onto the bar.)





The bars are aluminum, so very easy to cut and file off rough edges.





Next, since the 'wings' on the longer bar impeded sliding the other posts on, I needed to cut those off.





Here's a couple of shots of the longer bar after sliding the posts off.






OK, that's pretty much all the modding I needed to do. 

To mount the mics and get them in the exact coincident angle you want, all you need to do is set the microphone at the zero degree position, pointing straight forward.





Then rotate the post the appropriate number of detente clicks to get the necessary angle.  In this case, I've rotated the mics three clicks...fifteen degrees each...for a total of 45 degrees necessary for DIN, DINa, or NOS spacing. 

(Although in this picture, I've rotated the microphone as far as it will go, it's no problem to rotate farther than 45 degrees.  You simply rotate the post more at the start so that the zero degree position allows for more than three detente clicks.  Also note that you don't HAVE to put the mics at the 15 degree detente clicks, you can put them in between each 15 degree click if desired.)





The thumbscrew in the front tightens the post to prevent rotational movement and the thumbscrew on the bottom (which can't be seen very well in this picture, but you can see well in several other shots) tightens the post from movement laterally along the bar.





Although one of my capsules is missing because it's in Germany being refurbished, this is what the four mic mounting arrangement might look like, with Omni's on the end and DIN cardioids in the middle.  Generally, I think this is a fairly lightweight and solid set-up.  I'm not sure at this point about how this will do...say...12 feet in the air with an umbrella during a breezy day, but then again that's a problem we all have in those conditions.






Finally, here's what the shorter bar ended up looking like...




A final comment is that the above photo shows the microphones in DIN position (20cm spacing at 90 degrees coincident angle).

So, as you can tell from the pictures, the indexing is a little goofy on these bars, since the numbering starts at 1 instead of 0 and since the zero point is not in the dead center of the bar.  You just need to realize that there are 5 cm of spacing between the 1's and adjust.  This means that if there were 0's on the scale, the zero's would be 3 cm apart from each other.  So, to calculate the spacing, first add the two numbers together where the mic capsules are located and then add 3cm.  (Actually if you look closely at the picture, the mic capsules are close to the '9', so the spacing is probably closer to about 21cm in the picture.)

I hope someone finds this useful.  I'm pretty excited about this setup.

[Teen Wolf Blitzer]

Hey nice work dude.  I'm loving my bar thus far. 

[tgakidis]

Nice job Steve! 

[dactylus]

Thanks Steve!!  I too wanted a "four mic" Grace Spacebar when they first came out and I have resisted purchasing one up to this point.    

This more economical choice looks pretty good to me too.  Let us know how it goes once you get it into the field.

[OOK]

Wow that is sweet................T+

[Teen Wolf Blitzer]

I found the ball bearing is positioned on top of a spring in the rotation angle section of the mic mount - this provides the 'click' on angle detents: was somewhat easily re-inserted, but for those buying/using these bars - DO NOT unscrew the rear set screw too far or you might lose your 'bearings'! 

[F.O.Bean]

nice steve

[ArchivalAudio]

Damn! that is pretty darn sweet
thanx for sharing!
 

[uh huh]

that is sweet indeed   
i've done similar setups with the Sabra Som 1m bar and 4 mounts.  though in my case i needed the length (that's what she said) for wide A-B.  Sabra Som has no markings whatsoever to assure you're lined up, distance-wise or the toe between capsules. 
anyone know if Superlux will sell their bar with 4 mounts?

[n3mmr]

Just a few comments on this very old thread, since there is a link here from at least one recent thread:

The "distance markers" on the front edge are NOT at 10 mm intervals!
And the "1" marks are not at some well chosen distance from one another!
The marking interval isn't constant, even. It is somewhere between 13 and 16 mm it seems.
The distance detents are a nuisance, not helpful.

I have two if these myself, and I like them anyway! Once you have sorted out what the distances are, the markings ARE there. The distance detents can be filed/sanded/polished away, you should do that since they are not at very regular intervals.

When setting the mic angle: press the clamp post down, very hard, before tightening the angle set screw, otherwise it will not be stable.
I recommend disassembling the clamp posts, filing off the rotation stop, removing the spring and ball and replacing those with an approx 0.5 mm rough surfaced washer of slightly smaller outer diameter than the post circumference.

The "Wings" are eyelets for suspending the t-bars from above. To be useful, there should be four suspension points, arranged in a trapeze shape, or the suspended bar will not be very stable. So there's no reason to keep them. My advice is to file them off, drill and thread a 3/8 " unc in the same spot and put a thumb screw asa n end stop. You can then put two short t bars at the ends to provide a stable suspension.