Topic: Jecklin Disc

[Brian Skalinder]

Great info on what it is and how it works:

http://www.josephson.com/tn5.html

Mike French's take and subsequent discussion about Jecklin disc v. spaced omnis:

http://www.taperssection.com/index.php?board=3;action=display;threadid=800;start=0

Mike's webpage with pics of his homemade J-disc:

http://homepage.mac.com/jmfrench/PhotoAlbum16.html (dead)

David Sanders' Jecklin disc webpage:

http://www.scitaper.com/jecklin.htm (dead)

edit by Moke, to add updates;

Razorbacks Disc built for Bean thread. good stuff;
http://taperssection.com/index.php?topic=48334.0

Bean's j-disc in the making by rAzOrBaCk
http://taperssection.com/index.php?topic=48334.msg624203#msg624203

New J-disc setup with 'the arm' by freelunch;
http://taperssection.com/index.php?topic=45413.0

Brian Skalinder's DIY disc:
http://taperssection.com/index.php/topic,95491.msg1271661.html#msg1271661

[goose]

An interesting read on the Jecklin disc.  I have seen that page before - good information.  Something I got out of it this time around was a comment which seems to say that ADK TLs (multi patterned switchable mics) should NOT be used for this setup.
------------
 C. The Jecklin disc in practice
I. Microphones for recording with the Jecklin disc

For recording with the Jecklin disc, sound pressure microphones must always be used, i.e. "real" sound pressure microphones. Mircophones with a switchable directional characteristic, insofar as they are designed as double diaphragm microphones, may not be used.
------------
Am I understanding that correctly or no?  

MOKE - did you notice any issues with the setup?  I know you liked that sound better than without the baffle.....what do you think of that comment?

[bluevolvo]

soooo...been wanting to try this technique out for a while, and finally had the epiphany needed to make it happen.  i figure if a headliner is good enough for sound dampening in an auto (i work in the [YIKES!] industry) it should work pretty well in this application - shout out to azdel forming!!  it's also green since this scrap didn't end up in a landfill somewhere for the next 1000 years or so - plus i'd like to think it turned out pretty well and looks almost professional...only the maiden recording will tell...

real...$250

jDOG...$15
(using updated specifications; flying authentic MK-012 omni's)





shopping at Michaels Arts & Crafts...priceless

for the technical minded, the mounts are custom by length (ok it's just a grade 8 socket head cap screw) and detachable for transport:



close of mount connection.  precision center drilled on lathe; stud welded one side; 10-32 tapped other:

[Brian Skalinder]

Looks great!    Post a small sample after the first outing, if you're willing.

[mfrench]

nice!
you should fabricate a few shorter variable length mounts, to allow getting the mics closer to the disc face. I doubt you'd want to go wider, but having a couple of setting steps inward would increase the functionality.

[bluevolvo]

...you should fabricate a few shorter variable length mounts, to allow getting the mics closer to the disc face. I doubt you'd want to go wider...

Right on, that's why I went the way I did for the flexibility.  Went back and forth on the dismensions before going with the "35/36cm" per Jecklin's publishing.

Because I went with the MK-012's ended up with the mount a little farther forward than I would have liked, but they're the only Omni's I have and don't see buying something else - just don't use that pattern much.

Does anyone have an opinion on LD's or Card's on this setup?  I've searched a bit on LMA but didn't find alot.  Seems I've heard/seen someone running 414's before (Brian?).

[bluevolvo]

Looks great!    Post a small sample after the first outing, if you're willing.

Thx - sure will post up.  Ran it for my fav windy city girl Katie Todd this past sat at Harvestfest.  It was in a tent right off the lake so it was wicked cold and windy.  They did put up the sides but I think it may have made it worse - tents have really crappy acoustics

Couldn't have asked for a better spot, the staff was cool about the rig and I got ~30' DFC, but it was on the "dance floor" they had set up, and being at the very back edge of the tent the stand was up in the corner of the "roof" if you can picture that.

My first thoughts on the listen are positive, but it is Omni's and I had a couple super-over-zealous kt fans directly to my left (like her foot was 1.5" from my stand leg).  I don't have a good plugin for crowd noise reduction.  Also been a while since I ran the MK's and the bass is...super fat/near over-swamped... at times - prolly shoulda had the 10db pads in there.

[mfrench]

I ran the ADK A51TL LD's with a larger disc (15") with fair amount of success, dating back quite a few years now (8 years ago?)
I've also been entirely successful, and extremely impressed with a CD size disc baffle, and miniature lav omnis.

The mini-disc caused me to abandon the official Jecklin theories, as being way to restrictive.
I've had some good results with baffled cardioid as well, but, haven't experimented to have anything of value to add, other than to say, its worthy of further exploration.

Now that I have 4-channel recording capability, I'm seriously thinking about running a pair of sub-cards with a minimal amount of off-axis toe-out, paired with a pair of omnis on the same disc. The reason for the minimally off-axis sub-cards would be to reach deeper into the typical chamber ensembles on stage U configuration.
Or maybe a three mic set up with a card/sub-card at 0º above or below the disc, mixed with the flanking omnis.

I suggested the tighter mic spreaders, because I think you'll really like the effect of the more isolated mics.

[mfrench]

Here are a few experimental versions that came about over most of a decade of playing with the baffled omni / j-disc / Jecklin Disc technique (not adding in the HRTF theory days);

4.5" micro-baffle:



9" mini-baffle:



15" LD baffle w/ ADK's:

[Gutbucket]

Looks like the real deal. Nice work.

Maybe obvious, but here's a general guideline I've noticed- small baffles work really well with narrow mic spacings, larger spacings need bigger baffles. I don't think the mic size itself is the critical factor in this case.  I believe Jecklin's recommendation of using only SDCs is primarily for their more consistent polar pattern.

I love Mike's square micro-baffle for it's minimal sight impact.  I think of it as a way to coincidently mount omnis (or nearly so). If you want the 'sound' of more spacing between the mics to record some time difference stereo information, then the size of the disk required grows rapidly to maintain the same amount of channel separation you'd achieve with the mics close to the surface of a small baffle. 

Sonically, I think it better to err on the side of either closer baffle spacing than necessary or a larger baffle than necessary. That beats having the mics too far from a smallish baffle for it to be effective, yet not far enough apart for decent A-B stereo.

[bluevolvo]

thx for the replys.  I'm a few years behind everyone trying this out...too much time on my hands with the economy and not enough taping this year...

Or maybe a three mic set up with a card/sub-card at 0º above or below the disc, mixed with the flanking omnis.

I suggested the tighter mic spreaders, because I think you'll really like the effect of the more isolated mics.

Personally I'm a big fan of the 414 MS/012 split omni's sound - just don't run the MK's solo so much.  I'd like to try the 414's or 184's on the tighter side - even tho it may not be status quo if I like the way it sounds then what the heck.

couple full track FLAC&mp3 singles here:

http://www.righteousdog.com/thisisnotyourspace/2009/10/11/katietodd/1255280118

(scroll down to reply/bottom it's not in the jCARD)

I love kt, but everytime I see her it feels like I need to tell the soundtech to hit her up with some extra de-esser...