Gear / Technical Help => Microphones & Setup => Topic started by: m326 on November 21, 2020, 06:47:50 AM

Title: Ambient sound & Jecklin disc for quad?
Post by: m326 on November 21, 2020, 06:47:50 AM
Hi all, I know what end result I want - but I don't know how to get there.

Let me explain.. I like relaxation recordings, especially nature based ones but often the music puts me off. I want to be able to record my own nature sounds with the idea of having random bird calls from various places in the room, a rustling in the leaves here and there, an animal scampering... you get the idea. Quiet and peaceful, no music & no dogs barking!

With my Dr100 I have made some progress with dual stereo recordings, Reaper is set up for 5.1 audio - but only using 4 channels. The resulting .wav file is then converted to .mp4 which then gets copied to my NAS and played through Plex to my Sonos PlayBar & 2 surround speakers. Not an ideal process or setup for outputting small signals. I would really like to have more discreet speakers placed further apart, any opinions or alternative (budget conscious) hardware recommendations on this?

I have made a Jeckin Disc which seems to work well for me with good stereo separation using a pair of EM172 omni's.

This Christmas I'm getting a Zoom F6 recorder and am contemplating getting a set of 4 matched EM272 XLR microphones. Beings the Jecklin Disc was successful, has anyone tried to make a quad version of it? It seems to be an obvious thing to try - or are there better solutions out there?
I would think that, looking downwards onto the discs & seeing a cross, the microphones would need to be located much more centrally and perhaps because of this, the discs need not be so big? In my current disc, the mic supports are removable which means it packs flat, a quad version would be much bulkier and wind noise protection will add further to this, perhaps reducing portability.

Thanks in advance for your comments and help, I'm fairly new to the audio scene.. technical wavelengths go straight through my skull  ;)
Title: Re: Ambient sound & Jecklin disc for quad?
Post by: heathen on November 21, 2020, 11:22:28 AM
It seems like you're asking about playback setups and recording setups.  I'm pretty much just a two channel stereo guy when it comes to playback so I can't be much help there.  With regard to the recording setup, have you considered an ambisonic microphone?  If the Zoom F6 has an ambisonic mode like the F8, then something like the Sennheiser ambisonic mic would be a nice fit because the Zoom ambisonic mode is specifically designed to work with the Sennheiser mic ( it will also work with other ambisonic mics, though some mics like the Core Sound TetraMic don't let you take full advantage of the Zoom ambisonic mode capabilities).

For multiple mic setups, maybe look into things like IRT Cross and other arrays specifically intended for capturing ambience.
Title: Re: Ambient sound & Jecklin disc for quad?
Post by: m326 on November 22, 2020, 04:01:29 AM
Thanks for your reply heathen.
Although ideal, the Sennheiser mic is way out of my budget. The IRT cross idea is something I will research.. but again cost of mics for what is an occasional hobby idea would be a limiting factor, hence my more DIY approach.
Title: Re: Ambient sound & Jecklin disc for quad?
Post by: kuba e on November 22, 2020, 09:53:47 AM
I like primo Em172. I think they are great for nature recordings. I don't know if you have another use for FX6. If you only use it with Em172, maybe a Tascam Dr2d + Church audio preamp would suffice.

It is good idea to use four baffled omnis.  EDIT: Cross baffle with omnis in the corners is good idea. It should be similar to four coincident directional microphones. Also when the omni is placed in a corner, the direct/reverberant sound ratio increase and also the S/N ratio increase (the directivity and the improvement is only for frequencies where the baffle works). It's nicely explained by Gutbucket here https://taperssection.com/index.php?topic=186619.0 (https://taperssection.com/index.php?topic=186619.0)
A baffle as a four sides box should be also good. When you use a box, you introduce a time difference into the signals.
The smaller the baffle, the higher frequencies will get around it. The larger the baffle, the lower frequencies are blocked and also, in the case of a box, the greater the time difference.

Wait if Gutbucket joins. He experimented with 4 baffled microphones and also his oddball technique is very similar to it. I think he is also one of the few here who has done recordings for surround playback. Once, when I was inspired by Gutbucket and his oddball microphone technique, I pinned 4 microphones on me - a pair on the my shoulders, one center forward, one center backward. It was at a concert. But I wasn't in a good place, the microphones on the shoulders hadn't enough separation to create space for mixing in the center microphones (I am mixing only for stereo playback). But I would like to try 4 baffled microphones again. I need to get some bigger inconspicuous box.

Oddball microphone technique:https://taperssection.com/index.php?topic=191953.0 (https://taperssection.com/index.php?topic=191953.0)
I can't find it now, but I know that someone sent a picture from a recording studio - a large box of transparent plastic that served as a baffle, with musicians sitting around.
Title: Re: Ambient sound & Jecklin disc for quad?
Post by: m326 on November 25, 2020, 04:32:07 AM
Seems the EM172 stocks are depleted now, EM272 being an almost direct replacement.
I originally bought a Clippy EM172 stereo pair with 3.5mm jack plug and was quite impressed by them so when I bought my DR100 I got a XLR pair of 172's with XLR.. another improvement in sound.
The F6 has been purchased and wrapped for Christmas - so no changing that now. Must admit though, I'm a bit concerned about the reports that say the DR100 has quieter preamps.

Thanks for the info and links, I'm trying to take it all in.
Over the holiday period I'm going to make and try a cross baffle, I have all I need for it but I need to think of a way to make it fold flat for more portability.. 3D printer to the rescue no doubt.
Title: Re: Ambient sound & Jecklin disc for quad?
Post by: kuba e on November 25, 2020, 10:18:10 AM
I mixed two things together. The baffle may be rigid - 'boundary microphone' and the baffle may be damping - 'Jecklin disc'.

'Boundary microphones' in corners of a cross.  Edit: I thought more about it. It should work. The cross should be 90 deg (theoretically, problems arise at angles lower than 45 deg) and the microphones have to be placed exactly in the corners to avoid unwanted reflections. It's interesting. When I find plexiglass, I'll try it. A rigid baffle as a box or sphere is also fine. In all cases, the boundary microphones must be placed directly on the baffle surface to prevent unwanted reflections. And the rule of amplification and the improvement of the direct/reverberant ratio should apply to the frequencies at which the baffle works. Which can be a disadvantage when the baffle size is small. Because only the high frequencies are amplified, the low frequencies remain unamplified.

'Jecklin disc' as a cross. The material of the baffle must dampen a lot to prevent reflections. Then you don't have to put microphones right in the corners, they can be in the space between the baffle. The farther from the baffle, the smaller its influence. I think Jecklin discs in the cross is fine.

The third possibility is that you install the omnis in spheres, this will increase their directionality. When you have individual omnis in separate spheres, you can easily place them in space.

For a basic idea of ​​what frequency the baffle will affect, it is possible to use an approximate relationship - the baffle will affect sound wavelengths that are as long as the baffle dimension and shorter. E.g. a baffle of 60 cm will start to affect frequencies from 570Hz (wavelength 60 cm) and higher.

I am writing here what I have read here on the forum. Try waiting for someone who has experience with it to advise more.

You have a very nice present for Christmas!