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Gear / Technical Help => Microphones & Setup => Topic started by: stevetoney on March 09, 2010, 12:56:49 PM

Title: Blumlien Question
Post by: stevetoney on March 09, 2010, 12:56:49 PM
I was checking out a sample of a recording made with Schoeps Figure 8's in Blumlien.  This particular sample sounded very thin from capsules that usually are very full bodied and warm sounding.  The thin sound got me to thinking about applications of the Blumlien technique and led me to this question. 

Is it possible that phase cancellation would occur through a Blumlien pair, say, if you're DFC and the sound engineer mixed the PA speakers in mono (i.e. with the same thing coming out of both speakers)?  I'm just wondering why they would sound thin from a pair of capsules that have such a full bodied character...although of course it could just be how the PA sounded at that particular show.

Steve
Title: Re: Blumlien Question
Post by: mfrench on March 09, 2010, 01:12:22 PM
most fig8 specs that I've seen show a reduced bass response.
I've only used an ADK A51tl pair, and a Royer stereo ribbon mic, and they both had reduced bass spec.
Title: Re: Blumlien Question
Post by: Craig T on March 09, 2010, 01:14:20 PM
mk8's, like most fig8 caps, have significant LF rolloff.

http://www.schoeps.de/en/products/mk8/graphics
Title: Re: Blumlien Question
Post by: MarkE on March 09, 2010, 01:25:15 PM
No doubt there is a huge difference in your low end with figure 8. I always boost my low end in post when I used Bluemelin pattern. After tinkering with it, it sounds incredible in alot of said recordings..
MarkE
Title: Re: Blumlien Question
Post by: macdaddy on March 09, 2010, 04:45:19 PM
I find that blumlein gets rid of alot of the low stuff that is a distractor in the recordings. I like the idea that if I run blumlein, the recording is ready to go, whereas with other setups, a hpf is often times needed or (desireable). IMO, the less post-processing, the better.
Title: Re: Blumlien Question
Post by: boojum on March 09, 2010, 06:06:24 PM
I am using Chris Johnson's (Busman) Blumlein ribbon which picks up a pretty good bass line from an unamplified stand-up bass.  I would post an MP3 of a track but the 512K limits kind of precludes that.  I can recommend the mic.  I like it, it gives a good recording of what it hears and is very reasonably priced.  Kudos to Chris.

Tapermark has some tracks up on TTD if you care to download them.  He could tell you which have the best examples of bass.


Cheers
Title: Re: Blumlien Question
Post by: SmokinJoe on March 09, 2010, 07:21:54 PM
The rolloff like other said, but also it's absolutely critical that you source be "in front of you" contained within +/- 45 degrees so that you aren't picking up equal and opposite in the rear lobes, like you said.

If you run close to stage, flush with the PA, then you will pick up on stage stuff with the front lobes, and PA with the rear lobes, and yes, you will get cancellation.  If you run in the middle of a reflective room, you will get PA in the front lobes and reflections in the rear lobes, and cancellation.

So it's a good tool, but it has to be used correctly.  I haven't got the hang of it myself.  I've probably tried it 6 times, and got 2 keepers and 4 throwaways.
Title: Re: Blumlien Question
Post by: stevetoney on March 09, 2010, 08:49:10 PM
The rolloff like other said, but also it's absolutely critical that you source be "in front of you" contained within +/- 45 degrees so that you aren't picking up equal and opposite in the rear lobes, like you said.

If you run close to stage, flush with the PA, then you will pick up on stage stuff with the front lobes, and PA with the rear lobes, and yes, you will get cancellation.  If you run in the middle of a reflective room, you will get PA in the front lobes and reflections in the rear lobes, and cancellation.

So it's a good tool, but it has to be used correctly.  I haven't got the hang of it myself.  I've probably tried it 6 times, and got 2 keepers and 4 throwaways.

This is the type of input I was looking for and you're starting to confirm the thoughts that I had.  So, do you know what the 'rule of thumb' is for how you use Blumlien or in what situation's best to use it?  I'm thinking best used in unamplified scenarios, where you fairly centrally locate the mics?!?
Title: Re: Blumlien Question
Post by: SmokinJoe on March 10, 2010, 12:36:07 PM
Somebody on this board (VWMule?) has run LSD2 blumlein outdoors at Wanee amphitheater with great results.  Outdoors you normally have no reflections, so in my mind "add that to the good list".

I ran Blumlein here http://www.archive.org/details/dtb2007-11-13.lsd2.flac16f and that is what I consider one of my "successes".  It's an old opera house, pretty reflective, but I was hung off the balcony rail, right in front of the little "balcony wall" so I think perhaps that smothered some of the reflections from the main walls in the room.

Another "success" is this one, where I flipped the switches from XY cards to Blumlein half way through the show.  In this case, the PA and stage were within that +/- 45 degree rule, and the noise from the front was loud enough that overpowered whatever was reflecting back. http://www.archive.org/details/rads2007-06-20.lsd2-sbd-mix.flac16f

If you have a bunch of chatty people behind your mics, then the back lobes pick them up clearly, whereas something like cardioid XY would tend to reduce them, so in my mind that is not an ideal use of blumlein.

One of the classic uses of Blumlein I believe is for a bunch of bluegrass players that circle around the mic.  Some are on the front lobe, some are on the back lobes (phase inverted), but there is nothing to cancel out.

The times I've tried to run Blumlein "from the section" next to the SBD in a big room have all been "throw aways".

That's my observations.
Title: Re: Blumlien Question
Post by: stevetoney on March 10, 2010, 01:07:59 PM
Somebody on this board (VWMule?) has run LSD2 blumlein outdoors at Wanee amphitheater with great results.  Outdoors you normally have no reflections, so in my mind "add that to the good list".

I ran Blumlein here http://www.archive.org/details/dtb2007-11-13.lsd2.flac16f and that is what I consider one of my "successes".  It's an old opera house, pretty reflective, but I was hung off the balcony rail, right in front of the little "balcony wall" so I think perhaps that smothered some of the reflections from the main walls in the room.

Another "success" is this one, where I flipped the switches from XY cards to Blumlein half way through the show.  In this case, the PA and stage were within that +/- 45 degree rule, and the noise from the front was loud enough that overpowered whatever was reflecting back. http://www.archive.org/details/rads2007-06-20.lsd2-sbd-mix.flac16f

If you have a bunch of chatty people behind your mics, then the back lobes pick them up clearly, whereas something like cardioid XY would tend to reduce them, so in my mind that is not an ideal use of blumlein.

One of the classic uses of Blumlein I believe is for a bunch of bluegrass players that circle around the mic.  Some are on the front lobe, some are on the back lobes (phase inverted), but there is nothing to cancel out.

The times I've tried to run Blumlein "from the section" next to the SBD in a big room have all been "throw aways".

That's my observations.

Joe:

Thanks for the details.  I've had success running Blumlein too.  In fact, I was getting what I considered to be inconsistent results with the pair of U89s that I was using last summer until I put them in Blum.  Once I did that, I started getting better sounding recordings that were more consistent.  However, all of these were outdoors during the summer music festival season, so I think that experience is consistent with the feedback that you've provided.

Steve
Title: Re: Blumlien Question
Post by: H₂O on March 11, 2010, 04:18:13 PM
I ran Blumlien once and thought it sounded pretty good:
http://www.archive.org/details/brew2009-02-06.mk8.2488.flac24 (http://www.archive.org/details/brew2009-02-06.mk8.2488.flac24)

 
Title: Re: Blumlien Question
Post by: capnhook on March 11, 2010, 04:39:28 PM
I ran Blumlien once and thought it sounded pretty good:
http://www.archive.org/details/brew2009-02-06.mk8.2488.flac24 (http://www.archive.org/details/brew2009-02-06.mk8.2488.flac24)

chatty, though..
Title: Re: Blumlien Question
Post by: SmokinJoe on March 11, 2010, 06:20:07 PM
chatty, though..

I've taped the Brew about 25 times, and the crowd tends to be chatty.
Title: Re: Blumlien Question
Post by: H₂O on March 11, 2010, 06:31:17 PM
It was a very chatty show and the venue isn't the best to tape in
Title: Re: Blumlien Question
Post by: mfrench on March 11, 2010, 06:41:17 PM
This is a sample of a David Hykes concert that I recorded in Blumlein stereo. This is at the end of the show, after the show, where he was working with the audience trying to teach them harmonic chanting.
David Hykes is a renowned harmonic vocalist, throat singer, who has trained in tibet, nepal, mongolia, and other himalayan buddhist regions where the monks chant in split vocalizations, and throat singing.
The setting is in a small intimate film editing studio, with an audience of 35 people, and very respectful.
The mics are at the stagelip, in front of David, who is about 3'+ back from the mics on a 6' deep stage.
The audience is about ~5' behind the mics - the mics are at about 2' high, and everybody is seated on the floor on pillows, with a 6" stage height.
you can save yourself a bit of time by going to about 1/2 into the sample;
http://ia301119.us.archive.org/3/items/dhykes2006-01-18_otp_flac1644/dhykes2006-01-18_otp_t08.flac1644_vbr.mp3

there are other samples of David singing and playing a svarmangalim (indian zither that creates a droning effect), and a Tabla player, if anyone is interested in the msuic.
Title: Re: Blumlien Question
Post by: kbergend on March 15, 2010, 08:58:15 PM
Somebody on this board (VWMule?) has run LSD2 blumlein outdoors at Wanee amphitheater with great results.  Outdoors you normally have no reflections, so in my mind "add that to the good list".

I ran Blumlein here http://www.archive.org/details/dtb2007-11-13.lsd2.flac16f and that is what I consider one of my "successes".  It's an old opera house, pretty reflective, but I was hung off the balcony rail, right in front of the little "balcony wall" so I think perhaps that smothered some of the reflections from the main walls in the room.

Another "success" is this one, where I flipped the switches from XY cards to Blumlein half way through the show.  In this case, the PA and stage were within that +/- 45 degree rule, and the noise from the front was loud enough that overpowered whatever was reflecting back. http://www.archive.org/details/rads2007-06-20.lsd2-sbd-mix.flac16f

If you have a bunch of chatty people behind your mics, then the back lobes pick them up clearly, whereas something like cardioid XY would tend to reduce them, so in my mind that is not an ideal use of blumlein.

One of the classic uses of Blumlein I believe is for a bunch of bluegrass players that circle around the mic.  Some are on the front lobe, some are on the back lobes (phase inverted), but there is nothing to cancel out.

The times I've tried to run Blumlein "from the section" next to the SBD in a big room have all been "throw aways".

That's my observations.

I really love the vivid stereo image you get with Blumlein and use it whenever it makes sense, which is generally when I can set up close enough to a group of musicians to convey a sense of being in the middle of the action.  It usually provides a very realistic soundstage whether listening through speakers or headphones.  Some recent examples:

bluegrass circle jam at 2010 Folk Alliance, circa 4:30 AM (unamplified)
http://thespps.org/mp3s/partners/sppsshowcases/fa2010/mp3/bluejam2010-02-18.mp3f/bluejam2010-02-18t09.mp3

Della Mae doing Gram Parsons at 2010 Folk Alliance (unamplified)
http://thespps.org/mp3s/partners/sppsshowcases/fa2010/mp3/dellamae2010-02-18.mp3f/dellamae2010-02-18t04.mp3

Session Americana's 2009 holiday shows at Club Passim
http://tapers.org/mp3s/sessionamericana2009-12-12.matrix.mp3f/sa2009-12-12d1t03.mp3

The above recordings were all made with a Blumlein pair of Milab DC-196s placed right in front of the performers (actually in the middle of a circle of 9 players in the first sample).  In the first two recordings, the main Blumlein pair was supplemented by Milab VM-44 Links configured DIN on the same stand and mixed in at about -12dB to add a little depth to the soundstage.  In the last, a mono board feed was mixed in at about -6dB to boost the vocals so the separation is actually a little diluted.  I did pick up a lot of crowd noise from the enthusiastic audience seated behind the mics in the Club Passim recording, but for me that just adds to the feeling of being there.  Thankfully the audience mostly refrained from talking to each other during the songs.

Never had a problem with deficient bass myself, but judging from their plots the DC-196s have much less LF rolloff as figure-8s than most multi-pattern mics.

I've never even attempted running Blumlein in a typical FOB situation at a rock club or theater show, can't imagine it would sound very good for the reasons Joe alluded to.  I'm actually surprised his Derek Trucks show sounds as good as it does, but I suppose it's not much different from running XY if there's nothing in back of the rear diaphragms.

Yet to try it outdoors, but I plan to change that this summer! :)
Title: Re: Blumlien Question
Post by: ducati on March 16, 2010, 12:32:58 PM
This is a sample of a David Hykes concert that I recorded in Blumlein stereo. This is at the end of the show, after the show, where he was working with the audience trying to teach them harmonic chanting.


I found your Hykes recordings not long ago when browsing LMA for mic samples.  I have very much enjoyed them.  Thank you for sharing the shows!!