Ozzy & Plant with 2 mics taped together.

[wallace]

That's what I would guess..

BTW, has anybody seen the Grateful Dead Movie?? They've got some weird stereo mics for all the vocals.

[not_so_new]

I have seen times when remote guys will use two mics for a sports broadcast to help phase cancel the crowd noise from the talent.

That said I am pretty sure that the issue was not for controlling the crowd noise it was the lack of splitter snakes back in the day to feed the tracking channels and the FOH board (and forget about foldback, what is that?). This was a pretty common thing from live recordings in the 60's and 70's, I can't imagine every recording engineer used the same trick over and over again. I would think they were forced into it by necessity.

I could be wrong, I was not there.

[andychamp]

There was a thread about that same subject once on the alt.audio.pro.live-sound newsgroup. Try a google groups search.
I remember one of the many explanation offered had to do with feedback suppression by phase inversion on one of the two mics.

[themaidsroom]

i've seen some footage of jim morrison recording where it looks like he's
got both a 57 and a 67 in front of him........

i recorded someone the other day with both a 251 and a sm7 ..........
once the phase was right....it sounded good......


- jack

[seriousfun]

Originally Posted by andychamp

There was a thread about that same subject once on the alt.audio.pro.live-sound newsgroup. Try a google groups search.
I remember one of the many explanation offered had to do with feedback suppression by phase inversion on one of the two mics.

Bingo!

[not_so_new]

Originally Posted by seriousfun

Bingo!

Not competely sure about that but you could be right. I was always under the impression that no one hade come up with the idea of isolated splitter snakes at the time.

I guess I could be wrong but.....

[seriousfun]

From The Wall of Sound :

A major improvement in the quality of the vocal sound is due to the use of differential microphones. Each singer has a perfectly matched pair of Bruel and Kjaer microphones hooked up out if phase, only one of which he sings into. Any sound which goes equally into both microphones is canceled out when the two signals are added together. Therefore leakage of instruments and background noise into the vocal channel are minimized

[not_so_new]

Yep as I said above in my first post this (or was) a pretty common thing in live sporting events to cut out crowd noise so I guess I am not too surprised.

I do remember reading someplace about all the problems The Who had recording Live At Leeds and I thought I read that they did not have splitter snake "technology" yet and that was part of the problem.

Does anyone know when the first splitter snakes showed up?

Again I could very well be wrong about the above as well.... I was not there either.

[7 Hz]

Sorry, how the heck does the phase thing work?

The mics are taped together... capsules close... you can't just 'sing into one' - you are singing into both! So invert the phase and the VOCAL dissapears! Surely this is common sense! The only way it would vaguely work is to have the second (cardioid) mic tapes on backwards so it pointed to where the unwanted noise was coming from, but then it would be a juggling act to get it to cancel, what with off-centre frequency responce anomolies, it would be hard / impossible!

Also, mic splitting isn't new technology.

The only sane explanation is the extra mic is for the recording rig...

Or am I missing something?

[not_so_new]

Also, mic splitting isn't new technology.

I agree but I don't know exactly when it was first thought up? It looks easy with 20/20 hindsight but many things in the world are slap on the head "why didn't I think of that" ideas. Isolating the recording split off the snake might just have been one of these ideas.

About the out of phase thing... the idea is to only sing into one of the mics not both. Stage volume including feedback would show up at each microphone in almost equal amplitude but not in equal phase. The singers voice however would be higher in amplitude in only one mic and hence would not be canceled, at least not as much. In theory a great idea but in practice... that can be another matter.

[Kirk]

Originally Posted by 7 Hz

Sorry, how the heck does the phase thing work?

The mics are taped together... capsules close... you can't just 'sing into one' - you are singing into both! So invert the phase and the VOCAL dissapears! Surely this is common sense! The only way it would vaguely work is to have the second (cardioid) mic tapes on backwards so it pointed to where the unwanted noise was coming from, but then it would be a juggling act to get it to cancel, what with off-centre frequency responce anomolies, it would be hard / impossible!

Also, mic splitting isn't new technology.

The only sane explanation is the extra mic is for the recording rig...

Or am I missing something?

When you see two mikes taped together it probably is for the recording rig. But look at pics of the Grateful Dead in the mid-70's - you'll see two identical mikes spaced maybe 9 inches apart, on a special mike stand. That's the phase-cancellation situation. The mikes had to be closely matched. The reason they needed to do this was because during that period they were using a colossal specially-designed PA that put all instruments and vocals into dedicated speakers (that is, each instrument had its own dedicated stack) BEHIND the band, which required special feedback-handling techniques.

Also interesting, each member of the band had his own volume control for instrument and vocals, where appropriate. The FOH guy had no control over anybody's volume.

[Gregg Sartiano]

Zappa's band in "200 Motels" movie had a 2 mic thing going.

That movie is a TRIP!!!!

CENTERVILLE!!! A REALLY NICE PLACE TO LIIIIIIVE!!!

CENTERVILLE!!! IT'S REALLY NEAT!!!

[gdeoliveira]

They were supposed to kill feedback. Two microphones were wired out of phase. In close proximity like that will cancel each other out if the same signal, with the same strength is applied to both. If you sing into the closest one, your voice won't be canceled out (that signal being much stronger than the one going in to the second mic). The sound returning from the pa speakers though would enter both mics at pretty much the same level and at the same time, causing phase cancellation and avoiding feedback.

Try it. It really works. Nowadays, the intelligent graphic equalizers will solve the issue in a more elegant way..

[valleysound]

As with the Grateful Dead and the "Wall of Sound", the PA behind them was also the monitor system. There's no way to get vocals up to concert level in this manner with only one mic, so there were two wired out of phase or polarity, I don't remember the correct term.

[The Byre]

I always have to smile when this topic comes up.

The fact is that recordings before the age of the proper remote truck with all the toys were done with what ever the sound or camera crew had - and we just did not have good spitter boxes. If you look at the film footage again, you will see that there are two mics on the cabs as well.

[kojak]

yes, the two mic taped together thing is indeed to eliminate feedback, as monitor systems were in their infancy (if they were used at all), and most times there was either the PA on its own, or very large sidewash systems. if you look at old footage of the stones, mick can be seen using this technique.

also, as a sidenote re: the grateful dead's massive system...everyone did in fact have their own stack behind them, but the reason why the FOH guy had no control over anyone's sound was because there WAS no FOH guy. there were people giving feedback to the band so it remained more or less balanced, but there was no console to be wrangled. (this VERY large system was run completely on tube powered amps as well, making it the most labour-intensive PA to ever be built, and ultimately led to its demise due to the unbelievable cost involved in its upkeep.)

[Svens]

An Insider's Look at the Grateful Dead's Wall of Sound [audiojunkies]

[Remoteness]

Originally Posted by not_so_new

Not competely sure about that but you could be right. I was always under the impression that no one hade come up with the idea of isolated splitter snakes at the time.

I guess I could be wrong but.....

Originally Posted by The Byre

I always have to smile when this topic comes up.

The fact is that recordings before the age of the proper remote truck with all the toys were done with what ever the sound or camera crew had - and we just did not have good spitter boxes. If you look at the film footage again, you will see that there are two mics on the cabs as well.

I'm with you folks on this one.
Because of the fact that this was during a live performance film shoot most likely was dual mic'ing technique due to the fact that mic splitters were not available at the time.

I still double mic live shows when it's necessary, especially jazz dates when I want to use a better mics for horns than normally used for live sound.

[drtechno]

I used that technique before,

I call it the '57 special,
the 57's were used for recording and the other for PA.

x/y a set of 57's behind drummer

57 + ribbon mic (octava) on guitar and bass

sax '57

pg 52 on kick, 57 on snare


it gives it an old school sound feel to it. Its great on blues bands

though I think it would be interesting to do it again, with addition of tracking monitor mixes and PA 2-track for to subtract some of those sounds out or be able to tweek the bleed phase a little ( i love expiramentations)


I have to look at my notes of the dead's mad scientists left me to see, but;
here's a happy picture of the wall of sound:

I will build another "home plate" and the huge bass string thing too.... someday soon.

[Seanfir]

HI there!
Been wanting to get on this site for years...
the phase things didn't really work all that great in reality. The problem is that when the mics are not being covered they work great, but when they are covered one picks up more background noice because it's blocked by a human! They they feedback worse than if you just used one mic! A neat idea, but not as practical as what we use now... and the wall of sound was not an all tube PA, as mentioned, they used exclusively Macintosh Mc-2300 600 watt solid state amps. They were 80 pounds a piece at least. And they used a LOT of them... when the wall of sound rig was taken down, Garcia snagged a small pile of the amps and EVER since that time, you could see the two indigo dials of the Macintosh in his iconic rack. There is a classic pic I have of the woodstock sound rig in which there is obvious cable splitting going on... as there would have had to have been. I did hear, however, that LIVE DEAD was recorded using seperate record and PA mics as it was the first 16 track live recording and I am sure their sound desk (bought from bob heil, and one of the first ever in live sound) didn't have a splitter.

[Hamburg]

For what I know it was made for reducing pa- feedbacks. Both mic signals were simply added- but one mic was phase- reversed. The singer was singing in only one microphone....... so he was good audible on the pa system. The amplified signal from the pa arrived at both capsules at nearly the same time- one mic was out of phase and the signal was almost gone and didn`t produce a feedback. That´s what I know- and sorry for my bad english! Best from Hamburg- Rolf

[edwinhurwitz]

Originally Posted by Seanfir

HI there!
Been wanting to get on this site for years...
the phase things didn't really work all that great in reality. The problem is that when the mics are not being covered they work great, but when they are covered one picks up more background noice because it's blocked by a human! They they feedback worse than if you just used one mic! A neat idea, but not as practical as what we use now... and the wall of sound was not an all tube PA, as mentioned, they used exclusively Macintosh Mc-2300 600 watt solid state amps. They were 80 pounds a piece at least. And they used a LOT of them.

This is pretty close. There were 89 2300s and 3 3500s. The 2300s weighed 128 lbs and it was a Grateful Dead crew rite of passage to wrangle them by yourself, women included, often when one was tossed your way. The 3500s (mono tube amps used for the tweeters) weighed 125 lbs.

I love the sound of the old Macs. My bass rig in high school in the 70s was powered by a 2015 that is functionally pretty similar to the 2300 with 105 wpc and it has been abused like crazy and still works well (although I finally got it recapped last year) with a pair of ProAc Studio 100s these days. It looks like it has been dragged behind a truck from California to Colorado, but is functionally perfect. My MC30s also sound very sweet.

The real downfall of the differential mic'ing technique was less that it was not effective at curbing feedback but more that you had to sing with the chosen capsule practically down your throat and it really never sounded all that great.

I talked to Bill Kreutzmann briefly about his take on the Wall of Sound experience and he hated it. All the sound was flying over his head and he couldn't hear any definition. He was also a little leery of the huge mid/tweeter cluster swinging over his head. However, it's possible he had the worst seat in the house.

[gingataff]

I remember an interview with Ozzy a long time back where he was asked about the two mics. He said that at the time he thought two mics would be louder than one.

[The Byre]

Once again, Gearslutz answers the age old philosophical question 'Does a group of guys who don't know what they are talking about, know more or less than one guy who does not know what he is talking about?'

[tourtelot]

Originally Posted by The Byre

Once again, Gearslutz answers the age old philosophical question 'Does a group of guys who don't know what they are talking about, know more or less than one guy who does not know what he is talking about?'

Brilliant!

D.

[Brownsound]

I am surprised it hasn't been adopted by any of today's hipsters as a "look".
Or any of today's engineers as a "joke"...

[philper]

My friend Mindy Bagdon made the iconic 1980's punk movie "Louder Faster Shorter", all shot at the old Mabuhay Gardens club in SF. In the film the singers have not two but THREE mics taped together, a "bouquet" of mics gnarled together with a lot of paper masking tape. Why? Because they didn't know that transformer splitters even existed (they did, they just weren't aware of them), and they could not get the FOH, the monitor mix and the recording mix to be clean all at the same time if they Y'd anything (that particular building had awful power and was barraged with RF from a local TV station's transmitter link). The "bouquet" was the solution....you know...the audience was in and clamoring, the bands were people who were not much disposed to "taking direction", the show had to go on....

phil p

[Remoteness]

Love it!

Originally Posted by philper

My friend Mindy Bagdon made the iconic 1980's punk movie "Louder Faster Shorter", all shot at the old Mabuhay Gardens club in SF. In the film the singers have not two but THREE mics taped together, a "bouquet" of mics gnarled together with a lot of paper masking tape. Why? Because they didn't know that transformer splitters even existed (they did, they just weren't aware of them), and they could not get the FOH, the monitor mix and the recording mix to be clean all at the same time if they Y'd anything (that particular building had awful power and was barraged with RF from a local TV station's transmitter link). The "bouquet" was the solution....you know...the audience was in and clamoring, the bands were people who were not much disposed to "taking direction", the show had to go on....

phil p

[jammybastard]

If the footage was from the 60's/early 70s it wasn't always for phase cancellation as the PA's were loud enough to feedback or have phase issues.
Often one mic was for the film/tv recording and one was for the PA if there wasn't a splitter available.