Jump to content
Tong0615

Sanken COS-11s out of phase

Recommended Posts

Hello, I guess many colleagues here using SANKEN COS-11, I did a test with Impulse and Sine-wave last weekend, and it turned out, that all my SANKEN COS-11s are out of phase (compare to Sennheiser MKH8060 and DPA Lavs, both on Zaxcom and Wisycom Transmitter, recorded on NOMAD ), and just from interest, I took an SANKEN COS-11 from a colleague with Lectro Transmitter, it also seems to be out of phase (same comparison). 

Is anyone else has this problem? or this only happens to my SANKENs? I guess it's not a problem caused by wrong soldering, but more like a problem caused by the capsule.  

Share this post


Link to post
Share on other sites

Yes, I have had the same issue when using Sanken COS-11 and DPA lav mics. In the distant past when I was using only the COS-11 I, of course, did not have a problem. When I started using DPAs, I did check to see that everything would be in phase (electrically) and discovered that the two mics were not in phase. The tests were done with both Audio, Ltd. wireless and Zaxcom wireless. I settled in to using Zaxcom only with DPA lavs for all my wireless work and only very occasionally I would be using a DPA and a COS-11 at the same time in a scene. In those cases, I flip the phase on the input for the COS-11. 

Share this post


Link to post
Share on other sites

It's a Sanken thing. A good few years ago, I was in touch with audio post at the start of a show, and I sent him some tests.

The post guy (Fred Brennan- sound supervisor) checked waveforms, and discovered the anomaly.

This was with Lectro transmitters, but the problem may have to do with the requirements for two wire connections (which seem to be the most common for radio mics) and the voltage polarity on Sankens, I think. At any rate I have always reversed the phase on my body mic receivers since then.

The reversed polarity was between transmitted boom mics and the sankens.

Share this post


Link to post
Share on other sites

Hi, I just hook up all my mics and record just me talking at the same time into all of them, I also check new transmitters the same way, then look at waveforms on the computer. I usually do this test at the same time to check delays between the various components. 

Sincerely, Martin 

Share this post


Link to post
Share on other sites
1 hour ago, elior said:

Maybe that's your problem.

https://forum.zaxcom.com/forum/forums/nomad/35850-headphone-phase-reverse

There is a solution through the menu, I don't remember exactly where it is.

Don't listen to the recording through Nomad, try to listen via a DAW and you'll also see visually if the audio in reverse phase as Martin said.

Hi, thanks for the advice, the comparison was not done by ear, but by waveform in pro tools,. 

I do reverse the phase on nomad normally when I use Sanken COS-11, but when I am on set, and under pressure, and need to switch from other mics to Sanken, I will not be able to think about reverse phase in the setting, but concentrate on getting a clear and clean sound. And this Phasing issue caused more work in the post, as we have to find out if it is out of phase for every clip, and reverse the phase.

Share this post


Link to post
Share on other sites

In the heat of battle, this is not where you want to be figuring out if your mics are in phase or not. Of course it is going to create more work in post if you've done a scene using several mics and one or more are out of phase with eachother. I had a problem a long time ago when I borrowed an extra Lectro wireless set (a transmitter and receiver) to add to my Lectro quad box (in the old days when 4 wireless was usually way more than I needed). It turns out that the receiver that I borrowed had the leads to the output connector flipped, putting it out of phase with the others. Fairly easy to discover since this was back in the days where we were only mixing to mono --- while using both mics in close proximity to eachother I was getting phase cancellation and a very thin sound. I flipped the phase on my mixing panel for the input of the borrowed wireless and finished the day out. 

Now, since I really don't want to have to remember to flip the phase, I just don't mix my Sankens and my DPAs.

Share this post


Link to post
Share on other sites
10 hours ago, elior said:

Maybe that's your problem.

https://forum.zaxcom.com/forum/forums/nomad/35850-headphone-phase-reverse

There is a solution through the menu, I don't remember exactly where it is.

Don't listen to the recording through Nomad, try to listen via a DAW and you'll also see visually if the audio in reverse phase as Martin said.

 

8 hours ago, Tong0615 said:

Hi, thanks for the advice, the comparison was not done by ear, but by waveform in pro tools,. 

I do reverse the phase on nomad normally when I use Sanken COS-11, but when I am on set, and under pressure, and need to switch from other mics to Sanken, I will not be able to think about reverse phase in the setting, but concentrate on getting a clear and clean sound. And this Phasing issue caused more work in the post, as we have to find out if it is out of phase for every clip, and reverse the phase.

Hello, Tong, it looks like you were responding to Elior and not getting quite what he was saying. I say he, could be a she. Elior was referencing HP phase selection, while you appear to be referencing an input phase selection. The phase that Elior is referencing is in the "eng" menu, scroll to "advance" menu, then scroll down to "HP" phase selection.

The 2 settings are "default" and "legacy". 

Those settings were put into an update after I contacted Zaxcom. A couple years ago, I bought my first Nomad and the minute I turned it on, I noticed the HP phase was reversed. I contacted Zaxcom, and thus "legacy" and "default" were born on the next update. 

Sincerely, Martin 

P.S "Default" is "correct", while "legacy" is backwards (reversed). M.W.

 

Share this post


Link to post
Share on other sites

speaking of flip the phase: how often do you guys use this to help reduce phasing in your mix? e.g. 2 actors close to each other or a plant mixed in with the lav or just the Boom with a bit of lav.

I know that post will have different phase on different takes but I just can't stand that phasing sound in my mix and always try what sounds best.

Share this post


Link to post
Share on other sites
46 minutes ago, Matthias Richter said:

speaking of flip the phase: how often do you guys use this to help reduce phasing in your mix? e.g. 2 actors close to each other or a plant mixed in with the lav or just the Boom with a bit of lav.

Never. Haven't even tried that. There is a big difference between electrical phase (should actually be referred to as polarity) and the sort of acoustical phasey sound you can have with multiple microphones picking up the same source. I guess it never even occurred to me that flipping polarity might help in these acoustical situations (and maybe it doesn't help?). Seems a little tricky to me.

Share this post


Link to post
Share on other sites
40 minutes ago, Matthias Richter said:

it does help for sure. I hear it 😉

It's just that I can only do 180' whereas in post they can slip by the frame. 

The 2 are totally different. In 1 case the phasing is happening because of time difference, in the other it is happening because of time similarity. Which is why flipping the waves polarity doesn't eliminate acoustic phasing - but it will change the way is sounds.

Share this post


Link to post
Share on other sites

that's why I'm saying I can only do 180' (polarity) whereas in post they actually slip (timeline) the audio.

But if time diff is creating phasing and I hear that nasty hollow sound I'll try and hear what it SOUNDS like if I flip the polarity.

No one but me? Mmh ...

Share this post


Link to post
Share on other sites
19 minutes ago, Matthias Richter said:

that's why I'm saying I can only do 180' (polarity) whereas in post they actually slip (timeline) the audio.

But if time diff is creating phasing and I hear that nasty hollow sound I'll try and hear what it SOUNDS like if I flip the polarity.

No one but me? Mmh ...

Ok, ok. Geez. Yes, I do that too. I just didn't want to admit it. I just couldn't leave you on Gilligan's Island on this by yourself.

Share this post


Link to post
Share on other sites

I think most of us do it sometimes (to hear what it sounds like :-). I can't remember ever being convinced.

Share this post


Link to post
Share on other sites
I think most of us do it sometimes (to hear what it sounds like :-). I can't remember ever being convinced.

Yes, I have tried it too, on occasion. But I also received a very stern lecture once, some time ago, to never ever flip the phase. And if I could absolutely not avoid it, at least keep it flipped for the entire scene.

Share this post


Link to post
Share on other sites

Hi all, I wonder if this is just a matter of the amount of mics out there? In other words, (brace for analogy) Ferrari's aren't safer than Ford Mustangs because people wreck less Ferrari's than Mustangs, there are far fewer Ferrari's to wreck. So, maybe somebody gets a Sanken and whoever wires it, just wires it wrong? And because there are more Sankens, more Sankens get wired wrong?

Sincerely, Martin 

Share this post


Link to post
Share on other sites

Sanken COS-11 have 3 wires, ground, White (bias) and Black (audio). Normal wiring is to tie the white wire to the ground connection along with the ground wire and the black to the positive pin connection. I've wired dozens of Sanken COS-11's that way and no one has ever brought up any polarity/phase issues.

Share this post


Link to post
Share on other sites

It has absolutely nothing to do with the number of mics in use, the relative car population, nor even vodoo. 

It has to do with the way lavs are made, whether they're two-wire or three-wire configuration, and the individual wiring scheme chosen for any specific transmitter. In many cases, two-wire schemes result in phase reversal for three wire mics.  Some transmitters work only with a two-wire configuration, while others can be configured with either a two-wire or three-wire input. Going through a period of both positive and negative bias Trams didn't help any either. 

As a result of these variables, there's much confusion, misunderstanding, and phase-abuse.

In-phase is described as a positive sound pressure at the diaphragm resulting in a positive leading waveform at the output.  

Re Jeff's comment, in this case we're talking about electrical phase, not acoustical phase, which is too often even more misunderstood due to variations by both distance, frequency, time domain, reflections, and, oh yes... vodoo.

 

Share this post


Link to post
Share on other sites
4 hours ago, Eric Toline said:

Sanken COS-11 have 3 wires, ground, White (bias) and Black (audio). Normal wiring is to tie the white wire to the ground connection along with the ground wire and the black to the positive pin connection. I've wired dozens of Sanken COS-11's that way and no one has ever brought up any polarity/phase issues.

Eric, I've heard that the COS-11 cable is really difficult to solder, does this match your experience?
I'm asking because I could get the PT version quite a bit cheaper then with a connector, but my solder skills are just about average.

btw, for those who have a better understanding in electronics then me, Sanken has a nice page page with all the wire diagrams:
basics about 3 wire vs 2 wire:
http://www.sanken-mic.com/en/qanda/index.cfm/4.19

and all the transmitters:
http://www.sanken-mic.com/en/qanda/index.cfm

for example lector:
http://www.sanken-mic.com/en/qanda/index.cfm/11.20

no mention of phase there though.

chris

Share this post


Link to post
Share on other sites
12 minutes ago, John Blankenship said:

They mention phase reversal in the examples of 2-wire vs 3-wire.

Doh, I'm getting blind (or seriously distracted)...

Interesting that the say "It may have a negative phase output signal when it has a positive sound wave." - as if they weren't sure. Could that be because it depends on the transmitter? No mention under the transmitter specific wiring though (unless I missed something again).

chris

PS: they also mention gain differences, which could explain the difference in the "normal gain on COS-11" thread

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×