R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: x/y miking w/ Rode NT-4 and phasing  (Read 1916 times)

Dan Lawrence

  • Newbie
  • *
  • Offline Offline
  • Posts: 46
x/y miking w/ Rode NT-4 and phasing
« on: April 30, 2013, 11:45:47 am »

I've done a fair amount of reading on the x/y technique, but when it comes to a preset config like the Rode NT4, i assumed there would be few if any issues w/ positioning of capsules in relation to one another (since they are fixed).

I've had this mic for almost ten years, and seldom use it. I like the sound of the source it captures, except even in the most acoustically treated rooms, I get that hollow, far away sound.

I've been doing a lot of testing of phase issues w/ a Little Labs IBP phase sweeper, and I noticed that I can eliminate much of that hollowness w/ a phase adjustment of slightly more than 200 degrees (I have some uncertainty as to the exact number, as I am still seeking clarification on the details of the IBP's switching modes).

I have never read any suggestion that a true X/Y technique should require a inversion of one of the mics. Does this make sense to anyone? I've considered other issues like comb-filtering from reflections, but this "phasing" sound seems consistent in at least a half dozen different attempts at using this mic.

I don't have a DAW to see the waveforms, so I'm limited there for now. More importantly, I am trying to be sure my ear can distinguish the subtle nuances of mics and phasing. The IBP works wonders in that regard.

Any tips?

Thanks in advance

D
Logged

Dan Lawrence

  • Newbie
  • *
  • Offline Offline
  • Posts: 46
Re: x/y miking w/ Rode NT-4 and phasing
« Reply #1 on: May 02, 2013, 02:26:36 am »

I thought I'd add one detail I forgot to mention. My conviction that the issue is phasing became solidified when I confirmed the tell tale symptom, that soloing one channel or the other actually increases the meter levels by about +- 5 to 7 db.

peace ...

d
Logged

Timtape

  • Full Member
  • ***
  • Offline Offline
  • Posts: 103
  • Real Full Name: Tim Gillett
Re: x/y miking w/ Rode NT-4 and phasing
« Reply #2 on: May 02, 2013, 07:23:15 am »

It certainly sounds like they are 180 deg out of phase.
A proper XY setup should have minimal phase cancellations.


Just flip the phase of one mic in a DAW test recording. This should confirm if this is the problem. It should restore the proper stereo image and make for a strong mono summed output.

If this is the case, it sounds like the mic was assembled with two signal wires transposed.
Perhaps more likely, if it's a true balanced output cable, the cable may have some reversed connections.

Cheers Tim


 

Logged

Fletcher

  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 590
Re: x/y miking w/ Rode NT-4 and phasing
« Reply #3 on: May 02, 2013, 09:52:12 am »

I think Tim is pretty spot on... if the resultant level is changing 5-7db, that sounds like you have some pretty major cancellations going on in which case reversing the polarity sounds like the best course of action.

I responded to your other thread about the IBP... this might help you get a better handle on what is actually going on [or not - who knows].

Peace
Logged
CN Fletcher

mwagener wrote on Sat, 11 September 2004 14:33
We are selling emotions, there are no emotions in a grid


"Recording engineers are an arrogant bunch
If you've spent most of your life with a few thousand dollars worth of musicians in the studio, making a decision every second and a half... and you and  they are going to have to live with it for the rest of your lives, you'll get pretty arrogant too.  It takes a certain amount of balls to do that... something around three"
Malcolm Chisholm

Dan Lawrence

  • Newbie
  • *
  • Offline Offline
  • Posts: 46
Re: x/y miking w/ Rode NT-4 and phasing
« Reply #4 on: May 02, 2013, 07:50:21 pm »

Thanks to both. I'm thinking about writing to Rode, but don't know how they're customer service is. I also know that after 9+ years the problem is certainly mine to deal with. For now, I will just flip phase.

cheers
Logged

Fletcher

  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 590
Re: x/y miking w/ Rode NT-4 and phasing
« Reply #5 on: May 03, 2013, 10:13:40 am »

Rode has a US office in CA and are headquartered in Sydney.  Here's a link to their point of contact http://www.rodemic.com/contact

Please let us know how that works out for you.

Peace
Logged
CN Fletcher

mwagener wrote on Sat, 11 September 2004 14:33
We are selling emotions, there are no emotions in a grid


"Recording engineers are an arrogant bunch
If you've spent most of your life with a few thousand dollars worth of musicians in the studio, making a decision every second and a half... and you and  they are going to have to live with it for the rest of your lives, you'll get pretty arrogant too.  It takes a certain amount of balls to do that... something around three"
Malcolm Chisholm

Randyman...

  • Newbie
  • *
  • Offline Offline
  • Posts: 27
Re: x/y miking w/ Rode NT-4 and phasing
« Reply #6 on: May 03, 2013, 07:24:27 pm »

Are you using the Rode supplied "Y" Cable to get both capsules' discrete outputs, or some aftermarket variety of splitter cable?

It could just be that one set of the +/- balanced lines have be swapped at the 5-Pin XLR (that plugs into the mic) or at one of the 3-Pin XLR breakouts (that go to your individual preamps).

However, if the capsules were 180* out of phase (inverted polarity), you'd probably get more than a -5 to -7dB drop when summing the two coincident capsules together (closer to total cancellation IMO).

My buddy uses the NT4 for nature/ambiance type recordings, and I've never heard any kind of phase issues with his recordings (but I've never summed his recordings to mono, either).

:cool:
Logged
Randy Visentine
Semi-Pro Engineer

Dan Lawrence

  • Newbie
  • *
  • Offline Offline
  • Posts: 46
Re: x/y miking w/ Rode NT-4 and phasing
« Reply #7 on: May 04, 2013, 12:04:46 pm »

Thanks for that link Fletch. And I am using the original supplied Y cable. I also hope to test that to verify its wiring as soon as I figure out which pin on the stereo side goes where. I know the mic should sound great, w/o phasing, cuz many pros have lauded its performance, and I'd sure like to reach that level of satisfaction w/ it too.

Take Care

d
Logged
Pages: [1]   Go Up