Polar Response Patterns Not Working?

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gvdv

Member
As part of my research in helping me to decide on a better quality microphone than I currently have for vocals, I today went out and rented a Rode K2.

As some of you will know, the K2 is a condenser which comes with it's own power supply, and a continuously variable polar pattern.

I have never used a microphone where I have been able to vary the polar response patterns, and I was looking forward to some fairly varied results. However, although the microphone itself records well, I seem to be getting very subtle, almost negligible, results when moving between the extremes of cardiod, omni, and figure of 8 patterns.

The mic. seems to only 'reject' about 5% of any sound that is off-axis. Is this normal? My understanding was that, particularly in Figure 8 pattern, there would be a significant rejection of any sound not behind or in front of the microphone (i.e. any sounds at right angles to the 'input' source would be virtually unheard). I have consulted the manual, and am using the mic. correctly, so can't figure this out.

Is it possible for the polar response selector knob or the electronics that control it to be not working/ineffective in this regard?

Any help would be much appreciated.

Thanks,
 
The louder the sound the less rejection of course...you should notice more of a difference at a lower SPL...assuming your K2 is working correctly.

Why would you rent a mic like this one?...its not like its the u87 or something...its a low cost mic.
 
darrin_h2000 said:
The louder the sound the less rejection of course...you should notice more of a difference at a lower SPL...assuming your K2 is working correctly.

Why would you rent a mic like this one?...its not like its the u87 or something...its a low cost mic.
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Hi darrin_h2000, and mshilarious,
Thanks for the replies.

To answer your question, the K2 may be a low cost mic. relative to things like the U87, but it would be a significant investment for me to be thinking of spending close to $1000 CAN. on a mic., so it is good for me to be able to hire/rent this kind of equipment so that I can try it out, rather than committing to buying it outright straight away.

Also, I like to be quite thorough in my research, so that I feel that Ican make the best decision within the parameters of what I am looking for.

Mshilarious, does it sound to you like the K2 is working as it should?

For those reasons, I will be renting a couple of other mics., too, if they're available. Luckily, one of the places that I consistently buy audio gear from has a 30 day money-back, no-questions-asked policy after purchasing most items, so that can help if one is disappointed in a purchase, but I like to make sure that my purchases are the 'right' ones for me.
 
OK, here are some possibilities:

Large diaphragm multipattern mics are dual-diaphragm (both cardioid). You get different patterns by mixing the two diaphragms or reversing the polarity of one. This can be done a couple different ways, so there is potential for breakage in different spots. If one diaphragm is for some reason shot, you'll have a cardioid mic only.

Another possibility is it's just a crummy design, and the polar patterns aren't very tight. The fig-8 on a dual diaphragm mic is not going to be as tight as a true single diaphragm pressure gradient mic. But there should still be a good amount of cancellation at 90 degrees (which is NOT a function of absolute SPL, the cancellation being measured as the signal level difference between 0 degrees and 90 degrees, at least below the point where the mic clips).

I would be inclined to broadcast 1kHz from your monitor (just one!) and with the mic 1m away, rotate it and note the amount of cancellation at 90 and 180 degrees and various polar patterns. If that is way out of spec, yeah, something ain't right.
 
Hi mshilarious,
Thanks for that; very informative.

I already did some informative 'in situ' tests; singing and snapping my fingers while moving in a circle around the mic. while recording a track. I did that in the omni, cardiod and figure 8 settings and a couple in between, and there was some, but very minor, audio differences in a couple of the positions.

Also, the reviews I have read are clear that there should be a significant, noticeable difference in rejection when using the mic. in its various polar positions, so I think that this specimen is a dud, which says something about its hardiness.

So to all intents and purposes, I do have (as you described it) a cardioid only mic.. Think I'll take it back tomorrow, and ask them to find another one for me to rent.

Thanks, once again, for your reply.
 
Ya it sounds as thou you have a bad one there.
I own one and when it's in omni you can TELL it's in omni.
Haven't recorded in figure8 yet but did try it when I first got it and did about the same test that you did but with satisfied results.
Don't give up on the K2 just get an other one.
I know money is a factor here but try a KSM44 not variable but changeable patters.(just take a trip to the states how far into the great white north do you live)
Someone also told me you have to let a tube mic warm up for awhile before using it I don't know about that for I used it right out of the box and 4 hours later while still being on I'm not sure if I noticed that much of a difference.
 
moresound said:
Ya it sounds as thou you have a bad one there.
I own one and when it's in omni you can TELL it's in omni.
Haven't recorded in figure8 yet but did try it when I first got it and did about the same test that you did but with satisfied results.
Don't give up on the K2 just get an other one.
I know money is a factor here but try a KSM44 not variable but changeable patters.(just take a trip to the states how far into the great white north do you live)
Someone also told me you have to let a tube mic warm up for awhile before using it I don't know about that for I used it right out of the box and 4 hours later while still being on I'm not sure if I noticed that much of a difference.
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Hi moresound,
Thanks very much for this; very useful.

I had the K2 on for several hours tonight, and did 3 sets of recordings, so I think that that should have accounted for any 'warm up' factor.

Thanks for the recommendation of the KSM44; I will try that one, too (actually tried to ask for it today when I went to rent the K2, but couldn't remember the model number and hadn't written it down).

Do you have any experience of the other Rode mics. in the upper price range?

Thanks, once again,
 
Ya and I like them a lot granted they're no neumann but they get the job done.
there is the nt2000 variable for about $500 us /the nt2a switchable for about $300 us both are condenser.
now some really cool not so expensive mic that you should try out are
The MXL v67switchable for about $100 us and I'm not joking on this one all the big guys talk about it a great one to have.
The studio projects C1 large cardioid condenser (transformerless) $200 us or just check out there whole line.
Both of these companys make tube too but I haven't checked them out.But do check the v67 it's a keeper!
 
After this time? The best guess was that the mic was faulty, or more likely being used wrongly. I saw somebody use one end on - so everything was off axis bar the omni.

Do you have one you're having trouble with? ALL my variable pattern mics do what you expect. Cardioid has a null at the back, fig-8 at the sides and omnis just a tiny tonal shift where direct sound gets blocked my the frames or housings?
 
Because I have a Rode K2 and it's stuck in Omni...I have the power supply with the selector/attenuator it's not adjusting anything...
 
gvdv said:
Is it possible for the polar response selector knob or the electronics that control it to be not working/ineffective in this regard?
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The room acoustics come into play, as well as positioning of the mic. As typically about 80% of the acoustic energy recorded is reflected sound. That is why some polar patterns don't work in some acoustical spaces in conjunction with the current mic recording/positioning technique.
 
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