1. Register NOW and become part of this fantastic knowledge base forum! This message will go away once you have registered.

Problem with AT4050, or am I just stupid?

Discussion in 'Pro Audio Equipment' started by neirbod, Sep 3, 2005.

  1. neirbod

    neirbod Guest

    Hi all,

    Long time lurker, first time caller.

    I just received an AT 4050 from a very reputable eBay seller. It was a demo unit from a music store mic display, and appears to be in very good condition. It sounds great, with the big exception that, in figure 8 mode, the two lobes sound dramatically different. The front sounds similar to the mic in cardoid mode, but the back has far more low end, and is also more sensitive.

    I assume the mic is defective, but since this is my first multi-pattern mic there is also the possibility that I am doing something wrong. Any thoughts?

    Also, anyone have experience getting AT to repair a mic purchased off eBay? I figure I'll give that a shot before just returning the mic.

    Thanks,

    Dave
     
  2. Pre Amp

    Pre Amp Guest

    I'm sure AT would fix any of there products, reguardless of where you bought them. Just don't go saying, "I'm the 5th owner of this microphone". :oops:
    Also, maybe I misunderstood you, but it really doesn't sound like there is anything wrong with the mic. But I could be wrong
     
  3. moonbaby

    moonbaby Mmmmmm Well-Known Member

    What you are describing is pretty much par-for-the-course for a multi-pattern mic. Use it to your advantage...think of that great mic as a paintbrush ( yeah, I know it's a cliche). You get different colors by pattern selection and positioning it. A singer might sound better on 1 side of the "8",an amp better on the other. That is a truly fine mic, enjoy the ride, baby! :cool:
     
  4. moonbaby

    moonbaby Mmmmmm Well-Known Member

    P.S.: I should've said:"Yeah, that mic sounds like it was dropped on it's head...It's a total loss...I'll give you $100.00 fer it!" :wink:
     
  5. neirbod

    neirbod Guest

    Really? That seems strange to me. How can an MS mic technique work if the two lobes sound that different? Plus, the polar plot from AT indicates that the two lobes should sound the same. I am confused. Thanks for your help.

    [edit] Just found an interesting tidbit from the Electronic Musician review of the KSM44
    "The figure-8 pattern was nicely consistent, with the rear capsule sounding slightly darker than the front (like the other mics I tested)."

    So, I guess my mic ain't broke after all. Now I am REALLY confused about MS micing, but that is my problem, not the mics :) Thanks to you both for your input
    Smile

    Dave :)
     
  6. Pre Amp

    Pre Amp Guest

    No problem man.
    I agree that sometimes you use a mic (or any piece of equipment for that matter) and it sounds AWESOME on 90% of the settings. But the other 10% sounds sooo dramatic and over bearing, that you wonder "what would I ever do with that sound?"
    Cheers
     
  7. dpd

    dpd Active Member

    If the mic is working properly, a figure 8 has the same polar pattern front to back, sensitivity vs frequency. The only difference is that the two lobes have different polarity. (back is 180 deg out of phase from the front)
     
  8. neirbod

    neirbod Guest

    Well now I am again confused. What you say makes sense, and is backed up by the polar plot on the AT website. But others say figure 8 mics commonly have differing sounding lobes. Can anyone else comment on how their figure 8 mics behave?
     
  9. ghellquist

    ghellquist Member

    To me it seems like the back sida of your is way out of specification. I would consult directly with the factory and see what they have to say. Read the caveat at the end first though.

    I know of three different setups for figure 8-s commonly in use today.

    First there are the non-switchable figure 8-s that are made to be used for MS and similar uses. All I know of are small diameter mics. The ones I know from come from Neumann, Schoeps, Sennheiser. I own a Sennheiser MKH-30 and that one sounds exactly the same from both sides.

    Secondly there are the mics that are by purpose made to sound different from the two sides in a pattern 8. Some ribbon mics from AEA are made this way, it gives you two different "colours" to select from when recording.

    Thirdly there are the switchable large diameter mics that support a figure 8 pattern. All I have seen are made from two cardoid capsules placed back to back. These will never be quite the same as a single-pattern figure-8 but for most uses they will be quite good enough. There is a really difficult production process in matching the front and back side capsule to each others. A high quality manufacturer, say AT, should be able to match these so closely that normal ears will not hear a difference. This is how I believe the AT is supposed to work.

    Beware though that there is a specific situation where the two sides will sound different. This situation is if you listen to yourself through headphones while talking or singing in the mic. The reason is the sound now goes two ways, the intended way through the mic an amplification into your headphones. The other way is inside your own head. These two sources will interact and can make things sound different depending on the phase of your signal chain. Try it yourself by singing in a mic and changing the phase (inverting the signal).

    Gunnar
     
  10. neirbod

    neirbod Guest

    Gunnar,

    You got it! :cool:

    I had been listening through headphones and hearing a big difference in the sound. I just tried recording myself singing through both sides of the mic then listening to the playback through monitors. The sound is perfectly even on both sides. Thanks, I never would have though of a phasing issue in this type of situation.

    Dave
     
  11. John Stafford

    John Stafford Well-Known Member

    While Gunnar has solved your problem, it is interesting to listen for slight differences in the front and back when you use the mic in omni mode. The differences should be tiny, but make every mic unique. When you really get to know a mic, these things become more obvious, or so I've found. One of my mics needs a new capsule, which is a pity, as the 'bad' side has a certain charm on a few recordings (although it mostly sucks). It's a pity I can't afford to keep it as it is and buy a new one to go with it :cry:

    BTW in one review of the rather expensive Soundelux 251, it seemed there was no attempt to make a perfect figure-of-eight. I think the idea was to just make it sound astonishing in cardioid and omni with absolutely no compromises.

    I hope you are enjoying your 4050 -it is a rather charming mic.

    John
     

Share This Page