Welcome, Guest
Username: Password: Remember me
Here is the place to share your questions/comments about your setup of the UMIK-1 USB measurement microphone


NOTE: This is a "Community" forum. Please be mindful that community members are here to help as part of a community effort. We therefore appreciate your effort in keeping this forum a happy place!

If you have a specific issue (e.g. hardware, failure) and want help from our support team, please use our tech support portal (Support menu - > Contact Us).
Thanks a lot of your help in making a better community.
  • Page:
  • 1

TOPIC:

Is there something wrong with the microphone? 7 years 3 days ago #21276

  • spoekes
  • spoekes's Avatar Topic Author
  • Offline
  • New Member
  • New Member
  • Posts: 2
  • Thank you received: 0
Hi,
i recently purchased the umik-1 microphone to measure and fix some room acustic problems with REW.
When i am using the realtime analyser function in REW without sound there are some strange artifacts i can not correlate with the actual noise i am hearing (the room is not absolutly silent, but i wrapped the microphone into some soft cloth, to furher damp noise).

  1. The frequency response is somehow curved with high peak at 50Hz. I think this must be audible if it was an acual sound in the room
  2. There are some spikes with some sort of pattern (1K, 2K, 3K, 4K, 6k, 7k, 8K, 9K)
Please see the attached image.
Is this normal or is the microphone defect?
I am using the calibration file for the microphone (700-9340).

Thanks for your help.
Attachments:

Please Log in or Create an account to join the conversation.

Last edit: by spoekes. Reason: adding image

Is there something wrong with the microphone? 6 years 11 months ago #21306

  • devteam
  • devteam's Avatar
  • Away
  • Administrator
  • Administrator
  • Posts: 9120
  • Thank you received: 1417
@ spoekes

We're not sure what we're looking at here (i.e. picture is really small and scale can't be read).
- Most likely you're close to the room noise floor? These would be typical if the scale in dBSPL is really low.
- Not sure what you mean by wrapping a microphone in cloth (never heard of this technique before.. :-) but I'm not sure how that will work out for you. Even putting a windscreen on a microphone would affect the overall frequency response of a microphone (i.e. calibration file becoming incorrect especially at high frequency section). Maybe we're missing some information as to what is the objective here..

First time using a microphone to perform a room measurement maybe?

DevTeam
miniDSP, building a DSP community one board at a time.

Please Log in or Create an account to join the conversation.

Is there something wrong with the microphone? 6 years 11 months ago #21327

  • spoekes
  • spoekes's Avatar Topic Author
  • Offline
  • New Member
  • New Member
  • Posts: 2
  • Thank you received: 0
Hi DevTeam,
thanks for the reply!

We're not sure what we're looking at here (i.e. picture is really small and scale can't be read).

The uploaded image has 1920*1080 pixels, but is downsampled by the forum.

Most likely you're close to the room noise floor? These would be typical if the scale in dBSPL is really low.

This could be. But i thought some of the peaks looks more like artifacts in the signal way than noise

Not sure what you mean by wrapping a microphone in cloth (never heard of this technique before.. :-) ...

I did that to reduce room noise for the screenshot i made.

First time using a microphone to perform a room measurement maybe?

Yes, and since i can not cross check with another microphone, i thought it would be wise to ask, before i start with measurements.

Please Log in or Create an account to join the conversation.

Is there something wrong with the microphone? 6 years 6 months ago #23983

  • tecnogadget
  • tecnogadget's Avatar
  • Offline
  • New Member
  • New Member
  • Posts: 14
  • Thank you received: 2
Im having this weird issue, i dont know why but the Umik is showing a massive sustained peak at 50hz and 150hz
I've attached a capture of a Waterfall, measurement made in complete silence with no sound output at all. Acoustically treated room with good noise floor. As you can see, in the Waterfall plot, both peaks could be mistaken for room modals since they do not decay at all...but it can't be since the measurement was made in complete silence.




Why is this happening? I live in South America, we use 50hz and 220v...could that be the issue? Because it is messing up all my Subwoofer calibration measurements....tricking me into thinking i was having a 50hz decay problem even having lots of basstraps.

Could please somebody help me troubleshoot this?
Attachments:

Please Log in or Create an account to join the conversation.

Is there something wrong with the microphone? 6 years 6 months ago #24095

  • devteam
  • devteam's Avatar
  • Away
  • Administrator
  • Administrator
  • Posts: 9120
  • Thank you received: 1417
Sounds like a topic already started elsewhere. Please don't double post. Thanks!

DevTeam
miniDSP, building a DSP community one board at a time.

Please Log in or Create an account to join the conversation.

Last edit: by devteam.
  • Page:
  • 1
Moderators: devteam