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Old 30th April 2020 | Show parent
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Quote:
Originally Posted by ToniMartin View Post
Hej Jens! Cool. Det är faktisk i Stockholm jag har byggt mit extra studie. Sickla området Tack för dina svar och information!!

Perfect! Now it makes sense. The wavelength for 1KHz is approx the 34 cm you mention. I will try covering the desk later but need to deliver a project first (deadline today).

So what do people do to avoid these dips? I mean I can't remove the desk and I won't buy a new one since this is made for the studio. Any ideas or thoughts?

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Also I've checked the room response at another place in the studio by the acoustic piano I have standing by the wall:

https://ibb.co/g6p4Ppt

There was also a dip in the high freq. as well - more around 1,5KHz. Do you think this is related to waves coming directly from the speakers (behind me) and then creating destructive interference with the reflections from the wall/piano itself (in front of me)? The distance from the wall to the chair is around 60-70 cm which equals 3 X wavelength. Correct? I do have an acoustic panel on the wall there. Would it help to add another panel that is suited to dampen 1-2KHz?

This is unfortunately a very (VERY …) common issue in most studios, including the expensive ones.

The solution consists of a combination of two things:


1. An acoustically “small” desk (as seen by the speakers):

Question about dip at 1KHz-holonor-desk-1.jpg
Question about dip at 1KHz-holonor-desk-2.jpg

This normally means shallow and/or perforated horizontal surfaces, angled rack sections (enough angle to actually do something useful) and keeping the screens down low (and/or smaller screens).


2. Using speakers that offer controlled directivity in the vertical plane:

Cardioid speakers


In general, the total response is the vector sum of all phasors. If one or more of the vectors apart from direct sound is relatively strong, and out of phase (as discussed above) compared to the direct sound; you will see a dip at the frequency of interest.

I made a simple excel sheet to quickly calculate nulls due to floor (same for desk) related SBIR. I´ll add it here if anyone wants to check their floor/desk related issues and see if it adds up.
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Question about dip at 1KHz-holonor-desk-1.jpg   Question about dip at 1KHz-holonor-desk-2.jpg  
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