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R/E/P => R/E/P Archives => Acoustics in Motion => Topic started by: eightyeightkeys on November 08, 2010, 10:13:22 AM

Title: Taming Desk Reflections
Post by: eightyeightkeys on November 08, 2010, 10:13:22 AM

I don't have a console, but, I have a wrap-around workstation desk with an exposed (unused area) horizontal, wooden surface that is playing it's part in what I hear.
What are some good materials for taming/elimination desk reflections ?

Title: Re: Taming Desk Reflections
Post by: Thomas Jouanjean on November 08, 2010, 11:55:25 AM

eightyeightkeys wrote on Mon, 08 November 2010 09:13

There isn't really a particular one, best is to go via trial an error - and also consider what is healthy and will resist in the long term. Minimal desk design is your friend though... Think mastering desks.

You wouldn't believe how much 'flange' you get from the surface of a SSL 4000G+ for ex. But this is a given, no work-around.

What's even more annoying is that once you get a "minimal" table, then the floor effect kicks in full effect and that's a nasty one too.

And same same. Not really anything you can do about it.

Title: Re: Taming Desk Reflections
Post by: AndreasN on November 11, 2010, 08:09:00 AM

A large surface can be used to block the floor reflection if it intersects the path between speaker and listener. Speakers placed on stands some way behind the work surface may benefit from this approach.

Absorption is also an option. Thick chunks of foam is convenient.

http://recforums.prosoundweb.com/index.php/m/180996/7551/?sr ch=nordenstam#msg_180996

Title: Re: Taming Desk Reflections
Post by: Thomas Jouanjean on November 11, 2010, 06:23:45 PM

Depends on wavelength...

There are only compromises to be made with these issues. Pick your poison Confused

Title: Re: Taming Desk Reflections
Post by: Bogic Petrovic on November 12, 2010, 06:22:47 AM

For extremely small rooms (V<70m3), especially with some low frequency acoustic treatment, we found “no desk” is a probably best solution, if someone has prerequisites to do that. One of the conditions is to use only mouse/trackball and keyboard for working. Of course, some small DAW controller can be used too.

Idea is to split desk to two halves, and moves (reflecting) surfaces to left and right sides of the chair (above the racks, for example), and miss listener ears. In this case, it is revealed much more high frequency details than with any ordinary desk or/and desk treatments we already know (acoustic foam or cotton felt cover, etc.).

Also, (now) uncovered floor reflections has much smaller bad contribution in overall subjective sound image, because different and longer path, they spoil different frequency range and has much smaller intensity (4-10dB) ... and possibly because we are more naturally immune/adapted to it.

And yes, I agree, this is a story about compromises...

p.s. Also, a big LCD HD TV can be used for computer display, mounted between left and right loudspeaker. This solution solves VGA display diffraction problems too.

Title: Re: Taming Desk Reflections
Post by: DanDan on January 18, 2011, 10:19:12 PM

I presented some tests to show how much damage these reflections can do. Plus how an angle can pretty much solve it sometimes.
http://www.gearslutz.com/board/studio-building-acoustics/570 976-desktop-reflection-revealed.html

DD

Title: Re: Taming Desk Reflections
Post by: franman on February 03, 2011, 08:54:22 PM

The desk.. yes, such a problem. I just solved (diagnosed) a problem for a mastering client of mine. He had put together a second room based on some room proportions we used for an earlier room and stuck some gear in there. They tried and tried and couldn't get rid of problems with imaging, and ability to resolve small changes in eq, etc (1/2 dB.. can't hear it??).. In the original room, they had no such issues.

We spoke for a while on the phone and ended up discussing the 'old style' mastering desk they were using. I told him that without measuring or hearing the problem, it certainly sounded like the kinda of smearing that could be caused by early reflections off the desk. I suggested he try loosing the desk all together and see what happened. If it was good, then he could justify the purchase of a proper mastering console such as those from Sterling Modular (very popular with mastering engineers)..

Low and behold, I heard back from him about a week later and he told me.. "as usual, you were right on the money. The desk was a major part of the problems we were having. Now that we swapped it out for a proper desk we can hear small adjustments and the image is locked right in"...

Amazing! Acoustic consult via phone call... (and no charge to boot!.. such a deal).

fm